Combined evaluation of preoperative FDG uptake on PET, ground-glass opacity area on CT, and serum CEA level: identification of both low and high risk of recurrence in patients with resected T1 lung adenocarcinoma

Abstract

Patients with the same pathological stage of lung adenocarcinoma display marked variability in postoperative recurrence. The aim of this study was to predict the postoperative prognosis in patients with small-sized pulmonary adenocarcinoma on the basis of FDG uptake on PET, the extent of ground-glass opacity (GGO) on CT, and serum carcinoembryonic antigen (CEA) levels. We evaluated 87 patients (40 men, 47 women; mean age 64 years, age range 42-84 years) with lung adenocarcinoma of 3.0 cm or smaller. The level of FDG uptake (low or high), the extent of GGO (GGO or solid), and serum CEA levels (<20 ng/ml or > or =20 ng/ml) were correlated with the pathological findings of cell dedifferentiation, aggressiveness, N factor, and the incidence of relapse. The patients were divided into the following four groups: those with the GGO pattern (group I, 13 patients), those with solid pattern and low FDG uptake (group II, 35 patients), those with solid pattern, high FDG uptake, and CEA <20 ng/ml (group III, 32 patients), and those with solid pattern, high FDG uptake, and CEA > or =20 ng/ml (group IV, 7 patients). The incidence of cell dedifferentiation, aggressiveness, and lymph node metastasis were significantly different among the groups (p<0.0001); . The 5-year disease-free survival rates were 100% in group I, 80.1% in group II, 43.7% in group III, and 16.7% in group IV (p<0.0001). Combined evaluation of preoperative FDG uptake, GGO, and serum CEA level may enable patients with T1 lung adenocarcinoma at low risk and at high risk of postoperative recurrence to be identified.