Eighth edition T category is prognostic: the size of the solid component matters, not the ratio

Kazutoshi Hamanaka, Takashi Eguchi, Kimihiro Shimizu


During the past two decades, the prevalence of ground- glass nodule (GGN) and small-sized lung cancer has increased due to the wider use of thin-section computed tomography (CT) and CT screening. Due to its association with smoking, squamous cell carcinoma used to be the most frequent histological type; however, the incidence of adenocarcinoma has recently increased to 60–70% of lung cancer histologic types. This is probably due to the increase in lung cancer patients without smoking history and the higher opportunity for resection of part-solid nodules with ground-glass opacity (GGO). The increasing prevalence of lung adenocarcinoma cases with part-solid nodules enabled many studies to identify the radiological features and oncological characteristics of these tumors. Further, the importance of solid components has been clarified and several studies have attempted to predict the postoperative prognosis using ratios as consolidation-to-tumor ratio (CTR) and tumor disappearance ratio (TDR) (1,2).