Teilum Dorthe, Bjerre Karsten D, Tjønneland Anne M, Kroman Niels
Brystkirurgisk Klinik PBB, Copenhagen, Denmark.
BMJ Open. 2012 Jan 5;2(1):e000358. doi: 10.1136/bmjopen-2011-000358. Print 2012.
Background Vitamin D has been suggested to influence the incidence and prognosis of breast cancer, and studies have found better overall survival (OS) after diagnosis for breast cancer in summer-autumn, where the vitamin D level are expected to be highest. Objective To compare the prognostic outcome for early breast cancer patients operated at different seasons of the year. Design Open population-based cohort study. Setting Danish women operated 1978-2010. Cases 79 658 adjusted for age at surgery, period of surgery, tumour size, axillary lymph node status and hormone receptor status. Statistical analysis The association between OS and season of surgery was analysed by Cox proportional hazards regression models, at survival periods 0-1, 0-2, 0-5 and 0-10 years after surgery. A two-sided p value <0.05 was considered statistical significant. Results Only after adjustment for prognostic factors that may be influenced by vitamin D, 1-year survival was close to significantly associated season of surgery. 2, 5 and 10 years after surgery, the association between OS and season of surgery was not significant. Limitations Season is a surrogate measure of vitamin D. Conclusions The authors found no evidence of a seasonal variation in the survival after surgery for early breast cancer. Lack of seasonal variation in this study does not necessarily mean that vitamin D is of no importance for the outcome for breast cancer patients.
背景 维生素D被认为会影响乳腺癌的发病率和预后，并且研究发现，在维生素D水平预计最高的夏秋季节诊断出乳腺癌后，总体生存率（OS）更高。目的 比较一年中不同季节接受手术的早期乳腺癌患者的预后结果。设计 基于人群的开放性队列研究。地点 1978年至2010年接受手术的丹麦女性。病例 79658例，根据手术时年龄、手术时间、肿瘤大小、腋窝淋巴结状态和激素受体状态进行了调整。统计分析 通过Cox比例风险回归模型分析OS与手术季节之间的关联，分析手术0至1年、0至2年、0至5年和0至10年的生存期。双侧p值<0.05被认为具有统计学意义。结果 仅在对可能受维生素D影响的预后因素进行调整后，1年生存率与手术季节接近显著相关。手术后2年、5年和10年，OS与手术季节之间的关联不显著。局限性 季节是维生素D的替代指标。结论 作者未发现早期乳腺癌手术后生存率存在季节性变化的证据。本研究中缺乏季节性变化并不一定意味着维生素D对乳腺癌患者的预后不重要。
