Tworoger Shelley S, Sluss Patrick, Hankinson Susan E
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Cancer Res. 2006 Feb 15;66(4):2476-82. doi: 10.1158/0008-5472.CAN-05-3369.
Recent evidence suggests that prolactin may be positively associated with postmenopausal breast cancer risk; however, little data are available in younger women. Therefore, we conducted a prospective, nested case-control study to examine the relationship between plasma prolactin concentrations and breast cancer risk in predominately premenopausal women from the Nurses' Health Study II. Blood samples were collected from 1996 to 1999. The analysis includes 316 cases of breast cancer diagnosed after blood donation and before June 1, 2003, who had two controls matched on age, fasting status, time of day and month of blood collection, race/ethnicity, and timing of blood draw within the menstrual cycle. Sixty-three percent of participants provided a timed follicular and luteal menstrual phase blood sample; other women provided a single untimed sample. When including all women, we observed a positive association between prolactin and breast cancer risk [relative risk (RR), top quartile versus bottom quartile, 1.5; 95% confidence interval (95% CI), 1.0-2.3; P(trend) = 0.03] that was slightly stronger among estrogen receptor-positive/progesterone receptor-positive tumors (comparable RR, 1.9; 95% CI, 1.1-3.3; P(trend) = 0.04). Associations were similar among premenopausal women only. However, we did not find an association between prolactin and breast cancer risk among the subset of women who only provided timed samples (comparable RR, average of timed samples, 1.3; 95% CI, 0.8-2.3; P(trend) = 0.40). The association seemed stronger among women > or = 45 years old and for cases diagnosed within approximately 4 years of blood collection. Our data suggest a modest positive association between prolactin and breast cancer risk among predominately premenopausal women; however, further follow-up is needed to increase power for subgroup analyses.
近期证据表明，催乳素可能与绝经后乳腺癌风险呈正相关；然而，关于年轻女性的数据却很少。因此，我们进行了一项前瞻性巢式病例对照研究，以探讨护士健康研究II中主要为绝经前女性的血浆催乳素浓度与乳腺癌风险之间的关系。血样采集于1996年至1999年。分析纳入了316例在献血后且在2003年6月1日前被诊断为乳腺癌的病例，这些病例有两名在年龄、空腹状态、采血时间（日和月）及月份、种族/族裔以及月经周期内采血时间方面相匹配的对照。63%的参与者提供了定时的卵泡期和黄体期月经血样；其他女性提供了一份非定时的单次血样。当纳入所有女性时，我们观察到催乳素与乳腺癌风险之间存在正相关[相对风险（RR），最高四分位数与最低四分位数相比，为1.5；95%置信区间（95%CI），1.0 - 2. · 3；P（趋势） = 0.03]，在雌激素受体阳性/孕激素受体阳性肿瘤中这种相关性略强（RR相当，为1.9；95%CI，1.1 - 3.3；P（趋势） = 0.04）。仅在绝经前女性中，相关性类似。然而，在仅提供定时血样的女性亚组中，我们未发现催乳素与乳腺癌风险之间存在关联（RR相当，定时血样平均值为1.3；95%CI，0.8 - 2.3；P（趋势） = · 40）。这种关联在年龄≥45岁的女性以及在采血后约4年内被诊断出的病例中似乎更强。我们的数据表明，在主要为绝经前女性中，催乳素与乳腺癌风险之间存在适度的正相关；然而，需要进一步随访以提高亚组分析的效能。
