AUTHOR=Huang Jiao-Bao , Lu Jun , Wu Dong , Xu Bin-bin , Xue Zhen , Lin Guo-Sheng , Zheng Hua-Long , Shen Li-li , Lin Jia , Xie Jian-Wei , Wang Jia-Bin , Lin Jian-Xian , Chen Qi-Yue , Cao Long-Long , Zheng Chao-Hui , Huang Chang-Ming , Li Ping 

TITLE=Is Adjuvant Chemotherapy Beneficial to All Patients With pT3N0M0 Stage Gastric Cancer?

JOURNAL=Frontiers in Oncology

VOLUME=Volume 11 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2021.712432

DOI=10.3389/fonc.2021.712432

ISSN=2234-943X

ABSTRACT=Abstract
Background:Whether adjuvant chemotherapy (AC) for patients with gastric cancer pT3N0M0 is beneficial remains controversial.
Methods:We prospectively collected and retrospectively analyzed 235 patients with pT3N0M0 gastric cancer who underwent radical resection between February 2010 and January 2016.They were divided into two groups: the surgery-alone (SA) group(n=82)and the AC group(n=153). We analyzed the effects of AC on the overall survival(OS) and recurrence-free survival(RFS),and the relationship between the number of chemotherapy cycles (CC) and the recurrence rate (RR). 
Results:The 5-year OS and RFS of the participants were 80.9% and 87.7%, respectively.The OS in the AC group was significantly higher than in the SA group (86.9% versus 69.5%, p=0.003). The RFS of the AC and the SA groups were 88.9% and 85.4%, respectively, which were not significantly different(p=0.35).The independent risk factors affecting OS were perineural invasion-positive(PNI+)(HR=2.64, 95%CI: 1.45-4.82, p=0.003) and age ≥65 years (HR=2.58, 95%CI:1.39-4.8, p=0.003).The independent risk factor for RFS was also PNI+(HR=3.11, 95%CI: 1.48-6.54, p=0.003). Stratified analysis revealed that postoperative AC can significantly improve the OS of PNI+ patients (AC group versus SA group: 84.1% versus 45.5%, p=0.001) and RFS (86.4%vs63.6%, p=0.017).However,perineural invasion negative(PNI-) patients did not get the same results (p=0.13andp=0.48, respectively). According to the number of CC,Divided into CC＜3 groups and CC≥3 groups.The cumulative RR in the CC≥3 group of patients with PNI+ was significantly lower than that of the CC＜3 group(7.4%versus28.2%,p=0.037). 
Conclusion: For pT3N0M0 gastric cancer patients with PNI+,at least three cycles of postoperative AC can significantly reduce the overall RR. This finding should be verified using large external sample data.