Predictors of primary lung cancer in a solitary pulmonary lesion after a previous malignancy.

OBJECTIVE

A solitary pulmonary lesion in patients with a history of malignancy may be either primary lung cancer or a metastatic lung tumor or benign nodule. We retrospectively examined the preoperative predictive factors for determining the type of pathology.

METHODS

We used an exact logistic regression analysis to identify radiological and clinical predictors of primary lung cancer. The study included 187 patients who underwent pulmonary resection for a solitary pulmonary lesion and had received previous treatment for a malignancy.

RESULTS

There were 107 patients with primary lung cancer, 74 with metastatic lung tumors, and 6 with benign lesions. The previous malignancy included colorectal cancer in 71 patients. A disease-free interval exceeding 5 years and ground-glass opacity were found in 27.0% (20/74) and 1.4% (1/74) of metastatic lung tumors, respectively. Multivariate logistic regression analysis demonstrated that spiculation [adjusted odds ratio (a-OR), 1.74; 95% confidence interval (CI), 1.09-2.86], pleural indentation (a-OR 1.99, 95% CI 1.24-3.29), and ground-glass opacity (a-OR 5.28, 95% CI 2.61-13.1) on high-resolution computed tomography, maximum standardized uptake value (a-OR 1.14, 95% CI 1.02-1.29), current and former smokers (a-OR 1.96, 95% CI 1.21-3.30), and previous malignancy other than colorectal cancer (a-OR 2.02, 95% CI 1.26-3.37) were associated with primary lung cancer.

CONCLUSIONS

A combination of radiological findings, smoking history, and type of previous malignancy can improve the ability to predict primary lung cancer in the presence of a solitary pulmonary lesion that appears after previous treatment for a malignancy.