Prognosis and morphometrical features of non-bronchioloalveolar cell adenocarcinoma: an assessment of the non-alveolar replacing area and high grade atypical area

Abstract

Aim: It has become obvious that the prognosis of bronchioloalveolar cell carcinoma (BAC) in small peripheral adenocarcinoma of the lung is good, but most cases actually treated as pulmonary adenocarcinoma in hospitals tend to be non-bronchioloalveolar cell carcinoma (non-BAC). The prognoses of non-BAC are greatly varied. We studied the relationships between the morphometrical features and the prognoses of non-BAC.

Methods: In total, 69 cases of non-BAC measuring ≤20 mm in diameter across their greatest dimension were evaluated. We considered that the non-alveolar replacing area and the high grade atypical area were related to the prognosis, and therefore defined the ratio of both areas to the total area at the maximum face of the tumours as the non-alveolar replacing area ratio (NAAR) and the high grade atypical area ratio (HAAR), respectively. We thereafter analysed the relationships between both ratios and the prognosis.

Results: The NAAR and HAAR were significantly higher in the recurrent cases than in the recurrence free cases. We divided the non-BAC cases at the centre of both ratios into two groups, high and low. The 5 year survival rate of the high NAAR and high HAAR group was 48.3%, while that of the low NAAR and low HAAR group was 72.2%. The groups showing high rates for both ratios had significantly worse prognoses. A multivariate analysis indicated that the HAAR contributes most to the prognosis.

Conclusions: These results suggest that the NAAR and HAAR are closely associated with the prognosis of non-BAC.