Prognostic significance of [¹⁸F]fluorodeoxyglucose uptake on positron emission tomography in patients with pathologic stage I lung adenocarcinoma

BACKGROUND. [¹⁸F]Fluoro-2-deoxyglucose uptake on positron emission tomography (FDG-PET) has been frequently used for diagnosis and staging of lung cancer. The prognostic significance of FDG uptake on PET was evaluated in patients with pathologic Stage I lung adenocarcinoma (tumor stages were based on the TNM classification of the International Union Against Cancer). METHODS. Disease-free survival of 98 patients with pathologic Stage I lung adenocarcinoma who were treated by curative resection was examined in relation to sex, age, histologic grade of differentiation, surgical procedure, tumor stage, and FDG uptake measured as the maximum standardized uptake value (SUV). RESULTS. Sixty-three patients were had Stage IA disease and 35 patients had Stage IB disease. Six patients each with Stage IA and Stage IB disease developed disease recurrence after a mean postsurgical follow-up period of 31 months. Ten (23%) of the 43 patients with SUV ≥ 3.3 developed a recurrence compared with 2 (4%) of the 55 patients with SUV < 3.3 (P = .020). Ten (20%) of the 51 patients with moderately or poorly differentiated adenocarcinoma developed disease recurrence, compared with 2 (4%) of the 47 patients with well-differentiated adenocarcinoma (P = .056). Multivariate analysis demonstrated that histologic grade of differentiation was not correlated with the frequency of tumor recurrence (P = .286), whereas SUV was found to be marginally correlated (P = .079). CONCLUSIONS. FDG uptake appears to be predictive of disease-free survival in patients with Stage I lung adenocarcinoma. FDG uptake could yield important information for determining the likely value of postoperative adjuvant chemotherapy in such patients.