The association between biliary tract cancers and cancers of other sites

Exogenous estrogen and the risk of biliary tract cancer - a population-based study in a cohort of Swedish men treated for prostate cancer

BACKGROUND

To assess the role of exogenous estrogen in the etiology of biliary tract cancer, a nationwide population-based cohort study in Sweden was performed.

METHODS

The study included all men in Sweden with prostate cancer diagnosed in 1961-2008. Due to treatment standards, patients diagnosed in 1961-1980 were considered more exposed to estrogen, while those diagnosed in 1981-2008 were regarded less exposed. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated to estimate the risk of biliary tract cancer in cohort members compared to the corresponding Swedish male population.

RESULTS

After 849 307 person-years of follow-up in 203 131 prostate cancer patients, there were 41 incident gallbladder cancers and 36 cancers of the extra-hepatic bile ducts. In overall, there were no apparent differences in the risk of gallbladder cancer or bile duct cancer between patients diagnosed in 1961-1980 and patients diagnosed in 1981-2008. However, in patients diagnosed in 1961-1980, there was a statistically non-significant increased risk of gallbladder cancer (SIR 1.34; 95% CI 0.71-2.29) and extra-hepatic bile duct cancer (SIR 1.20; 95% CI 0.55-2.28) > 5 years of follow-up after the prostate cancer diagnosis. No such association was found for patients diagnosed in 1981-2008. Sensitivity analyses excluding prostate cancer patients exposed to potential confounding factors did not change the SIRs.

CONCLUSIONS

Long exposure to high doses of exogenous estrogen might increase the risk of biliary tract cancer. However, any potential excess risk of bile duct cancer resulted by prolonged exposure to high doses of exogenous estrogen seems to be small.

Synchronous carcinoma of the ampulla of vater and colon cancer

Carcinoma of the papilla of Vater is a relatively rare tumor and its coexistence with other primary sporadic cancers is very exceptional. Here we report the case of a 76-year-old man who presented with painless obstructive jaundice, pathologically elevated liver function tests and increased serum levels of carbohydrate antigen 19-9 and carcinoembryonic antigen. Endoscopic retrograde cholangiography revealed a large polypoid mass in the ampulla of Vater. A large tumor in the ascending colon was also incidentally detected by abdominal computed tomography. Endoscopic biopsies from both lesions showed adenocarcinomas. Metastases to the liver and to the hepatoduodenal ligament and hepatic artery lymph nodes were found during surgery. Right colectomy and a biliary bypass were performed. Histological analysis showed an ampullary adenocarcinoma with metastases to regional lymph nodes and the liver and a colonic adenocarcinoma with local invasion into the pericolic fat. Treatment with gemcitabine plus cisplatin was suggested postoperatively. The association of sporadic ampullary and colonic adenocarcinomas and the mutually increased risk of developing either a synchronous or a metachronous tumor following each other should be considered in patients with primary ampullary or colorectal cancer during the preoperative evaluation and postoperative follow-up of these patients.

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.

Association of ampullary and colorectal malignancies

BACKGROUND

Because of the similarities in terms of carcinogenesis and natural history between cancer of the ampulla of Vater and colorectal cancer, the authors examined whether ampullary and colorectal malignancies occur in the same individuals at increased rates.

METHODS

We used data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute for the period from January 1973 through December 1999. Person-years of follow-up for patients with ampullary (or colorectal) cancer were used to calculate the expected number of cases of colorectal (or ampullary) cancer as a second primary malignancy. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated using Byar limits and assuming a Poisson distribution.

RESULTS

The authors identified 2043 white patients with ampullary cancer who were included in the SEER registry between 1973 and 1999. Over an aggregate 5674 person-years of follow-up, 30 patients, compared with an expected 14, developed colorectal cancer, yielding an overall SIR of 2.14 (95% CI, 1.45-3.06). Similarly, 57 of 262,066 white patients with colorectal cancer developed ampullary cancer over an aggregate 1,270,255 person-years of follow-up, yielding an SIR of 2.18 (95% CI, 1.69-2.85).

CONCLUSIONS

Patients with ampullary cancer are at increased risk for a second primary colorectal malignancy, and patients with colorectal cancer are at increased risk for a second primary ampullary malignancy. These findings suggest that ampullary and colorectal malignancies share common environmental and/or genetic risk factors.