Age alone is not a barrier to efficacy of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: analysis of 1138 patients from the UK and Ireland Colorectal Peritoneal Metastases Registry

Background: The management of colorectal peritoneal metastases continues to be a challenge but recent evidence suggests cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can improve survival. Uncertainty about the relationship between age and tumour biology makes patient selection challenging particularly when reported procedure related morbidity is high and impact on survival outcomes unknown. The UK and Ireland Colorectal Peritoneal Metastases Registry was reviewed to assess the influence of age on efficacy of CRS and HIPEC.

Methods: A review of outcomes from the UK and Ireland Colorectal Peritoneal Metastases Registry was performed. Data from 2000 to 2021 were included from five centres in the UK and Ireland, and the cohort were sub-divided into three age groups; <45 years, 45-65 years and >65 years old. Primarily, we examined post-operative morbidity and survival outcomes across the three age groups. In addition, we examined the impact that the completeness of cytoreduction, nodal status, or adverse pathological features had on long-term survival.

Results: During the study period, 1138 CPM patients underwent CRS HIPEC. 202 patients(17.8%) were <45 years, 549 patients(48.2%) aged 45-65 years and 387 patients(34%) >65 years. Overall, median length of surgery (CRS and HIPEC), median PCI score and rate of HIPEC administration was similar in all three groups, as was overall rates of major morbidity and/or mortality. Complete cytoreduction rates (CC0) were similar across the three cohorts; 77%, 80.6% and 81%, respectively. Median overall survival for all patients was 38 months following complete cytoreduction.

Conclusion: Age did not appear to influence morbidity or long-term survival following CRS and HIPEC. When complete cytoreduction is achieved survival outcomes are good. The addition of HIPEC can be performed safely and may reduce local recurrence within the peritoneum.