Noguchi S, Yamamoto H, Inaji H, Imaoka S, Koyama H
Department of Surgery, Center for Adult Diseases, Osaka, Japan.
Cancer. 1990 Mar 15;65(6):1375-9. doi: 10.1002/1097-0142(19900315)65:6<1375::aid-cncr2820650621>3.0.co;2-j.
The influence of medroxyprogesterone acetate (MPA) on estrogen receptor (ER) and progesterone receptor (PR) levels was studied in 20 postmenopausal patients with ER-positive and PR-positive primary breast cancers. Each patient underwent drill biopsy and subsequently mastectomy. The drill biopsy and surgical specimens were assayed for the total ER and PR levels (cytosolic plus nuclear fraction) by enzyme immunoassay. Between the drill biopsy and mastectomy, ten patients received no treatment (control group) and the other ten patients were given MPA (1200 mg/day) for 7 days. In the control group, the total ER and PR levels of the surgical specimens decreased by 68.2 +/- 7.3% and 60.7 +/- 8.4%, respectively, taking the receptor values of the drill biopsy specimens as 100%, although no treatment was given preoperatively. This decrease seems to be attributable to the receptor degradation due to damages occurring during mastectomy. In the MPA group, the total ER and PR levels of the surgical specimens decreased by 64.2 +/- 8.0% and 23.3 +/- 7.6%, respectively. The decrease in PR, but not ER, was statistically significant between the control and MPA groups (P less than 0.01). These results demonstrate that MPA down regulates PR but not ER in human breast cancer and challenge the conventional idea, extrapolated from the results on the endometrium and endometrial cancer, that MPA antagonizes endogenous estrogens by down regulating ER.
研究了醋酸甲羟孕酮（MPA）对20例雌激素受体（ER）和孕激素受体（PR）均为阳性的绝经后原发性乳腺癌患者体内ER和PR水平的影响。每位患者均接受了穿刺活检，随后进行了乳房切除术。通过酶免疫测定法检测穿刺活检组织和手术标本中总的ER和PR水平（胞浆加核部分）。在穿刺活检和乳房切除术之间，10例患者未接受任何治疗（对照组），另外10例患者接受MPA（1200mg/天）治疗7天。在对照组中，尽管术前未进行任何治疗，但以穿刺活检标本的受体值为100%，手术标本中总的ER和PR水平分别下降了68.2±7.3%和60.7±8.4%。这种下降似乎归因于乳房切除术中发生的损伤导致的受体降解。在MPA组中，手术标本中总的ER和PR水平分别下降了64.2±8.0%和23.3±7.6%。对照组和MPA组之间PR水平的下降具有统计学意义（P<0.01），而ER水平下降无统计学意义。这些结果表明，MPA在人类乳腺癌中下调PR但不下调ER，这对从子宫内膜和子宫内膜癌的研究结果推断出的传统观点提出了挑战，即MPA通过下调ER来拮抗内源性雌激素。
