The value of tumour markers in lung cancer.

The pre-treatment serum levels of neuron-specific enolase (NSE), phosphohexose isomerase (PHI) and circulating immune complexes (CC) as tumour markers were compared to measurements of standard haematology and biochemical indices in 73 patients with lung cancer, as an aid to differentiation of tumour type, estimating disease extent, predicting response to therapy and prognosis. Elevated NSE greater than or equal to 12.5 ng ml-1, PHI greater than or equal to 55 mgl-1 levels were observed in 55% of cases for NSE, 90% for PHI and 49% for CC. NSE was significantly elevated in 61% (25/41) of patients with SCLC (P less than 0.005) compared to 41% (13/32) with NSCLC. CC levels were significantly raised in 72% (23/32) of patients with NSCLC (P less than 0.05) compared to 32% with SCLC. The levels of NSE and PHI were not related to tumour stage but CC was significantly raised in limited compared to extensive disease in SCLC (P less than 0.05). Serum albumin was significantly lower in NSCLC compared to SCLC, and median values of alkaline phosphatase, gamma-glutamyltranspeptidase and aminoaspartate transferase were significantly higher in patients with extensive disease. The pre-treatment serum values of NSE, PHI, and CC did not predict the response to therapy or prognosis in the 73 patients with lung cancer. The most important prognostic factor was the number of abnormal routine laboratory parameters (greater than 4) in this group of patients.