The Role of Neoadjuvant and Adjuvant Systemic Chemotherapy with Cytoreductive Surgery and Heated Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: A Systematic Review.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is an effective treatment for colorectal peritoneal metastases (CPM), increasing overall survival in selected patients. The aim of this systematic review was to assess the effect of neoadjuvant and adjuvant systemic chemotherapy on overall survival in patients with CPM undergoing CRS and HIPEC, compared with those who receive CRS and HIPEC alone.

METHODS: A systematic literature review was performed using the PubMed database, and the preferred reporting items for systematic reviews and meta-analyses guidelines formed the structure of the review. Data regarding publication details, study design, patient pathology, treatments received, follow-up periods, overall survival and safety were collected and tabulated, and study quality was assessed using the MINORS score for non-randomized studies.

RESULTS: Sixteen of 288 studies met the inclusion criteria. Seven publications related to the role of neoadjuvant chemotherapy, and there was no strong evidence for the efficacy of neoadjuvant chemotherapy. Of note, one study observed worse survival outcomes when neoadjuvant therapy was used. Fourteen studies investigated the role of adjuvant chemotherapy and there was limited evidence that adjuvant systemic chemotherapy improves survival following CRS and HIPEC.

CONCLUSIONS: Systemic adjuvant chemotherapy may be associated with improved overall survival, but the role of systemic neoadjuvant chemotherapy cannot be determined by the currently available evidence. The delivery of a combination of the two modes of systemic chemotherapy has not been investigated in a randomized controlled trial to date. Further research designed to investigate the role of these modalities in the patient's treatment is required.