ANTI-HU ANTIBODIES IN PATIENTS WITH SMALL-CELL LUNG-CANCER - ASSOCIATION WITH COMPLETE RESPONSE TO THERAPY AND IMPROVED SURVIVAL

Purpose: Anti-Hu antibodies (HuAb) recognise antigens expressed by neu rons and small-cell lung cancer (SCLC). High titers of HuAb were initi ally reported in serum from patients with paraneoplastic encephalomyel itis/sensory neuropathy (PEM/SN) and SCLC. Preliminary studies have in dicated that some SCLC patients without PEM/SN harbor low titer of HuA b in their serum, and that the SCLC of these patients may grow more in dolently. Based on these observations, we conducted a multicenter pros pective study of SCLC patients without PEM/SN to determine the inciden ce and prognostic implications of HuAb. Methods: Serum samples were co llected at diagnosis of SCLC in 196 patients without PEM/SN. HuAb were determined by immunoblot of purified recombinant Hug antigen. Results : HuAb were detected in 32 (16%) of the 196 patients. Of the 170 patie nts who received treatment for the tumor, 27 (16%) were HuAb positive. HuAb was associated with limited disease stage (59.3% v 38.6%; P = .0 47), complete response to therapy (55.6% v 19.6%; P <.001), and longer survival (14.9 v 10.2 months; P = .018). In a logistic regression ana lysis, HuAb status was an independent predictor of complete response i nduction. The probability of achieving a complete response was more th an five times higher in HuAb-positive than in HuAb-negative patients ( odds ratio, 5.4; 95% confidence interval, 1.71 to 16.89; P=.004). Cox multivariate analysis indicated that HuAb status was not independently associated with survival. Conclusion: The presence of HuAb at diagnos is of SCLC is a strong and independent predictor of complete response to treatment. This feature accounts for the association between HuAb a nd longer survival. (C) 1997 by American Society of Clinical Oncology.