Subsequent Cancer Occurrence Research Articles

Risk for subsequent cancer after diagnosis of basal-cell carcinoma. A population-based, epidemiologic study.

Considerable debate is taking place over whether patients with basal-cell carcinoma and other skin neoplasms are at increased risk for internal cancer. To investigate risk for subsequent cancer in patients with basal-cell carcinoma. Population-based cohort study. Denmark, from 1978 ot 1991. 37674 patients followed for a maximum of 14 years after a first diagnosis of basal-cell carcinoma. The occurrence of subsequent cancer was compared with the expected cancer pattern (which was determined on the basis of national incidence data). Standardized incidence ratios (SIRs), ratios of actual to expected number of cases of cancer, yielded estimates of the relative risk. During 190945 patient-years of follow-up, 3663 new cases of cancer occurred where only 3245 were expected. As anticipated, malignant melanoma occurred frequently (SIR, 2.64 [95% CI, 2.21 to 3.13]), but patients were also at increased risk for noncutaneous cancer (SIR, 1.19 [CI, 1.13 to 1.24] for men and 1.09 [CI, 1.03 to 1.16] for women). The excess risk for noncutaneous cancer pertained to cancer of the lip (SIR, 2.07), salivary glands (SIR, 2.45), larynx (SIR, 1.41), lung (SIR, 1.40), breast (SIR, 1.13), and kidney (SIR, 1.30) and non-Hodgkin lymphoma (SIR, 1.36). Patients receiving a diagnosis of basal-cell carcinoma before 60 years of age (SIR, 1.26) had a statistically higher risk for developing new cancer (P < 0.01) than did those receiving the diagnosis at 60 years of age or older (SIR, 1.11). This applied to breast cancer (SIR, 1.37 in patients < 60 years of age compared with 1.05 in those > or = 60 years of age), testicular cancer (SIR, 3.52 in patients < 60 years of age compared with 0 seen and 1.96 expected in those > or = 60 years of age), and non-Hodgkin lymphoma (SIR, 2.50 in patients < 60 years of age compared with 1.16 in those > or = 60 years of age), and non-hodgkin lymphoma (SIR, 2.50 in patients < 60 years of age compared with 1.16 in those > or = 60 years of age). In addition to having an increased risk for new skin cancer, patients with basal-cell carcinoma have an increased risk for noncutaneous cancer at various sites. Increased risks for testicular cancer, breast cancer, and non-Hodgkin lymphoma should be kept in mind, particularly for patients in whom basal-cell carcinoma is diagnosed when they are at a young age.

Population-based study of tamoxifen therapy and subsequent ovarian, endometrial, and breast cancers.

The success of tamoxifen in reducing the occurrence of contralateral breast cancer among breast cancer patients in clinical trials has prompted the study of its use in the primary prevention of breast cancer. Long-term risks associated with tamoxifen therapy, however, are still being evaluated, particularly with respect to subsequent cancer occurrence at sites other than the breast. This population-based, nested case-control study investigated the risks of second primary cancers of the ovary, endometrium, and contralateral breast among women receiving tamoxifen for breast cancer in conventional medical practice. A cohort of women diagnosed with breast cancer during 1978 through 1990 was identified from a population-based cancer registry. Case subjects included all women in the cohort who subsequently developed second primary ovarian (n = 39), endometrial (n = 42), or contralateral breast (n = 234) cancer prior to 1992. Control subjects were a random sample of the cohort who did not develop a second primary malignancy; they were matched to the case subjects on age, disease stage, and year of initial breast cancer diagnosis (approximately two control subjects per case subject). Information on tamoxifen use as well as on potential risk factors for the second primary cancers was obtained through medical record abstractions and physician questionnaires. The percentage of women who had received tamoxifen was 18% and 20%, respectively, among ovarian cancer case subjects and control subjects; 26% and 31%, respectively, among endometrial cancer case subjects and control subjects; and 10% and 18%, respectively, among contralateral breast cancer case subjects and control subjects. The mean duration of tamoxifen use was less than 2 years for all groups. The relative risks for ovarian and endometrial cancers in women who took tamoxifen were relatively low but were consistent with no association (for ovarian cancer, matched odds ratio [mOR] = 0.6 and 95% confidence interval [CI] = 0.2-1.8; for endometrial cancer, mOR = 0.6 and 95% CI = 0.2-1.9). Tamoxifen therapy was associated with a decreased risk of contralateral breast cancer (mOR = 0.5; 95% CI = 0.3-0.9), especially if the drug had been taken for more than 1 year (mOR = 0.4; 95% CI = 0.2-0.9) or if the women were postmenopausal at initial breast cancer diagnosis (mOR = 0.4; 95% CI = 0.2-0.8). These data suggest that short durations of tamoxifen therapy are not associated with an increased risk of endometrial or ovarian cancer but are associated with a reduction in contralateral breast cancer risk. It would not be appropriate, however, to generalize these results to women who receive tamoxifen for longer periods.

Carcinoid tumors in Denmark 1978-1989 and the risk of subsequent cancers. A population-based study.

Previous studies have suggested an excess cancer risk in patients with carcinoid tumors. This association was reexamined using truly population-based data. By means of data from the Danish Cancer Registry all carcinoid tumors diagnosed in Denmark between 1978 and 1989 were identified. All patients with primary carcinoid tumors were studied for the occurrence of subsequent cancers. The numbers of subsequent cancers observed in the follow-up period were compared with the expected numbers calculated from population rates. A total of 1029 patients with carcinoid tumors were identified (464 men and 565 women). The annual age-adjusted incidence rates (world standardized) for carcinoid tumors during 1978-1989 were stable at about 1.1 per 100,000 person-years for both men and women. The patients were followed for the occurrence of subsequent cancers over a period comprising 2512 person-years. Thirty subsequent cancers were identified in 29 patients. The overall relative risk of subsequent cancers was 1.1 (95% CI, 0.8-1.6). Subsequent cancers of the thyroid were in excess (RR, 21.4; 95% CI, 2.4-77.1; n = 2), as were tumors of the brain and nervous system (RR, 5.4; 95% CI, 1.1-15.9; n = 3) and non-Hodgkin's lymphomas (RR, 5.8; 95% CI, 1.2-16.9; n = 3). Overall, this population-based study does not support previous studies of an excess cancer risk in patients with carcinoid tumors. Increased risks of cancers of the thyroid, tumors of the brain and nervous system, and non-Hodgkin's lymphomas were observed, but these findings were based on few cases.

Natural history of colorectal polyps and the effect of polypectomy on occurrence of subsequent cancer

To elucidate the natural history of colorectal polyps and to observe the influence of endoscopic polypectomy on the incidence of colorectal cancer, we conducted a retrospective cohort study of all patients who had undergone colonoscopic examination at the Center for Adult Diseases, Osaka, between April 1974 and December 1985. The study subjects consisted of a control group (760 non-polyp patients) and a polyp group (648 polyp patients, including 136 treated by polypectomy at the initial examination). These subjects were followed up until the end of 1987 by record linkage with the Osaka Cancer Registry's file to observe the occurrence of colorectal cancer. The O/E (observed/expected numbers derived from the general population) was 5.1 (95% confidence interval = 2.5-9.4) and 1.0 (0.1-3.6) for the polyp and control group, respectively. When subjects in the polyp group were categorized into polypectomy and non-polypectomy sub-groups, the O/E was 2.3 (0.1-12.6) and 8.0 (3.4-15.8) respectively. The relative risk of undergoing polypectomy to developing subsequent cancer was estimated at 0.3 (0.1-2.1). These results suggest an increased risk of developing cancer among polyp patients and the possibility of prophylactic effect of polypectomy against subsequent cancer. A large-scale and long-term follow-up study is required to confirm these findings.

The absence of a relationship between cholecystectomy and the subsequent occurrence of cancer of the proximal colon.

Reports of an increased incidence of right-sided colonic cancers have coincided with an expanding knowledge of the carcinogenic potential of secondary bile acids which are increased after cholecystectomy, suggesting a possible relationship between cholecystectomy and the subsequent occurrence of proximal colonic cancer. The hospital records of 582 patients undergoing resection of colorectal cancers were reviewed. Fifty-four patients (9 per cent) had had prior cholecystectomies. The distribution of colonic cancers in these patients was identical to that in noncholecystectomized patients. To obtain a prospective view, 249 patients undergoing cholecystectomy between 1958 and 1960 were followed up to 1980. A cancer of the sigmoid colon or rectum occurred in four patients, three to 22 years after cholecystectomy. No patient was readmitted with a carcinoma of the proximal colon. These data fail to support a relationship between cholecystectomy and the subsequent development of a cancer of the cecum or ascending colon.

Cancer Incidence by Levels of Cholesterol

In 5,209 subjects studied for 24 years in Framingham, Mass, 691 cases of cancer were documented, with histological confirmation for 94%. Predetermined personal characteristics were tested for associations with subsequent occurrence of cancer at specific sites using multiple logistic regression. Significant associations of various cancer sites with cigarette smoking, alcohol use, education, height, weight, and parity agreed with other studies. Serum cholesterol level was inversely associated with incidence of colon cancer and with other sites only in men; these inverse associations were statistically significant after adjustment for age, alcohol consumption, cigarette smoking, education, systolic blood pressure, and relative weight. Associations may reflect effects of competing lethal diseases, underlying pathophysiological mechanisms that promote or inhibit development of cancer in men, biologic or social response to early and undiagnosed states of cancer.