乳腺癌化疗？或许并会不因此而获益

  近日，一篇发表于国际杂志the Journal of American Geriatrics Society上的研究论文中，来自休斯顿德克萨斯大学的研究人员通过研究指出，化疗虽然可以延长大多数老年癌症患者的寿命，但对于80岁以上的乳腺癌患者而言，她们因化疗而生存的概率则会明显降低。
  研究者Xianglin Du表示，化疗会减少老年乳腺癌患者的死亡风险效应，这或许取决于多种因子的作用，即肿瘤对化疗敏感性较低，随着机体变老化疗药物剂量的降低，化疗在杀灭癌细胞的同时还会杀灭健康细胞。文章中，研究者对来自医疗数据库中的相关监测、流行病学等数据进行了分析，该数据库中包括了从1992年至2009年统计的14，440名诊断为I期和IIIA期受体激素阴性的乳腺癌患者及26，893名诊断为III期结直肠癌的男性和女性患者，所有受试者年龄均在65岁以上。
  在患乳腺癌的女性中，化疗降低65至69岁患者的死亡风险为30%，降低70至74岁女性的死亡风险为26%，75岁至79岁女性的死亡风险为24%，而对于80岁以上的女性患者而言，化疗并不会明显降低个体的死亡风险。然而当利用化疗、阿霉素及环磷酰胺结合后治疗80岁以上的乳腺癌患者，就会发现结合疗法会降低患者29%的死亡风险。
  因此研究者指出，化疗降低乳腺癌患者死亡风险或许会因年龄差异而异，而对于患结直肠癌的男女性患者而言也有这样的表现，而化疗对于任何年龄段(最高到89岁)的结直肠癌患者均是有效的。此前研究表明化疗并不能够有效治疗70岁以上的乳腺癌患者，但临床试验被认为是样本尺寸太小或许会导致这样的结果，而本文研究中研究者利用了大尺寸的样本进行研究同样证实了这样的结果。（转化医学网360zhyx.com）
  以上为转化医学网原创翻译整理，转载请注明出处和链接！
转化医学网推荐的原文摘要：

Comparative Effectiveness of Chemotherapy Regimens in Prolonging Survival for Two Large Population-Based Cohorts of Elderly Adults with Breast and Colon Cancer in 1992–2009
Journal of the American Geriatrics Society    DOI: 10.1111/jgs.13523
Xianglin L. Du MD, PhD1,2,*, Yefei Zhang MS1,3, Rohan C. Parikh MS2, David R. Lairson PhD2 andYi Cai MS1,3
Objectives
To compare the effectiveness of chemotherapy in prolonging survival according to age in breast and colon cancer.
Design
Retrospective cohort study with a matched cohort analysis based on the conditional probability of receiving chemotherapy.
Setting
The 16 Surveillance, Epidemiology, and End Results (SEER) areas from the SEER-Medicare linked database.
Participants
Women diagnosed with Stage I to IIIa hormone receptor–negative breast cancer (n = 14,440) and 26,893 men and women with Stage III colon cancer (n = 26,893) aged 65 and older in 1992 to 2009.
Measurements
The main exposure was the receipt of chemotherapy, and the main outcome was mortality.
Results
In women with breast cancer aged 65 to 69, the risk of all-cause mortality was statistically significantly lower in those who received chemotherapy than in those who did not in the entire cohort (hazard ratio (HR) = 0.70, 95% confidence interval (CI) = 0.57–0.88) and in a propensity-matched cohort (HR = 0.82, 95% CI = 0.70–0.96) after adjusting for measured confounders. These patterns were similar in participants aged 70 to 74 and 75 to 79, but in women aged 80 to 84 and 85 to 89, risk of all-cause mortality was no longer significantly lower in those receiving chemotherapy in the entire and matched cohorts, except that, in a small number of women who received doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan), risk of mortality was significantly lower for those aged 80 to 84. Chemotherapy appeared to be effective in all ages from 65 through 84 in participants with Stage III colon cancer. For example, in those aged 85 to 89, chemotherapy was significantly associated with lower risk of mortality in the entire cohort (HR = 0.79, 95% CI = 0.67–0.92) and the matched cohort (HR = 0.79, 95% CI = 0.66–0.95).
Conclusion
The effectiveness of chemotherapy decreased with age in participants with breast cancer, in whom chemotherapy appears to be effective until age 79 except for the doxorubicin-cyclophosphamide combination, which was effective in participants aged 80 to 84. In individuals with Stage III colon cancer, chemotherapy appears to be effective to age 89. These findings were consistent with those of randomized clinical trials.