Background

It is unknown whether carcinogenic and endocrine disrupting polychlorinated biphenyls (PCBs) influence mortality following breast cancer. We examined plasma levels of 17 PCB congeners in association with mortality among women with breast cancer.

Methods

Participants included 456 white and 292 black women in North Carolina who were diagnosed with primary invasive breast cancer from 1993 to 1996, and who had PCB and lipid measurements from blood samples obtained an average of 4.1 months after diagnosis. Over a median follow-up of 20.6 years, there were 392 deaths (210 from breast cancer). We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and breast cancer-specific 5-year mortality, and 20-year mortality (conditional on 5-year survival) in association with tertiles and continuous ln-transformed lipid-adjusted PCB levels.

Results

The highest (vs. lowest) tertiles of PCB74, PCB99, and PCB118 were associated with 5-year breast cancer-specific mortality HRs of 1.46 (95%CI = 0.86–2.47), 1.57 (95%CI = 0.90–2.73), and 1.86 (95%CI = 1.07–3.23), respectively. Additionally, one-ln unit increases in PCB74, PCB99, PCB118, and total PCBs were each associated with 33–40% increases in 5-year breast cancer-specific mortality rates. The PCBs were not, however, associated with longer-term breast cancer-specific mortality. For all-cause mortality, one-ln unit increases in PCB118, PCB146, PCB153, PCB182, PCB187, and total PCBs were associated with 20–37% increases in 20-year all-cause mortality rates among women who survived at least 5 years.

Conclusion

PCBs may increase the risk of short-term breast cancer-specific mortality and long-term all-cause mortality among women with breast cancer.

中文翻译：

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血浆中多氯联苯（PCB）的水平和乳腺癌的死亡率：卡罗来纳州乳腺癌研究。

背景

致癌和内分泌干扰性多氯联苯（PCBs）是否会影响乳腺癌患者的死亡率，目前尚不清楚。我们检查了血浆中17种多氯联苯同源物的水平与乳腺癌女性的死亡率。

方法

参加者包括北卡罗来纳州的456位白人妇女和292位黑人妇女，他们从1993年至1996年被诊断出患有原发性浸润性乳腺癌，并且从血液样本中检测出PCB和血脂水平平均在诊断后4.1个月获得。在20.6年的中位随访中，有392人死亡（210人死于乳腺癌）。我们使用Cox回归来估计全因和特定于乳腺癌的5年死亡率和20年死亡率（以5年生存为条件）的协变量调整后的风险比（HRs）和95％置信区间（CIs）。与三分位数和连续ln转换的脂质调节后的PCB水平相关。

结果

PCB74，PCB99和PCB118的最高（相对最低）三分位数与5年乳腺癌特异性死亡率HR相关，分别为1.46（95％CI = 0.86-2.47），1.57（95％CI = 0.90-2.73），和1.86（95％CI = 1.07–3.23）。此外，PCB74，PCB99，PCB118和总PCB的单位增加1英寸，与5年乳腺癌特异性死亡率的增加33-40％有关。然而，多氯联苯与长期乳腺癌特异性死亡率无关。对于全因死亡率，PCB118，PCB146，PCB153，PCB182，PCB187和PCB总数增加1英寸单位，可使存活至少5年的女性20年全因死亡率增加20-37％ 。

结论

多氯联苯可能会增加乳腺癌女性短期乳腺癌特定死亡率和长期全因死亡率的风险。