Objective: Positron emission tomography has proven to be an invaluable tool for diagnosing and staging non-small cell lung cancer. The authors analyzed relationships between the preoperative maximum standardized uptake values (SUVmax) of masses and early recurrence rates in patients with stage I pulmonary adenocarcinoma.
Methods: One hundred and seven patients with stage I pulmonary adenocarcinoma who underwent curative resection between September 2003 and June 2007 were enrolled in this study. All patients underwent preoperative positron emission tomography (PET). The relation between mass SUVmax values and recurrence prior to May 2008 was analyzed retrospectively.
Results: At diagnosis 57 patients had stage Ia disease and 50 stage Ib disease. The overall recurrence rate was 16% (17/107). The patients were divided into quartiles by SUVmax values (group 1; SUVmax<1.2, group 2; 1.2</=SUVmax<2.4, group 3; 2.4</=SUVmax<4.6, and group 4; 4.6</=SUVmax). The 3-year disease-free survival (DFS) rate was significantly lower in higher SUVmax quartiles (i.e., 100%, 92%, 78% vs 62% for groups 1, 2, 3, and 4, respectively; p=0.000, log-rank test). The median SUVmax of the 74 patients with a tumor of </=3 cm was 2 (range 0.6-2.9), and among these patients, an SUVmax of </=2.0 was found to be correlated with a higher DFS rate (100% vs 79%, p=0.006). Thirty-three patients had a mass of >3 cm and a median SUVmax of 4 (range 2-19.9), and among these, an SUVmax of </=4.0 was also found to be correlated with a higher DFS rate (83% vs 46%, p=0.025).
Conclusions: Patients with higher preoperative SUVmax values have significantly higher recurrence rates. Our findings indicate that even in stage I adenocarcinoma patients, mass size and SUVmax are related to higher rates of recurrence, and thus, these patients require more attentive observation after curative resection.