Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jan 15, 2020; 12(1): 101-112
Published online Jan 15, 2020. doi: 10.4251/wjgo.v12.i1.101
Adenosquamous carcinoma may have an inferior prognosis to signet ring cell carcinoma in patients with stages I and II gastric cancer
Yu-Xin Chu, Hong-Yun Gong, Qin-Yong Hu, Qi-Bin Song
Yu-Xin Chu, Hong-Yun Gong, Qin-Yong Hu, Qi-Bin Song, Department of Oncology (Division I), Cancer Center, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
Author contributions: Chu YX drafted the manuscript; Gong HY performed data extraction; Hu QY performed statistical analysis; and Song QB supervised the study.
Supported by the National Natural Science Foundation of China, No. 81670123 and No. 81670144.
Institutional review board statement: This study was approved by the Institutional Review Board of Wuhan University Renmin Hospital.
Informed consent statement: The patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: We have no financial relationships to disclose.
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/
Corresponding author: Qinyong Hu, MD, Academic Research, Department of Oncology I, Cancer Center, Renmin Hospital of Wuhan University, Jiefang Road No. 238, Wuhan 430060, Hubei Province, China. rm001223@whu.edu.cn
Received: August 30, 2019
Peer-review started: August 30, 2019
First decision: October 14, 2019
Revised: October 25, 2019
Accepted: October 31, 2019
Article in press: October 31, 2019
Published online: January 15, 2020
Abstract
BACKGROUND

Primary gastric adenosquamous carcinoma (ASC) is an exceedingly rare histological subtype. Gastric signet ring cell carcinoma (SRC) is a unique subtype with distinct tumor biology and clinical features. The prognosis of gastric ASC vs SRC has not been well established to date. We hypothesized that further knowledge about these distinct cancers would improve the clinical management of such patients.

AIM

To investigate the clinicopathological characteristics and prognosis of gastric ASC vs SRC.

METHODS

A cohort of gastric cancer patients was retrospectively collected from the Surveillance, epidemiology, and end results program database. The 1:4 propensity score matching was performed among this cohort. The clinicopathological features and prognosis of gastric ASC were compared with gastric SRC by descriptive statistics. Kaplan-Meier method was utilized to calculate the median survival of the two groups of patients. Cox proportional hazard regression models were used to identify prognostic factors.

RESULTS

Totally 6063 patients with gastric ASC or SRC were identified. A cohort of 465 patients was recruited to the matched population, including 370 patients with SRC and 95 patients with ASC. Gastric ASC showed an inferior prognosis to SRC after propensity score matching. In the post-matching cohort, the median cancer specific survival was 13.0 (9.7-16.3) mo in the ASC group vs 20.0 (15.7-24.3) mo in the SRC group, and the median overall survival had a similar trend (P < 0.05). ASC and higher tumor-node-metastasis stage were independently associated with a poor survival, while radiotherapy and surgery were independent protective factors for improved prognosis. Subgroup survival analysis revealed that the prognosis of ASC was inferior to SRC only in stages I and II patients.

CONCLUSION

ASC may have an inferior prognosis to SRC in patients with stages I and II gastric cancer. Our study supports radiotherapy and surgery for the future management of this clinically rare entity.

Keywords: Adenosquamous carcinoma, Signet ring cell carcinoma, Surveillance, Epidemiology, and End results, Propensity score matching, Prognosis, Survival

Core tip: The prognosis of gastric adenosquamous carcinoma (ASC) vs signet ring cell carcinoma (SRC) has not been well established to date. Our study used both propensity score matching method and multivariate Cox regression analysis to adjust the potential bias caused by the imbalanced distribution of confounding factors. We found that ASC may have an inferior prognosis to SRC in patients with stages I and II gastric cancer. Radiotherapy and surgery were proved to be independent protective factors for improving their prognosis.