Matsuyama Y, Tominaga T, Nomura Y, Koyama H, Kimura M, Sano M, Miura S, Takashima S, Mitsuyama S, Ueo H, Ohashi Y
Biostatistics/Epidemiology and Preventive Health Sciences, School of Health Sciences and Nursing, University of Tokyo.
Ann Oncol. 2000 Dec;11(12):1537-43. doi: 10.1093/oxfordjournals.annonc.a010406.
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.
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.
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.
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.
接受他莫昔芬治疗的乳腺癌女性患子宫内膜癌的风险增加。我们进行了一项回顾性队列研究，以评估在日本辅助性他莫昔芬治疗乳腺癌后发生第二原发性癌症的风险。
本研究的对象为6148名女性，她们于1982年1月至1990年12月期间在日本的9家机构被诊断为I期、II期或IIIA期单侧原发性乳腺癌并接受了手术治疗。每位患者的信息来自各机构的病历或前瞻性编制的计算机数据库。
在这6148名女性中，3588名（58.4%）接受他莫昔芬作为辅助治疗，2560名（41.6%）未接受。他莫昔芬治疗组患者的中位随访期为7.64年，未接受他莫昔芬治疗组患者的中位随访期为8.10年。他莫昔芬治疗的持续时间大多为两年或更短（80.7%），很少有患者接受他莫昔芬治疗超过五年。他莫昔芬治疗组和未接受他莫昔芬治疗组患者10年时所有第二癌症的累积发病率分别为4.61%和4.09%（P = 0.62），调整多个协变量后所有第二癌症的发病率比（IRR）为1.06（95%置信区间（CI）：0.77 - 1.47）。他莫昔芬治疗组和未接受他莫昔芬治疗组患者中子宫内膜癌的病例数分别为9例和3例，IRR为2.37（95% CI：0.64 - 8.77，P = 0.20）。在发生子宫内膜癌的12名患者中，4名死于癌症（其中3名的死因是乳腺癌），截至1996年3月，其他8名患者仍存活。胃癌是最常见的第二癌症，IRR为1.34（95% CI：0.76 - 2.38，P = 0.31）。在接受他莫昔芬治疗的患者中，结直肠癌和肝癌等任何其他类型的胃肠道癌症均未出现大幅增加。
与他莫昔芬治疗相关的第二原发性癌症的发病率和风险较低。对于日本乳腺癌患者，辅助性他莫昔芬治疗的潜在益处超过了第二原发性癌症的风险。
