atrial-natriuretic-factor and Paraneoplastic-Syndromes

The term paraneoplastic syndrome refers to the ability of some tumors to produce signs and symptoms at a distance from the site of the primary tumor or its metastases. Paraneoplastic syndromes may develop before the diagnosis of carcinoma is made. Paraneoplastic syndromes associated with small cell lung cancer (SCLC) include endocrinologic abnormalities secondary to peptide hormone production, and neurologic sequelae due to autoantibody production. This article reviews the common paraneoplastic syndromes that may occur in patients with SCLC.

Topics: ACTH Syndrome, Ectopic; Atrial Natriuretic Factor; Carcinoma, Small Cell; Cerebellar Diseases; Encephalomyelitis; Humans; Inappropriate ADH Syndrome; Lambert-Eaton Myasthenic Syndrome; Lung Neoplasms; Paraneoplastic Syndromes; Retinal Diseases

It is well documented in literature that a majority of small-cell lung cancers are associated with paraneoplastic phenomena. We report the case of a 63-year-old man diagnosed with small-cell lung carcinoma, in whom a severe hyponatremia and renal sodium loss with inappropriate antidiuresis were also found during a routine laboratory testing. Syndrome of inappropriate antidiuretic hormone secretion was first suspected in this patient, but another complex pathogenetic mechanism involving atrial natriuretic peptides could be associated, potentiating the deflation of the plasma sodium level. In our patient, the plasma-atrial natriuretic peptide base level, determined with a sensitive radioimmunoassay, was above the normal range (183 pg/mL; normal range, 50 pg/mL, +/- 10 pg/mL), and the antidiuretic hormone plasma level had an oscillatory pattern, varying between 5.5 pg/mL and 7 pg/mL (normal range, 0-4.7 pg/mL). We discuss the pathogenesis and clinical aspects of this association and the therapeutic options for these types of patients.

Topics: Arginine Vasopressin; Atrial Natriuretic Factor; Carcinoma, Small Cell; Humans; Hyponatremia; Inappropriate ADH Syndrome; Lung Neoplasms; Male; Middle Aged; Osmolar Concentration; Paraneoplastic Syndromes; Radiography; Radioimmunoassay; Sodium; Water-Electrolyte Imbalance

To determine whether inappropriately secreted vasodilatory peptides have a role in the pathogenesis of orthostatic (postural) hypotension, a recognised paraneoplastic effect of bronchial malignancies usually attributed to immune mediated destruction of autonomic ganglia.. Serum concentrations of three vasodilatory peptides, atrial natriuretic peptide (ANP), vasoactive intestinal polypeptide (VIP) and calcitonin gene related peptide (CGRP), were measured in 111 patients with bronchial carcinoma and 35 controls prospectively screened for orthostatic hypotension (> 20 mmHg drop in systolic blood pressure on repeated occasions on standing from the supine position) and in whom other causes of this condition were excluded.. Twenty two (20%) patients with carcinoma and two (6%) controls had orthostatic hypotension according to the criteria used. Serum concentrations of ANP, VIP and CGRP were elevated above normal in, respectively, 25 (23%), 10 (9%) and eight (7%) patients with carcinoma and in six (18%), zero and three (9%) controls. There was no correlation between orthostatic hypotension and concentrations of any of the vasodilatory peptides.. Elevated serum concentrations of ANP and CGRP were no more frequent in subjects with bronchial carcinoma than in controls and could not be attributed to the tumour, although there was a possible association for VIP. Orthostatic hypotension was more common in patients with carcinoma, but there was no evidence that the peptides measured played a role in its pathogenesis.

Topics: Aged; Atrial Natriuretic Factor; Calcitonin Gene-Related Peptide; Case-Control Studies; Humans; Hypotension, Orthostatic; Lung Neoplasms; Middle Aged; Paraneoplastic Syndromes; Prospective Studies; Vasoactive Intestinal Peptide

Metabolic disturbances of Na, K, Ca and glucose as paraneoplastic syndrome were reviewed on the basis of recent progress of such areas. These abnormalities usually occur due to the production of hormones or other physiologically active substances by tumor tissues. Hyponatremia is the most common abnormality of Na metabolism in patients with cancers such as lung cancer, malignant lymphoma, thymoma and so on. Usual cause of hyponatremia as paraneoplastic syndrome is inadequate secretion of Antidiuretic Hormone (SIADH), which brings dilution hyponatremia associated with water intoxication. Recently hyponatremia due to abnormal secretion of atrial natriuretic peptide has been noted. Ca metabolism disturbance associated with cancer is usually observed as hypercalcemia and it is said that such hypercalcemia is seen in about 10% of cancer patients. Main cause of hypercalcemia associated with cancer is local osteolytic hypercalcemia (LOH) due to bone metastasis or humoral hypercalcemia of malignancy (HHM). The most common etiology of HHM is the production of Parathormone (PTH) related peptide (PTH-rP) massively secreted from cancer tissues. PTH-rP has been recently well investigated and its molecular, mRNA and gene structure have been already determined. The progress of this area is very rapid and PTH-rP will be assayed in the clinical laboratory in near future. As for glucose metabolism disturbance as paraneoplastic syndrome, hypoglycemia is the most common abnormality. This type of hypoglycemia has been noted in relation with excessive production of somatomedin.

Topics: Atrial Natriuretic Factor; Calcium; Glucose; Humans; Hypercalcemia; Hyponatremia; Inappropriate ADH Syndrome; Paraneoplastic Syndromes; Potassium; Sodium