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The role of radioimmunoassay (RIA) in the diagnosis and management of endocrine tumors, such as pituitary tumors, insulinomas, and gastrinomas, has long been well established. A variety of nonendocrine tumors are capable of elaborating one or more humoral substances that resemble immunologically well-known, well-characterized biologically active hormones or their prohormone precursors or metabolic products. The possible value of mass screening for carcinoma of the lung by the detection of precursor adrenocorticotropic hormone (ACTH) in plasma was tested. However, the usefulness was limited by the potential for false-positive, i.e., elevation of marker concentration in the plasma of heavy smokers even in the absence of invasive carcinoma. Although on occasion a dramatic decrease of plasma ACTH after surgical resection or on some chemotherapeutic schedules has been observed, this does not occur with sufficient regularity to serve definitely as an objective measure of efficacy of therapy. The limitations of nonhormonal tumor markers, such as carcinoembryonic antigen (CEA), are also considered.

Eight patients with mediastinal or retroperitoneal germ cell tumors who had undergone testicular biopsy or orchiectomy were retrospectively analyzed for primary testicular abnormalities, subfertility, and abnormal sex hormone levels. Testicular tissue was abnormal in all patients, revealing peritubular fibrosis (six), decreased spermatogenesis (eight), interstitial edema (five), Sertoli cells only (one), and Leydig cell hyperplasia (two). Detailed hormone analysis in five patients revealed elevations of luteinizing hormone in four, decreased serum testosterone in two, elevations of estradiol in two, and elevation of human chorionic gonadotropin in one patient. A history of infertility was documented 2 months to 13 years before presentation in four patients and suspected in another. Extragonadal germ cell tumors, like their testicular counterparts are associated with primary germ cell defects, some of which seem to be independent of gonadotropin production by the tumor. In addition, the rather high incidence of antecedent infertility suggests that either a congenital or acquired primary germ cell defect contributes to defective spermatogenesis and the development of cancer in incompletely migrated germ cells.

To provide further understanding of humoral hypercalcemia in Hodgkin's disease (HD) the authors describe the clinical features and laboratory investigation of three patients recently treated at Massachusetts General Hospital. All were middle-aged men who presented with symptomatic hypercalcemia which led to a diagnosis of bulky intraabdominal HD. None had evidence of bone involvement or hyperparathyroidism. In the two cases tested 1,25(OH)2D3 was elevated at the time of diagnosis. These characteristics are remarkably similar to those of ten patients with HD and probable humoral hypercalcemia described in the literature. The diagnosis of HD was supported in Cases 1 and 3 by genomic blot analysis which showed no evidence of T-cell or B-cell tumor origin. In an in vitro assay, primary tumor medium from Case 1 stimulated dose-dependent bone resorption which was not entirely ascribable to 1,25(OH)2D3. The authors conclude that humoral hypercalcemia in HD predominantly affects males of middle age, that intraabdominal bulky disease is common, and that hypercalcemia appears to be mediated by tumor related production of 1,25(OH)2D3 in concert with a second factor.

A rare adenosquamous carcinoma of the colon occurred in a 41-year-old patient. Its presentation with hypercalcemia, in the absence of osseous metastases, has not been described previously. The hypercalcemia in this case was due to the elaboration of a parathyroid hormone-like substance by the tumor. The general characteristics of primary adenosquamous and squamous cell carcinomas of the colon are presented. These tumors present with advanced disease, in younger patients, and follow a highly aggressive course, as compared with adenocarcinomas of the colon. The cause of the malignancies, in the light of current theories regarding their genesis, is discussed.

Plasma human neurophysins (HNPs) were evaluated as tumor markers for patients with small cell carcinoma of the lung (SCCL) who were entered on limited disease and extensive disease treatment trials conducted by Cancer and Acute Leukemia Group B (CALGB). HNP values obtained before treatment showed 44% of tumors secreting vasopressin-associated HNP (VP-HNP), 14% secreting oxytocin-associated HNP (OT-HNP), and 11% producing both HNPs. There was a significantly higher incidence of HNP-secreting tumors for patients with extensive disease and two or more metastatic lesions than for patients with limited disease. There were no clear differences in response to treatment or in survival between patients with HNP-secreting tumors and those with nonsecreting tumors. Response to treatment evaluated by the change in plasma HNP, gave a 91% agreement with independently derived clinical impressions. Our data indicates that HNP evaluations provide sufficient sensitivity to forecast clinical response when it cannot be clearly assessed by conventional methods.