Second cancers after adjuvant tamoxifen therapy for breast cancer in Japan |
| |
| Authors: | Y. Matsuyama T. Tominaga Y. Nomura H. Koyama M. Kimura M. Sano S. Miura S. Takashima S. Mitsuyama H. Ueo Y. Ohashi |
| |
| Affiliation: | (1) Biostatistics/Epidemiology and Preventive Health Sciences, School of Health Sciences and Nursing, University of Tokyo, Japan;(2) Department of Surgery, Tokyo Metropolitan Komagome Hospital, Japan;(3) Department of Breast Surgery, National Kyushu Cancer Center, Japan;(4) Department of Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan;(5) Division of Surgery, Gunma Cancer Center Hospital, Japan;(6) Division of Surgery, Niigata Cancer Center Hospital, Japan;(7) Department of Breast Surgery, Aichi Cancer Center Hospital, Japan;(8) Department of Surgery, Shikoku Cancer Center Hospital, Japan;(9) Department of Surgery, Kitakyushu Municipal Medical Center, Japan;(10) Department of Surgery, Oita Prefectural Hospital, Japan |
| |
| Abstract: | Background:Women treated with tamoxifen for breast cancer are atincreased risk of endometrial cancer. We conducted a retrospective cohortstudy to evaluate the risk of second primary cancers after adjuvant tamoxifentherapy for breast cancer in Japan.Patients and methods:The subjects of the study were 6148 womenwho had been diagnosed with stage I, II, or IIIA unilateral primary breastcancer and had received surgical treatment during the period from January 1982through December 1990 at nine institutions in Japan. The information on eachpatient was obtained from medical records or a prospectively compiled computerdatabase at each institution.Results:Of the 6148 women, 3588 (58.4%) were administeredtamoxifen as an adjuvant treatment and 2560 (41.6%) were notadministered. Median follow-up periods were 7.64 years for tamoxifen-treatedpatients and 8.10 years for non-tamoxifen-treated patients, respectively. Theduration of tamoxifen treatment was mostly two years or less (80.7%),and few patients received tamoxifen for more than five years. The cumulativeincidence rates of all second cancers at 10 years were 4.61% and4.09% among tamoxifen-treated and non-tamoxifen-treated patients(P = 0.62), respectively, and the incidence rate ratio (IRR) forall second cancers was 1.06 (95% confidence interval (CI):0.77–1.47) after adjustment of several covariates. The numbers ofendometrial cancers was 9 and 3 among tamoxifen-treated andnon-tamoxifen-treated patients, respectively, and the IRR was 2.37 (95%CI: 0.64–8.77, P = 0.20). Of the 12 patients who developedendometrial cancer, 4 died of cancer (for 3 of them, the cause of death wasbreast cancer), and the other 8 patients were alive as of March 1996. Stomachcancer was the most frequent second cancer and the IRR was 1.34 (95%CI: 0.76–2.38, P = 0.31). There was no substantialincrease in any other type of gastrointestinal cancer such as colorectal andliver cancers among tamoxifen-treated patients.Conclusions:The incidence and risk of second primary cancersassociated with tamoxifen therapy is low. The potential benefit of adjuvanttamoxifen therapy in breast cancer patients outweighs the risk of secondprimary cancers for Japanese breast cancer patients. |
| |
| Keywords: | adjuvant therapy breast cancer second cancer tamoxifen |
| 本文献已被 Oxford SpringerLink 等数据库收录！ |
|
