Abstract 1634P
Background
Early reports discussed the prognostic factors of patients with metastatic GIST treated with cytoreductive surgery (CRS). However, the role of C-HIPEC, after CRS, for the treatment of peritoneal metastatic GIST remains unknown.
Methods
A retrospective analysis of patients with peritoneal metastatic GIST treated with CRS + C-HIPEC combined with targeted therapy from a single institution was performed. C-HIPEC was introduced 1 or more days after CRS, with mitoxantrone, or doxorubicin with cisplatin. Overall survival (OS), and progression free survival (PFS) from time of surgery was determined. One-to-one propensity score matching (PSM) analyses were conducted to balance selection bias. Univariate and multivariate analysis were performed using a Cox proportional-hazards model.
Results
Between 2007 and 2018, we performed 104 operations on 87 patients with peritoneal metastatic GIST. C-HIPEC was conducted following 35 operations. After a median follow up of 23 months, the median OS and PFS were 40 months and 16 months. After PSM, both C-HIPEC group and non-C-HIPEC group had 28 operations. Either the median OS or PFS was not significantly difference in both groups, with 35 months of C-HIPEC vs 37 months of non-C-HIPEC (HR = 1.22 [95%CI: 0.56-2.67], P = 0.6187)，and 13 months in both groups( HR = 0.99 [95%CI: 0.53-1.85], P = 0.9865). Among all patients, 30 days post-operative grade III-IV morbidity rate was 16.3% (C-HIPEC 14.3% and non-C-HIPEC 17.4%, respectively, [P = 0.901]). Multifocal progression, with liver and/or extra-abdominal metastasis, tumor rupture and diameter of resected tumors ≥ 6.5cm were prognostic of worse OS. Multifocal progression, with liver and/or extra-abdominal metastasis and mitotic index >5/50 HPF were associated with worse PFS.
Conclusions
C-HIPEC is safe to perform after CRS for metastatic GISTs. However, lacking of infusional regimen of targeted therapy, C-HIPEC using traditional chemotherapy medications did not increase survival benefits compared to CRS alone.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.