Treatment of Peritoneal Carcinomatosis

Primary Treatment Recommendation by Cancer Type

The National Comprehensive Cancer Network recommends systemic chemotherapy as the standard treatment for gastric cancer with peritoneal carcinomatosis, but cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) should be offered to highly selected patients with limited disease burden (PCI ≤10) at specialized centers 1, 2
For colorectal cancer with peritoneal carcinomatosis, complete cytoreductive surgery plus systemic chemotherapy WITHOUT HIPEC is recommended based on the PRODIGE 7 trial, which demonstrated no survival benefit and increased late complications with HIPEC addition 3

The National Comprehensive Cancer Network suggests that patients with ECOG PS 0-2 should proceed to disease burden assessment, while those with ECOG PS ≥3 or Karnofsky <60% should be offered best supportive care only 2
Patients with low PCI (≤10) are candidates for systemic therapy followed by potential CRS + HIPEC, while those with high PCI (>10) should receive systemic therapy, clinical trial, or best supportive care only 1
Initial systemic therapy should include molecular testing, such as HER2, PD-L1, CLDN18.2, and MSI/MMR status, and treatment should be based on molecular profile 1, 2

The PRODIGE 7 trial established that HIPEC provides no survival benefit and increases late complications, and therefore HIPEC should not be used for colorectal peritoneal carcinomatosis 3
Complete cytoreductive surgery WITHOUT HIPEC is recommended for patients with isolated peritoneal disease, and treatment should be performed at specialized centers with substantial experience 3

Diagnostic laparoscopy has a sensitivity of 85% and specificity of 100% for detecting peritoneal metastases, while CT imaging has a sensitivity of only 28-51% and specificity of 97-99% 4, 5
PET-CT detects only 3% of occult peritoneal metastases 4

Median overall survival for gastric cancer patients treated with CRS + HIPEC is 11-24 months, while those treated with systemic chemotherapy alone have a median overall survival of 5-6 months 2, 4
For colorectal cancer, 15% of patients remain progression-free at 5 years with complete CRS, and mortality rate related to CRS treatment is 8% 3

A multidisciplinary team composition for CRS consideration should include medical oncology expertise, surgical oncology with substantial CRS experience, radiology, pathology, and palliative care specialists 2, 3, 4