Neoadjuvant therapy of endometrial cancer with the aromatase inhibitor letrozole: endocrine and clinical effects.
OBJECTIVE
To investigate the short-term hormonal and clinical effects of the aromatase inhibitor letrozole (Femara) in patients with endometrial cancer.


METHODS
Ten previously untreated, post-menopausal patients (mean age 59 years) with endometrial cancer, predominantly stage I disease, received letrozole 2.5mg per day for 14 days before surgery. Clinical, sonographic, morphologic, cytologic, and hormonal-metabolic parameters (blood estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), glucose, and cholesterol by radioimmunoassay, enzyme immune assay, or enzyme-colorimetric methods; tumor progesterone receptors by ligand-binding assay; and aromatase activity by 3H-water release assay) were evaluated before and after treatment.


RESULTS
Treatment was well-tolerated in all patients. In two patients, pain relief in the lower part of the belly and/or decrease in intensity of uterine discharge was reported. In the three cases, substantial decreases in endometrial M-echo (ultrasound) signal were noted; the mean value of this parameter after treatment was 31.1% lower than before treatment. Blood estradiol concentration decreased by an average of 37.8% after letrozole therapy, and tumor progesterone receptor levels and aromatase activity decreased by 34.4 and 17.5%, respectively. Treatment with letrozole did not influence surgery.


CONCLUSIONS
These data show that short-term treatment with letrozole in the neoadjuvant setting resulted in some positive clinical changes. Longer-term and larger-scale trials of neoadjuvant letrozole in endometrial cancer are warranted.
Berstein
Lev
L
Laboratory Oncoendocrinology, N.N. Petrov Research Institute of Oncology, St. Petersburg 197758, Russia. levmb@endocrin.spb.ru
Maximov
Sergei
S
Gershfeld
Eduard
E
Meshkova
Irina
I
Gamajunova
Vera
V
Tsyrlina
Evgenia
E
Larionov
Alexei
A
Kovalevskij
Anatolii
A
Vasilyev
Dmitry
D
D000368:Aged; D047072:Aromatase Inhibitors; D016889:Endometrial Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D000077289:Letrozole; D007986:Luteinizing Hormone / Q000097:blood; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009570:Nitriles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D017698:Postmenopause; D011980:Receptors, Progesterone / Q000032:analysis; D016896:Treatment Outcome; D014230:Triazoles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D014463:Ultrasonography
D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors; D009570:Nitriles; D011980:Receptors, Progesterone; D014230:Triazoles; D004958:Estradiol; D000077289:Letrozole; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone