The Survival Benefits of Chemotherapy for Undifferentiated Carcinoma With Osteoclast‐Like Giant Cells of Pancreas: A Retrospective Analysis and Individual Participant Data Meta‐Analysis

ABSTRACT Background and Aim Undifferentiated carcinoma with osteoclast‐like giant cells of pancreas (UCOGCP) is a rare type of pancreatic adenocarcinoma (PDAC). However, the efficacy of chemotherapy in UCOGCP has not been evaluated so far due to the scarcity of cases. This study aims to evaluate the efficacy of chemotherapy in UCOGCP combined with previous individual participant data (IPD) and SEER database data. Methods Forty‐nine patients with UCOGCP were enrolled from the Surveillance, Epidemiology, and End Results (SEER) database. Based on whether they had received chemotherapy or not, we divided UCOGCP patients into chemotherapy group ( N  = 32) and non‐chemotherapy group ( N  = 17). The survival time of the chemotherapy group and non‐chemotherapy group was assessed by Kaplan–Meier analysis and Cox analysis. IPD data for UCOGCP were collected in PubMed, Embase, Cochrane, and ScienceDirect. The results based on the SEER database were verified by IPD meta‐analysis. Results The Kaplan–Meier analysis indicated that patients who received chemotherapy experienced a longer survival time compared to those who did not (OS: p  = 0.00061, CSS: p  = 0.00047). Univariate (OS: HR: 0.31 [0.15, 0.63], p  = 0.001; CSS: HR: 0.28 [0.13, 0.60], p  = 0.001) and multivariate (OS: HR: 0.33 [0.14, 0.78], p  = 0.012; CSS: HR: 0.30 [0.12, 0.73], p  = 0.008) Cox regression showed that chemotherapy was the independent prognostic protective factor for UCOGCP. IPD meta‐analysis showed that chemotherapy can significantly improve the prognosis of patients who received primary tumor resection (PTR, p  = 0.0084). Conclusion In contrast to not receiving chemotherapy, chemotherapy is effective in prolonging survival in UCOGCP patients with or without PTR. This provides a foundation for the use of UCOGCP chemotherapy.