Primary Gastric Squamous Cell Carcinoma: Challenges in Treatment Strategy

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Primary gastric squamous cell carcinoma (GSCC) is an extremely rare malignancy, representing only 0.04-0.07% of all gastric tumors.
• This rare cancer carries a poor prognosis, and standardized treatment protocols are lacking globally.

Purpose of the Study:

• To present a case of advanced primary gastric squamous cell carcinoma (GSCC).
• To discuss the diagnostic and treatment strategies for this rare entity.

Main Methods:

• A 59-year-old female patient with epigastric pain was diagnosed with GSCC via gastroscopy and biopsy.
• Staging involved CT scans, esophagogastroduodenoscopy, colonoscopy, and physical examination.
• The patient underwent radical surgery (total gastrectomy, distal pancreatectomy, splenectomy, D2+ lymphadenectomy) followed by adjuvant chemotherapy (XELOX regimen).

Main Results:

• Histopathology confirmed poorly differentiated squamous cell carcinoma with serosal invasion, greater omentum invasion, lymphovascular invasion (LVI+), and perineural invasion (PNI+).
• Post-operative staging was pT4bN3aM0 with 7/25 lymph nodes positive for metastasis.
• Immunohistochemistry showed positivity for p63, CK5/6, and CK7, with negative p16.

Conclusions:

• Accurate diagnosis of primary GSCC requires excluding other primary squamous cell carcinoma sites.
• Radical resection (R0) combined with aggressive adjuvant chemotherapy is the optimal treatment for advanced GSCC.
• Individualized treatment is crucial due to the rarity of GSCC, with decisions on neoadjuvant vs. upfront surgery based on resectability and multidisciplinary discussion.