Koenig K L, Toniolo P, Bruning P F, Bonfrer J M, Shore R E, Pasternack B S
Institute of Environmental Medicine, New York University Medical Center, New York 10010.
Cancer Epidemiol Biomarkers Prev. 1993 Sep-Oct;2(5):411-4.
Prolactin, a hormone indispensable for milk secretion, has been shown to enhance the development and growth of mammary tumors in rodents; however, its importance in human breast cancer is uncertain. Serum prolactin levels are known to fluctuate considerably under normal conditions, and lack of precision in the hormone measurements may have contributed to the largely negative findings in humans to date. The purpose of this study was to investigate the reliability of prolactin measurements in women using stored serum from an ongoing prospective study of breast cancer. Separate groups of postmenopausal and premenopausal women who donated multiple blood samples at approximately 1-year intervals were studied. The reliability of a single log prolactin determination, as measured by the intraclass correlation coefficient, was 0.76 for the postmenopausal women (95% confidence interval, 0.66-0.85) and 0.48 for the premenopausal women (95% confidence interval, 0.31-0.62). These findings suggest that a single measurement is sufficient to characterize the serum prolactin level of postmenopausal women for epidemiological research. For premenopausal women, however, multiple samples are desirable. Controlling for phase of the menstrual cycle does not appear to substantially improve the reliability of premenopausal measurements.
催乳素是一种乳汁分泌所必需的激素，已被证明可促进啮齿动物乳腺肿瘤的发展和生长；然而，其在人类乳腺癌中的重要性尚不确定。已知血清催乳素水平在正常情况下会有很大波动，而且激素测量缺乏精确性可能是迄今人类研究中大多得出阴性结果的原因。本研究的目的是利用一项正在进行的乳腺癌前瞻性研究中储存的血清，调查女性催乳素测量的可靠性。研究了绝经后和绝经前女性分别组成的群体，她们大约每隔1年捐献多次血样。通过组内相关系数测量，绝经后女性单次对数催乳素测定的可靠性为0.76（95%置信区间，0.66 - 0.85），绝经前女性为0.48（95%置信区间，0.31 - 0.62）。这些发现表明，对于流行病学研究而言，单次测量足以表征绝经后女性的血清催乳素水平。然而，对于绝经前女性，需要多个样本。控制月经周期阶段似乎并不能显著提高绝经前测量的可靠性。
