Transferrin receptor expression in nonsmall cell lung cancer. Histopathologic and clinical correlates

Background. In the search for tumor-related antigens with survival-predictive value, previous studies have yielded varied conclusions regarding the expression of one such antigen, the transferrin receptor in lung cancer. The goal of this study was to define the frequency of expression of transferrin receptor in lung cancer specimens and gather preliminary data regarding the prognostic value of this tumor-related antigen. Methods. Tissue immunoreactivity was studied with a murine monoclonal antibody to transferrin receptor in patients with nonsmall cell lung cancer who underwent surgical resection at the Medical Center Hospital of Vermont during the period from January, 1988, to May, 1991. Results. The study group consisted of 32 patients (21 males and 11 females) with an average follow-up length of 27 months (standard deviation of 16 months). There were 17 patients with adenocarcinoma, 14 with squamous cell carcinoma, and 1 with large cell carcinoma. At the end of data accumulation, a total of 16 deaths had been recorded (8 with squamous cell, 8 with adenocarcinoma). Normal lung tissue did not stain for transferrin receptor; however, 13 of 17 (76%) adenocarcinomas, 13 of 14 (93%) squamous cell carcinomas, and the 1 large cell carcinoma stained positively for transferrin receptor. Staining for transferrin receptor was graded according to pattern and intensity and categorized as absent-weak or strong. Survival analysis was performed to evaluate patient outcome based on a variety of clinical and experimentally determined characteristics. Groups based on N-status (NO vs. N1 + N2, P = 0.08), stage (Stage 1 vs. Stage 2 + 3, P = 0.13), age (younger than 60 vs. 60 years or older, P = 0.09), and transferrin receptor staining (absent-weak vs. strong, P = 0.14) achieved nearly significant differences in survival. Further analysis of the differences in survival for groupings based on transferrin receptor staining found that these differences in survival reached significance for patients with larger tumors (T2 or T3, P = 0.02). Conclusions. Transferrin receptor is expressed in the majority of lung cancers and the presence of transferrin receptor in nonsmall cell lung cancers may be an indicator of poorer prognosis in certain groups of patients.