Lung cancer, immune status, histopathology and smoking. Is oat cell carcinoma lymphodependent?

Life table analysis and partial correlation analysis have been used to examine the importance and interaction of those factors reported to affect prognosis in lung cancer, in a group of men taking part in a recent trial (Anthony et al. 1978). In patients with squamous carcinoma the lymphocyte count at diagnosis was a genuine correlate of survival, those with higher counts living longer. Patients who had smoked more heavily were younger when their tumours were found, had better differentiated carcinomas and longer survival. Those with poorer differentiation had weaker skin test reactivity but the expected shorter survival was seen only when controls for symptom pattern history and resectability were applied. These data could be explained by control of tumour extension by cell-mediated immunity, earlier induction of better differentiated tumours in heavier smokers, more insidious onset of symptoms in those with better differentiated tumours and the depression of cell-mediated immunity by poorly differentiated tumours. In contrast, the longer survivors among patients with oat cell carcinoma had lower lymphocyte and monocyte counts at the time of diagnosis. Lymphocyte and monocyte counts contributed independently to survival in keeping with oat cell carcinoma being lymphodependent (Prehn 1977) and resistant to immune cytolysis.