Reasons for the delays in the definitive diagnosis of lung cancer for more than one year from the recognition of abnormal chest shadows.

OBJECTIVE: Primary lung cancer generally has a poor prognosis if not diagnosed at an early stage. But some lung cancers grow very slowly. In particular, adenocarcinoma is sometimes observed for years with no change of tumor size. In this study, we examined the reasons for the delays in reaching a definitive diagnosis of lung cancer.

METHODS: We retrospectively reviewed primary lung cancer cases between January 1995 and December 1999 and examined those whose definitive diagnoses were delayed for more than a year.

RESULTS: A total of 222 primary lung cancers were diagnosed. Of those, 19 patients (group A, 8.6%) were diagnosed after more than a year, and the other 203 (group B, 91.4%) were diagnosed within one year. The proportion of women in group A was significantly higher than that in group B (p<0.05). The mean age of group A was significantly younger than that of group B (p<0.05). The Brinkman Index of group A was significantly lower than that of group B (p<0.05). The histologic types were significantly different between the two groups (p<0.05). In group A, 18 patients (94.7%) had adenocarcinomas. Five primary reasons for the delays in group A were identified: 1) Four patients were tentatively diagnosed as inflammation or benign tumor on CT and were consequently not followed-up. 2) The chest CT shadows in 6 patients were suspected lung cancers but transbronchial lung biopsy findings did not show malignancy. 3) Four patients were tentatively diagnosed as inflammation or benign tumor on CT, but the tumors showed only very slow growth or no change at all. 4) The chest CT shadows of 2 patients were suspected lung cancer, but the patients refused to undergo video-assisted thoracic surgery (VATS) or closer examination. 5) Three patients did not consult medical facilities for a second examination.

CONCLUSIONS: Many of the adenocarcinomas reviewed in our study grew slowly or remained unchanged for years. Doctors are mainly responsible for the delays in the definitive diagnosis and should aggressively perform VATS or closer examinations without hesitation.