An audit of prognostic significance of histological subtype in surgically resected adenocarcinomas

Introduction: Lung adenocarcinoma accounts for around 50% of all non-small cell lung cancer (NSCLC) in the UK. Prognosis in lung adenocarcinoma have been shown to be highly variable depending on histological subtype, irrespective of stage at diagnosis. Adenocarcinoma in situ (AIS), minimally invasive (MIA) and lepidic predominant adenocarcinomas have significantly better post-operative survival at 5 years (93%) compared to Papillary (71%), Acinar (68%), Solid (39%) and Micropapillary (MP) (38%) predominant adenocarcinomas. Aim: To determine whether histological subtype of adneocarcinoma affects prognosis following surgical resection Methods: We retrospectively reviewed the histological subtype of all patients with adenocarcinoma who underwent surgical resection over a 3 year period. Results: 79 patients underwent surgical resection for NSCLC. 40/79 were adenocarcinomas. 13/79(16%) relapsed within 3 years. 8/13(62%) were adenocarcinomas. Relapse group (8): 4/8(50%) Acinar/Papillary group, 4/8 (50%)MP/Solid group. Non-relapse (31*): 2/31(7%) AIS/MIA/Lepidic group, 14/31(45%) Acinar/Papillary group, 15/31(48%)MP/Solid group. *1 patient was excluded from the data Conclusions: Correlation of post-operative survival with predominant histological subtype of adenocarcinoma has been shown to demonstrate significant differences in survival at 5 years. Our data over a 3 year period shows a similar distribution of intermediate and high risk subtypes between the sub-group that relapsed following surgical resection and those that didn9t. This data suggests that histological subtype is not predictive of relapse at 3 years however further analysis is required to assess outcomes at 5 years.