What's new in endocrine factors of tumor growth?

In this review some aspects of endocrinological factors in cancer are discussed. The first part addresses the determination of steroid hormone receptors in cancer of the breast. The importance of steroid hormone receptor determination for the clinical management of breast cancer patients is emphasized. Current methods for receptor measurement are critically evaluated and it is concluded that rigorous standardization of tissue handling procedures and of radiochemical methodology is mandatory to improve the reliability of the presently available methods. The development of new techniques for receptor determination has been met with high expectations. Monoclonal antireceptor antibodies in principle allow the development of a radioimmunoassay but are not widely available as yet. Histochemical methods for receptor localization have so far failed to meet accepted criteria of specificity. Therefore radiochemical determination at present remains the only reliable method. The second part addresses the production of peptide hormones by endocrine tumours of the gastroenteropancreatic (GEP) system and by non-neuroendocrine neoplasms. In the endocrine tumours of the GEP system a wide range of peptide hormones can be detected by immunocytochemistry, but most frequently the pattern of hormone production is comparable with that in the normal organ of origin. Clinical symptoms of excess hormone production occur much less frequently than hormone production is found by immunological methods and is usually caused by one hormone. It is proposed that these neoplasms are classified according to the hormone which causes the leading clinical symptoms and/or the hormone with the highest serum level. Peptide hormone producing cells in classical carcinoma are an intriguing phenomenon which has shed some new light on the embryological origin of neuroendocrine cells in the relevant organs and also on the histogenesis of neuroendocrine as well as non-neuroendocrine neoplasms.