Li C I, Rossing M A, Voigt L F, Daling J R
Fred Hutchinson Cancer Research Center, Program in Epidemiology, Division of Public Health Sciences, Seattle, Washington 98104, USA.
Cancer Causes Control. 2000 Oct;11(9):805-11. doi: 10.1023/a:1008942616092.
Breast and thyroid cancer have been observed to occur more frequently than expected as multiple primary tumors in women. The study presented herein focuses on the effects of age at diagnosis and treatment for the first cancer on the development of the second cancer.
This retrospective cohort study used a study population consisting of 38,632 women diagnosed with primary invasive breast cancer and 2189 women diagnosed with primary invasive thyroid cancer between 1974 and 1994. Cases were identified from records of the Cancer Surveillance System of western Washington and followed for subsequent cancer development through 1995.
Seventy-one women were diagnosed during their lives with both breast and thyroid cancers. Including cancers diagnosed during the same month as or after the initial cancer, the relative risk (RR) of breast cancer among women with thyroid cancer was 1.5 (95% confidence interval [CI] 1.1-2.0), and the RR of thyroid cancer among women with breast cancer was 1.5 (95% CI 1.1-2.2). Among women with thyroid cancer, risk of breast cancer was greatest when the latter cancer was diagnosed under 45 years of age (RR = 2.3, 95% CI 1.1-4.4). First course of treatment, including radiation or hormonal therapy to treat thyroid cancer, and radiation, chemotherapy, or hormonal therapy to treat breast cancer, did not alter a woman's risk of developing the second cancer.
The data suggest that the incidence of breast and thyroid cancer may be related, and that in particular women with thyroid cancer may be at a moderately increased risk of developing breast cancer before age 45.
乳腺癌和甲状腺癌作为女性的多种原发性肿瘤，其发生频率高于预期。本文介绍的研究聚焦于首次癌症诊断和治疗时的年龄对第二种癌症发生的影响。
这项回顾性队列研究使用的研究人群包括1974年至1994年间被诊断为原发性浸润性乳腺癌的38632名女性和被诊断为原发性浸润性甲状腺癌的2189名女性。病例来自华盛顿州西部癌症监测系统的记录，并随访至1995年观察后续癌症发生情况。
71名女性在其一生中被诊断患有乳腺癌和甲状腺癌。包括在首次癌症诊断当月或之后诊断的癌症，甲状腺癌女性患乳腺癌的相对风险（RR）为1.5（95%置信区间[CI]1.1 - 2.0），乳腺癌女性患甲状腺癌的RR为1.5（95%CI 1.1 - 2.2）。在甲状腺癌女性中，当第二种癌症在45岁以下被诊断时，患乳腺癌的风险最大（RR = 2.3，95%CI 1.1 - 4.4）。首次治疗方案，包括治疗甲状腺癌的放疗或激素治疗，以及治疗乳腺癌的放疗、化疗或激素治疗，并未改变女性患第二种癌症的风险。
数据表明乳腺癌和甲状腺癌的发病率可能相关，特别是甲状腺癌女性在45岁之前患乳腺癌的风险可能适度增加。
