Prognostic value of FDG uptake in early stage non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) has a poor prognosis even for early stages of the disease (stage I and II). We studied the prognostic value of PET FDG in patients with completely resected stage I and II NSCLC. METHODS: Retrospective study of 96 patients with NSCLC whose staging included 18F-FDG PET (fluoro deoxy glucose positron emission tomography). Histopathological stage was either stage I (75) or stage II (n=21). FDG uptake was measured as maximal standardized uptake value for body weight (SUVmax). Mean follow-up was 45+/-30 months (1-142 months). Overall and cancer-free survival rates were recorded. RESULTS: SUVmax were higher for stage II than for stage I (10.5+/-4.5 vs 8.5+/-5, p=0.04). Mean tumor volumes were equivalent for both stages (33 cm3, p=0.18), excluding a partial volume effect. The median SUVmax in the whole study population was 7.8. The median survival was significantly longer in patients with a lower (SUVmax7.8 (p=0.001). For stage II tumors (n=21), no statistical difference was observed: 72 months vs 40 months for SUVmax7.8, respectively (p=0.11), although there was a clear trend towards reduced survival for highly metabolic tumors. Disease-free survival was also significantly better for lower metabolic tumors: 96.1 months vs 87.7 months (p=0.01). CONCLUSION: High FDG uptake is associated with reduced overall survival and disease-free survival of patients with completely resected stage I-II NSCLC. Whether patients with highly metabolic tumors should undergo a closer postoperative surveillance or adjuvant chemotherapy has to be addressed in a properly designed prospective trial.

Intra-tumoral vascular or perineural invasion as prognostic factors for long-term survival in early stage non-small cell lung carcinoma.

OBJECTIVE: In recent studies focusing on the prognostic significance of histologic features of NSCLC tumors, vessel invasion was correlated to survival across all surgical stages. We similarly analyzed whether intra-tumoral permeation could affect survival in subgroups of stage I and II NSCLC. METHODS: A retrospective single institution analysis of a prospectively computed database. Specimens were analyzed for intra-tumoral vascular, lymphatic and nervous permeation. Overall mortality was determined and for each stage, a Cox regression analysis of selected variables was performed. Detailed histologic information was available in all patients. Follow-up was 100% complete (median=69 months). RESULTS: From 1989 to 2004, out of 346 patients with stage I and II NSCLC, 253 patients with p stage I (75.7%) and 81 patients with p stage II (24.3%) underwent surgery with complete resection, for a completeness resection rate of 97% (334/346). We performed 70 pneumonectomies, 255 lobectomies and 9 lesser resections (respectively, 21%, 76.3% and 2.7%). In-hospital mortality was 2.1%. The incidence of intra-tumoral permeation was 14.4% (48/334). Permeation correlated both with T status (p=0.04), grade of differentiation (p=0.03) and stage (p=0.02). Median survival and overall 5-year survival for patients with and without permeation were 42.3 months (95% CI [20-64.6]) and 72.1 months (95% CI [56.9-87.2]), respectively; and 44% and 54%, respectively (p=NS). However, intra-tumoral permeation was not a significant predictor for overall death (HR=1.1 [95% CI=0.74-1.66). CONCLUSION: In this large institutional study of early stage NSCLC, the presence of intra-tumoral permeation was correlated both to T, grade of differentiation, as well as to stage. However, in contrast to recent reports, we did not find that intra-tumoral permeation adversely affects long-term survival.