Mutational characteristics of young and elderly gastric cancer: a comparative study

Long Li; Yin Li; Li Lin; Yanling Liu; Linshan Duan; Dan Wang; Shuyu Cheng; Guoyan Liu

doi:10.21037/jgo-21-934

Mutational characteristics of young and elderly gastric cancer: a comparative study

J Gastrointest Oncol. 2022 Feb;13(1):77-83. doi: 10.21037/jgo-21-934.

Authors

Long Li^#¹, Yin Li^#², Li Lin^#³, Yanling Liu^#⁴, Linshan Duan⁴, Dan Wang¹, Shuyu Cheng¹, Guoyan Liu^{1

4

5}

Affiliations

¹ Medical College of Xiamen University, Xiamen University, Xiamen, China.
² Xiamen International Travel Healthcare Center, Xiamen, China.
³ Department of Gastrointestinal Surgery and Xiamen City Key Laboratory of Gastrointestinal Cancer, Zhongshan Hospital, Xiamen University, China.
⁴ School of Pharmaceutical Sciences, Xiamen University, Xiamen, China.
⁵ Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen, China.

^# Contributed equally.

Abstract

Background: Young gastric cancer (YGC) has been indicated as having a worse prognosis than in elderly gastric cancer (EGC). It has been reported that YGC and EGC patients show different genomic profiles; however, there has been no comparative study conducted to reveal their mutational characteristics.

Methods: Firstly, we divided and analyzed the mutational landscape and 50 cancer-related genes characters of YGC (n=18) and EGC (n=18) patients from The Cancer Genome Atlas-Stomach Adenocarcinoma (TCGA-STAD). A total of 8 gastric cancer samples including 4 YGC and 4 EGC patients were collected to detect 50 cancer-related genes by multiplex polymerase chain reaction (PCR) next generation sequencing. The R/maftools package was used to describe the mutational characteristics.

Results: Our results showed that the EGC group harbored more mutations than the YGC group. In 50 cancer-related genes in our cohort, the YGC group tended to be different from the EGC group using multiplex PCR next generation sequencing. In the YGC group, candidate mutations were identified within the following genes: IDH2, PDGFRA, KRAS, FLT3, FGFR2, and FGFR3. The YGC group showed less tumor mutational burden (TMB) level then EGC.

Conclusions: The YGC group tended to be more sensitive to molecularly targeted therapy because of it having more somatic mutations in 50 cancer-related genes using targeted next-generation sequencing.

Keywords: Young gastric cancer (YGC); elderly gastric cancer (EGC); molecularly targeted therapy; targeted next-generation sequencing; tumor mutation burden (TMB).