Editorial:Identification, risk stratification, and optimized management for Lynch Syndrome

Non peer reviewe

An update on immune checkpoint therapy for the treatment of lynch syndrome

During the recent years, immune checkpoint-based therapy has proven highly effective in microsatellite instable (MSI) solid tumors irrespective of organ site. MSI tumors are associated with a defective mismatch repair (MMR) system and a highly immune-infiltrative tumor microenvironment—both characteristics of Lynch syndrome. Lynch syndrome is a multi-tumor syndrome that not only confers a high risk of colorectal and endometrial cancer but also cancer in, eg the upper urinary tract, ovaries, and small bowel. Since the genetic predisposition for Lynch syndrome are pathogenic variants in one of the four MMR genes, MLH1, MSH2, MSH6 or PMS2, most of the Lynch syndrome cancers show MMR deficiency, MSI, and activation of the immune response system. Hence, Lynch syndrome cancer patients may be optimal candidates for immune checkpoint-based therapies. However, molecular differences have been described between sporadic MSI tumors (developed due to MLH1 promoter hypermethylation) and Lynch syndrome tumors, which may result in different treatment responses. Furthermore, the response profile of the rare Lynch syndrome cases may be masked by the more frequent cases of sporadic MSI tumors in large clinical trials. With this review, we systematically collected response data on Lynch syndrome patients treated with FDA- and EMA-approved immune checkpoint-based drugs (pembrolizumab, atezolizumab, durvalumab, avelumab, ipilimumab, and nivolumab) to elucidate the objective response rate and progression-free survival of cancer in Lynch syndrome patients. Herein, we report Lynch syndrome-related objective response rates between 46 and 71% for colorectal cancer and 14–100% for noncolorectal cancer in unselected cohorts as well as an overview of the Lynch syndrome case reports. To date, no difference in the response rates has been reported between Lynch syndrome and sporadic MSI cancer patients

Disease expression in juvenile polyposis syndrome : a retrospective survey on a cohort of 221 European patients and comparison with a literature-derived cohort of 473 SMAD4/BMPR1A pathogenic variant carriers

Purpose Juvenile polyposis syndrome (JPS) is a rare, autosomal-dominantly inherited cancer predisposition caused in approximately 50% of cases by pathogenic germline variants in SMAD4 and BMPR1A. We aimed to gather detailed clinical and molecular genetic information on JPS disease expression to provide a basis for management guidelines and establish open access variant databases. Methods We performed a retrospective, questionnaire-based European multicenter survey on and established a cohort of SMAD4/BMPR1A pathogenic variant carriers from the medical literature. Results We analyzed questionnaire-based data on 221 JPS patients (126 kindreds) from ten European centers and retrieved literature-based information on 473 patients. Compared with BMPR1A carriers, SMAD4 carriers displayed anemia twice as often (58% vs. 26%), and exclusively showed overlap symptoms with hemorrhagic telangiectasia (32%) and an increased prevalence (39% vs. 13%) of gastric juvenile polyps. Cancer, reported in 15% of JPS patients (median age 41 years), mainly occurred in the colorectum (overall: 62%, SMAD4: 58%, BMPR1A: 88%) and the stomach (overall: 21%; SMAD4: 27%, BMPR1A: 0%). Conclusion This comprehensive retrospective study on genotype-phenotype correlations in 694 JPS patients corroborates previous observations on JPS in general and SMAD4 carriers in particular, facilitates recommendations for clinical management, and provides the basis for open access variant SMAD4 and BMPR1A databases.Peer reviewe

The apparent genetic anticipation in PMS2-associated Lynch syndrome families is explained by birth cohort effect

BACKGROUND: PMS2-associated Lynch syndrome is characterized by a relatively low colorectal cancer penetrance compared with other Lynch syndromes. However, age at colorectal cancer diagnosis varies widely, and a strong genetic anticipation effect has been suggested for PMS2 families. In this study, we examined proposed genetic anticipation in a sample of 152 European PMS2 families. METHODS: The 152 families (637 family members) that were eligible for analysis were mainly clinically ascertained via clinical genetics centers. We used weighted Cox-type random effects model, adjusted by birth cohort and sex, to estimate the generational effect on the age of onset of colorectal cancer. Probands and young birth cohorts were excluded from the analyses. Weights represented mutation probabilities based on kinship coefficients, thus avoiding testing bias. RESULTS: Family data across three generations, including 123 colorectal cancers, were analyzed. When compared with the first generation, the crude HR for anticipation was 2.242 [95% confidence interval (CI), 1.162-4.328] for the second generation and 2.644 (95% CI, 1.082-6.464) for the third generation. However, after correction for birth cohort and sex, the effect vanished [HR = 1.302 (95% CI, 0.648-2.619) and HR = 1.074 (95% CI, 0.406-2.842) for second and third generations, respectively]. CONCLUSIONS: Our study did not confirm previous reports of genetic anticipation in PMS2-associated Lynch syndrome. Birth-cohort effect seems the most likely explanation for observed younger colorectal cancer diagnosis in subsequent generations, particularly because there is currently no commonly accepted biological mechanism that could explain genetic anticipation in Lynch syndrome. IMPACT: This new model for studying genetic anticipation provides a standard for rigorous analysis of families with dominantly inherited cancer predisposition

No difference in penetrance between truncating and missense/aberrant splicing pathogenic variants in mlh1 and msh2: A prospective lynch syndrome database study

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.Fil: Dominguez Valentin, Mev. St Mark’s Hospital; Reino Unido. The Norwegian Radium Hospital; Noruega. European Hereditary Tumour Group; Reino UnidoFil: Plazzer, John Paul. St Mark’s Hospital; Reino Unido. The Royal Melbourne Hospital; AustraliaFil: Sampson, Julian R.. European Hereditary Tumour Group; Reino Unido. Cardiff University; Reino UnidoFil: Engel, Christoph. European Hereditary Tumour Group; Reino Unido. Universitat Leipzig; AlemaniaFil: Aretz, Stefan. Universitat Bonn; AlemaniaFil: Jenkins, Mark A.. University of Melbourne; AustraliaFil: Sunde, Lone. Aalborg University; DinamarcaFil: Bernstein, Inge. Aalborg University; DinamarcaFil: Capella, Gabriel. European Hereditary Tumour Group; Reino Unido. St Mark’s Hospital; Reino Unido. Institut Català d’Oncologia; EspañaFil: Balaguer Prunés, Francesc. Universidad de Barcelona; EspañaFil: Macrae, Finlay. European Hereditary Tumour Group; Reino Unido. The Royal Melbourne Hospital; AustraliaFil: Winship, Ingrid M.. University of Melbourne; AustraliaFil: Thomas, Huw. Imperial College London; Reino UnidoFil: Evans, Dafydd Gareth. University of Manchester; Reino UnidoFil: Burn, John. Universidad de Newcastle; Australia. The Royal Melbourne Hospital; Australia. St Mark’s Hospital; Reino UnidoFil: Greenblatt, Marc. University of Vermont; Estados UnidosFil: de Vos tot Nederveen Cappel, Wouter H.. Isala Clinics; Países BajosFil: Sijmons, Rolf H.. University of Groningen; Países Bajos. St Mark’s Hospital; Reino Unido. European Hereditary Tumour Group; Reino UnidoFil: Nielsen, Maartje. Leids Universitair Medisch Centrum; Países BajosFil: Bertario, Lucio. Fondazione IRCCS Istituto Nazionale dei Tumori; ItaliaFil: Bonanni, Bernardo. Fondazione IRCCS Istituto Nazionale dei Tumori; ItaliaFil: Tibiletti, Maria Grazia. Università dell’Insubria; ItaliaFil: Cavestro, Giulia Martina. Vita-Salute San Raffaele University; ItaliaFil: Lindblom, Annika. Karolinska Huddinge Hospital; SueciaFil: Della Valle, Adriana. Hospital Fuerzas Armadas; UruguayFil: Lopez Kostner, Francisco. Clínica Universidad de los Andes; ChileFil: Alvarez, Karin. Clínica Universidad de los Andes; ChileFil: Gluck, Nathan. Universitat Tel Aviv; IsraelFil: Katz, Lior. Sheba Medical Center; IsraelFil: Heinimann, Karl. University Hospital Basel; SuizaFil: Piñero, Tamara Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaFil: Pavicic, Walter Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; Argentin

Cancer incidence and survival in Lynch syndrome patients receiving colonoscopic and gynaecological surveillance : first report from the prospective Lynch syndrome database

Objective Estimates of cancer risk and the effects of surveillance in Lynch syndrome have been subject to bias, partly through reliance on retrospective studies. We sought to establish more robust estimates in patients undergoing prospective cancer surveillance. Design We undertook a multicentre study of patients carrying Lynch syndrome-associated mutations affecting MLH1, MSH2, MSH6 or PMS2. Standardised information on surveillance, cancers and outcomes were collated in an Oracle relational database and analysed by age, sex and mutated gene. Results 1942 mutation carriers without previous cancer had follow-up including colonoscopic surveillance for 13 782 observation years. 314 patients developed cancer, mostly colorectal (n=151), endometrial (n=72) and ovarian (n=19). Cancers were detected from 25 years onwards in MLH1 and MSH2 mutation carriers, and from about 40 years in MSH6 and PMS2 carriers. Among first cancer detected in each patient the colorectal cancer cumulative incidences at 70 years by gene were 46%, 35%, 20% and 10% for MLH1, MSH2, MSH6 and PMS2 mutation carriers, respectively. The equivalent cumulative incidences for endometrial cancer were 34%, 51%, 49% and 24%; and for ovarian cancer 11%, 15%, 0% and 0%. Ten-year crude survival was 87% after any cancer, 91% if the first cancer was colorectal, 98% if endometrial and 89% if ovarian. Conclusions The four Lynch syndrome-associated genes had different penetrance and expression. Colorectal cancer occurred frequently despite colonoscopic surveillance but resulted in few deaths. Using our data, a website has been established at http://LScarisk.org enabling calculation of cumulative cancer risks as an aid to genetic counselling in Lynch syndrome.Peer reviewe