Impact of family history of colon cancer on development of multiple primaries after diagnosis of colon cancer

Young patients with colorectal cancer have increased risk of second primary cancers

OBJECTIVE

Because the number of long-term survivors of colorectal cancer has increased, second primary cancer has become an important issue. However, previous studies were heterogeneous in design, and few data for Asia-Pacific area were available.

METHODS

This was a retrospective population-based study conducted using the national database of the Taiwan Cancer Registry. Patients who have histology-proven primary colon cancer and rectal cancer from 1995 to 2005 were enrolled in this study. All second primary cancer events had to be histology proven. The standardized incidence ratio of second primary cancer was used as an indicator. Standardized incidence ratio was counted as the number of observed second primary cancer divided by the expected number of cancer cases in the general population.

RESULTS

A total of 65 648 eligible index patients were enrolled, and 3810 second primary cancer events were identified. The standardized incidence ratio for all of the patients was 1.03 (95% confidence interval: 0.99-1.06), which implied that the risk of second primary cancer was not significantly elevated in the index patients compared with that of the general population. The standardized incidence ratio for the patients aged <50, 50-70 and >70 years was 2.52 (95% confidence interval: 2.28-2.78), 1.18 (95% confidence interval: 1.12-1.23) and 0.80 (95% confidence interval: 0.76-0.84), respectively. In young patients (aged <50 years), the standardized incidence ratio increase was statistically significant and persisted for over 10 years and this significantly increased across all subgroups. The small intestine, the large intestine, the female genital organs and the lungs were the most common sites of second primary cancer in young patients.

CONCLUSIONS

Young patients with colorectal cancer have an increased risk of developing second primary cancer.

Risks of primary extracolonic cancers following colorectal cancer in lynch syndrome

BACKGROUND

Lynch syndrome is a highly penetrant cancer predisposition syndrome caused by germline mutations in DNA mismatch repair (MMR) genes. We estimated the risks of primary cancers other than colorectal cancer following a diagnosis of colorectal cancer in mutation carriers.

METHODS

We obtained data from the Colon Cancer Family Registry for 764 carriers of an MMR gene mutation (316 MLH1, 357 MSH2, 49 MSH6, and 42 PMS2), who had a previous diagnosis of colorectal cancer. The Kaplan-Meier method was used to estimate their cumulative risk of cancers 10 and 20 years after colorectal cancer. We estimated the age-, sex-, country- and calendar period-specific standardized incidence ratios (SIRs) of cancers following colorectal cancer, compared with the general population.

RESULTS

Following colorectal cancer, carriers of MMR gene mutations had the following 10-year risk of cancers in other organs: kidney, renal pelvis, ureter, and bladder (2%, 95% confidence interval [CI] = 1% to 3%); small intestine, stomach, and hepatobiliary tract (1%, 95% CI = 0.2% to 2%); prostate (3%, 95% CI = 1% to 5%); endometrium (12%, 95% CI = 8% to 17%); breast (2%, 95% CI = 1% to 4%); and ovary (1%, 95% CI = 0% to 2%). They were at elevated risk compared with the general population: cancers of the kidney, renal pelvis, and ureter (SIR = 12.54, 95% CI = 7.97 to 17.94), urinary bladder (SIR = 7.22, 95% CI = 4.08 to 10.99), small intestine (SIR = 72.68, 95% CI = 39.95 to 111.29), stomach (SIR = 5.65, 95% CI = 2.32 to 9.69), and hepatobiliary tract (SIR = 5.94, 95% CI = 1.81 to 10.94) for both sexes; cancer of the prostate (SIR = 2.05, 95% CI = 1.23 to 3.01), endometrium (SIR = 40.23, 95% CI = 27.91 to 56.06), breast (SIR = 1.76, 95% CI = 1.07 to 2.59), and ovary (SIR = 4.19, 95% CI = 1.28 to 7.97).

CONCLUSION

Carriers of MMR gene mutations who have already had a colorectal cancer are at increased risk of a greater range of cancers than the recognized spectrum of Lynch syndrome cancers, including breast and prostate cancers.

Excess risk of subsequent primary cancers among colorectal carcinoma survivors, 1975-2001

BACKGROUND

Studies of persons with colorectal cancer have reported increased risk of subsequent primary cancers. Results have not been consistent, however, and there is little information about such risk in specific races and ethnic populations.

METHODS

Using 1975-2001 data from the Surveillance, Epidemiology, and End Results (SEER) Program, we assembled 262,600 index cases of colorectal carcinoma to assess the occurrence of subsequent primary cancers in 13 noncolonic sites. Observed (O) subsequent cancers were compared with those expected (E) based on age-/sex-/race-/year-/site-specific rates in the SEER population. The standardized incidence ratio (SIR) and the absolute excess risk (AER) represent 'O / E' and 'O - E,' respectively.

RESULTS

Colorectal carcinoma patients had significantly elevated SIRs for small gut, stomach (males), kidney, and corpus uteri cancers, ranging from 1.13 for stomach cancer in males to 3.45 for small gut cancer in females. Elevated SIRs for additional sites were seen in certain population subgroups: pancreas and ovary in persons aged <50 years, and prostate in black males. The excess burden, as assessed by AER, was notable for prostate cancer in black males and for corpus uteri cancer in females aged <50 years (26.5 and 9.5 cancers per 10,000 person-years, respectively), and it persisted beyond 5 years of follow-up.

CONCLUSIONS

Although significantly elevated SIRs were found for several cancers, the excess burden was notable only for cancer of the prostate in black males and of the corpus uteri in females under age 50.

Modulation of CDK2-AP1 (p12DOC−1) expression in human colorectal cancer

We have previously demonstrated an association between microsatellite instability and decreased CDK2-AP1 (p12(DOC-1)) expression in human colorectal cancer (CRC) cell lines. In those same studies, induction of CDK2-AP1 expression promoted both cell cycle arrest and apoptosis. The goals of our present study were to better understand the mechanisms leading to reduced CDK2-AP1 expression in microsatellite unstable (MSI) CRC and to study further the effect of CDK2-AP1 modulation on cell proliferation and apoptosis utilizing RNA interference (RNAi) techniques. We used direct sequencing to screen for mutations of the poly (T)8 microsatellite-like region in the 3' end of the CDK2-AP1 gene in 24 CRC cell lines. We then utilized an in vitro human mismatch repair (MMR) recombinant system to assess for correction of the mutation and changes in CDK2-AP1 expression secondary to hMLH1 transfection. We also investigated the effect of CDK2-AP1 modulation in four settings: (1) native CDK2-AP1 absence, (2) endogenous CDK2-AP1 expression, (3) RNAi-induced CDK2-AP1 inhibition and (4) induced CDK2-AP1 over expression. The mutation - del T poly (T)8 - at the 3' end of the CDK2-AP1 gene was found in 3/12 (25%) of MSI CRC cell lines, but in none of the microsatellite stable samples (0/12). Interestingly, when wild-type MMR protein - MLH1 - was induced in an in vitro human recombinant system, the del T poly (T)8 mutation was reversed and CDK2-AP1 expression increased. RNAi-mediated CDK2-AP1 inhibition was associated with decreased apoptosis and increased cell proliferation in CDK2-AP1-non deficient CRC cell lines. We conclude that mutations in the microsatellite-like sequence of the CDK2-AP1 gene in MSI CRC are associated with decreased CDK2-AP1 expression. In addition, modulation of CDK2-AP1 expression in human CRC alters cell proliferation and apoptosis.

Clinical pathology and hereditary predisposition in patients with primary colorectal cancer: An analysis of 594 cases

AIM: To analyze the features of clinical pathology and hereditary predisposition of primary colorectal cancer (CRC) patients.

METHODS: A total of 594 primary CRC inpatients were continuously investigated in our hospital and cooperation hospitals. They were proved to be primary colorectal cancer by histopathological examination. The following data of all patients should be registered: sex, family history of colorectal cancer, site, number and histological type of primary cancer. Tumor sites were classified as proximal colon to the splenic flexure, distal colon to the splenic flexure and whole colorectum. Hereditary predisposition of CRC is that CRC patients have two or more first- or second-degree relatives (or both) with CRC. And hereditary predisposition of malignant tumor is that CRC patients have two or more first- or second-degree relatives (or both) with malignant tumor. Hereditary nonpolyposis colorectal cancer (HNPCC) was diagnosed by any of Amsterdam criteria, Amsterdam criteria II and Japanese criteria of HNPCC. CRC patients were divided into seven groups by the age being diagnosed.

RESULTS: The distribution of the age diagnosed as colorectal cancer was not normal distribution. The median diagnosed age of CRC patients was 65.1 years. There were more patients in -70 years group than other groups. In age of 70 years before, the proportion of patients was increasing with the increasing of age and more elder patients were found. But in more than 70 years old group, the proportion of patients was decreased by the increasing of patients age. Most of colorectal caner were located distal to the splenic flexure, and rectal cancer was in 45.3% patients. There was no correlation between tumor site and the age in CRC (P > 0.05). The most frequent histological type was adenocarcinoma (87.5%). In addition, the proportion of mucoid adenocarcinoma and signet-ring cell carcinoma were 8.2% and 5.2%, respectively. The proportion of signet-ring cell carcinoma was higher in older groups (P < 0.05). As to the proportion of multiple primary cancers, multiple primary CRCs, hereditary predisposition of cancer and hereditary predisposition of colorectal cancer were 13.1%, 10.1%, 17.2% and 5.2%, respectively. The incidence of HNPCC diagnosed by Amsterdam criteria, Amsterdam criteria Ⅱ and Japanese criteria of HNPCC were 0.5%, 2.9% and 2.4%, respectively. The correlation had been found between the occurrences of multiple primary cancers and multiple primary CRCs with familial history of malignant tumors (P < 0.05), and there were more multiple primary cancers and multiple primary CRCs in CRC patients with familial history of malignant tumors. But obvious correlation was not found between the occurrence of multiple primary cancers and multiple primary CRCs with familial history of CRCs (P > 0.05).

CONCLUSION: Age of patients with colorectal cancer is not normal distribution, and the proportion of elder patients with colorectal cancer becomes higher in all CRC patients. Most of tumors locate distal to the splenic flexure and adenocarcinoma is the most common histological type. There are 17.2% colorectal cancer patients with hereditary cancer predisposition. The occurrences of multiple primary cancers and multiple primary CRCs are correlated with familial history of malignant tumors.

Evidence for an age-related influence of microsatellite instability on colorectal cancer survival

It is well established that microsatellite instability (MSI), the hallmark of defective DNA mismatch repair (MMR), is associated with prolonged survival in colorectal cancer compared with tumours that are microsatellite stable (MSS). MSI in sporadic colorectal tumours is primarily due to epigenetic silencing of MLH1. However, there are no prospective population-based studies of survival in patients with germline MMR gene mutations who develop cancer. Although MSI is almost universal in tumours from HNPCC family members, there is a potential confounding effect of ascertainment and other biases that could explain the apparent survival benefit in HNPCC families. Resolving whether germline MMR gene mutations impact on survival is important because it potentially undermines the rationale for surveillance of mutation carriers. Here, we report an investigation of the influence of MSI on survival in cohorts of cancer patients (aged < 30 years at diagnosis, n = 118; non-age-selected, n = 181) in the context of clinicopathologic variables. There was a substantial age-related influence of tumour MSI status on survival. In young patients with tumour MSI, 65% of patients with MSI tumours had germline MSH2 or MLH1 mutations. Clinicopathologic variables and tumour MSI of the cohort were studied with respect to survival and compared with control groups. Young patients had excess MSI tumours (p < 0.000001), mucinous tumours (p < 0.01), advanced disease (p approximately 0.001) and poorer 5-year survival compared with older cases. Cox proportional hazard analysis identified Dukes' stage, age at diagnosis and calendar year of treatment as independent predictors of survival. There was no detectable association between tumour MSI and survival in young patients, although we confirmed previous observations that MSI is associated with better prognosis in later onset cohorts. These findings underscore the rationale for surveillance and early identification of tumours in MMR gene carriers as well as refining understanding of the influence of MSI on cancer progression.