P30.03 Impact of Visceral Pleural Invasion (VPI) and lymphovascular Invasion (LVI) on Stage I Non-Small Cell Lung Cancer (NSCLC) Outcomes

Abstract

Stage I patients (pts) have 5-year survival ranging 50-75% suggesting heterogeneity within. While American Joint Committee on Cancer 8th edition upstages tumors with visceral pleural invasion (VPI) to IB, other histological features specifically lymphovascular invasion (LVI) are not accounted for in current staging. However, there is data to suggest that LVI increases risk for recurrence. Guidelines such as NCCN recommend consideration of adjuvant chemotherapy for patients with VPI and LVI despite convincing data to support this. We conducted a retrospective study of patients with stage I lung cancer who had LVI and/or VPI to understand their outcomes. 267 resected stage I cases from 2015-2019 were included. Medical records were reviewed for demographics, smoking history, histological features, TNM staging (AJCC edition 7), disease recurrence, systemic treatment, and date of death. Data lock occurred January 2020. Patients were considered lost-to-follow-up if their last visit occurred in 2018 or earlier. Chi-square test was used to compare proportions. Median age was 69 years (range 44-91). Majority were female (58.4%), smokers (77.9%), & had adenocarcinoma (77.5%). 142 (53.2%) pts had lobectomy while 125 (46.8%) had sub-lobar resection. 216 (80.9%) were pathological stage Ia and 51 (19.1%) were stage Ib. 33 (12.0%) had chemotherapy. Recurrence & death from any cause occurred in 25 (9.3%) & 19 (7.1%) pts respectively. Median follow-up (FU) of the total cohort was 22.4 months (mos) (range 0.0-75.1 mos), with 23.9 mos (0.0-75.1) for pts with stage Ia disease and 26.1 mos (range 1.2-62.9) for patients with stage Ib. 83 (31.1%) pts were considered lost to follow up, of those 64 (24.0%) were with stage Ia disease and 19 (7.1%) with stage Ib disease. Data comparing LVI/VPI positive to negative populations is presented in the table below.Tabled 1LVI/VPI statusAdjuvant Chemo No. (%)Recurrence No. (%)P valueAll-Cause-Mortality No. (%)P valueStage Ia N=216+ N=21 (9.7%)3 (22.1%)4 (22.2%)P= 0.0323 (14.3%)P=0.126- N=195 (90.2%)13 (6.7%)12 (6.2%)11 (5.6%)Stage Ib N=51+ N= 29 (56.8%)9 (31.0%)1 (3.4%)P= 0.0344 (13.8%)P=0.271- N= 22 (43.1%)8 (36.4%)5 (22.7%)1 (4.5%) Open table in a new tab More stage Ib pts were found to have VPI and/or LVI on pathology than Ia pts (p=0.00001), & more LVI/VPI positive (of stage Ia and Ib) pts received adjuvant chemotherapy (p=005535). Limitations include retrospective nature, sample size, and accuracy of follow-up. A multivariate analysis was not performed due to small sample size.