Stage I nonsmall cell lung carcinoma: analysis of survival and implications for screening.

BACKGROUND: Skepticism about the radical curability of lung carcinoma, even when diagnosed in Stage I, has been long fostered by the epidemiologists' dogma against lung cancer screening, and by official recommendations not to screen for lung carcinoma. Follow-up of patients with asymptomatic screen-detected Stage I nonsmall cell lung carcinoma (NSCLC), however, shows that patients who underwent radical resection have long term survival rates, whereas patients nonsurgically treated or undergoing suboptimal operations have much poorer prognosis. The latter clinical outcome data strongly suggest the importance of detecting lung carcinoma when it is in Stage I and cast serious doubts on the recommendation not to screen for lung carcinoma. DATA: The scrutiny of the biology, epidemiology, and clinical features of Stage I NSCLC clarifies important aspects of the ongoing controversy concerning the value of screening for early diagnosis (Stage I) of lung carcinoma. The biologic characteristics of Stage I NSCLC (histologic types, doubling time, metastases) indicate its malignant potential. The asymptomatic screen-diagnosed Stage I carcinomas have longer doubling time than the more advanced cancers; nevertheless, they are not overdiagnosed tumors because they cause fatal outcome if they are not resected. Chest X-ray screening identifies approximately 50% of cancers in Stage I. Screening by helical low dose computed tomography scan detects greater than 80% of lung carcinomas in Stage I. The resectability, the surgical techniques (lobectomy vs. limited resections), and the influence of the extent of surgical resection of Stage I NSCLC on prognosis are reviewed. These data show that radical surgical treatment offers 5-year survival rate to 60-80% of patients with Stage I NSCLC. SYNTHESIS: Asymptomatic Stage I lung carcinomas, detected by screening or by incidental findings, are truly malignant, because they metastasize and cause fatal outcome if they are not radically resected. The possibility to cure lung carcinomas relies on radical resection (lobectomy or, less frequently, pneumonectomy) of early diagnosed (Stage I) disease, which is usually asymptomatic. The limited parenchymal resections (segment or wedge resections) do not fulfill the requirements of radicality because they are accompanied by higher incidence of local recurrences and shorter survival rates.
CONCLUSIONS: The documented improvement of long term survival of NSCLC, which can be achieved by early diagnosis and radical resection, strongly indicates that the current dogma against lung cancer screening is untrue. Every effort should be made to detect the disease when it is in Stage I and radically operable, by implementing screening in at risk smokers and former smokers, with the most effective screening method that is locally available.