Woohyun Jung1, Jin-Haeng Chung2, Sungwon Yum1, Kwhanmien Kim3, Choon Taek Lee4, Sanghoon Jheon3, Sukki Cho5. 1. Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seoul, Republic of Korea. 2. Department of Pathology, Seoul National University Bundang Hospital, Seoul, Republic of Korea; Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea. 3. Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seoul, Republic of Korea; Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea. 4. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. 5. Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seoul, Republic of Korea; Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: skcho@snubh.org.
Abstract
OBJECTIVES: We evaluated the differential prognostic impact of spread through air spaces (STAS) in early-stage lung adenocarcinoma after lobectomy according to the pT descriptor. METHODS: The study population included 506 patients who underwent lobectomy with mediastinal lymph node dissection for pT1b, pT1c, and pT2a adenocarcinoma between 2011 and 2016. We divided the study population into 2 groups according to STAS status, ie, STAS (+) versus STAS (-), and stratified them according to the pT descriptor. A Cox proportional hazard model and inverse probability of treatment weight-adjusted Kaplan-Meier curves were used to evaluate the prognostic impact of STAS on recurrence-free survival (RFS) and its independency in each stratum. RESULTS: Multivariable Cox proportional hazard regression analysis demonstrated that in pT1b and pT1c strata, STAS (+) patients had a 7.02-fold and 2.89-fold greater risk of recurrence than STAS (-) patients, respectively. However, in the pT2a stratum, STAS did not affect RFS. And the RFS of the STAS (+) pT1b/c strata was similar to that of the pT2a stratum. In the pT1b/c strata, inverse probability of treatment weighting-adjusted Kaplan-Meier curves also showed that RFS was significantly worse when STAS was present. Furthermore, the risks for locoregional and distant recurrence were both greater when STAS was present. CONCLUSIONS: The presence of STAS increased the risk of recurrence independently from other poor prognostic factors in patients with pT1b/cN0M0 adenocarcinoma who underwent lobectomy, but not in pT2a patients. The presence of STAS in pT1b/cN0M0 adenocarcinoma was associated with a similar risk of recurrence to that of pT2aN0M0 adenocarcinoma.
OBJECTIVES: We evaluated the differential prognostic impact of spread through air spaces (STAS) in early-stage lung adenocarcinoma after lobectomy according to the pT descriptor. METHODS: The study population included 506 patients who underwent lobectomy with mediastinal lymph node dissection for pT1b, pT1c, and pT2a adenocarcinoma between 2011 and 2016. We divided the study population into 2 groups according to STAS status, ie, STAS (+) versus STAS (-), and stratified them according to the pT descriptor. A Cox proportional hazard model and inverse probability of treatment weight-adjusted Kaplan-Meier curves were used to evaluate the prognostic impact of STAS on recurrence-free survival (RFS) and its independency in each stratum. RESULTS: Multivariable Cox proportional hazard regression analysis demonstrated that in pT1b and pT1c strata, STAS (+) patients had a 7.02-fold and 2.89-fold greater risk of recurrence than STAS (-) patients, respectively. However, in the pT2a stratum, STAS did not affect RFS. And the RFS of the STAS (+) pT1b/c strata was similar to that of the pT2a stratum. In the pT1b/c strata, inverse probability of treatment weighting-adjusted Kaplan-Meier curves also showed that RFS was significantly worse when STAS was present. Furthermore, the risks for locoregional and distant recurrence were both greater when STAS was present. CONCLUSIONS: The presence of STAS increased the risk of recurrence independently from other poor prognostic factors in patients with pT1b/cN0M0 adenocarcinoma who underwent lobectomy, but not in pT2a patients. The presence of STAS in pT1b/cN0M0 adenocarcinoma was associated with a similar risk of recurrence to that of pT2aN0M0 adenocarcinoma.