López-Carrillo L, Blair A, López-Cervantes M, Cebrián M, Rueda C, Reyes R, Mohar A, Bravo J
National Institute of Public Health, Mexico Secretariat of Health, Cuernavaca, Morelos, Mexico.
Cancer Res. 1997 Sep 1;57(17):3728-32.
Some, but not all, epidemiological studies have suggested that dichlorodiphenyltrichloroethane (DDT) may play a role in the development of breast cancer. These investigations have been conducted in countries where this substance has been banned for at least 20 years. We conducted a study in Mexico, a country in which DDT is still being used to control malaria. In a hospital-based case-control study, we compared 141 histologically confirmed cases of breast cancer with 141 age-matched controls (+/-3 years). All subjects were identified at three referral hospitals of Mexico City between March 1994 and April 1996. Reproductive histories and other variables were obtained by structured interviews, DDT/DDE levels were determined in serum by gas-liquid chromatography. The arithmetic mean of serum DDE in lipid basis was 562.48 +/- 676.18 ppb (range, 10.24-4661.44) for the cases and 505.46 +/- 567.22 ppb (range, 0.004 to 4361.75) for the controls, but this difference was not statistically significant. The age-adjusted odds ratios for breast cancer regarding the serum level of DDE were 0.69 (95% confidence interval, 0.38-1.24) and 0.97 (confidence interval, 0.55-1.70) for the contrasts between tertile 1 (lowest level) and tertiles 2 and 3, respectively. These estimates were unaffected by adjustment for body mass, accumulated time of breast-feeding and menopause, and other breast cancer risk factors. These results do not lend support to the hypothesis that DDT is causally related to breast cancer at the body-burden levels found in our study population but do not exclude the possibility that higher levels of exposure could still play a role in the etiology of this tumor.
一些（但并非全部）流行病学研究表明，二氯二苯三氯乙烷（DDT）可能在乳腺癌的发生发展中起作用。这些研究是在该物质已被禁用至少20年的国家进行的。我们在墨西哥开展了一项研究，该国仍在使用DDT来控制疟疾。在一项基于医院的病例对照研究中，我们将141例经组织学确诊的乳腺癌病例与141名年龄匹配的对照（±3岁）进行了比较。所有受试者均于1994年3月至1996年4月期间在墨西哥城的三家转诊医院确定。通过结构化访谈获取生殖史和其他变量，采用气液色谱法测定血清中的DDT/DDE水平。病例组以脂质计的血清DDE算术平均值为562.48±676.18 ppb（范围为10.24 - 4661.44），对照组为505.46±567.22 ppb（范围为0.004至4361.75），但这种差异无统计学意义。血清DDE水平处于第1三分位数（最低水平）与第2和第3三分位数相比，乳腺癌的年龄调整优势比分别为0.69（95%置信区间为0.38 - 1.24）和0.97（置信区间为0.55 - 1.70）。这些估计值不受体重、累计母乳喂养时间和绝经以及其他乳腺癌危险因素调整的影响。这些结果不支持DDT与我们研究人群中发现的体内负荷水平的乳腺癌存在因果关系这一假设，但不排除更高暴露水平仍可能在该肿瘤病因中起作用的可能性。
