Prognostic factors and treatment strategies of limited-stage primary esophageal small-cell carcinoma-a SEER database analysis.

BACKGROUND

Primary esophageal small-cell carcinoma (PESC) is a rare tumor with poor efficacy, and there is currently no standardized treatment method. Our aim is to explore the prognostic factors and possible optimal treatment modalities for limited-stage PESC.

METHODS

We retrospectively searched the Surveillance, Epidemiology, and End Results (SEER) database from 1975 to 2019 for data of patients with limited-stage PESC. Kaplan-Meier method was used to plot survival curves, calculate survival rates, and Log-rank was used to test the differences among survival curves. Prognostic factors were explored through univariate and multivariate Cox regression survival analyses; Cox regression survival analysis was also conducted to analyze the risk of death among treatment groups and compare the survival differences among each treatment group. The non-single treatment (ST) group was defined as the comprehensive treatment (CT) group and it was compared against the ST group.

RESULTS

A total of 186 cases of limited-stage PESC were included in the study, there were differences in survival time among different groups due to differences in age, year, median household income, and N stage (P<0.001, P=0.041, P=0.002, P=0.001). The median overall survival (mOS) of the surgical group (19 months) was longer than that of the nonsurgical group (11 months) (P=0.01). The mOS of the chemotherapy group (16 months) was longer than that of the non-chemotherapy group (4 months) (P<0.001). The mOS of the radiotherapy group (16 months) was longer than that of the non-radiotherapy group (8 months) (P<0.001). Univariate analysis showed that age ≥80 years (P=0.006), year (1997-2007) (P=0.01), year (2008-2019) (P=0.01), N2 (P=0.003), surgery (P=0.02), radiotherapy (P<0.001), and chemotherapy (P<0.001) were prognostic factors affecting overall survival (OS) in limited-stage PESC patients. Multivariate analysis showed that SEER stage (P=0.02), age (P=0.007), radiotherapy (P<0.001), surgery (P=0.006), and chemotherapy (P<0.001) were independent prognostic factors affecting OS in patients of limited-stage PESC. Prognosis was better in the non-monotherapy group than in each monotherapy group. The CT group is superior to the ST group (P<0.001). The surgery combined with chemotherapy (SC) group had the longest mOS and the highest reduced risk of death, but there was no statistical difference.

CONCLUSIONS

SEER stage, age, radiotherapy, chemotherapy, and surgery were independent prognostic factors in limited-stage patients; CT outperformed ST; the SC group had the longest median survival, but showed no statistical difference.