Implications of Potential Positive Correlation Between Autologous Tumor-Cell-Killing Activity and Prognosis in Lung Cancer

of circulating IGF-1 and completely block tumor growth.The new antiestrogens, should they become available in the clinic, may facilitate the survival of node-positive patients and be useful to maintain the control of tumor growth in advanced breast cancer.Regrettably, the physiological side-effects that could be associated with the long-term treatment of node negative disease (i.e., atherosclerosis and osteoporosis) may preclude an application in these patients.The concept of a dual ER-mediated control mechanism for regulating breast tumor growth will provide new opportunities to block endocrine-dependent growth completely.The possibility that tamoxifen and other less estrogenic antiestrogens may retard the growth of some ER-negative tumors heralds the broader application of an effective anticancer agent.Indeed, the beneficial therapeutic effect of tamoxifen in patients with a wide range of malignancies (i.e., melanoma, pancreatic carcinoma), cited in numerous anecdotal reports, may be a consequence of reduced serum IGF-1 levels.Pharmacological methods to lower markedly or to eliminate serum IGF-1 levels may prove to be a valuable therapeutic strategy to control a variety of malignancies.Perhaps phase I clinical studies with pure antiestrogens will demonstrate antitumor effects in cancers other than breast cancer via an IGF-1 mediated mechanism.