Limited resection for clinical Stage IA non-small-cell lung cancers based on a standardized-uptake value index

Abstract

OBJECTIVES: In a previous study, we found that a standardized-uptake value (SUV) index obtained from positron emission tomography (PET)/computed tomography (CT) data was significantly correlated with prognosis in patients with pathological Stage I lung adenocarcinoma. However, this value has not been studied in early stage lung cancer patients undergoing limited resection. In this study, we investigated if an SUV index could be used to identify patients with clinical Stage IA lung cancers that were appropriate for limited resection. METHODS: This was a retrospective study of prospectively collected data from 183 patients with clinical Stage IA non-small-cell lung cancer undergoing both PET-CT examinations and surgery from May 2004 to December 2010. A corrected SUV was defined as the SUV index, which was calculated from the ratio of the tumour SUV(max) to the liver SUV(mean). The associations between survival, recurrence and several clinical factors, including the SUV index, were evaluated. RESULTS: The following pathological stages were identified: Stage IA (n = 133; 72.7%), Stage IB (n = 31; 16.9%), Stage IIA (n = 11; 6.0%), Stage IIB (n = 1; 0.5%) and Stage IIIA (n = 7; 3.8%). There were 50 upstaged cases (27.3%). The 5-year overall survival, 5-year cancer-specific survival and 5-year freedom from recurrence (FFR) rates after surgery were 83.5, 91.6 and 83.1%, respectively. Twenty-six (14.2%) patients developed recurrences. Multivariate analysis showed that an SUV index was a significant predictive factor for recurrence (P = 0.01). The 5-year FFR rates in patients with an SUV indices <1.0 and ≥1.0 were 100 and 77.1%, respectively (P < 0.01). The 5-year cancer-specific survival rates in patients with an SUV indices <1.0 and ≥1.0 were 100 and 88.7%, respectively (P = 0.04). CONCLUSIONS: In clinical Stage IA lung cancer patients, the SUV index was a significant predictive marker for recurrence. Patients with SUV indices <1.0 were less likely to have a recurrence. Thus, clinical Stage IA patients with SUV indices <1.0 should be candidates for limited resection.