Hereditary non-polyposis colorectal cancer: clinical features and survival. Results from the Danish HNPCC register

The clinical features of ovarian cancer in hereditary nonpolyposis colorectal cancer

OBJECTIVE

Hereditary nonpolyposis colorectal cancer (HNPCC) is a hereditary cancer susceptibility disorder associated with a very high risk for carcinoma of the colon and an elevated risk for certain extracolonic cancers including ovarian cancer. Our aim in this study was to describe the clinicopathologic features of ovarian cancer in HNPCC family members.

METHODS

. Members of the International Collaborative Group on HNPCC collected retrospective data on 80 ovarian cancer patients who were members of HNPCC families, including 31 known mutation carriers, 35 presumptive carriers (by colorectal/endometrial cancer status), and 14 at-risk family members.

RESULTS

Mean age at diagnosis of ovarian cancer was 42.7. Nonepithelial tumors made up only 6.4% of the cancers, and borderline tumors comprised just 4.1% of the epithelial cancers. Among frankly malignant epithelial cases, most cancers were well or moderately differentiated, and 85% were FIGO stage I or II at diagnosis. Synchronous endometrial cancer was reported in 21.5% of cases.

CONCLUSIONS

Ovarian cancer in HNPCC differs from ovarian cancer in the general population in several clinically important respects. It occurs at a markedly earlier age. It is more likely to be epithelial. If it is a frankly invasive epithelial cancer, it is more likely to be well or moderately differentiated. HNPCC patients with ovarian cancer are more likely to have a synchronous endometrial cancer than other ovarian cancer patients and are more likely to be diagnosed at an early stage.

Microsatellite instability in sporadic colorectal cancer is not an independent prognostic factor

Hereditary non-polyposis colorectal cancer (HNPCC) is linked to an inherited defect in the DNA mismatch repair system. DNA from HNPCC tumours shows microsatellite instability (MSI). It has been reported that HNPCC patients have a better prognosis than patients with sporadic colorectal cancer. We examined whether the presence of MSI in a series of unselected colorectal tumours carries prognostic information. In a series of 181 unselected colorectal tumours, 22 tumours (12%) showed MSI. Survival analysis at 5-10 years follow-up showed no statistically significant difference in prognosis between MSI-positive and -negative tumours. Our results suggest that the MSI phenotype as such is not an independent prognostic factor.

Genetic testing in hereditary colorectal cancer: indications and procedures

Approximately 25% of colorectal cancers occur in younger individuals or those with a personal or family history of the disease, suggesting a heritable susceptibility. The minority of these cases are accounted for by one of the well-described hereditary colorectal cancer syndromes, familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). The recent identification and cloning of the genes responsible for FAP and HNPCC, along with other colon cancer susceptibility genes, has led to the wide-spread availability of genetic testing for hereditary colorectal cancer. Genetic testing raises clinical, ethical, legal, and psychosocial questions that must urgently be discussed. This review highlights areas of knowledge and uncertainty about genetic predisposition testing for colorectal cancer and provides clinicians with practical recommendations regarding the proper indications and procedures for this testing.

Survival of patients with hereditary colorectal cancer: comparison of HNPCC and colorectal cancer in FAP patients with sporadic colorectal cancer

Conflicting data exist on the prognosis of hereditary colorectal cancer. HNPCC patients, in particular, are often reported to have a better survival. We examined 2,340 colorectal-cancer patients treated in our Institution: 144 HNPCC patients (Amsterdam Criteria), 161 FAP patients and 2,035 patients with sporadic cancer. Data on hereditary-cancer patients treated between 1980 and 1995 was collected in a registry. The 2,035 sporadic colorectal-cancer patients (controls) included all new cases treated in the Department of Gastrointestinal-Tract Surgery during the same period. Observed survival was estimated using the Kaplan-Meier method. Cumulative survival probability was estimated at 5 years within each group and stratified by various clinical and pathological variables. The age distribution at diagnosis of sporadic patients was significantly higher than that of FAP and HNPCC patients (median 60 years vs. 43 and 49 years; p < 0.0001). In the HNPCC group, 40% had a right cancer location, vs. 14% in the FAP group and 13% in the sporadic-cancer group. In the sporadic group, 51% were early-stage cancers (Dukes A or B) vs. 48.4% and 52.1% in the FAP and HNPCC groups respectively. In the HNPCC, FAP and sporadic-cancer groups, the 5-year cumulative survival rate was 56.9%, 54.4% and 50.6% respectively. Survival analysis by the Cox proportional-hazards method revealed no substantial survival advantage for HNPCC and FAP patients compared with the sporadic group, after adjustment for age, gender, stage and tumor location. The hazard ratio for HNPCC was 1.01 (95% CI 0.72-1.39) and 1.27 (95% CI 0.95-1.7) for FAP patients compared with the sporadic-colorectal-cancer group.

Familial prostate cancer: outcome following radiation therapy with or without adjuvant androgen ablation

PURPOSE

To compare the outcome of familial versus sporadic prostate carcinoma after definitive external radiation.

METHODS AND MATERIALS

Between 1987 and 1996, 1214 men with clinically localized prostate cancer (T1-T4, N0/NX, M0) received definitive radiation therapy in our department. By retrospective review of charts and questioning of patients, a record on the presence or absence of prostate cancer in a first degree relative was obtained in 1164 men. Univariate and multivariate analysis was performed on these cases with relapse or rising prostate-specific antigen (PSA), local recurrence, metastasis, and survival as endpoints.

RESULTS

Familiar prostate cancer was present in 148 of 1164 men (13%). Men with familial disease were slightly but significantly younger (mean 66 years) at diagnosis than those with sporadic disease (mean 68 years) (p = 0.02). Apart from this there were no significant differences between the two groups in T-stage, Gleason score, pretreatment PSA levels, DNA ploidy, or serum testosterone levels. There were no significant differences in treatment parameters including radiation dose and the use of adjuvant androgen ablation. With a median follow-up of 42 months, there was no difference in freedom from relapse or rising PSA at 6 years between those with a family history (54%) and those without a family history (58%) (p = 0.171). Likewise there was no difference between the two groups when local recurrence or metastasis was the endpoint. Multiple subgroup analyses (younger and older; T1/T2 and T3; low Gleason and high Gleason; no androgen ablation and androgen ablation; race) failed to reveal any differences in outcome in any category between familial and sporadic disease. Among patients with a rising post-treatment PSA profile, PSA doubling times were similar in those with sporadic and familial disease.

CONCLUSIONS

This study provides no evidence for any substantial difference between familial and sporadic prostate cancer either in clinicopathological features, in response to treatment, or in ultimate outcome.

Varying features of early age-of-onset "sporadic" and hereditary nonpolyposis colorectal cancer patients

PURPOSE

Although the criteria for clinical diagnosis of hereditary nonpolyposis colorectal cancer are not fully agreed on, young age seems to be a common trait. The purpose of this study is to identify clinicopathologic features of hereditary nonpolyposis colorectal cancer in early age-of-onset colorectal cancer patients stratified as a function of family cancer history.

METHODS

Two hundred thirty consecutive colorectal cancer patients 40 years or older at time of diagnosis were registered into an ongoing database during a ten-year period. Accurate family history was obtained via medical records, telephone calls, and questionnaires on 146 patients. According to extent of family history of cancer, patients were stratified into seven groups: 1) fulfilling Amsterdam criteria, 2) fulfilling less strict criteria, 3) having at least one first-degree relative with colorectal cancer, 4) having at least one distant relative with colorectal cancer, 5) having at least one first-degree relative with any cancer, 6) having at least one distant relative with any cancer, 7) having no family history of cancer.

RESULTS

Twenty-two of 146 patients fulfilled Amsterdam and less strict hereditary nonpolyposis colorectal cancer criteria (15 percent). These hereditary nonpolyposis colorectal cancer patients were significantly younger (31 vs. 35 years; P = 0.0003) and had more metachronous colorectal cancer (27 percent vs. 2 percent; P = 0.007) and less colorectal cancer with nodal or metastatic spread than the non-hereditary nonpolyposis colorectal cancer patients (35 percent vs. 65 percent; P = 0.01).

CONCLUSION

Precise familial cancer assessment in early age-of-onset colorectal cancer increases the yield of hereditary nonpolyposis colorectal cancer diagnosis. Because of the frequent development of metachronous colorectal cancer and favorable prognosis, extensive rather than segmental surgery should be considered in early age-of-onset colorectal cancer patients belonging to hereditary nonpolyposis colorectal cancer families.

Hereditary non-polyposis colorectal cancer syndrome

Hereditary non-polyposis colorectal cancer (HNPCC) syndrome may account for up to 4% of the total colorectal cancer burden in our community. It is assuming an increasingly important role, both as a clinical management issue and as a model for the application of laboratory and clinical genetic services in cancer detection and prevention. Recent developments in the understanding of the molecular biology of the condition have underpinned recommendations for consideration of genetic testing for DNA mismatch repair gene mutation, recommendations that may have far-reaching implications in terms of the numbers of patients offered genetic testing and for associated costs (both financial and psychological). The aim of this review is to highlight the clinical, pathologic and molecular biologic features of HNPCC that underlie the clinical management of affected index patients and their at-risk family members.

Accumulated clonal genetic alterations in familial and sporadic colorectal carcinomas with widespread instability in microsatellite sequences

A subset of hereditary and sporadic colorectal carcinomas is defined by microsatellite instability (MSI), but the spectra of gene mutations have not been characterized extensively. Thirty-nine hereditary nonpolyposis colorectal cancer syndrome carcinomas (HNPCCa) and 57 sporadic right-sided colonic carcinomas (SRSCCa) were evaluated. Of HNPCCa, 95% (37/39) were MSI-positive as contrasted with 31% (18/57) of SRSCCa (P < 0.000001), but instability tended to be more widespread in SRSCCa (P = 0.08). Absence of nuclear hMSH2 mismatch repair gene product by immunohistochemistry was associated with germline hMSH2 mutation (P = 0.0007). The prevalence of K-ras proto-oncogene mutations was similar in HNPCCa and SRSCCa (30% (11/37) and 30% (16/54)), but no HNPCCa from patients with germline hMSH2 mutation had codon 13 mutation (P = 0.02), and two other HNPCCa had multiple K-ras mutations attributable to subclones. 18q allelic deletion and p53 gene product overexpression were inversely related to MSI (P = 0.0004 and P = 0.0001, respectively). Frameshift mutation of the transforming growth factor beta type II receptor gene was frequent in all MSI-positive cancers (85%, 46/54), but mutation of the E2F-4 transcription factor gene was more common in HNPCCa of patients with germline hMSH2 mutation than in those with germline bMLH1 mutation (100% (8/8) versus 40% (2/5), P = 0.04), and mutation of the Bax proapoptotic gene was more frequent in HNPCCa than in MSI-positive SRSCCa (55% (17/31) versus 13% (2/15), P = 0.01). The most common combination of mutations occurred in only 23% (8/35) of evaluable MSI-positive cancers. Our findings suggest that the accumulation of specific genetic alterations in MSI-positive colorectal cancers is markedly heterogeneous, because the occurrence of some mutations (eg, ras, E2F-4, and Bax genes), but not others (eg, transforming growth factor beta type II receptor gene), depends on the underlying basis of the mismatch repair deficiency. This genetic heterogeneity may contribute to the heterogeneous clinical and pathological features of MSI-positive cancers.