Browsing by Subject "Lynch syndrome"

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  • PLSD Collaborators; Dominguez-Valentin, Mev; Sampson, Julian R.; Møller, Pål; Seppälä, Toni T. (2021)
  • Seppala, Toni; Pylvanainen, Kirsi; Evans, Dafydd Gareth; Jarvinen, Heikki; Renkonen-Sinisalo, Laura; Bernstein, Inge; Holinski-Feder, Elke; Sala, Paola; Lindblom, Annika; Macrae, Finlay; Blanco, Ignacio; Sijmons, Rolf; Jeffries, Jacqueline; Vasen, Hans; Burn, John; Nakken, Sigve; Hovig, Eivind; Rodland, Einar Andreas; Tharmaratnam, Kukatharmini; Cappel, Wouter H. de Vos tot Nederveen; Hill, James; Wijnen, Juul; Jenkins, Mark; Genuardi, Maurizio; Green, Kate; Lalloo, Fiona; Sunde, Lone; Mints, Miriam; Bertario, Lucio; Pineda, Marta; Navarro, Matilde; Morak, Monika; Frayling, Ian M.; Plazzer, John-Paul; Sampson, Julian R.; Capella, Gabriel; Moslein, Gabriela; Mecklin, Jukka-Pekka; Moller, Pal; Collaboration Mallorca Grp (2017)
    Background: We have previously reported a high incidence of colorectal cancer (CRC) in carriers of pathogenic MLH1 variants (path_MLH1) despite follow-up with colonoscopy including polypectomy. Methods: The cohort included Finnish carriers enrolled in 3-yearly colonoscopy (n = 505; 4625 observation years) and carriers from other countries enrolled in colonoscopy 2-yearly or more frequently (n = 439; 3299 observation years). We examined whether the longer interval between colonoscopies in Finland could explain the high incidence of CRC and whether disease expression correlated with differences in population CRC incidence. Results: Cumulative CRC incidences in carriers of path_MLH1 at 70-years of age were 41% for males and 36% for females in the Finnish series and 58% and 55% in the non-Finnish series, respectively (p > 0.05). Mean time from last colonoscopy to CRC was 32.7 months in the Finnish compared to 31.0 months in the non-Finnish (p > 0.05) and was therefore unaffected by the recommended colonoscopy interval. Differences in population incidence of CRC could not explain the lower point estimates for CRC in the Finnish series. Ten-year overall survival after CRC was similar for the Finnish and non-Finnish series (88% and 91%, respectively; p > 0.05). Conclusions: The hypothesis that the high incidence of CRC in path_MLH1 carriers was caused by a higher incidence in the Finnish series was not valid. We discuss whether the results were influenced by methodological shortcomings in our study or whether the assumption that a shorter interval between colonoscopies leads to a lower CRC incidence may be wrong. This second possibility is intriguing, because it suggests the dogma that CRC in path_MLH1 carriers develops from polyps that can be detected at colonoscopy and removed to prevent CRC may be erroneous. In view of the excellent 10-year overall survival in the Finnish and non-Finnish series we remain strong advocates of current surveillance practices for those with LS pending studies that will inform new recommendations on the best surveillance interval.
  • Niskakoski, Anni; Pasanen, Annukka; Porkka, Noora; Eldfors, Samuli; Lassus, Heini; Renkonen-Sinisalo, Laura; Kaur, Sippy; Mecklin, Jukka-Pekka; Bützow, Ralf; Peltomäki, Päivi (2018)
    AbstractObjective The diagnosis of carcinoma in both the uterus and the ovary simultaneously is not uncommon and raises the question of synchronous primaries vs. metastatic disease. Targeted sequencing of sporadic synchronous endometrial and ovarian carcinomas has shown that such tumors are clonally related and thus represent metastatic disease from one site to the other. Our purpose was to investigate whether or not the same applies to Lynch syndrome (LS), in which synchronous cancers of the gynecological tract are twice as frequent as in sporadic cases, reflecting inherited defects in DNA mismatch repair (MMR). Methods MMR gene mutation carriers with endometrial or ovarian carcinoma or endometrial hyperplasia were identified from a nationwide registry. Endometrial (n = 35) and ovarian carcinomas (n = 23), including 13 synchronous carcinoma pairs, were collected as well as endometrial hyperplasias (n = 56) and normal endometria (n = 99) from a surveillance program over two decades. All samples were studied for MMR status, ARID1A and L1CAM protein expression and tumor suppressor gene promoter methylation, and synchronous carcinomas additionally for somatic mutation profiles of 578 cancer-relevant genes. Results Synchronous carcinomas were molecularly concordant in all cases. Prior or concurrent complex (but not simple) endometrial hyperplasias showed a high degree of concordance with endometrial or ovarian carcinoma as the endpoint lesion. Conclusions Our investigation suggests shared origins for synchronous endometrial and ovarian carcinomas in LS, in analogy to sporadic cases. The similar degrees of concordance between complex hyperplasias and endometrial vs. ovarian carcinoma highlight converging pathways for endometrial and ovarian tumorigenesis overall.
  • Kalamo, Mari; Mäenpää, Johanna; Seppälä, Toni; Mecklin, Jukka-Pekka; Pylvänäinen, Kirsi; Staff, Synnöve (2021)
    Background Due to increased risk of endometrial and ovarian cancer, women belonging to known Lynch Syndrome (LS) families are recommended to undergo germline testing. Current practice in Finland is to offer counselling to women with pathogenic variant and advocate risk-reducing surgery (RRS) after completion of childbirth. The present study aimed to clarify the impacts of positive germline testing on family planning and reproductive decisions of these women, which are relatively unknown. Methods Seventy-nine carriers of germline MMR gene pathogenic variant (path_MMR) were identified from the Finnish LS Registry as having genetic testing performed before the age of 45 years and not having undergone hysterectomy or oophorectomy. These women were sent a questionnaire concerning family planning, intimate relationships and psychosocial wellbeing. Results Thirty-five women (44.3%) responded. Parity of path_MMR carriers (2.1) was slightly higher than parity among Finnish women in general (1.8). No significant differences were found between parity, number of induced abortions or sterilizations before and after genetic testing. Only minority of subjects reported any influence on family planning (20%) or negative impact on feminine self and body image (14%). Conclusions The positive germline testing does not seem to have a major negative impact on family planning, intimate relationships or feminine self and body image. According to the open comments, counselling, supportive and empathic attitude of the professionals seem to have a significant impact on this. These results are a valuable addition to the counselling of LS women at reproductive age.
  • Ahadova, Aysel; Pfuderer, Pauline Luise; Ahtiainen, Maarit; Ballhausen, Alexej; Bohaumilitzky, Lena; Kösegi, Svenja; Müller, Nico; Tang, Yee Lin; Kosmalla, Kosima; Witt, Johannes; Endris, Volker; Stenzinger, Albrecht; von Knebel Doeberitz, Magnus; Bläker, Hendrik; Renkonen-Sinisalo, Laura; Lepistö, Anna; Böhm, Jan; Mecklin, Jukka-Pekka; Seppälä, Toni T.; Kloor, Matthias (2021)
    Regular colonoscopy even with short intervals does not prevent all colorectal cancers (CRC) in Lynch syndrome (LS). In the present study, we asked whether cancers detected under regular colonoscopy surveillance (incident cancers) are phenotypically different from cancers detected at first colonoscopy (prevalent cancers). We analyzed clinical, histological, immunological and mutational characteristics, including panel sequencing and high-throughput coding microsatellite (cMS) analysis, in 28 incident and 67 prevalent LS CRCs (n total = 95). Incident cancers presented with lower UICC and T stage compared to prevalent cancers (p < 0.0005). The majority of incident cancers (21/28) were detected after previous colonoscopy without any pathological findings. On the molecular level, incident cancers presented with a significantly lower KRAS codon 12/13 (1/23, 4.3% vs. 11/21, 52%; p = 0.0005) and pathogenic TP53 mutation frequency (0/17, 0% vs. 7/21, 33.3%; p = 0.0108,) compared to prevalent cancers; 10/17 (58.8%) incident cancers harbored one or more truncating APC mutations, all showing mutational signatures of mismatch repair (MMR) deficiency. The proportion of MMR deficiency-related mutational events was significantly higher in incident compared to prevalent CRC (p = 0.018). In conclusion, our study identifies a set of features indicative of biological differences between incident and prevalent cancers in LS, which should further be monitored in prospective LS screening studies to guide towards optimized prevention protocols.
  • Mäki-Nevala, Satu; Valo, Satu; Ristimaki, Ari; Sarhadi, Virinder; Knuutila, Sakari; Nyström, Minna; Renkonen-Sinisalo, Laura; Lepistö, Anna; Mecklin, Jukka-Pekka; Peltomäki, Päivi (2019)
    Background: DNA mismatch repair (MMR) defects are a major factor in colorectal tumorigenesis in Lynch syndrome (LS) and 15% of sporadic cases. Some adenomas from carriers of inherited MMR gene mutations have intact MMR protein expression implying other mechanisms accelerating tumorigenesis. We determined roles of DNA methylation changes and somatic mutations in cancer-associated genes as tumorigenic events in LS-associated colorectal adenomas with intact MMR. Methods: We investigated 122 archival colorectal specimens of normal mucosae, adenomas and carcinomas from 57 LS patients. MMR-deficient (MMR-D, n 49) and MMR-proficient (MMR-P, n 18) adenomas were of particular interest and were interrogated by methylation-specific multiplex ligation-dependent probe amplification and Ion Torrent sequencing. Findings: Promoter methylation of CpG island methylator phenotype (CIMP)-associated marker genes and selected colorectal cancer (CRC)-associated tumor suppressor genes (TSGs) increased and LINE-1 methylation decreased from normal mucosa to MMR-P adenomas to MMR-D adenomas. Methylation differences were statistically significant when either adenoma group was compared with normal mucosa, but not between MMR-P and MMR-D adenomas. Significantly increased methylation was found in multiple CIMP marker genes (1612, NEUROGI,CRABP1, and CDKN2A) and TSGs (SERPI and SFRP2) in MMR-P adenomas already. Furthermore, certain CRC-associated somatic mutations, such as KRAS, were prevalent in MMR-P adenomas. Interpretation: We conclude that DNA methylation changes and somatic mutations of cancer-associated genes might serve as an alternative pathway accelerating LS-associated tumorigenesis in the presence of proficient MMR. Fund: Jane and Aatos Erkko Foundation, Academy of Finland, Cancer Foundation Finland, Sigrid juselius Foundation, and HiL1FE. (C) 2019 Published by Elsevier B.V.
  • Porkka, Noora; Olkinuora, Alisa; Kuopio, Teijo; Ahtiainen, Maarit; Eldfors, Samuli; Almusa, Henrikki; Mecklin, Jukka-Pekka; Peltomäki, Päivi (2020)
    Inherited DNA mismatch repair (MMR) defects cause predisposition to colorectal, endometrial, ovarian, and other cancers occurring in Lynch syndrome (LS). It is unsettled whether breast carcinoma belongs to the LS tumor spectrum. We approached this question through somatic mutational analysis of breast carcinomas from LS families, using established LS-spectrum tumors for comparison. Somatic mutational profiles of 578 cancer-relevant genes were determined for LS-breast cancer (LS-BC, n = 20), non-carrier breast cancer (NC-BC, n = 10), LS-ovarian cancer (LS-OC, n = 16), and LS-colorectal cancer (LS-CRC, n = 18) from the National LS Registry of Finland. Microsatellite and MMR protein analysis stratified LS-BCs into MMR-deficient (dMMR, n = 11) and MMR-proficient (pMMR, n = 9) subgroups. All NC-BCs were pMMR and all LS-OCs and LS-CRCs dMMR. All but one dMMR LS-BCs were hypermutated (> 10 non-synonymous mutations/Mb; average 174/Mb per tumor) and the frequency of MMR-deficiency-associated signatures 6, 20, and 26 was comparable to that in LS-OC and LS-CRC. LS-BCs that were pMMR resembled NC-BCs with respect to somatic mutational loads (4/9, 44%, hypermutated with average mutation count 33/Mb vs. 3/10, 30%, hypermutated with average 88 mutations/Mb), whereas mutational signatures shared features of dMMR LS-BC, LS-OC, and LS-CRC. Epigenetic regulatory genes were significantly enriched as mutational targets in LS-BC, LS-OC, and LS-CRC. Many top mutant genes of our LS-BCs have previously been identified as drivers of unselected breast carcinomas. In conclusion, somatic mutational signatures suggest that conventional MMR status of tumor tissues is likely to underestimate the significance of the predisposing MMR defects as contributors to breast tumorigenesis in LS.
  • Björkman, Patrick; Kantonen, Ilkka; Blomqvist, Carl; Venermo, Maarit; Alback, Anders (2019)
    Aortic sarcomas have not been linked to Lynch syndrome in humans, although other soft tissue malignancies have been. We report the case of a 31-year-old man with Lynch syndrome, who presented with abdominal pain and severe claudication. The clinical and diagnostic workup revealed near occlusion of the infrarenal aorta due to aortic angiosarcoma. En bloc resection of the visceral and infrarenal aorta with right nephrectomy was performed, facilitated by temporary extracorporeal bypass to the visceral arteries. The aorta was reconstructed with a bifurcated Dacron graft. At the 24-month follow-up examination, the patient was free of disease but was experiencing chronic diarrhea.
  • Kalamo, Mari H.; Mäenpää, J. U.; Seppälä, T. T.; Mecklin, J. P.; Huhtala, H.; Sorvettula, K.; Pylvänäinen, K.; Staff, S. (2020)
    To prevent endometrial carcinoma in Lynch syndrome (LS), regular gynecological surveillance visits and prophylactic surgery are recommended. Previous data have shown that prophylactic hysterectomy is an effective means of cancer prevention, while the advantages and disadvantages of surveillance are somewhat unclear. We aimed to evaluate female LS carriers' attitudes towards regular gynecological surveillance and factors influencing their decision-making on prophylactic surgery that have not been well documented. Pain experienced during endometrial biopsies was also evaluated. Postal questionnaires were sent to LS carriers undergoing regular gynecological surveillance. Questionnaires were sent to 112 women with LS, of whom 76 responded (68%). Forty-two (55%) had undergone prophylactic hysterectomy by the time of the study. The majority of responders (64/76; 84.2%) considered surveillance appointments beneficial. Pain level during endometrial biopsy was not associated with the decision to undergo prophylactic surgery. The level of satisfaction the women had with the information and advice provided during surveillance was significantly associated with the history of prophylactic hysterectomy (satisfaction rate of 73.2% versus 31.8% of nonoperated women, p = 0.003). The women who had undergone prophylactic surgery were older than the nonoperated women both at mutation testing (median of 42.3 years versus 31.6 years, p <0.001) and at the time of the study (median of 56.9 years versus 46.0 years, respectively, p <0.001). Women with LS pathogenic variants have positive experiences with gynecological surveillance visits, and their perception of the quality of the information and advice obtained plays an important role in their decision-making concerning prophylactic surgery.
  • Mäki-Nevala, Satu; Ukwattage, Sanjeevi; Wirta, Erkki-Ville; Ahtiainen, Maarit; Ristimäki, Ari; Seppälä, Toni T.; Lepistö, Anna; Mecklin, Jukka-Pekka; Peltomäki, Päivi (2021)
    Immunological and epigenetic changes are interconnected and contribute to tumorigenesis. We determined the immunoprofiles and promoter methylation of inflammation-related genes for colitis-associated colorectal carcinomas (CA-CRC). The results were compared with Lynch syndrome (LS)-associated colorectal tumors, which are characterized by an active immune environment through inherited mismatch repair defects. CA-CRCs (n = 31) were immunohistochemically evaluated for immune cell scores (ICSs) and PDCD1 and CD274 expression. Seven inflammation-associated genes (CD274, NTSR1, PPARG, PTGS2, PYCARD, SOCS1, and SOCS2), the repair gene MGMT, and eight standard marker genes for the CpG Island Methylator Phenotype (CIMP) were investigated for promoter methylation in CA-CRCs, LS tumors (n = 29), and paired normal mucosae by multiplex ligation-dependent probe amplification. All but one CA-CRCs were microsatellite-stable and all LS tumors were microsatellite-unstable. Most CA-CRCs had a high ICS (55%) and a positive CD274 expression in immune cells (52%). NTSR1 revealed frequent tumor-specific hypermethylation in CA-CRC and LS. When compared to LS mucosae, normal mucosae from patients with CA-CRC showed significantly higher methylation of NTSR1 and most CIMP markers. In conclusion, CA-CRCs share a frequent ICShigh/CD274(pos) expression pattern with LS tumors. Elevated methylation in normal mucosa may indicate field cancerization as a feature of CA-CRC-associated tumorigenesis.
  • Seppala, Toni T.; Ahadova, Aysel; Dominguez-Valentin, Mev; Macrae, Finlay; Evans, D. Gareth; Therkildsen, Christina; Sampson, Julian; Scott, Rodney; Burn, John; Möslein, Gabriela; Bernstein, Inge; Holinski-Feder, Elke; Pylvänäinen, Kirsi; Renkonen-Sinisalo, Laura; Lepistö, Anna; Lautrup, Charlotte Kvist; Lindblom, Annika; Plazzer, John-Paul; Winship, Ingrid; Tjandra, Douglas; Katz, Lior H.; Aretz, Stefan; Hueneburg, Robert; Holzapfel, Stefanie; Heinimann, Karl; Della Valle, Adriana; Neffa, Florencia; Gluck, Nathan; Cappel, Wouter H. de Vos Tot Nederveen; Vasen, Hans; Morak, Monika; Steinke-Lange, Verena; Engel, Christoph; Rahner, Nils; Schmiegel, Wolff; Vangala, Deepak; Thomas, Huw; Green, Kate; Lalloo, Fiona; Crosbie, Emma J.; Hill, James; Capella, Gabriel; Pineda, Marta; Navarro, Matilde; Blanco, Ignacio; ten Broeke, Sanne; Nielsen, Maartje; Ljungmann, Ken; Nakken, Sigve; Lindor, Noralane; Frayling, Ian; Hovig, Eivind; Sunde, Lone; Kloor, Matthias; Mecklin, Jukka-Pekka; Kalager, Mette; Moller, Pal (2019)
    BackgroundRecent epidemiological evidence shows that colorectal cancer (CRC) continues to occur in carriers of pathogenic mismatch repair (path_MMR) variants despite frequent colonoscopy surveillance in expert centres. This observation conflicts with the paradigm that removal of all visible polyps should prevent the vast majority of CRC in path_MMR carriers, provided the screening interval is sufficiently short and colonoscopic practice is optimal.MethodsTo inform the debate, we examined, in the Prospective Lynch Syndrome Database (PLSD), whether the time since last colonoscopy was associated with the pathological stage at which CRC was diagnosed during prospective surveillance. Path_MMR carriers were recruited for prospective surveillance by colonoscopy. Only variants scored by the InSiGHT Variant Interpretation Committee as class 4 and 5 (clinically actionable) were included. CRCs detected at the first planned colonoscopy, or within one year of this, were excluded as prevalent cancers.ResultsStage at diagnosis and interval between last prospective surveillance colonoscopy and diagnosis were available for 209 patients with 218 CRCs, including 162 path_MLH1, 45 path_MSH2, 10 path_MSH6 and 1 path_PMS2 carriers. The numbers of cancers detected within 3.5years since last colonoscopy were 36, 93, 56 and 33, respectively. Among these, 16.7, 19.4, 9.9 and 15.1% were stage III-IV, respectively (p=0.34). The cancers detected more than 2.5years after the last colonoscopy were not more advanced than those diagnosed earlier (p=0.14).ConclusionsThe CRC stage and interval since last colonoscopy were not correlated, which is in conflict with the accelerated adenoma-carcinoma paradigm. We have previously reported that more frequent colonoscopy is not associated with lower incidence of CRC in path_MMR carriers as was expected. In contrast, point estimates showed a higher incidence with shorter intervals between examinations, a situation that may parallel to over-diagnosis in breast cancer screening. Our findings raise the possibility that some CRCs in path_MMR carriers may spontaneously disappear: the host immune response may not only remove CRC precursor lesions in path_MMR carriers, but may remove infiltrating cancers as well. If confirmed, our suggested interpretation will have a bearing on surveillance policy for path_MMR carriers.
  • Seppälä, Toni T; Ahadova, Aysel; Dominguez-Valentin, Mev; Macrae, Finlay; Evans, D. G; Therkildsen, Christina; Sampson, Julian; Scott, Rodney; Burn, John; Möslein, Gabriela; Bernstein, Inge; Holinski-Feder, Elke; Pylvänäinen, Kirsi; Renkonen-Sinisalo, Laura; Lepistö, Anna; Lautrup, Charlotte K; Lindblom, Annika; Plazzer, John-Paul; Winship, Ingrid; Tjandra, Douglas; Katz, Lior H; Aretz, Stefan; Hüneburg, Robert; Holzapfel, Stefanie; Heinimann, Karl; Valle, Adriana D; Neffa, Florencia; Gluck, Nathan; de Vos tot Nederveen Cappel, Wouter H; Vasen, Hans; Morak, Monika; Steinke-Lange, Verena; Engel, Christoph; Rahner, Nils; Schmiegel, Wolff; Vangala, Deepak; Thomas, Huw; Green, Kate; Lalloo, Fiona; Crosbie, Emma J; Hill, James; Capella, Gabriel; Pineda, Marta; Navarro, Matilde; Blanco, Ignacio; ten Broeke, Sanne; Nielsen, Maartje; Ljungmann, Ken; Nakken, Sigve; Lindor, Noralane; Frayling, Ian; Hovig, Eivind; Sunde, Lone; Kloor, Matthias; Mecklin, Jukka-Pekka; Kalager, Mette; Møller, Pål (BioMed Central, 2019)
    Abstract Background Recent epidemiological evidence shows that colorectal cancer (CRC) continues to occur in carriers of pathogenic mismatch repair (path_MMR) variants despite frequent colonoscopy surveillance in expert centres. This observation conflicts with the paradigm that removal of all visible polyps should prevent the vast majority of CRC in path_MMR carriers, provided the screening interval is sufficiently short and colonoscopic practice is optimal. Methods To inform the debate, we examined, in the Prospective Lynch Syndrome Database (PLSD), whether the time since last colonoscopy was associated with the pathological stage at which CRC was diagnosed during prospective surveillance. Path_MMR carriers were recruited for prospective surveillance by colonoscopy. Only variants scored by the InSiGHT Variant Interpretation Committee as class 4 and 5 (clinically actionable) were included. CRCs detected at the first planned colonoscopy, or within one year of this, were excluded as prevalent cancers. Results Stage at diagnosis and interval between last prospective surveillance colonoscopy and diagnosis were available for 209 patients with 218 CRCs, including 162 path_MLH1, 45 path_MSH2, 10 path_MSH6 and 1 path_PMS2 carriers. The numbers of cancers detected within < 1.5, 1.5–2.5, 2.5–3.5 and at > 3.5 years since last colonoscopy were 36, 93, 56 and 33, respectively. Among these, 16.7, 19.4, 9.9 and 15.1% were stage III–IV, respectively (p = 0.34). The cancers detected more than 2.5 years after the last colonoscopy were not more advanced than those diagnosed earlier (p = 0.14). Conclusions The CRC stage and interval since last colonoscopy were not correlated, which is in conflict with the accelerated adenoma-carcinoma paradigm. We have previously reported that more frequent colonoscopy is not associated with lower incidence of CRC in path_MMR carriers as was expected. In contrast, point estimates showed a higher incidence with shorter intervals between examinations, a situation that may parallel to over-diagnosis in breast cancer screening. Our findings raise the possibility that some CRCs in path_MMR carriers may spontaneously disappear: the host immune response may not only remove CRC precursor lesions in path_MMR carriers, but may remove infiltrating cancers as well. If confirmed, our suggested interpretation will have a bearing on surveillance policy for path_MMR carriers.
  • Vornanen, Marleena; Aktan-Collan, Katja; Hallowell, Nina; Konttinen, Hanna; Haukkala, Ari (2019)
    Genome-wide sequencing may generate secondary findings (SFs). It is recommended that validated, clinically actionable SFs are reported back to patients/research participants. To explore publics’ perspectives on the best ways to do this, we performed a vignette study among Finnish adults. Our aim was to explore how lay people react to different types of hypothetical genomic SFs. Participants received a hypothetical letter revealing a SF predisposing to a severe but actionable disease - cardiovascular disease (familial hypercholesterolemia, long QT syndrome) or cancer (Lynch syndrome, Li–Fraumeni syndrome). Participants (N=29) wrote down their initial reactions, and discussed (N=23) these in focus groups. Data were analyzed using inductive thematic analysis. Reactions to hypothetical SFs varied according to perceived severity and familiarity of the diseases. SFs for cancer were perceived as more threatening than for cardiovascular diseases, but less distressing than risk for psychiatric or neurological disorders, which participants spontaneously brought up. Illness severity in terms of lived experience, availability of treatment, stigma, and individual’s responsibility to control risk were perceived to vary across these disease types. In addition to clinical validity and utility, SF reporting practices need to take into account potential familiarity and lay illness representations of different diseases. Illness representations may influence willingness to receive SFs, and individuals’ reactions to this information.
  • Olkinuora, Alisa; Gylling, Annette; Almusa, Henrikki; Eldfors, Samuli; Lepistö, Anna; Mecklin, Jukka-Pekka; Nieminen, Taina Tuulikki; Peltomäki, Päivi (2020)
    Some 10-50% of Lynch-suspected cases with abnormal immunohistochemical (IHC) staining remain without any identifiable germline mutation of DNA mismatch repair (MMR) genes. MMR proteins form heterodimeric complexes, giving rise to distinct IHC patterns when mutant. Potential reasons for not finding a germline mutation include involvement of an MMR gene not predicted by the IHC pattern, epigenetic mechanism of predisposition, primary mutation in another DNA repair or replication-associated gene, and double somatic MMR gene mutations. We addressed these possibilities by germline and tumor studies in 60 Lynch-suspected cases ascertained through diagnostics (n= 55) or research (n= 5). All cases had abnormal MMR protein staining in tumors but no point mutation or large rearrangement of the suspected MMR genes in the germline. In diagnostic practice, MSH2/MSH6 (MutS Homolog 2/MutS Homolog 6) deficiency promptsMSH2mutation screening; in our study, 3/11 index individuals (27%) with this IHC pattern revealed pathogenic germline mutations inMSH6. Individuals with isolated absence of MSH6 are routinely screened forMSH6mutations alone; we found a predisposing mutation inMSH2in 1/7 such cases (14%). Somatic deletion of theMSH2-MSH6region, joint loss of MSH6 and MSH3 (MutS Homolog 3) proteins, and hindered MSH2/MSH6 dimerization offered explanations to misleading IHC patterns. Constitutional epimutation hypothesis was pursued in the MSH2 and/or MSH6-deficient cases plus 38 cases with MLH1 (MutL Homolog 1)-deficient tumors; a primaryMLH1epimutation was identified in one case with an MLH1-deficient tumor. We conclude that bothMSH2andMSH6should be screened in MSH2/6- and MSH6-deficient cases. In MLH1-deficient cases, constitutional epimutations ofMLH1warrant consideration.
  • PLSD; Dominguez-Valentin, Mev; Plazzer, John-Paul; Sampson, Julian R.; Renkonen-Sinisalo, Laura; Lepistö, Anna; Peltomäki, Päivi; Lindberg, Lars; Seppälä, Toni T. (2021)
    Background. Lynch syndrome is the most common genetic predisposition for hereditary cancer. Carriers of pathogenic changes in mismatch repair (MMR) genes have an increased risk of developing colorectal (CRC), endometrial, ovarian, urinary tract, prostate, and other cancers, depending on which gene is malfunctioning. In Lynch syndrome, differences in cancer incidence (penetrance) according to the gene involved have led to the stratification of cancer surveillance. By contrast, any differences in penetrance determined by the type of pathogenic variant remain unknown. Objective. To determine cumulative incidences of cancer in carriers of truncating and missense or aberrant splicing pathogenic variants of the MLH1 and MSH2 genes. Methods. Carriers of pathogenic variants of MLH1 (path_MLH1) and MSH2 (path_MSH2) genes filed in the Prospective Lynch Syndrome Database (PLSD) were categorized as truncating or missense/aberrant splicing according to the InSiGHT criteria for pathogenicity. Results. Among 5199 carriers, 1045 had missense or aberrant splicing variants, and 3930 had truncating variants. Prospective observation years for the two groups were 8205 and 34,141 years, respectively, after which there were no significant differences in incidences for cancer overall or for colorectal cancer or endometrial cancers separately. Conclusion. Truncating and missense or aberrant splicing pathogenic variants were associated with similar average cumulative incidences of cancer in carriers of path MLH1 and path_MSH2.
  • Kasela, Mariann; Nyström, Minna; Kansikas, Minttu (2019)
    PMS2 is one of the four susceptibility genes in Lynch syndrome (LS), the most common cancer syndrome in the world. Inherited mutations in DNA mismatch repair (MMR) genes, MLH1, MSH2, and MSH6, account for approximately 90% of LS, while a relatively small number of LS families segregate a PMS2 mutation. This and the low cancer penetrance in PMS2 families suggest that PMS2 is only a moderate or low-risk susceptibility gene. We have previously shown that even a partial expression decrease in MLH1, MSH2, or MSH6 suggests that heterozygous LS mutation carriers have MMR malfunction in constitutive tissues. Whether and how PMS2 expression decrease affects the repair capability is not known. Here, we show that PMS2 knockdown cells retaining 19%, 33%, or 53% of PMS2 expression all have significantly reduced MMR efficiency. Surprisingly, the cells retaining expression levels comparable to PMS2 mutation carriers indicate the lowest repair efficiency.
  • Dominguez-Valentin, Mev; Seppälä, Toni T.; Engel, Christoph; Aretz, Stefan; Macrae, Finlay; Winship, Ingrid; Capella, Gabriel; Thomas, Huw; Hovig, Eivind; Nielsen, Maartje; Sijmons, Rolf H.; Bertario, Lucio; Bonanni, Bernardo; Tibiletti, Maria Grazia; Cavestro, Giulia Martina; Mints, Miriam; Gluck, Nathan; Katz, Lior; Heinimann, Karl; Vaccaro, Carlos A.; Green, Kate; Lalloo, Fiona; Hill, James; Schmiegel, Wolff; Vangala, Deepak; Perne, Claudia; Strauss, Hans-Georg; Tecklenburg, Johanna; Holinski-Feder, Elke; Steinke-Lange, Verena; Mecklin, Jukka-Pekka; Plazzer, John-Paul; Pineda, Marta; Navarro, Matilde; Vidal, Joan Brunet; Kariv, Revital; Rosner, Guy; Alejandra Pinero, Tamara; Laura Gonzalez, Maria; Kalfayan, Pablo; Sampson, Julian R.; Ryan, Neil A. J.; Evans, D. Gareth; Moller, Pal; Crosbie, Emma J. (2020)
    Purpose: To survey risk-reducing hysterectomy and bilateral salpingo-oophorectomy (BSO) practice and advice regarding hormone replacement therapy (HRT) in women with Lynch syndrome. Methods: We conducted a survey in 31 contributing centers from the Prospective Lynch Syndrome Database (PLSD), which incorporates 18 countries worldwide. The survey covered local policies for risk-reducing hysterectomy and BSO in Lynch syndrome, the timing when these measures are offered, the involvement of stakeholders and advice regarding HRT. Results: Risk-reducing hysterectomy and BSO are offered to path_MLH1 and path_MSH2 carriers in 20/21 (95%) contributing centers, to path_MSH6 carriers in 19/21 (91%) and to path_PMS2 carriers in 14/21 (67%). Regarding the involvement of stakeholders, there is global agreement (similar to 90%) that risk-reducing surgery should be offered to women, and that this discussion may involve gynecologists, genetic counselors and/or medical geneticists. Prescription of estrogen-only HRT is offered by 15/21 (71%) centers to women of variable age range (35-55 years). Conclusions: Most centers offer risk-reducing gynecological surgery to carriers of path_MLH1, path_MSH2 and path_MSH6 variants but less so for path_PMS2 carriers. There is wide variation in how, when and to whom this is offered. The Manchester International Consensus Group developed recommendations to harmonize clinical practice across centers, but there is a clear need for more research.
  • Mäki-Nevala, Satu; Ukwattage, Sanjeevi; Olkinuora, Alisa; Almusa, Henrikki; Ahtiainen, Maarit; Ristimäki, Ari; Seppälä, Toni; Lepistö, Anna; Mecklin, Jukka-Pekka; Peltomäki, Päivi (2021)
    Ulcerative colitis increases colorectal cancer risk by mechanisms that remain incompletely understood. We approached this question by determining the genetic and epigenetic profiles of colitis-associated colorectal carcinomas (CA-CRC). The findings were compared to Lynch syndrome (LS), a different form of cancer predisposition that shares the importance of immunological factors in tumorigenesis. CA-CRCs (n = 27) were investigated for microsatellite instability, CpG island methylator phenotype and somatic mutations of 999 cancer-relevant genes ("Pan-cancer" panel). A subpanel of "Pan-cancer" design (578 genes) was used for LS colorectal tumors (n = 28). Mutational loads and signatures stratified CA-CRCs into three subgroups: hypermutated microsatellite-unstable (Group 1, n = 1), hypermutated microsatellite-stable (Group 2, n = 9) and nonhypermutated microsatellite-stable (Group 3, n = 17). The Group 1 tumor was the only one with MLH1 promoter hypermethylation and exhibited the mismatch repair deficiency-associated Signatures 21 and 15. Signatures 30 and 32 characterized Group 2, whereas no prominent single signature existed in Group 3. TP53, the most common mutational target in CA-CRC (16/27, 59%), was similarly affected in Groups 2 and 3, but DNA repair genes and Wnt signaling genes were mutated significantly more often in Group 2. In LS tumors, the degree of hypermutability exceeded that of the hypermutated CA-CRC Groups 1 and 2, and somatic mutational profiles and signatures were different. In conclusion, Groups 1 (4%) and 3 (63%) comply with published studies, whereas Group 2 (33%) is novel. The existence of molecularly distinct subgroups within CA-CRC may guide clinical management, such as therapy options.
  • Dominguez-Valentin, Mev; Seppälä, Toni T.; Sampson, Julian R.; Macrae, Finlay; Winship, Ingrid; Evans, D. Gareth; Scott, Rodney J.; Burn, John; Moeslein, Gabriela; Bernstein, Inge; Pylvaenaeinen, Kirsi; Renkonen-Sinisalo, Laura; Lepistö, Anna; Lindblom, Annika; Plazzer, John-Paul; Tjandra, Douglas; Thomas, Huw; Green, Kate; Lalloo, Fiona; Crosbie, Emma J.; Hill, James; Capella, Gabriel; Pineda, Marta; Navarro, Matilde; Vidal, Joan Brunet; Ronlund, Karina; Nielsen, Randi Thyregaard; Yilmaz, Mette; Elvang, Louise Laurberg; Katz, Lior; Nielsen, Maartje; ten Broeke, Sanne W.; Nakken, Sigve; Hovig, Eivind; Sunde, Lone; Kloor, Matthias; Doeberitz, Magnus v Knebel; Ahadova, Aysel; Lindor, Noralane; Steinke-Lange, Verena; Holinski-Feder, Elke; Mecklin, Jukka-Pekka; Moller, Pal (2019)
    Background We previously reported that in pathogenic mismatch repair (path_MMR) variant carriers, the incidence of colorectal cancer (CRC) was not reduced when colonoscopy was undertaken more frequently than once every 3 years, and that CRC stage and interval since last colonoscopy were not correlated. Methods The Prospective Lynch Syndrome Database (PLSD) that records outcomes of surveillance was examined to determine survival after colon cancer in relation to the time since previous colonoscopy and pathological stage. Only path_MMR variants scored by the InSiGHT variant database as class 4 or 5 (clinically actionable) were included in the analysis. Results Ninety-nine path_MMR carriers had no cancer prior to or at first colonoscopy, but subsequently developed colon cancer. Among these, 96 were 65 years of age or younger at diagnosis, and included 77 path_MLH1, 17 path_MSH2, and 2 path_MSH6 carriers. The number of cancers detected within <1.5, 1.5-2.5, 2.5-3.5 and at > 3.5 years after previous colonoscopy were 9, 43, 31 and 13, respectively. Of these, 2, 8, 4 and 3 were stage III, respectively, and only one stage IV (interval 2.5-3.5 years) disease. Ten-year crude survival after colon cancer were 93, 94 and 82% for stage I, II and III disease, respectively (p <0.001). Ten-year crude survival when the last colonoscopy had been <1.5, 1.5-2.5, 2.5-3.5 or > 3.5 years before diagnosis, was 89, 90, 90 and 92%, respectively (p = 0.91). Conclusions In path_MLH1 and path_MSH2 carriers, more advanced colon cancer stage was associated with poorer survival, whereas time since previous colonoscopy was not. Although the numbers are limited, together with our previously reported findings, these results may be in conflict with the view that follow-up of path_MMR variant carriers with colonoscopy intervals of less than 3 years provides significant benefit.
  • Dominguez-Valentin, Mev; Seppälä, Toni T; Sampson, Julian R; Macrae, Finlay; Winship, Ingrid; Evans, D. G; Scott, Rodney J; Burn, John; Möslein, Gabriela; Bernstein, Inge; Pylvänäinen, Kirsi; Renkonen-Sinisalo, Laura; Lepistö, Anna; Lindblom, Annika; Plazzer, John-Paul; Tjandra, Douglas; Thomas, Huw; Green, Kate; Lalloo, Fiona; Crosbie, Emma J; Hill, James; Capella, Gabriel; Pineda, Marta; Navarro, Matilde; Vidal, Joan B; Rønlund, Karina; Nielsen, Randi T; Yilmaz, Mette; Elvang, Louise L; Katz, Lior; Nielsen, Maartje; ten Broeke, Sanne W; Nakken, Sigve; Hovig, Eivind; Sunde, Lone; Kloor, Matthias; Knebel Doeberitz, Magnus v; Ahadova, Aysel; Lindor, Noralane; Steinke-Lange, Verena; Holinski-Feder, Elke; Mecklin, Jukka-Pekka; Møller, Pål (BioMed Central, 2019)
    Abstract Background We previously reported that in pathogenic mismatch repair (path_MMR) variant carriers, the incidence of colorectal cancer (CRC) was not reduced when colonoscopy was undertaken more frequently than once every 3 years, and that CRC stage and interval since last colonoscopy were not correlated. Methods The Prospective Lynch Syndrome Database (PLSD) that records outcomes of surveillance was examined to determine survival after colon cancer in relation to the time since previous colonoscopy and pathological stage. Only path_MMR variants scored by the InSiGHT variant database as class 4 or 5 (clinically actionable) were included in the analysis. Results Ninety-nine path_MMR carriers had no cancer prior to or at first colonoscopy, but subsequently developed colon cancer. Among these, 96 were 65 years of age or younger at diagnosis, and included 77 path_MLH1, 17 path_MSH2, and 2 path_MSH6 carriers. The number of cancers detected within < 1.5, 1.5–2.5, 2.5–3.5 and at > 3.5 years after previous colonoscopy were 9, 43, 31 and 13, respectively. Of these, 2, 8, 4 and 3 were stage III, respectively, and only one stage IV (interval 2.5–3.5 years) disease. Ten-year crude survival after colon cancer were 93, 94 and 82% for stage I, II and III disease, respectively (p < 0.001). Ten-year crude survival when the last colonoscopy had been < 1.5, 1.5–2.5, 2.5–3.5 or > 3.5 years before diagnosis, was 89, 90, 90 and 92%, respectively (p = 0.91). Conclusions In path_MLH1 and path_MSH2 carriers, more advanced colon cancer stage was associated with poorer survival, whereas time since previous colonoscopy was not. Although the numbers are limited, together with our previously reported findings, these results may be in conflict with the view that follow-up of path_MMR variant carriers with colonoscopy intervals of less than 3 years provides significant benefit.