Tumor-proliferative activity, progesterone receptor status, estrogen receptor level, and clinical outcome of estrogen receptor-positive advanced breast cancer.
The relations among pretreatment tumor-proliferative activity, progesterone receptor (PgR) status, estrogen receptor (ER) level, and clinical outcome were analyzed in a series of 45 ER-positive advanced breast cancer postmenopausal women treated with tamoxifen (20 mg/day) until disease progression. Tritiated thymidine ([3H]dThd) Labeling Index (LI) by autoradiographic assay was utilized for proliferative activity analysis, whereas the dextran-coated charcoal method was used for ER and PgR evaluation (cutoff value, 10 fmol/mg of protein cytosol). The median [3H]dThd LI value was 1.8%; 73% of cases were PgR positive, and 53% were highly ER positive (greater than 100 fmol/mg of protein cytosol). Clinical responses were more frequently observed in slowly than in quickly proliferating tumors (86% versus 60%; P less than 0.05) but were similar for PgR-positive and -negative cases, as well as for those with high and low ER positivity. Only [3H]dThd LI was found to individualize patients with different survival rates (at 40 mo of follow-up, 78% versus 40% in slowly and quickly proliferating tumors, respectively). The [3H]dThd LI, monitored in ten patients by a second tumor biopsy after 14 days of tamoxifen therapy, was found to have a significantly lower median value (P = 0.03). These data indicate that pretreatment [3H]dThd LI provides information, which is not available in a study of PgR and ER status, on the clinical outcome of ER-positive advanced breast cancer patients treated by hormone therapy.
Paradiso
A
A
Medical Oncology Division, Oncology Institute, Bari, Italy.
Tommasi
S
S
Mangia
A
A
Lorusso
V
V
Simone
G
G
De Lena
M
M
D001943:Breast Neoplasms / Q000503:physiopathology* / Q000628:therapy; D002455:Cell Division; D005260:Female; D006801:Humans; D008593:Menopause; D009362:Neoplasm Metastasis; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D012189:Retrospective Studies; D016019:Survival Analysis; D013629:Tamoxifen / Q000627:therapeutic use
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen