Familial colorectal cancer type X: polyp burden and cancer risk stratification via a family history score

Risk for Hereditary Neoplastic Syndromes in Women with Mismatch Repair-Proficient Endometrial Cancer

Endometrial cancer (EC) is a prevalent malignancy in women, and those who are proficient in the DNA mismatch repair (pMMR) pathway may have a family history (FH) that meets the criteria for a hereditary neoplastic condition (HNS). This study aimed to estimate the risk of HNS in women with pMMR endometrial tumors by analyzing their FH. To achieve this, we collaborated with a primary study and collected FH information by telephone. The final sample comprised 42 women who responded to the Primary Screening Questionnaire. Their family pedigrees were drawn and categorized according to internationally standardized criteria for the risk of HNS. Results showed that 26 women (61%) were found to be at risk for HNS, with Bethesda criteria being met by 23%, Amsterdam criteria by 15%, and 4% met the attenuated familial adenomatous polyposis criteria. Our results emphasize the importance of FH and the need to encourage healthcare professionals to collect and document FH more frequently, even if it is self-reported. By identifying individuals with HNS, we can improve their outcomes and reduce the burden of cancer in families with a predisposition to cancer.

Comparison of long-term outcomes between Lynch sydrome and sporadic colorectal cancer: a propensity score matching analysis

Background

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome. Comparison of prognosis between LS and sporadic CRC (SCRC) were rare, with conflicting results. This study aimed to compare the long-term outcomes between patients with LS and SCRC.

Methods

Between June 2008 and September 2018, a total of 47 patients were diagnosed with LS by genetic testing at Fudan University Shanghai Cancer Center. A 1:2 propensity score matching was performed to obtain homogeneous cohorts from SCRC group. Thereafter, 94 SCRC patients were enrolled as control group. All of enrolled patients received curative surgeries and standardized postoperative monitoring. The long-term survival rates between the two groups were compared, and the prognostic factors were also analyzed.

Results

The 5-year overall survival rate of LS group was 97.6%, which was significantly higher than of 82.6% for SCRC group (χ² = 4.745, p = 0.029). The 5-year recurrence free survival rate showed no significant differences between the two groups (78.0% for LS group vs. 70.6% for SCRC patients; χ² = 1.260, p = 0.262). The 5-year tumor free survival rates in LS group was 62.1% for LS patients, which were significantly lower than of 70.6% for SCRC group (χ² = 4.258, p = 0.039). Subgroup analysis of recurrent patients show that the LS group had longer overall survival than the SCRC group after combined chemotherapy. By multivariate analysis, we found that tumor recurrence of primary CRC [Risk ratio (95% (confidence interval): 48.917(9.866–242.539); p < 0.001] and late TNM staging [Risk ratio (95% (confidence interval): 2.968(1.478–5.964); p = 0.002] were independent risk factors for OS.

Conclusion

LS patients have better long-term survival prognosis than SCRC patients, even though the two groups have statistically comparable recurrence free survival. Combined chemotherapy is an effective treatment for LS patients who developed primary CRC recurrence. Standardized postoperative monitoring for LS patients may enable detection of metachronous tumors at earlier stages, which was a guarantee of a favorable prognosis despite lower tumor free survival.

Comparison Between Familial Colorectal Cancer Type X and Lynch Syndrome: Molecular, Clinical, and Pathological Characteristics and Pedigrees

Objective

This study aimed to compare the molecular, clinical, and pathological characteristics and pedigrees of familial colorectal cancer type X (FCCTX) with those of Lynch syndrome (LS) to provide a theoretical basis for the management of FCCTX.

Methods

Overall, 46 cases of FCCTX and 47 LS probands and affected families were enrolled between June 2008 and September 2018 for this study. Multigene cancer panel tests that included 139 genes were performed for all patients, and variants in each group were described. The clinical, pathological, and pedigree characteristics were also compared between the two groups.

Results

In total, 42 variants were detected in 27 (58.7%) cases in the FCCTX group, with BRCA1, BRCA2, POLE, POLD1, ATR, and ATM being the most frequently mutated genes. The mean onset age of colorectal cancer (CRC) was significantly older in the FCCTX group than in the LS group (53.57 ± 12.88 years vs. 44.36 ± 11.26 years, t = −9.204, p < 0.001). The proportion of patients with rectal cancer was also higher in the FCCTX group than in the LS group [43.5% (20/46) vs. 10.6% (5/47), χ² = 12.823, p = 0.005]. Within a median follow-up time of 53.9 ± 37.0 months, the proportion of patients who developed metachronous CRC was significantly higher in the LS group than in the FCCTX group [34.0% (16/47) vs. 13.0% (6/46), χ² = 5.676, p = 0.017]. When comparing pedigrees, older age at cancer onset and rectal cancer clustering were observed in the FCCTX families. A higher prevalence in male patients was also observed in the FCCTX families.

Conclusion

FCCTX is an entity distinct from LS, but its genetic etiology remains unknown. A larger multigene panel would be recommended for determining the underlying pathogenic variants. Considering the pathology and moderate penetrance of the CRC link to FCCTX, less stringent surgical treatments and colonoscopy surveillance would be preferable. Rectum preference is a typical feature of FCCTX. Colonoscopy surveillance in FCCTX families could be less intensive, and more attention should be given to male members.

Risks of Colorectal Cancer and Cancer-Related Mortality in Familial Colorectal Cancer Type X and Lynch Syndrome Families

BACKGROUND

The risk of cancers is well characterized in Lynch syndrome (LS) families but has been less studied in familial colorectal cancer type X (FCCTX) families.

METHODS

In this article, we compare the risk estimates of first and second colorectal cancers (CRCs) in 168 FCTTX and 780 LS families recruited through the Colon Cancer Family Registry as well as the risk of cancer-related deaths and disease-free survival (DFS) after a first CRC. Our methodology is based on a survival analysis approach, developed specifically to model the occurrence of successive cancers (ie, first and second CRCs) in the presence of competing risk events (ie, death from any causes).

RESULTS

We found an excess risk of first and second CRC in individuals with LS compared to FCCTX family members. However, for an average age at first CRC of 60 years in FCCTX families and 50 years in LS families, the DFS rates were comparable in men but lower in women from FCCTX vs LS families, eg , 75.1% (95% confidence interval [CI] = 69.0% to 80.9%) vs 78.9% (95% CI = 76.3% to 81.3%) for the 10-year DFS. The 10-year risk of cancer-related death was higher in FCCTX families vs LS families, eg, 15.4% in men (95% CI = 10.9% to 19.8%) and 19.3% in women (95% CI = 13.6% to 24.7%) vs 8.9% (95% CI = 7.5% to 11.4%) and 8.7% (95% CI = 7.1% to 10.8%), respectively.

CONCLUSIONS

Individuals with CRCs arising in the context of FCCTX do not experience the same improved DFS and overall survival of those with LS, and that difference may be relevant in management decisions.

Association of a let-7 miRNA binding region of TGFBR1 with hereditary mismatch repair proficient colorectal cancer (MSS HNPCC)

The purpose of this study was to identify novel colorectal cancer (CRC)-causing alleles in unexplained familial CRC cases. In order to do so, coding regions in five candidate genes (MGMT, AXIN2, CTNNB1, TGFBR1 and TGFBR2) were sequenced in 11 unrelated microsatellite-stable hereditary non-polyposis CRC (MSS HNPCC) cases. Selected genetic variants were genotyped in a discovery set of 27 MSS HNPCC cases and 85 controls. One genetic variant, rs67687202, in TGFBR1 emerged as significant (P = 0.002), and it was genotyped in a replication set of 87 additional MSS HNPCC-like cases and 338 controls where it was also significantly associated with MSS HNPCC cases (P = 0.041). In the combined genotype data, rs67687202 was associated with a moderate increase in CRC risk (OR = 1.68; 95% CI = 1.13-2.50; P = 0.010). We tested a highly correlated SNP rs868 in 723 non-familial CRC cases compared with 629 controls, and it was not significantly associated with CRC risk (P = 0.370). rs868 is contained in a let-7 miRNA binding site in the 3'UTR of TGFBR1, which might provide a functional basis for the association in MSS HNPCC. In luciferase assays, the risk-associated allele for rs868 was associated with half the luciferase expression in the presence of miRNA let-7b-5p compared with protective allele, suggesting more binding of let-7b-5p and less TGFBR1 expression. Thus, rs868 potentially is a CRC risk-causing allele. Our results support the concept that rs868 is associated with lower TGFBR1 expression thereby increasing CRC risk.

Cancer risk and overall survival in mismatch repair proficient hereditary non-polyposis colorectal cancer, Lynch syndrome and sporadic colorectal cancer

Mismatch repair proficient hereditary non-polyposis colorectal cancer (MSS-HNPCC) encloses a heterogeneous group of families consisting of different unknown genetic syndromes and/or aggregations cases. The lack of information about the hereditability of cancer risk in these families makes it difficult to carry out an individualized Genetic Counseling. Therefore, deep description of such families becomes important for a better classification and search for underlying susceptibility causes. The aim of this study is to describe and compare the clinical, morphological features, tumor KRAS status and overall survival in MSS-HNPCC, Lynch and sporadic colorectal cancer. A total of 37 MSS-HNPCC families, 50 Lynch families and 612 sporadic CRC were included. Clinical and morphological data were evaluated by reviewing medical and pathology reports of 55, 69 and 102 tumors respectively. KRAS/BRAF status were detected by allele specific real-time PCR. Standardized incidence ratios (SIR) were calculated among 602 MSS-HNPCC relatives and 668 Lynch relatives. Main features distinguishing MSS-HNPCC were diagnosis age (55.1 ± 12.6), preferential distal location (76%), polyp detection (45%) and familial colorectal cancer incidence (SIR = 6.6). In addition, we found increased incidences rates for kidney, stomach and uterus tumors. KRAS mutation rates were similar in the study populations (48.8 ± 5.8) but higher than those described before by Sanger sequencing. MSS-HNPCC overall survival was similar to Lynch in B Dukes' stage tumors and between Lynch and sporadic in C stage tumors. Anatomical and morphological data of MSS-HNPCC are consistent with other described populations. Our studies disclose an increased HNPCC-extracolonic tumors incidence and improved overall survival in MSS-HNPCC families.

Genetic diagnosis of high-penetrance susceptibility for colorectal cancer (CRC) is achievable for a high proportion of familial CRC by exome sequencing

PURPOSE

Knowledge of the contribution of high-penetrance susceptibility to familial colorectal cancer (CRC) is relevant to the counseling, treatment, and surveillance of CRC patients and families.

PATIENTS AND METHODS

To quantify the impact of germline mutation to familial CRC, we sequenced the mismatch repair genes (MMR) APC, MUTYH, and SMAD4/BMPR1A in 626 early-onset familial CRC cases ascertained through a population-based United Kingdom national registry. In addition, we evaluated the contribution of mutations in the exonuclease domain (exodom) of POLE and POLD1 genes that have recently been reported to confer CRC risk.

RESULTS

Overall mutations (pathogenic, likely pathogenic) in MMR genes make the highest contribution to familial CRC (10.9%). Mutations in the other established CRC genes account for 3.3% of cases. POLE/POLD1 exodom mutations were identified in three patients with family histories consistent with dominant transmission of CRC. Collectively, mutations in the known genes account for 14.2% of familial CRC (89 of 626 cases; 95% CI = 11.5, 17.2).

CONCLUSION

A genetic diagnosis is feasible in a high proportion of familial CRC. Mainstreaming such analysis in clinical practice should enable the medical management of patients and their families to be optimized. Findings suggest CRC screening of POLE and POLD1 mutation carriers should be comparable to that afforded to those at risk of HNPCC. Although the risk of CRC associated with unexplained familial CRC is in general moderate, in some families the risk is substantive and likely to be the consequence of unidentified genes, as exemplified by POLE and POLD1. Our findings have utility in the design of genetic analyses to identify such novel CRC risk genes.

Familial colorectal cancer type X: genetic profiles and phenotypic features

Heredity is a major cause of colorectal cancer, but although several rare high-risk syndromes have been linked to disease-predisposing mutations, the genetic mechanisms are undetermined in the majority of families suspected of hereditary cancer. We review the clinical presentation, histopathologic features, and the genetic and epigenetic profiles of the familial colorectal cancer type X (FCCTX) syndrome with the aim to delineate tumor characteristics that may contribute to refined diagnostics and optimized tumor prevention.

Characterisation of familial colorectal cancer Type X, Lynch syndrome, and non-familial colorectal cancer

BACKGROUND

Familial Colorectal Cancer Type X (FCCTX) is defined as individuals with colorectal cancer (CRC) who families meet Amsterdam Criteria-1 (AC1), but whose tumours are DNA-mismatch-repair-proficient, unlike Lynch syndrome (LS). FCCTX does not have an increased risk of extra-colonic cancers. This analysis compares epidemiologic and clinicopathologic features among FCCTX, LS, and 'non-familial' (non-AC1) CRC cases.

METHODS

From the Colon Cancer Family Registry, FCCTX (n=173), LS (n=303), and non-AC1 (n=9603) CRC cases were identified. Questionnaire-based epidemiologic information and CRC pathologic features were compared across case groups using polytomous logistic regression.

RESULTS

Compared with LS, FCCTX cases were less likely to be current (vs never) smokers; have a proximal subsite (vs rectal) tumour; or have mucinous histology, poor differentiation, or tumour-infiltrating lymphocytes. There were no observed differences in co-morbidities or medication usage.

CONCLUSIONS

FCCTX were less likely to be current tobacco users; other exposures were similar between these groups. Histopathologic differences highly suggestive of LS CRCs do not appear to be shared by FCCTX.

Familial colon cancer syndromes: an update of a rapidly evolving field

Colorectal cancer (CRC) is a major cause of morbidity and mortality in the world. Up to 30 % of CRCs have evidence of a familial component, and about 5 % are thought to be due to well-characterized inherited mutations. This review will focus on recent developments in the understanding of the individual hereditary CRC syndromes, including Lynch syndrome, familial CRC type X, familial adenomatous polyposis, MutYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, PTEN hamartomatous syndrome, and serrated polyposis syndrome. Advances within the area of hereditary colon cancer syndromes paint a picture of a rapidly moving, rapidly maturing, and increasingly collaborative field with many opportunities for ongoing research and development.