Comparison of the short-term biological effects of 7alpha-[9-(4,4,5,5,5-pentafluoropentylsulfinyl)-nonyl]estra-1,3,5, (10)-triene-3,17beta-diol (Faslodex) versus tamoxifen in postmenopausal women with primary breast cancer.
AuthorsRobertson, John F R
Nicholson, Robert I
Bundred, Nigel J
Fox, J N
Gee, Julia M
Wakeling, A E
AffiliationDepartment of Surgery, Nottingham City Hospital, Nottingham, United Kingdom.
MetadataShow full item record
Abstract7Alpha-[9-(4,4,5,5,5-pentafluoropentylsulfinyl)-nonyl]estra-1,3,5, (10)-triene-3,17beta-diol (ICI 182,780; Faslodex) is a novel steroidal antiestrogen. This partially blind, randomized, multicenter study compared the effects of single doses of long-acting ICI 182,780 with tamoxifen or placebo on estrogen receptor (ERalpha) and progesterone receptor (PgR) content, Ki67 proliferation-associated antigen labeling index (Ki67LI), and the apoptotic index in the primary breast tumors of postmenopausal women. Previously untreated patients (stages T(1)-T(3); ER-positive or -unknown) were randomized and received a single i.m. dose of ICI 182,780 50 mg (n = 39), ICI 182,780 125 mg (n = 38), or ICI 182,780 250 mg (n = 44) or oral tamoxifen 20 mg daily (n = 36) or matching tamoxifen placebo (n = 43) for 14-21 days before tumor resection surgery with curative intent. The ER and PgR H-scores, together with the Ki67LI were determined immunohistochemically in the matched pretreatment biopsy and the posttreatment surgical specimens. The apoptotic index was determined by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling on the same samples. The effects of treatment on each of these parameters were compared using analysis of covariance. ICI 182,780 produced dose-dependent reductions in ER and PgR H-scores and in the Ki67LI. The reductions in ER expression were statistically significant at all doses of ICI 182,780 compared with placebo (ICI 182,780 50 mg, P = 0.026; 125 mg, P = 0.006; 250 mg, P = 0.0001), and for ICI 182,780 250 mg compared with tamoxifen (P = 0.024). For PgR H-score, there were statistically significant reductions after treatment with ICI 182,780 125 mg (P = 0.003) and 250 mg (P = 0.0002) compared with placebo. In contrast, tamoxifen produced a significant increase in the PgR H-score relative to placebo, and consequently, all doses of ICI 182,780 produced PgR values that were significantly lower than those in the tamoxifen-treated group. All doses of ICI 182,780 significantly reduced Ki67LI values compared with placebo (ICI 182,780 50 mg, P = 0.046; 125 mg, P = 0.001; 250 mg, P = 0.0002), but there were no significant differences between any doses of ICI 182,780 and tamoxifen. ICI 182,780 did not alter the apoptotic index when compared with either placebo or tamoxifen. Short-term exposure to ICI 182,780 reduces the ERalpha in breast tumor cells in a dose-dependent manner by down-regulating ER protein concentration. The reductions in tumor PgR content by ICI 182,780 demonstrate that ICI 182,780, unlike tamoxifen, is devoid of estrogen-agonist activity. Reductions in tumor cell proliferative activity (as indicated by Ki67LI) show that ICI 182,780 is likely to have antitumor activity in the clinical setting.
CitationComparison of the short-term biological effects of 7alpha-[9-(4,4,5,5,5-pentafluoropentylsulfinyl)-nonyl]estra-1,3,5, (10)-triene-3,17beta-diol (Faslodex) versus tamoxifen in postmenopausal women with primary breast cancer. 2001, 61 (18):6739-46 Cancer Res.
- Investigation of a new pure antiestrogen (ICI 182780) in women with primary breast cancer.
- Authors: DeFriend DJ, Howell A, Nicholson RI, Anderson E, Dowsett M, Mansel RE, Blamey RW, Bundred NJ, Robertson JF, Saunders C
- Issue date: 1994 Jan 15
- Antiproliferative effects of idoxifene in a placebo-controlled trial in primary human breast cancer.
- Authors: Dowsett M, Dixon JM, Horgan K, Salter J, Hills M, Harvey E
- Issue date: 2000 Jun
- Dose-dependent change in biomarkers during neoadjuvant endocrine therapy with fulvestrant: results from NEWEST, a randomized Phase II study.
- Authors: Kuter I, Gee JM, Hegg R, Singer CF, Badwe RA, Lowe ES, Emeribe UA, Anderson E, Sapunar F, Finlay P, Nicholson RI, Bines J, Harbeck N
- Issue date: 2012 May
- A potent specific pure antiestrogen with clinical potential.
- Authors: Wakeling AE, Dukes M, Bowler J
- Issue date: 1991 Aug 1
- Efficacy of letrozole extended adjuvant therapy according to estrogen receptor and progesterone receptor status of the primary tumor: National Cancer Institute of Canada Clinical Trials Group MA.17.
- Authors: Goss PE, Ingle JN, Martino S, Robert NJ, Muss HB, Piccart MJ, Castiglione M, Tu D, Shepherd LE, Pritchard KI, Livingston RB, Davidson NE, Norton L, Perez EA, Abrams JS, Cameron DA, Palmer MJ, Pater JL, National Cancer Institute of Canada Clinical Trials Group MA.17.
- Issue date: 2007 May 20