Discrepancy between recommendations regarding hyperthermic intraperitoneal chemotherapy (HIPEC) in ovarian cancer management: a narrative review

Background and objective: Hyperthermic intraperitoneal chemotherapy (HIPEC) is still controversial in ovarian cancer (OC) management. Doubts are related mainly to HIPEC effectiveness, but also to its safety. European Society of Medical Oncology and European Society of Gynecologic Oncology do not consider HIPEC as a standard of care. Opposite to European recommendations, National Comprehensive Cancer Network found HIPEC as a treatment option in patients undergoing interval debulking surgery in first-line treatment. This may be confusing for oncologists in clinical practice. The aim of this narrative review is to present literature review focusing on efficacy, confounding factors, complications and immunological issue of HIPEC in OC management.

Methods: PubMed was searched for meta-analyses, randomized trials, observational studies, experimental studies to outline the role of HIPEC in OC management since January 2015 until August 2023. Keywords included "hyperthermic intraperitoneal chemotherapy", "HIPEC", "ovarian cancer", "immune response". References from full-text articles were screened for additional studies.

Key content and findings: Most meta-analyses found that HIPEC improved survival in patients with OC and none of the meta-analyses showed that addition HIPEC to surgery was associated with a worse treatment outcome compared to surgery alone. Positive effect on treatment outcome was found more common in first-line treatment than recurrent disease. Positive effect on treatment outcome was more common in first-line treatment (especially during interval debulking surgery) than recurrent disease. HIPEC efficacy can be affected by patients' characteristics (BRCA status, platinum sensitivity), cytostatic type and dose, intensity of hyperthermia and peritoneal flow characteristics. Apart from strict cytotoxic effect, HIPEC can induce anti-cancer immune response.

Conclusions: Although factors confounding HIPEC efficacy are not well-defined, survival improvement, related to addition HIPEC to surgery in OC, was observed. Future studies should focus on determining a subgroup of patients, who benefit from HIPEC. This will contribute to the unification of European and American recommendations.