Formestane: effective therapy in postmenopausal women with advanced breast cancer.
Aromatase inhibitors are a useful therapeutic option in the management of endocrine-dependent advanced breast cancer. Formestane (Lentaron) is the first irreversible aromatase inhibitor to be extensively investigated. In a phase II study to determine the effects of formestane on serum estradiol and urinary 17-hydroxycorticosteroid (17-OHCS) levels and to evaluate its clinical activity, 72 postmenopausal patients with advanced breast cancer were given formestane 250 mg intramuscularly every 2 weeks. Of 66 patients fully evaluable, 56 were estrogen receptor (ER) positive, and 43 had a disease-free interval > or = 2 years. Metastases were assessable in soft tissue (53%), bone (53%) and viscera (47%); 34 patients had 1, 32 had > or = 2 metastatic lesions. Serum estradiol levels fell significantly (p < 0.01) after 2 weeks and remained unchanged thereafter, whereas urinary 17-OHCS levels did not change during treatment. Objective responses were obtained in 19 patients (29%), of whom 8 had complete response. In relation to disease sites, similar responses were obtained in soft tissue (33%) and viscera (30%), whereas response in bone was 18%. The overall tolerability of formestane was satisfactory, and only two patients complained of local side effects. We conclude that formestane is an effective aromatase inhibitor in postmenopausal patients with hormone-dependent breast cancer, and does not interfere with adrenal steroidogenesis.
Bajetta
E
E
Division of Medical Oncology B, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy.
Zilembo
N
N
Buzzoni
R
R
Noberasco
C
C
Martinetti
A
A
Ferrari
L
L
Bartoli
C
C
Sacchini
V
V
Attili
A
A
Lepera
P
P
D015065:17-Hydroxycorticosteroids / Q000652:urine; D000368:Aged; D000735:Androstenedione / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D047072:Aromatase Inhibitors; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D018572:Disease-Free Survival; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy* / Q000378:metabolism; D017698:Postmenopause; D011960:Receptors, Estrogen / Q000378:metabolism*
D015065:17-Hydroxycorticosteroids; D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D011960:Receptors, Estrogen; D000735:Androstenedione; D004958:Estradiol; C014594:formestane