Prognostic significance of the size of central fibrosis in peripheral adenocarcinoma of the lung

Background. The prognostic significance of the characteristics of central fibrosis in peripheral adenocarcinoma of the lung has been reported. However, the prognostic significance of the size of central fibrosis has never been evaluated. Methods. A total of 100 consecutive surgically resected peripheral adenocarcinomas of the lung measuring 3.0 cm or less in maximum dimension were reviewed histologically, and the maximum dimension of central fibrosis was measured on conventional hematoxylin and eosin stain. Results. Median follow-up for patients alive was 54 months. The overall 5-year survival rate was 75%. Twenty-one patients with adenocarcinoma having central fibrosis 5 mm or smaller in maximum dimension had a 5-year survival rate of 100%, whereas the other 79 patients had a 5-year survival less than 70%. Multivariate analysis showed the size of central fibrosis to be an independent prognostic factor as significant as vascular invasion and locoregional lymph node metastasis (p = 0.010, 0.024, and 0.024, respectively). Conclusions. The size of central fibrosis is an independent prognostic factor in peripheral lung adenocarcinoma, as significant as the well-established prognostic factors vascular invasion and lymph node metastasis.