Neoadjuvant chemoradiotherapy followed by surgery for operable carcinoma esophagus: Ground reality in a tertiary care center of rural India - A retrospective audit

Involvement of DPP3 in modulating oncological features and oxidative stress response in esophageal squamous cell carcinoma

Resistance to therapy in esophageal squamous cell carcinoma (ESCC) is a critical clinical problem and identification of novel therapeutic targets is highly warranted. Dipeptidyl peptidase III (DPP3) is a zinc-dependent aminopeptidase and functions in the terminal stages of the protein turnover. Several studies have reported overexpression and oncogenic functions of DPP3 in numerous malignancies. The present study aimed to determine the expression pattern and functional role of DPP3 in ESCC. DPP3 expression was assessed in normal and tumor tissues using quantitative real-time (qRT)-PCR and corroborated with ESCC gene expression datasets from Gene Expression Omnibus (GEO) and The cancer genome atlas (TCGA). DPP3 stable knockdown was performed in ESCC cells by shRNA and its effect on cell proliferation, migration, cell cycle, apoptosis, and activation of nuclear factor erythroid 2-related factor 2 (NRF2) pathway was assessed. The results suggested that DPP3 is overexpressed in ESCC and its knockdown leads to reduced proliferation, increased apoptosis, and inhibited migration of ESCC cells. Additionally, DPP3 knockdown leads to down-regulation of the NRF2 pathway proteins, such as NRF2, G6PD, and NQO1 along with increased sensitivity toward oxidative stress-induced cell death and chemotherapy. Conclusively, these results demonstrate critical role of DPP3 in ESCC and DPP3/NRF2 axis may serve as an attractive therapeutic target against chemoresistance in this malignancy.

Survival Outcomes of Patients with Esophageal Cancer Who Did Not Proceed to Surgery after Neoadjuvant Treatment

BACKGROUND

This retrospective study examined outcomes in esophageal squamous cell carcinoma (ESCC) patients who did not undergo surgical resection after neoadjuvant chemoradiotherapy (nCRT).

METHODS

Patients receiving nCRT between 2012 and 2020 were divided into two groups: group 1 (scheduled surgery) and group 2 (no surgery). Group 2 was further categorized into subgroups based on reasons for not proceeding to surgery: group 2a (disease progression), group 2b (poor general conditions), and group 2c (patient refusal). Overall survival (OS) was the primary outcome.

RESULTS

Group 1 comprised 145 patients, while subgroups 2a, 2b, and 2c comprised 24, 16, and 31 patients, respectively. The 3-year OS rate was significantly lower in group 2 compared with group 1 (34% versus 56%, p < 0.001). A subgroup analysis showed varying 3-year OS rates: 13% for group 2a, 25% for group 2b, and 58% for group 2c (p < 0.001). Propensity score matching for group 2c and group 1 revealed no significant difference in 3-year OS rates (p = 0.91).

CONCLUSION

One-third of ESCC patients receiving nCRT did not undergo surgical resection. Overall survival in this group was generally poorer, except for those who refused surgery (group 2c).