Ichikawa T, et al. - Whether the proportion of cancer cells to non-cancerous stroma within the invasive area is related to the prognosis of patients with lung adenocarcinoma, was assessed. Findings suggested that in lung adenocarcinoma, a lower cancer cell to stroma ratio within the invasive area could be a significant prognostic factor. This suggested that not only the invasive size but also the invasive character might be an important histologic prognostic parameter.