Prognostic analysis of pancreatic cancer with different metastatic patterns undergoing hyper-thermic intraperitoneal chemotherapy combined with systemic therapy

Objective To investigate the prognosis of pancreatic cancer with different metas-tatic patterns undergoing hyperthermic intraperitoneal chemotherapy (HIPEC) combined with systemic therapy.

Methods The retrospective cohort study was conducted. The clinicopathological data of 161 pancreatic cancer patients with different metastatic patterns who underwent HIPEC combined with systemic therapy at Zhongshan Hospital, Fudan University from February 2023 to December 2024 were collected. There were 100 males and 61 females, aged 63(56,71) years. Of the 161 patients, 142 cases were diagnosed with metastatic pancreatic cancer at initial presentation, and 19 cases had recurrent metastatic pancreatic cancer after radical surgery for pancreatic cancer. Based on tumor metastasis patterns, there were 76 cases of isolated peritoneal metastasis and 85 cases of peritoneal metastasis plus other organ metastasis. Observation indicators: (1) treatment status; (2) survival status; (3) analysis of factors affecting the prognosis of patients with isolated peritoneal metastatic pancreatic cancer. Comparison of measurement data with skewed distribution between groups was conducted using the Wilcoxon rank sum test. Comparison of count data between groups was conducted using the chi‑square test or Fisher exact probability. Comparison of ordinal data between groups was conducted using the Wilcoxon rank sum test. The Kaplan‑Meier method was used to calculate survival rates and plot survival curves, and the Log‑rank test was used for survival analysis. The receiver operating characteristic (ROC) curves were drawn to convert tumor markers with significant diagnostic value into binary variables based on the optimal diagnostic threshold. Univariate and multivariate analyses were conducted using the Cox proportional hazards regression model.

Results (1) Treat-ment status: there was no significant difference in the number of HIPEC procedure, chemotherapy, chemotherapy regimens, radiotherapy, and conversion surgery between patients with isolated peritoneal metastasis and patients with peritoneal metastasis plus other organ metastasis (P>0.05). (2) Survival status: all 161 patients were followed up for 25.5(range, 23.0-28.6) months. The overall survival time for 76 patients with isolated peritoneal metastasis was 14.0(range, 12.2-17.9) months, with 1‑year overall survival rate as 60.3%. The overall survival time for 85 patients with peritoneal metastasis plus other organ metastasis was 11.3(range, 8.6-13.5) months, with 1‑year overall survival rate as 45.7%. There was a significant difference in overall survival between patients with isolated peritoneal metastasis and patients with peritoneal metastasis plus other organ metastasis (χ²=4.857, P<0.05). The progression-free survival time was 6.07(range, 5.17-not reached) months for 76 patients with isolated peritoneal metastasis versus 4.67(range, 3.87-6.37) months for 85 patients with peritoneal metastasis plus other organ metastasis, showing a significant difference between them (χ²=5.382, P<0.05). (3) Analysis of factors affecting the prognosis of patients with isolated peritoneal metastatic pancreatic cancer: results of multivariate analysis showed that nutritional risk screening 2002 (NRS2002) grade as nutritional risk and CA125 ≥72.65 U/mL were independent risk factors for the prognosis of patients with isolated peritoneal metastatic pancreatic cancer who underwent HIPEC combined with systemic therapy (hazard ratio=4.166, 4.491, 95% confidence interval as 1.788-9.710, 1.898-10.626, P<0.05). Further survival curve analysis demonstrated that of the 76 patients with isolated peritoneal metastatic pancreatic cancer, the overall survival time was 12.2(range, 8.0-16.4) months for cases with NRS2002 grade as nutritional risk versus 17.3(range, 11.1-29.5) months for cases with NRS2002 grade as non-nutritional risk, showing a significant difference between them (χ²=7.853, P<0.05). The overall survival time was 11.1(range, 7.8-14.4) months for cases with ≥72.65 U/mL versus 20.8(range, 10.2-31.4) months for cases with CA125 <72.65 U/mL, showing a significant difference between them (χ²=16.223, P<0.05).

Conclusions There is a difference in prognosis between pancreatic cancer patients with isolated peritoneal metastasis and patients with peritoneal metastasis plus other organ metastasis. NRS2002 grade as nutritional risk and CA125 ≥72.65 U/mL are independent risk factors for the prognosis of patients with isolated peritoneal metastatic pancreatic cancer who underwent HIPEC combined with systemic therapy.