Plasma insulin-like growth factor-1 and serum IGF-binding protein 3 can beassociated with the progression of breast cancer, and predict the risk of recurrence and the probability of survival in African-American and Hispanicwomen

In vitro studies have shown that insulin-like growth factor (IGF) is a mito gen for breast cancer cells. However, the associations of plasma IGF-I with tumor histopathology in high-risk groups need further investigation. We hy pothesize that plasma IGF-I and serum IGFBP3 concentrations in breast cance r patients may provide useful information on the progression of their disea se, and determine the probability of recurrence and survival. We have carri ed out a retrospective study on 130 minority breast cancer patients. Plasma IGF-I and serum IGFBP3 were correlated with tumor histopathology, menopaus al status, treatment modality, recurrence rates, and probability of surviva l. Plasma IGF-I and serum IGFBP3 were measured by radioimmunoassay. Our stu dies show that breast cancer patients have elevated plasma IGF-I and serum IGFBP3 levels. In addition we observed the following: IGF-I did not correla te with age and nodal stage. IGF-I and IGFBP3 increased with tumor size (T4 ). IGF-I did not correlate with estrogen receptor status, but did increase in progesterone-receptor-positive patients. IGF-I levels were higher in pre menopausal patients and in women with cancer recurrence. Tamoxifen reduced IGF-I levels significantly and reduced the risk of recurrence. The survival probability was greater in patients with plasma IGF-I levels <120 ng/ml. i n conclusion, lowering of plasma IGF-I may offer the following benefits: (a ) reduce the risk of developing breast cancer in high-risk groups; (b) slow the progression of breast cancer in patients at early stages of cancer; (c ) lower the risk of recurrence, and (d) increase the probability of surviva l. Copyright (C) 1999 S. Karger AG, Basel.