Clinicopathological features and impact of adjuvant chemotherapy on the long-term survival of patients with multiple gastric cancers: a propensity score matching analysis

Abstract

Background: Little is known about the correlation between the clinicopathological features, postoperative treatment, and prognosis of multiple gastric cancers (MGCs). In this study, we aimed to investigate the correlation between these features and the impact of postoperative adjuvant chemotherapy on the long-term survival of patients with MGC.

Methods: The clinical and pathological data of patients diagnosed with gastric adenocarcinoma who had radical gastrectomy from January 2007 to December 2016 were analyzed. Using propensity score matching, the prognostic differences, and the impact of postoperative adjuvant chemotherapy between those with MGC and solitary gastric cancers (SGC) were compared.

Results: Among the 4107 patients investigated, the incidence of MGC was 3.2% (133/4107). Before matching, patients with MGC and SGC had disparities in the type of gastrectomy, pathological tumor stage (pT), pathological node stage (pN), and pathological tumor-node-metastasis stage (pTNM). After a 1:4 ratio matching, the clinical data of 133 cases of MGC and 532 cases of SGC were found to be comparable. The 5-year overall survival (OS) rate was 56.6% in the entire matched cohort, 48.1% in the MGC group, and 58.7% in the SGC group (P = 0.013). Multivariate analysis revealed that MGC, age, pT stage, pN stage, and adjuvant chemotherapy were independent predictors of OS (all P < 0.05). Stratified analyses demonstrated that for the cohort of advanced gastric cancer (AGC) patients who did not had adjuvant chemotherapy, the 5-year OS rate of advanced cases of MGC was inferior than that of SGC patients (34.0% vs. 46.1%, respectively; P = 0.025) but there were no significant difference in the 5-year OS rate between advanced MGC and SGC patients who had adjuvant chemotherapy (48.0% vs. 53.3%, respectively; P = 0.292). Further, we found that the 5-year OS rate of advanced MGC who had adjuvant chemotherapy was significantly higher than those who did not had adjuvant chemotherapy (48.0% vs. 34.0%, P = 0.026).

Conclusions: Patients with advanced MGC was identified as having a poorer survival as to SGC patients, but the implementation of postoperative adjuvant chemotherapy showed that it had the potential to significantly improve the long-term prognoses of MGC patients.

Keywords: Adjuvant; American Joint Committee on Cancer; Chemotherapy; Eighth edition; Multiple gastric cancer; Prognosis; Propensity score matching; Solitary gastric cancer.

Fig. 1

Case screening process of this study. SGC solitary gastric cancer, MGC multiple gastric cancer

Fig. 2

Distributions of the multiple gastric cancers (MGC). There were 43.7% of the MGC located in only one-third of the stomach (blue circle), 45.8% distributed throughout two-thirds of the stomach (yellow triangle), and the other 10.5% covering more than two third of the stomach (red rhombus)

Fig. 3

Impact of MGC on OS. a In all stages (early and advanced) of gastric cancer. The 5-year OS rate was 56.6% for the entire study cohort. For the MGC and SGC groups, the 5-year OS rates were 48.1% and 58.7%, respectively (P = 0.013). b In the early stage. The 5-year OS rate was 91.2%. For the MGC and SGC groups, the 5-year OS rates were 83.3% and 91.8%, respectively (P = 0.852). c In the advanced stage. The 5-year OS rate was 49.4%. For the MGC and SGC groups, the 5-year OS rates were 43.0% and 51.1%, respectively (P = 0.036). d The 5-year OS rates of MGC patients who underwent total gastrectomy and distal gastrectomy were 45.4% and 61.5%, respectively (P = 0.114). MGC multiple gastric cancers, SGC solitary gastric cancers, OS overall survival

Fig. 4

Impact of chemotherapy and advanced MGC on OS. a Impact of MGC on the OS of patients without chemotherapy. The 5-year OS rate of AGC patients who did not receive adjuvant chemotherapy was 43.4%. For the MGC and SGC groups, the 5-year OS rates were 34.0% and 46.1%, respectively (P = 0.025). b Impact of MGC on the OS of patients who had adjuvant chemotherapy. The 5-year OS rate of AGC patients who received adjuvant chemotherapy was 52.2%. For the MGC and SGC groups, the 5-year OS rates were 48.0% and 53.3%, respectively (P = 0.292). c Impact of adjuvant chemotherapy on the OS of patients with advanced MGC. The 5-year OS rate of patients with advanced MGC was 43.0%, of which the groups with and without adjuvant chemotherapy were 48.0% and 34.0%, respectively (P = 0.026). MGC multiple gastric cancers, OS overall survival