TY - JOUR
T1 - The estrogen suppression after sequential treatment with formestane in advanced breast cancer patients
AU - Zilembo, Nicoletta
AU - Bajetta, Emilio
AU - Bichisao, Ettore
AU - Martinetti, Antonia
AU - La Torre, Ignazia
AU - Bidoli, Paolo
AU - Longarini, Raffaella
AU - Portale, Tindara
AU - Seregni, Ettore
AU - Bombardieri, Emilio
PY - 2004/5
Y1 - 2004/5
N2 - In postmenopausal patients, estrogens have an important role in breast cancer growth and aromatase inhibitors (AI) suppress the aromatase enzyme system which converts androgens into estrogens. The aim of this study was to evaluate the effect on estrogen suppression of formestane 250 mg i.m. fortnightly, given immediately after the failure of a previous treatment with non-steroidal AI. Twenty-two advanced breast cancer patients progressing on letrozole, anastrozole and aminoglutethimide entered the study. At the beginning of the study, the serum estrogen levels were suppressed by the previous treatment with non-steroidal AI, and the following treatment with formestane moderately maintained this suppression; in four patients serum estrogen levels increased fivefold after 10 weeks. Neither complete nor partial responses were observed; 11 patients (50%) showed a stable disease lasting ≥6 months, and the median time to progression was 6 months (range 3-9 months). No correlation was observed between clinical responses and serum estrogen suppression. Tolerability was satisfactory, and no patient withdrew from the study due to adverse events. In conclusion, formestane has demonstrated a moderate activity in estrogen suppression, and there is evidence that, at the failure of a previous treatment with non-steroidal AI, the sequential use of steroidal AI is feasible. This approach can be used in clinical practice in order to offer a disease control with a satisfactory quality of life.
AB - In postmenopausal patients, estrogens have an important role in breast cancer growth and aromatase inhibitors (AI) suppress the aromatase enzyme system which converts androgens into estrogens. The aim of this study was to evaluate the effect on estrogen suppression of formestane 250 mg i.m. fortnightly, given immediately after the failure of a previous treatment with non-steroidal AI. Twenty-two advanced breast cancer patients progressing on letrozole, anastrozole and aminoglutethimide entered the study. At the beginning of the study, the serum estrogen levels were suppressed by the previous treatment with non-steroidal AI, and the following treatment with formestane moderately maintained this suppression; in four patients serum estrogen levels increased fivefold after 10 weeks. Neither complete nor partial responses were observed; 11 patients (50%) showed a stable disease lasting ≥6 months, and the median time to progression was 6 months (range 3-9 months). No correlation was observed between clinical responses and serum estrogen suppression. Tolerability was satisfactory, and no patient withdrew from the study due to adverse events. In conclusion, formestane has demonstrated a moderate activity in estrogen suppression, and there is evidence that, at the failure of a previous treatment with non-steroidal AI, the sequential use of steroidal AI is feasible. This approach can be used in clinical practice in order to offer a disease control with a satisfactory quality of life.
KW - Advanced breast cancer
KW - Aromatase inhibitors
KW - Estrogen suppression
KW - Formestane
UR - http://www.scopus.com/inward/record.url?scp=19244365879&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=19244365879&partnerID=8YFLogxK
U2 - 10.1016/j.biopha.2003.12.009
DO - 10.1016/j.biopha.2003.12.009
M3 - Article
C2 - 15183852
AN - SCOPUS:19244365879
VL - 58
SP - 255
EP - 259
JO - Biomedicine and Pharmacotherapy
JF - Biomedicine and Pharmacotherapy
SN - 0753-3322
IS - 4
ER -