Morimoto T, Yamamoto H, Komaki K, Konishi N, Tanaka T, Yamakawa T, Mori T, Sasa M, Monden Y
School of Medical Science, University of Tokushima, Japan.
Tokushima J Exp Med. 1990 Dec;37(3-4):59-68.
In the present study, chemotherapy with 5-fluorouracil(5-Fu), endocrine therapy with tamoxifen (TAM), and chemoendocrine therapy with concominant use of 5-FU and TAM were performed and compared for DMBA-induced rat mammary carcinoma, a hormone-dependent tumor. The study was designed to assess the usefulness of chemoendorine therapy based on the antitumor effects and changes in hormone receptor levels. The response rates in the groups treated with 5-Fu or TAM alone and the combination of 5-Fu and TAM were 60%, 50% and 62%, respectively. There was no difference in these response rates. The tumor regression rates in these treatment groups were 22 +/- 69%, 20 +/- 54% and 46 +/- 37%; again there was no difference among the three groups. After treatment, the estrogen receptor (ER) and progesterone receptor (PgR) levels decreased significantly in the groups treated with TAM alone and the combination of 5-FU and TAM but remained unchanged in the group treated with 5-FU alone. The decreases in the ER and PgR levels in responsive tumors after treatment were considerably greater in the groups greated with TAM alone and the combination of 5-FU and TAM than in the group treated with 5-FU alone. However, the changes in the receptor levels in nonresponsive tumors did not differ among the three treatment groups. Moreover, there were no differences in the antitumor effects and changes in receptor levels between the groups treated with TAM alone and the combination of 5-FU and TAM. These results suggest that the antitumor effect observed in the combination therapy with 5-FU and TAM was mainly due to the action of TAM. In brief, the expected additive effects of chemoendocrine therapy were not observed.
在本研究中，对二甲基苯并蒽（DMBA）诱导的大鼠乳腺癌（一种激素依赖性肿瘤）进行了5-氟尿嘧啶（5-Fu）化疗、他莫昔芬（TAM）内分泌治疗以及5-Fu与TAM联合的化学内分泌治疗，并进行了比较。该研究旨在根据抗肿瘤作用和激素受体水平的变化评估化学内分泌治疗的有效性。单独使用5-Fu或TAM以及5-Fu与TAM联合治疗组的缓解率分别为60%、50%和62%。这些缓解率没有差异。这些治疗组的肿瘤消退率分别为22±69%、20±54%和46±37%；三组之间同样没有差异。治疗后，单独使用TAM以及5-FU与TAM联合治疗组的雌激素受体（ER）和孕激素受体（PgR）水平显著降低，但单独使用5-FU治疗组的水平保持不变。治疗后反应性肿瘤中ER和PgR水平的降低在单独使用TAM以及5-FU与TAM联合治疗组中比单独使用5-FU治疗组显著更大。然而，无反应性肿瘤中受体水平的变化在三个治疗组之间没有差异。此外，单独使用TAM以及5-FU与TAM联合治疗组之间在抗肿瘤作用和受体水平变化方面没有差异。这些结果表明，5-FU与TAM联合治疗中观察到的抗肿瘤作用主要归因于TAM的作用。简而言之，未观察到化学内分泌治疗预期的相加效应。
