Treatment of metastatic breast cancer with somatostatin analogues - A meta-analysis

Background: Somatostatin analogues appear to have antiproliferative effects in breast cancer by inhibiting various hormones. Several small phase 1 and 2 clinical trails have evaluated the efficacy of somatostatin analogues, b ut the results are varied. The purpose of this study was to use the techniq ue of meta-analysis to determine the effect of somatostatin analogues on tu mor response, toxicity, and serum hormone levels in women with metastatic b reast cancer. Methods: All published and unpublished trials were reviewed. Mete-analysis was preformed by best linear unbiased estimate regression with observations weighted inversely to their variance. Significance was considered at P < . 05. Results: Fourteen studies (N = 210) were included. Positive tumor response was reported in 87 patients (41.4%). Mean duration of response was 3.9 mont hs. Response was beat when somatostatin analogues were given as first-line therapy (69.5% versus 28.5%, P < .006) and in patients with less than or eq ual to2 metastases (45.0% versus 5.6%, P = .3). Mild side effects occurred in 47 of 185 patients (25.4%). Therapy was associated with a decrease in se rum insulin-like growth factor (IGF-1) and an increase in growth hormone. Conclusions: In patients with metastatic breast cancer, treatment with soma tostatin analogues was associated with a tumor response of over 40% with fe w side effects. Best results were achieved when somatostatin analogues were given as first-line therapy.