Our objective was to examine the association between 18F-fluorodeoxyglucose (FDG) uptake on PET scan and prognosis in patients with surgically treated, clinical stage IA non-small cell lung cancer (NSCLC).
We reviewed data collection forms and Veterans Affairs administrative records of 75 patients with surgically treated, stage IA NSCLC who were enrolled in a prospective study of PET imaging from 1999 to 2001. We used Cox proportional hazards analysis to examine the association between FDG uptake and survival 4 years following enrollment.
Most patients were men (97%), and the mean age was 68 ± 9 years. Almost half of the patients (44%) had adenocarcinoma, and 35% underwent a sublobar resection. The mean maximum standardized uptake value (SUVmax) was 4.9 ± 2.5 in survivors and 7.1 ± 3.9 in nonsurvivors (P = .045). Before and after adjustment for age, tumor size, histology, and type of resection, the hazard of death was significantly higher in patients with squamous cell histology (adjusted hazard ratio [HR], 4.54; 95% CI, 1.09-18.9) and those with higher degrees of FDG uptake (adjusted HR, 1.21 per 1 unit increment; 95% CI, 1.01-1.45). At a threshold value of 5 for SUVmax, 34 of 39 patients (87%) with low FDG uptake survived, compared with only 24 of 36 patients (67%) with high FDG uptake (P = .04). Visual assessment of FDG uptake was not associated with an increased hazard of death (HR 0.66; 95% CI, 0.19-2.29).
High FDG uptake as measured by SUVmax identifies individuals with clinical stage IA NSCLC who are at increased risk of death following surgery. Such high-risk patients may be good candidates for participation in future trials of adjuvant therapy.