Risk of second primary cancer in the contralateral breast in women treated for early-stage breast cancer: A population-based study
Risk of second primary cancer in the contralateral breast in women treated for early-stage breast cancer: A population-based study
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DOI：
10.1016/s0360-3016(03)00203-7
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发表时间：
2003-07-15
影响因子：
7
通讯作者：
Emami, B
中科院分区：
文献类型：
--
作者：
Gao, X;Fisher, SG;Emami, B
目的：探讨对侧乳腺癌（CBC）早期患者放疗（RT）等潜在危险因素。方法和材料：采用监测、流行病学和最终结果数据库（1973-1996）研究乳腺癌后CBC的发生率。Cox比例风险回归模型用于估计CBC的相对风险（RR），并对混杂因素进行调整，包括年龄、种族、组织学亚型和rt的使用。在监测、流行病学和最终结果数据库中没有关于激素治疗和化疗使用的信息。结果：134,501例局部浸润性或导管内乳腺癌患者存活至少3个月，其中5679例（4.2%）出现CBC。CBC 10年和20年精算率分别为6.1%和12%。在多因素分析中，髓样癌（RR = 1.18, 95%可信区间[CI] 1.02-1.37）、黑人（RR = 1.20, 95% CI 1.08-1.33）和初诊时年龄bb0 - 55岁（RR = 1.15, 95% CI 1.08-1.22）与CBC风险增加相关。37379例接受RT治疗的患者中有1234例（3.3%）发生CBC， 97122例未接受RT治疗的患者中有4445例（4.6%）发生CBC。总体而言，在多变量分析中，RT与CBC风险增加无关（RR = 1.04, 95% CI 0.97-1.10）。与放疗相关的CBC风险随随访时间的长短而显著不同。在前5年随访期间，RT与CBC风险增加无关（经年龄调整的RR = 0.96, 95% CI 0.88-1.04）。对于存活50年的患者，RT与CBC风险增加14%相关（RR = 1.14, 95% CI 1.03-1.26）。初始诊断时，55岁患者的CBC风险明显增加（RR = 1.15, p = 0.04）。放疗患者5年、10年、15年和20年的CBC精算率分别为2.9%、6.5%、10.2%和13.4%；无放疗患者相应的发生率分别为3.0%、6.0%、8.9%和11.8%。在10年、15年和20年精算率中，放疗相关的CBC风险绝对增加分别为0.5%、1.3%和1.6%。结论：CBC在乳腺癌后并不罕见，特别是在某些亚群患者中。放疗与长期CBC风险增加的关系非常小。这种微小的CBC风险增加不应影响局部浸润性乳腺癌或原位导管癌患者治疗选择的临床决策。所有早期乳腺癌患者都应避免对侧乳房进行不必要的辐射照射。(C) 2003 Elsevier Inc.
Purpose: To study the potential risk factors, including radiotherapy (RT) for contralateral breast cancer (CBC), in patients treated for early-stage breast cancer.Methods and Materials: The Surveillance, Epidemiology, and End Results database (1973-1996) was used to study the incidence of CBC after breast cancer. The Cox proportional hazards regression model was used to estimate the relative risk (RR) of CBC, with adjustment for confounders, including age, race, histologic subtype, and use of RT. Information on the use of hormonal therapy and chemotherapy was not available in the Surveillance, Epidemiology, and End Results database.Results: A CBC was documented in 5679 (4.2%) of the 134,501 localized invasive or intraductal breast cancer patients surviving at least 3 months. The 10- and 20-year actuarial rate of CBC was 6.1% and 12%, respectively. In multivariate analysis, medullary carcinoma (RR = 1.18, 95% confidence interval [CI] 1.02-1.37), black race (RR = 1.20, 95% CI 1.08-1.33), and age >55 years at initial diagnosis (RR = 1.15, 95% CI 1.08-1.22) were associated with increased CBC risk. A total of 1234 (3.3%) of 37,379 patients who received RT developed CBC, and 4445 (4.6%) of 97,122 patients who did not receive RT developed CBC. Overall, RT was not associated with an increased risk of CBC (RR = 1.04, 95% CI 0.97-1.10) in multivariate analysis. The CBC risk associated with RT varied substantially with the length of follow-up. During the first 5 years of follow-up, RT was not associated with an increased CBC risk (age-adjusted RR = 0.96, 95% CI 0.88-1.04). For patients surviving for >5 years, RT was associated with a 14% increase in CBC risk (RR = 1.14, 95% CI 1.03-1.26). The increased CBC risk with RT was evident in patients aged 55 years (RR = 1.15, p = 0.04) at initial diagnosis. The 5-, 10-, 15-, and 20-year actuarial rate of CBC was 2.9%, 6.5%, 10.2%, and 13.4%, respectively, for patients with RT; the corresponding rates were 3.0%, 6.0%, 8.9%, and 11.8% for patients without RT. The absolute increase in CBC risk associated with RT was 0.5%, 1.3%, and 1.6% in the 10-, 15-, and 20-year actuarial rate, respectively.Conclusion: CBC is not uncommon after breast cancer, especially for certain subsets of patients. RT was associated with a very small increased long-term CBC risk. This minimal increase in CBC risk should not affect clinical decision-making in treatment selection for patients with localized invasive breast cancer or ductal carcinoma in situ. Unnecessary radiation exposure to the contralateral breast should be avoided for all patients with early-stage breast cancer. (C) 2003 Elsevier Inc.