[Ectopic hormone formation and tumor markers in bronchial neoplasms]

Carcinoma of the bronchus can produce several polypeptide hormones and therefore has the capacity to cause most syndromes of endocrine hyperfunction. All pituitary hormones can be synthesized ectopically; furthermore, the production of hormones from the hypothalamus (CRF), the placenta (HCG, HPL) and the C-cells of the thyroid (calcitonin), as well as parathormone and prostaglandins has been described. The paraneoplastic syndrome may often be more dangerous for the patient than the tumor growth itself, and can lead to early death. On the other hand, it may allow the early detection of an unsuspected tumor. The ectopic hormones and other nonendocrine proteins and peptides can be used as tumor markers, and can demonstrate the effect of treatment and early recurrence or metastases. An ideal tumor marker should have the following characteristics: 1. production exclusively by neoplastic tissue, 2. direct correlation with tumor size, 3. substances common to all tumor types ("large spectrum tumor marker") although specific tumor markers for special tumors should be available, 4. the assays must be easy and automation should be possible. At present no tumor marker satisfies all these conditions. The measurement of several tumor markers and the use of discriminant analysis may extend their diagnostic value and open the way for biochemical detection of cancer in the future.