The Effect of Obesity on Response to Neoadjuvant Therapy in Locally Advanced Gastric Cancer

The effect of obesity on response to neoadjuvant chemotherapy (NACT) remains unknown. We aimed to investigate the effect of obesity on response to NACT and survival in locally-advanced gastric cancer (GC).

From 2010 to 2019, 142 GC patients with clinical stage III disease who underwent curative surgery after NACT were enrolled. Patients were divided into 3 groups according to body mass index (BMI) as follows; BMI < 25 kg/m2, BMI = 25-30 kg/m2, and BMI > 30 kg/m2. The Mandard tumor regression grading system was used for tumor regression grade (TRG).

Of the 142 GC patients, 45(31.7%) were female. The median age was 58 years. BMI was < 25 kg/m2 in 60 (42.3%) patients, 25-30 kg/m2 in 44 (31%) patients, and > 30kg/m2 in 38 (26.8%) patients. The numbers of patients with TRGI-II, TRGIII, and TRGIV-V were 35 (24.6%), 44 (31%), and 63 (44.4%), respectively. There was no statistically significant difference among BMI groups in terms of disease-free survival (DFS) and overall survival (OS) (p = 0.919 and p = 0.398, respectively). According to TRG groups; mDFS was 46 months in TRG I-II, 28 months in TRG III, and 18 months in TRG IV-V (p <0.001). In multivariate analysis, presence of perineural invasion and lymphovascular invasion were the factors affecting TRG.

In our study, we found that pre-treatment obesity did not affect the TRG in clinical stage III GC patients. However, a better TRG status was associated with improved survival.
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