Intracellular diacylglycerol: a mitogenic second messenger proposable as marker of transformation in squamous cell carcinoma of the lung.

In this study, we examined 50 patients with documented lung cancer projecting in the bronchial lumen unilaterally. Bronchial lavage from the affected and unaffected sides provided neoplastic and normal cells in which we studied an intracellular mitogenic second messenger, diacylglycerol, associated with transformation. The levels of diacylglycerol in cells from the affected side were compared with that from the healthy side, thus providing an internal control for each patient. Our data show that the levels of diacylglycerol in lavage fluid relative to affected bronchus are elevated in 56% of all the patients examined. This elevation reaches 77% in patients with squamous cell carcinoma, a value of sensitivity higher than 'traditional' markers for cancer of the lung. Thus, these findings may have significant implications for the use of diacylglycerol measurement as a novel biomarker for early detection of lung cancer, and for monitoring recurrences after treatment.