Serum zinc levels and urinary zinc excretion in patients with bronchogenic carcinoma. Effects of tumor resection.

Low serum zinc levels and high urinary zinc excretion were found in 25 patients with bronchogenic carcinoma. Twenty of them underwent successful removal of the tumor by lobectomy or pneumonectomy; in the other 5 patients surgical exploration revealed unresectable pulmonary lesions. The latter had significantly lower serum zinc and higher urinary zinc levels than the patients in whom surgical removal of the tumor could be performed. Tumor resection was followed by restoration of serum and urinary zinc to normal. In contrast, in the inoperable patients a further decrease in serum zinc and no significant change in urinary zinc excretion were noted 15 days after thoracic exploration. In both patient groups a significant negative correlation existed between preoperatively obtained values of serum and urinary zinc. Hypozincemia in patients with bronchogenic carcinoma may result from an increase in urinary zinc losses, probably related to a decrease in zinc binding to plasma proteins. Determination of serum and urinary zinc may be useful in evaluating the prognosis of primary lung cancer.