Toronto, Canada—Survival is not improved with routine surveillance using computed tomography (CT) versus chest x-ray in patients who have undergone resection for stage I non–small-cell lung cancer (NSCLC), according to the results of a new analysis presented at the 2014 American Association for Thoracic Surgery meeting.
Lead investigator Traves D. Crabtree, MD, Associate Professor of Surgery, Division of Cardiothoracic Surgery, Washington University, St Louis, MO, and colleagues, reviewed the records of 554 patients who had undergone resection for stage I NSCLC between January 2000 and April 2013 at their institution. A total of 232 patients underwent routine postoperative CT surveillance, and 322 patients had routine chest x-ray surveillance. Of these, 149 patients were excluded from the analysis, because they had not been followed up with only CT or chest x-ray.
The median follow-up was 2.5 years (range, 0.3-9.9 years) for the CT group and 3.5 years (range, 0.1-13.1 years) for the chest x-ray group. The 5-year postoperative overall survival (OS) rates were 67.8% in the CT group and 74.8% in the chest x-ray group. Overall, 22% of patients who had chest x-rays were found to have lung malignancy versus 27% of patients in the CT group. The mean time from original lung resection to the diagnosis of the successive malignancy was 1.93 years for the patients receiving CT and 2.56 years for patients in the chest x-ray group.
A Cox proportional hazard survival analysis showed that the type of imaging was not a significant predictor of survival. Rather, the significant predictors of survival included increasing age, higher Charlson Comorbidity Index, and sublobar versus lobar resection.
A propensity score-matching analysis also revealed no differences in survival between the patients followed with CT versus chest x-ray.
The 5-year OS rates from surgery among patients who were diagnosed with a successive malignancy were 33.5% for the CT group and 40.2% for the chest x-ray group. Among 63 patients having a CT with a successive malignancy, 29 (46%) were treated with curative intent; for the 72 patients having chest x-ray, 31 (43%) were treated with curative intent.
However, a significant difference between the 2 groups was found in the mean time from surgery to the diagnosis of a successive malignancy: 2 years for patients in the CT group versus 3.5 years for patients in the chest x-ray group.
“A randomized, controlled trial would help determine the impact of postoperative surveillance strategies on survival,” concluded Dr Crabtree and his colleagues in their write-up of the results.
