Indeterminate pulmonary nodules in rectal cancer: A recommendation for follow‐up guidelines

Abstract

Incidental visualization of indeterminate pulmonary nodules is considered a clinical dilemma. We identified patients for inclusion in this study by searching for the term "indeterminate nodules" in the radiology database of rectal cancer patients who underwent surgery. Patients with definite metastatic disease were excluded. In total, 224 patients underwent chest computerized tomography (CT) and 59 of these patients had indeterminate pulmonary nodules detected more than twice by CT scan. Six patients (10.2%) were confirmed to have metastatic lesions on follow-up evaluation. Pulmonary nodule size (P=0.028), pathologic N status (P=0.049), positive nodal status (P=0.036) and the number of positive lymph nodes (P=0.033) were significant risk factors for pulmonary metastasis. In the pulmonary metastasis group, the patients who had received adjuvant oxaliplatin-based (FOLFOX4) chemotherapy had longer intervals to developing metastasis compared to patients who had not received it. It is not necessary to perform excessive surveillance routinely for all rectal cancer patients who have indeterminate pulmonary lesions. Intensive follow-up chest CT or other invasive diagnostic modalities should be considered only in patients with pulmonary nodules larger than 5.7 mm or positive nodal status. In addition, patients receiving adjuvant FOLFOX4 chemotherapy should be followed-up for longer periods.