Age and smoking as risk factors for malignancy in patients with peripheral solitary pulmonary nodules

Abstract

The objectives of the present study were to find if there is any correlation between patients' age, tobacco smoking and tumour malignancy and determine if these variables should be considered risk factors for malignancy.Patients and methods: The study included 145 patients with peripheral pulmonary tumours of less than 3 cm in diameter that received a video-assisted thoracoscopic (VATS) resection for tissue diagnosis between 1997 and 2009. Results: The mean patients' age was 62.60 ± 0.95 years. The youngest patient was 17 years old, and the oldest - 82 years old. The study sample included 61 women and 84 men; the men were statistically significantly more than the women (57.3% and 42.07%, respectively) (t=2.74 , P<0.01). Of the 145 patients we operated, 69 (47.59%) had benign tumours, and 76 (52.41%) – malignant; of the latter, 41 (53.95%) had a primary lung carcinoma and 35 (46.05%) - lung metastases. All lesions had a diameter that was in the range of 0.30 cm to 3 cm (mean 1.41 ± 0.06 cm). Malignant tumours were found to have their peak in the age between 61 and 70 years followed by tumours in patients over 70 years (χ²=14.06, df=6, P=0.029 ). The malignant tumours found in smokers were 48.2%, which is about 2.5 times higher than the malignant lesions found in non-smokers (19.4 %). Conclusion:  The results we had in this study suggest that age over 60 and tobacco smoking  are statistically significant risk factors for malignancy.

Key words: solitary pulmonary nodule, age, smoking, malignancy