BACKGROUND: Women treated with tamoxifen for breast cancer are at increased risk of endometrial cancer. We conducted a retrospective cohort study to evaluate the risk of second primary cancers after adjuvant tamoxifen therapy for breast cancer in Japan. PATIENTS AND METHODS: The subjects of the study were 6148 women who had been diagnosed with stage I, II, or IIIA unilateral primary breast cancer and had received surgical treatment during the period from January 1982 through December 1990 at nine institutions in Japan. The information on each patient was obtained from medical records or a prospectively compiled computer database at each institution. RESULTS: Of the 6148 women, 3588 (58.4%) were administered tamoxifen as an adjuvant treatment and 2560 (41.6%) were not administered. Median follow-up periods were 7.64 years for tamoxifen-treated patients and 8.10 years for non-tamoxifen-treated patients, respectively. The duration of tamoxifen treatment was mostly two years or less (80.7%), and few patients received tamoxifen for more than five years. The cumulative incidence rates of all second cancers at 10 years were 4.61% and 4.09% among tamoxifen-treated and non-tamoxifen-treated patients (P = 0.62), respectively, and the incidence rate ratio (IRR) for all second cancers was 1.06 (95% confidence interval (CI): 0.77-1.47) after adjustment of several covariates. The numbers of endometrial cancers was 9 and 3 among tamoxifen-treated and non-tamoxifen-treated patients, respectively, and the IRR was 2.37 (95% CI: 0.64-8.77, P = 0.20). Of the 12 patients who developed endometrial cancer, 4 died of cancer (for 3 of them, the cause of death was breast cancer), and the other 8 patients were alive as of March 1996. Stomach cancer was the most frequent second cancer and the IRR was 1.34 (95% CI: 0.76-2.38, P = 0.31). There was no substantial increase in any other type of gastrointestinal cancer such as colorectal and liver cancers among tamoxifen-treated patients. CONCLUSIONS: The incidence and risk of second primary cancers associated with tamoxifen therapy is low. The potential benefit of adjuvant tamoxifen therapy in breast cancer patients outweighs the risk of second primary cancers for Japanese breast cancer patients.
BACKGROUND:Women treated with tamoxifen for breast cancer are at increased risk of endometrial cancer. We conducted a retrospective cohort study to evaluate the risk of second primary cancers after adjuvant tamoxifen therapy for breast cancer in Japan. PATIENTS AND METHODS: The subjects of the study were 6148 women who had been diagnosed with stage I, II, or IIIA unilateral primary breast cancer and had received surgical treatment during the period from January 1982 through December 1990 at nine institutions in Japan. The information on each patient was obtained from medical records or a prospectively compiled computer database at each institution. RESULTS: Of the 6148 women, 3588 (58.4%) were administered tamoxifen as an adjuvant treatment and 2560 (41.6%) were not administered. Median follow-up periods were 7.64 years for tamoxifen-treated patients and 8.10 years for non-tamoxifen-treated patients, respectively. The duration of tamoxifen treatment was mostly two years or less (80.7%), and few patients received tamoxifen for more than five years. The cumulative incidence rates of all second cancers at 10 years were 4.61% and 4.09% among tamoxifen-treated and non-tamoxifen-treated patients (P = 0.62), respectively, and the incidence rate ratio (IRR) for all second cancers was 1.06 (95% confidence interval (CI): 0.77-1.47) after adjustment of several covariates. The numbers of endometrial cancers was 9 and 3 among tamoxifen-treated and non-tamoxifen-treated patients, respectively, and the IRR was 2.37 (95% CI: 0.64-8.77, P = 0.20). Of the 12 patients who developed endometrial cancer, 4 died of cancer (for 3 of them, the cause of death was breast cancer), and the other 8 patients were alive as of March 1996. Stomach cancer was the most frequent second cancer and the IRR was 1.34 (95% CI: 0.76-2.38, P = 0.31). There was no substantial increase in any other type of gastrointestinal cancer such as colorectal and liver cancers among tamoxifen-treated patients. CONCLUSIONS: The incidence and risk of second primary cancers associated with tamoxifen therapy is low. The potential benefit of adjuvant tamoxifen therapy in breast cancerpatients outweighs the risk of second primary cancers for Japanese breast cancerpatients.
Authors: Won Jae Huh; Shradha S Khurana; Jessica H Geahlen; Kavita Kohli; Rachel A Waller; Jason C Mills Journal: Gastroenterology Date: 2011-10-14 Impact factor: 22.682
Authors: Neal D Freedman; Jiyoung Ahn; Lifang Hou; Jolanta Lissowska; Witold Zatonski; Meredith Yeager; Stephen J Chanock; Wong Ho Chow; Christian C Abnet Journal: Carcinogenesis Date: 2008-11-17 Impact factor: 4.944
Authors: R Scott Braithwaite; Rowan T Chlebowski; Joseph Lau; Suzanne George; Rachel Hess; Nananda F Col Journal: J Gen Intern Med Date: 2003-11 Impact factor: 5.128
Authors: S Vidal-Millan; I Zeichner-Gancz; D Flores-Estrada; B E Vela-Rodríguez; M I Vazquez-López; C D Robles-Vidal; M T Ramirez-Ugalde; M Chávez-MacGregor Journal: Med Oncol Date: 2005 Impact factor: 3.064
Authors: Min Yi; Janice N Cormier; Yan Xing; Sharon Hermes Giordano; Christy Chai; Funda Meric-Bernstam; Georges Vlastos; Henry M Kuerer; Nadeem Q Mirza; Thomas A Buchholz; Kelly K Hunt Journal: Ann Surg Oncol Date: 2012-12-06 Impact factor: 5.344
Authors: Henry T Lynch; Murray Joseph Casey; Carrie L Snyder; Chhanda Bewtra; Jane F Lynch; Matthew Butts; Andrew K Godwin Journal: Mol Oncol Date: 2009-02-21 Impact factor: 6.603