Gastric neuroendocrine carcinoma (G-NEC) is a rare and aggressive tumor originating from neuroendocrine cells in the stomach lining. It is characterized by a high propensity for recurrence and a generally poor prognosis. Due to its rarity, there is limited data and no established consensus on the optimal postoperative adjuvant therapy, making treatment decisions challenging for healthcare providers.

This study is a retrospective analysis focusing on evaluating survival rates, identifying prognostic factors, and formulating treatment recommendations for patients with G-NEC. By analyzing real-world clinical data, we aim to better understand the factors that influence patient outcomes and to develop evidence-based strategies for improving survival. Our goal is to provide clinicians with valuable insights and tools to make more informed treatment decisions, ultimately enhancing the quality of care and outcomes for patients with this challenging disease.

Inclusion Criteria:

• (1) patients who underwent radical surgery without any neoadjuvant therapy;
• (2) pathology confirmed NEC or mixed adenoneuroendocrine carcinoma (MANEC).

Exclusion Criteria:

• (1) history of other malignant neoplasms;
• (2) treatment with endoscopic submucosal dissection or endoscopic mucosal resection or thoracotomy;
• (3) incomplete clinical data (including pathological, adjuvant chemotherapy, and follow-up information);
• (4) receipt of alternative adjuvant treatment regimens;
• (5) death within 30 days postoperatively.

This study includes adult patients diagnosed with gastric neuroendocrine carcinoma (G-NEC) or mixed adenoneuroendocrine carcinoma (MANEC) who underwent radical surgery at 38 tertiary hospitals in China between January 2006 and December 2020. The study population consists of patients who received either no adjuvant chemotherapy, etoposide and platinum derivatives-based chemotherapy, or fluorouracil-based chemotherapy following surgery.

Patient Privacy: As this study involves sensitive medical information, we must ensure that any data sharing plan complies with all relevant privacy laws and regulations.

Ethical Considerations: We are consulting with our ethics committee to determine the most appropriate approach to data sharing that respects patient consent and maintains the integrity of the research.

Data Standardization: Given the multi-center nature of this study, we are working on standardizing our data collection and storage processes across all 38 participating hospitals to ensure consistency and quality of any potentially shared data.

Collaborative Potential: We recognize the value of data sharing in advancing gastric neuroendocrine carcinoma research and are exploring potential collaborations with other research groups.

Resource Allocation: We are assessing the resources required to prepare the data for sharing, including de-identification processes and creation of data dictionaries.