# Case report: pathological complete response after S-1/oxaliplatin regimen combined with trastuzumab and tislelizumab in patients with locally advanced gastric cancer

## TL;DR

A patient with advanced gastric cancer showed a complete response after receiving a combination of S-1/oxaliplatin, trastuzumab, and tislelizumab before surgery.

## Contribution

This is the first reported case of using SOX with trastuzumab and tislelizumab as a neoadjuvant therapy for gastric cancer.

## Key findings

- The patient achieved a pathological complete response after four cycles of combination chemotherapy.
- The patient underwent successful radical surgery with no significant side effects after six months of follow-up.
- The regimen may be an effective neoadjuvant treatment for locally advanced gastric cancer.

## Abstract

The efficacy of a regimen combining Tegafur, Gimeracil and Oteracil Potassium Capsules (S-1), oxaliplatin (SOX) with trastuzumab and tislelizumab chemotherapy for advanced gastric cancer (GC) has not been reported.

A 56-year-old male was diagnosed with GC combined with peripheral lymph node metastasis. The patient received neoadjuvant chemotherapy, including SOX, tislelizumab and trastuzumab. After 4 cycles of chemotherapy, the tumor shrank significantly, and radical surgery was performed with good clinical results. To date, the patient has been followed up for 6 months with no significant side effects.

In this study, the patient received combination chemotherapy with SOX trastuzumab and tislelizumab and successfully underwent radical surgery with good clinical outcomes. Combined SOX with trastuzumab and tislelizumab may be an effective neoadjuvant chemotherapy regimen.