Retrospective Cohort Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 14, 2015; 21(22): 6905-6913
Published online Jun 14, 2015. doi: 10.3748/wjg.v21.i22.6905
Clinicopathologic and molecular features associated with patient age in gastric cancer
Ji Yeon Seo, Eun Hyo Jin, Hyun Jin Jo, Hyuk Yoon, Cheol Min Shin, Young Soo Park, Nayoung Kim, Hyun Chae Jung, Dong Ho Lee
Ji Yeon Seo, Department of Internal Medicine and Healthcare Research Institute, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul 135-984, South Korea
Eun Hyo Jin, Hyun Chae Jung, Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul 110-744, South Korea
Hyun Jin Jo, Hyuk Yoon, Cheol Min Shin, Young Soo Park, Nayoung Kim, Dong Ho Lee, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do 463-707, South Korea
Author contributions: Seo JY and Lee DH designed the research; Seo JY and Jin EH performed the research; Seo JY, Jo HJ, Yoon H and Shin CM analyzed and interpreted data; Seo JY and Lee DH wrote the paper; Seo JY, Park YS, Kim N, Jung HC and Lee DH critically reviewed the manuscript.
Ethics approval: This study protocol was approved by the Ethical Committee at the Seoul National University Bundang Hospital (IRB number: B-1403/244-116).
Informed consent: Informed consent was exempted, which was approved by the Ethical Committee at the Seoul National University Bundang Hospital.
Conflict-of-interest: There are no potential conflicts of interest to disclose.
Data sharing: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dong Ho Lee, MD, PhD, Department of Internal Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea. dhljohn@yahoo.co.kr
Telephone: +82-31-7877006 Fax: +82-31-7874051
Received: November 17, 2014
Peer-review started: November 18, 2014
First decision: December 11, 2014
Revised: January 10, 2015
Accepted: February 11, 2015
Article in press: February 11, 2015
Published online: June 14, 2015
Processing time: 213 Days and 2.9 Hours
Abstract

AIM: To compare characteristics and prognosis of gastric cancer based on age.

METHODS: A retrospective study was conducted on clinical and molecular data from patients (n = 1658) with confirmed cases of gastric cancer in Seoul National University Bundang Hospital (Seoul, South Korea) from 2003 to 2010 after exclusion of patients diagnosed with lymphoma, gastrointestinal stromal tumor, and metastatic cancer in the stomach. DNA was isolated from tumor and adjacent normal tissue, and a set of five markers was amplified by polymerase chain reaction to assess microsatellite instability (MSI). MSI was categorized as high, low, or stable if ≥ 2, 1, or 0 markers, respectively, had changed. Immunohistochemistry was performed on tissue sections to detect levels of expression of p53, human epidermal growth factor receptor (HER)-2, and epidermal growth factor receptor. Statistical analysis of clinical and molecular data was performed to assess prognosis based on the stratification of patients by age (≤ 45 and > 45 years).

RESULTS: Among the 1658 gastric cancer patients, the number of patients with an age ≤ 45 years was 202 (12.2%; 38.9 ± 0.4 years) and the number of patients > 45 years was 1456 (87.8%; 64.1 ± 0.3 years). Analyses revealed that females were predominant in the younger group (P < 0.001). Gastric cancers in the younger patients exhibited more aggressive features and were at a more advanced stage than those in older patients. Precancerous lesions, such as atrophic gastritis and intestinal metaplasia, were observed less frequently in the older than in the younger group (P < 0.001). Molecular characteristics, including overexpression of p53 (P < 0.001), overexpression of HER-2 (P = 0.006), and MSI (P = 0.006), were less frequent in gastric cancer of younger patients. Cancer related mortality was higher in younger patients (P = 0.048), but this difference was not significant after adjusting for the stage of cancer.

CONCLUSION: Gastric cancer is distinguishable between younger and older patients based on both clinicopathologic and molecular features, but stage is the most important predictor of prognosis.

Keywords: Age; Gastric cancer; Microsatellite instability; Molecular pathology; Prognosis; Stage

Core tip: Whether gastric cancer exhibits distinguishable characteristics based on age remains controversial. In this original article, results are presented that highlight differences in clinical characteristics, pathology, and molecular features of younger and older gastric cancer patients. In particular, the pathologic degree of precancerous lesions associated with each group illuminated potential differences in the pathogenesis of the disease. Although gastric cancer in younger patients presented with more aggressive features, the primary factor in predicting the prognosis of patients with the disease was the stage of the cancer, and not the age of the patient.