Published online Jan 15, 2020. doi: 10.4251/wjgo.v12.i1.101
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
Adenosquamous carcinoma (ASC) is a rare entity in gastric cancer, which exhibits early tumor progression and a poorer prognosis than other typical gastric adenocarcinoma. Gastric signet ring cell carcinoma (SRC) is a unique subtype with distinct tumor biology and clinical features. We hypothesized that further knowledge about these distinct cancers would improve the clinical management of such patients.
Given the relative rarity of these two subtypes in gastric cancer, the study on gastric ASC with large series is still lacking. The clinicopathological characteristics and prognosis of ASC vs SRC has not been well established to date. The current study adopted a large cohort of such patients from the Surveillance, Epidemiology, and End Results (SEER) database. Study on the clinicopathological features, treatment, and prognosis of such patients may bring deeper knowledge on these tumors and provide additional assistance for their treatment.
The goal of our study was to evaluate the clinicopathological characteristics and prognosis of ASC vs SRC based on a large cohort from the SEER database. Achieving this objective may provide additional assistance for their management.
We conducted a retrospective study using a large cohort from the SEER database. The clinicopathological features of patients with ASC vs SRC were comprehensively compared by chi-square tests. We used both propensity-score matching (PSM) method and multivariate Cox regression analysis to adjust the potential bias caused by the imbalanced distribution of confounding factors. Clinical outcomes including cancer-specific survival (CSS) and overall survival (OS) were also compared by the Kaplan-Meier method. The prognostic factors were identified.
A total of 6063 eligible patients were collected. After PSM, 370 patients with SRC and 95 patients with ASC were analyzed. In the post-matching cohort, gastric ASC showed an inferior prognosis to SRC in both CSS and OS. ASC and higher TNM stage were independently associated with a poor survival (HR > 1, P < 0.05), while radiotherapy (HR = 0.587; 95%CI: 0.444-0.776, P < 0.001) and surgery were independent protective factors for favorable prognosis (HR < 1, P < 0.05). Subgroup survival analysis revealed that the inferior prognosis was most significant in stages I and II patients.
ASC may have an inferior prognosis to SRC in patients with stages I and II gastric cancer, so greater attention should be paid to these patients. Our study supports radiotherapy and surgery for the future management of this clinically rare entity. Improved clinical and biological understanding of ASC vs SRC may lead to more individualized therapy for such patients.
Our study shows that gastric ASC has an inferior prognosis to SRC in stages I and II patients. Precautions should be taken to such patients. Radiotherapy and surgery have the potential to improve their clinical outcomes. Future long-term prospective studies are warranted to validate our findings.