Maureen E. Mork

High prevalence of hereditary cancer syndromes in adolescents and young adults with colorectal cancer

PURPOSE Established guidelines recommend evaluation for hereditary cancer syndromes in patients younger than 50 years diagnosed with colorectal cancer (CRC). This group has been well described in the literature; however, patients diagnosed as adolescents and young adults are not well represented in CRC studies. Here, we define the clinical profile, including the extent of hereditary cancer syndromes and family history of cancer, in patients diagnosed with CRC at age 35 or younger. PATIENTS AND METHODS We reviewed patients who underwent genetic counseling at our institution during 5 years (2009 to 2013). Data were collected regarding demographics, clinicopathologic information, tumor and genetic testing, and family history. Patients with an identified hereditary cancer syndrome were compared with those without a syndrome. RESULTS Of the 193 patients with evaluable data, 35% had an identifiable hereditary cancer syndrome, including 23 with Lynch syndrome, 22 with mutation-negative Lynch syndrome, 16 with familial adenomatous polyposis, two with constitutional mismatch repair deficiency, two with biallelic MUTYH mutations, and one with Li-Fraumeni syndrome. Patients without a hereditary syndrome more frequently presented with metastatic disease, whereas patients with a syndrome were more likely to present at earlier stages and to have a family history of cancer. Nevertheless, a substantial proportion of the hereditary syndromes (19%) were diagnosed in individuals with no family history of the disease. CONCLUSION We conclude that patients diagnosed with CRC at age 35 years or younger should receive genetic counseling regardless of their family history and phenotype.

Genomic Landscape of Colorectal Mucosa and Adenomas

The molecular basis of the adenoma-to-carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas. We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances (AI) in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach. Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer driver genes (APC, KRAS, FBXW7, TCF7L2) and AIs in chromosomes 5, 7, and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation. The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis. Cancer Prev Res; 9(6); 417–27. ©2016 AACR.

Lynch Syndrome: A Primer for Urologists and Panel Recommendations

PURPOSE Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is a common genetic disease. The predisposition of patients with Lynch syndrome to urological cancer, particularly upper tract urothelial carcinoma, is underappreciated. Urologists may be involved in several aspects of care involving Lynch syndrome, including identifying undiagnosed patients, surveillance of those with established Lynch syndrome or screening family members, in addition to treating patients with Lynch syndrome in whom upper tract urothelial carcinoma develops. We sought to increase awareness in the urological community about Lynch syndrome and provide some guidance where little currently exists. MATERIALS AND METHODS Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement we reviewed the available published literature and guidelines from 1998 to 2014 on Lynch syndrome and its association with upper tract urothelial carcinoma. Recommendations based on the literature and the consensus of expert opinion are provided. RESULTS No randomized or prospective study has been done to evaluate Lynch syndrome in the setting of urological cancer. All data were based on retrospective studies. Lynch syndrome is an autosomal dominant genetic disease caused by germline mutations in 4 mismatch repair genes, leading to the accumulation of DNA errors in microsatellite regions. Upper tract urothelial carcinoma develops in up to 28% of patients with known Lynch syndrome. The diagnosis of Lynch syndrome is established by clinical criteria, tumor tissue testing and genetic evaluation. Urologists should suspect Lynch syndrome when a patient with upper tract urothelial carcinoma presents before age 60 years or meets the 3-2-1 rule. Screening patients with Lynch syndrome for upper tract urothelial carcinoma presents a particular challenge. While no ideal screening test exists, at a minimum routine urinalysis is recommended using the American Urological Association guideline of 3 or more red blood cells per high power field as a trigger for further assessment. Upper tract urothelial carcinoma associated with Lynch syndrome presents at a younger age than sporadic upper tract urothelial carcinoma. It shows a higher proportion of ureteral cancer with a female preponderance and a possible predisposition to bilaterality. CONCLUSIONS Lynch syndrome is a common genetic disease that is an underappreciated cause of upper tract urothelial carcinoma and possibly other urological cancers. Optimal screening for upper tract urothelial carcinoma in this population is unclear. Further study is needed to identify the best screening test and interval of testing. Urologists should consider routine tissue testing of de novo upper tract urothelial carcinoma tissue in individuals at risk.

Patient-reported disease knowledge and educational needs in Lynch syndrome: findings of an interactive multidisciplinary patient conference

BackgroundPatients with Lynch Syndrome, the most common hereditary colorectal cancer syndrome, benefit from genetic education and family counseling regarding diagnostic testing and cancer surveillance/prevention recommendations. Although genetic counseling is currently the most common venue where such education and counseling takes place, little is known about the level of disease knowledge and education needs as directly reported by patients and families with Lynch Syndrome. Furthermore, experiences with forums for larger-scale knowledge transfer have been limited in the current literature.MethodsWe conducted a one-day interactive multidisciplinary patient conference, designed to complement individual genetic counseling for updating disease knowledge, supportive networking and needs assessment among Lynch Syndrome patients and their family members. The patient conference was designed utilizing the conceptual framework of action research. Paired pre- and post-conference surveys were administered to 44 conference participants anonymously to assess patient-reported disease knowledge and education needs.ResultsA multidisciplinary team of expert providers utilized a variety of educational formats during the one-day conference. Four main focus areas were: genetic testing, surveillance/prevention, living with Lynch Syndrome, and update on research. Thirty-two participants (73%) completed the pre-conference, and 28 (64%) participants completed the post-conference surveys. Nineteen respondents were affected and the remaining were unaffected. The scores of the disease-knowledge items significantly increased from 84% pre- to 92% post-conference (p = 0.012). Patients reported a high level of satisfaction and identified further knowledge needs in nutrition (71%), surveillance/prevention options (71%), support groups (36%), cancer risk assessment (32%), active role in medical care (32%), and research opportunities (5%).ConclusionOur experience with a dedicated patient education conference focused on Lynch Syndrome demonstrated that such an educational format is effective for updating or reinforcing disease knowledge, for identifying patient-reported unmet educational needs, as well as for peer-support.

Role of microsatellite instability-low as a diagnostic biomarker of Lynch syndrome in colorectal cancer

Lynch syndrome is the most common Mendelian disorder predisposing persons to hereditary colorectal cancer. Carriers of MSH6 mutations constitute less than 10% of the total of cases with Lynch syndrome and present with a weaker clinical phenotype, including low levels of microsatellite instability (MSI-L) in colorectal tumors. The frequency of MSH6 mutation carriers among patients presenting with MSI-L colorectal cancer has yet to be determined, as has the appropriate genetic workup in this context. We have reviewed here the clinicopathologic characteristics, immunohistochemistry, and genetic testing results for 71 patients at a single institution diagnosed with MSI-L colorectal cancers. Of 71 patients with MSI-L tumors, 21 underwent genetic testing for MSH6 mutations, three of whom presented with loss of staining of MSH6 and only one of whom carried a pathogenic germline MSH6 mutation in exon 4 (c.2677_2678delCT; p.Leu893Alafs*6). This latter patient had a significant family history of cancer and had a rectal primary tumor that showed instability only in mononucleotide markers. In this cohort of MSI-L patients, we detected no notable clinicopathologic or molecular characteristic that would help to distinguish a group most likely to harbor germline MSH6 mutations. Therefore, we conclude that the prevalence of MSH6 mutations among patients with MSI-L tumors is very low. Microsatellite instability analysis combined with immunohistochemistry of mismatch repair proteins adequately detects potential MSH6 mutation carriers among MSI-L colorectal cancers.

Universal Point of Care Testing for Lynch Syndrome in Patients with Upper Tract Urothelial Carcinoma

Purpose Patients with Lynch syndrome are at risk for upper tract urothelial carcinoma. We sought to identify the incidence and most reliable means of point of care screening for Lynch syndrome in patients with upper tract urothelial carcinoma. Materials and Methods A total of 115 consecutive patients with upper tract urothelial carcinoma without a history of Lynch syndrome were universally screened during followup from January 2013 through July 2016. We evaluated patient and family history using AMS (Amsterdam criteria) I and II, and tumor immunohistochemistry for mismatch repair proteins and microsatellite instability. Patients who were positive for AMS I/II, microsatellite instability or immunohistochemistry were classified as potentially having Lynch syndrome and referred for clinical genetic analysis and counseling. Patients with known Lynch syndrome served as positive controls. Results Of the 115 patients 16 (13.9%) screened positive for potential Lynch syndrome. Of these patients 7.0% met AMS II criteria, 11.3% had loss of at least 1 mismatch repair protein and 6.0% had high microsatellite instability. All 16 patients were referred for germline testing, 9 completed genetic analysis and counseling, and 6 were confirmed to have Lynch syndrome. All 7 patients with upper tract urothelial carcinoma who had a known history of Lynch syndrome were positive for AMS II criteria and at least a single mismatch repair protein loss while 5 of 6 had high microsatellite instability. Conclusions We identified 13.9% of upper tract urothelial carcinoma cases as potential Lynch syndrome and 5.2% as confirmed Lynch syndrome at the point of care. These findings have important implications for universal screening of upper tract urothelial carcinoma, representing one of the highest rates of undiagnosed genetic disease in a urological cancer.

Is it all Lynch syndrome?: An assessment of family history in individuals with mismatch repair-deficient tumors

Purpose:Mismatch repair-deficient (MMRD) colorectal cancer (CRC) and endometrial cancer (EC) may be suggestive of Lynch syndrome (LS). LS can be confirmed only by positive germ-line testing. It is unclear if individuals with MMRD tumors but no identifiable cause (MMRD+/germ-line−) have LS. Because LS is hereditary, individuals with LS are expected to have family histories of LS-related tumors. Our study compared the family histories of MMRD+/germ-line− CRC and/or EC patients with LS CRC and/or EC patients.Methods:A total of 253 individuals with an MMRD CRC or EC from one institution were included for analysis in one of four groups: LS; MMRD+/germ-line−; MMRD tumor with variant of uncertain significance (MMRD+/VUS); and sporadic MSI-H (MMRD tumor with MLH1 promoter hypermethylation or BRAF mutation). Family histories were analyzed utilizing MMRpro and PREMM1,2,6. Kruskal–Wallis tests were used to compare family history scores.Results:MMRD+/germ-line− individuals had significantly lower median family history scores (MMRpro = 8.1, PREMM1,2,6 = 7.3) than did LS individuals (MMRpro = 89.8, PREMM1,2,6 = 26.1, P < 0.0001).Conclusion:MMRD+/germ-line− individuals have less suggestive family histories of LS than individuals with LS. These results imply that MMRD+/germ-line− individuals may not all have LS. This finding highlights the need to determine other causes of MMRD tumors so that these patients and their families can be accurately counseled regarding screening and management.Genet Med 17 6, 476–484.

Identification of a novel PMS2 alteration c.505C>G (R169G) in trans with a PMS2 pathogenic mutation in a patient with constitutional mismatch repair deficiency

Constitutional mismatch repair deficiency syndrome (CMMRD) is a rare autosomal recessive predisposition to colorectal polyposis and other malignancies, often childhood-onset, that is caused by biallelic inheritance of mutations in the same mismatch repair gene. Here, we describe a patient with a clinical diagnosis of CMMRD based on colorectal polyposis and young-onset endometrial cancer who was identified to have two alterations in trans in PMS2: one known pathogenic mutation (c.1831insA; p.Ile611Asnfs*2) and one novel variant of uncertain significance (c.505C>G; p.Arg169Glu), a missense alteration. We describe the clinical and molecular features in the patient harboring this novel alteration c.505C>G, who meets clinical criteria for CMMRD and exhibits molecular evidence supporting a diagnosis of CMMRD. Although experimental validation is needed to confirm its pathogenicity, PMS2 c.505C>G likely has functional consequences that contributes to our patient’s phenotype based on the patient’s clinical presentation, tumor studies, and bioinformatics analysis.

Can Microsatellite Status of Colorectal Cancer Be Reliably Assessed after Neoadjuvant Therapy

Purpose: Determination of microsatellite instability (MSI) by PCR is the gold standard; however, IHC of mismatch repair (MMR) proteins is frequently performed instead. The reliability of these methods on postneoadjuvant therapy specimens is unknown. We examined the effect of neoadjuvant therapy on MSI results by PCR and IHC. Experimental design: A total of 239 colorectal cancers resected after neoadjuvant therapy were assessed for MSI with PCR and IHC. PCR and IHC results for matched paired pre- and posttreatment specimens were compared. In parallel, 2 isogenic cell lines conditioned for MMR functioning and 2 different patient-derived xenografts (PDXs) were exposed to chemotherapy, radiation, or both. We also examined whether establishment of PDXs induced MSI changes in 5 tumors. IHC and MSI were tested after treatment to assess for changes. Results: We identified paired pre- and posttreatment specimens for 37 patients: 2 with PCR only, 34 with IHC only, and 1 with both. All 3 patients with PCR had microsatellite stable pre- and posttreatment specimens. Of the 35 patients with IHC, 30 had intact MMR proteins in pre- and posttreatment specimens, 1 had equivocal MLH1 staining in the pretreatment and loss in the posttreatment specimen, and 4 had intact pretreatment MSH6 but variable posttreatment staining. In the experimental setting, no changes in MSI status were detected after treatment or tumor implantation in animals. Conclusions: Our findings show that the expression of MMR proteins, commonly MSH6, can change after neoadjuvant therapy and confirm PCR as the gold-standard test for MSI after neoadjuvant therapy. Clin Cancer Res; 23(17); 5246–54. ©2017 AACR.

In silico systems biology analysis of variants of uncertain significance in lynch syndrome supports the prioritization of functional molecular validation

Lynch syndrome (LS) is a genetic condition secondary to germline alterations in the DNA mismatch repair (MMR) genes with 30% of changes being variants of uncertain significance (VUS). Our aim was to perform an in silico reclassification of VUS from a large single institutional cohort that will help prioritizing functional validation. A total of 54 VUS were detected with 33 (61%) novel variants. We integrated family history, pathology, and genetic information along with supporting evidence from eight different in silico tools at the RNA and protein level. Our assessment allowed us to reclassify 54% (29/54) of the VUS as probably damaging, 13% (7/54) as possibly damaging, and 28% (15/54) as probably neutral. There are more than 1,000 VUS reported in MMR genes and our approach facilitates the prioritization of further functional efforts to assess the pathogenicity to those classified as probably damaging. Cancer Prev Res; 10(10); 580–7. ©2017 AACR.