Cytoreductive surgery with hyperthermic intraoperative peritoneal chemotherapy versus standard of care in people with peritoneal metastases from colorectal, ovarian or gastric origin: Systematic review and individual participant data meta-analyses of effectiveness and cost-effectiveness

Each year, approximately 7 million people worldwide (including 160,000 people in UK) develop cancers of the bowel, ovary, or stomach. Around 10% of these patients develop 'peritoneal metastases' where the cancer has spread to the lining of the abdomen. The usual treatment (or 'standard of care') for these patients is chemotherapy the use of drugs that aim to kill cancer cells. Some patients also receive an operation to remove the cancer, known as cytoreductive surgery. Despite these treatments, people with peritoneal metastases from bowel, ovary, or stomach cancer have a short life expectancy, ranging from 6 months to 2 years. There is a clear need to improve the outcomes for these patients. One treatment that may help is known 'hyperthermic intraoperative peritoneal chemotherapy' (HIPEC). This is where, straight after receiving cytoreductive surgery, patients are given chemotherapy that has been heated to 42°C, delivered into the lining of the abdomen. Several studies have shown that cytoreductive surgery (CRS) plus HIPEC improves survival compared to standard of care. However, there have been some questions about the results of these studies. Importantly, some people develop complications following their treatment. Therefore, it is uncertain whether to recommend CRS+HIPEC for use in these patients. Aims of the research Our research has three main aims: 1. To determine whether CRS + HIPEC improves survival and other outcomes for people with peritoneal metastases from the bowel, ovary, and stomach cancer compared with standard of care. 2. To establish the extent of complications following treatment with CRS + HIPEC compared with standard of care. 3. To determine whether CRS + HIPEC should be used routinely in the NHS for people with peritoneal metastases from these cancers and whether it provides good value for money. Design and methods used We plan to bring together the results of all of the trials that have compared CRS + HIPEC with standard of care. We will look at the results for patients with cancer of the bowel, ovary or stomach. This type of research is called a systematic review and meta-analysis. The type of systematic review and meta-analysis we are planning uses 'individual participant data' or 'IPD' from all of the trials we find. This involves collecting and performing analysis using data on individual participants in the studies. IPD meta-analysis is often called the 'gold standard' because it produces better estimates of the effects of treatments and allows us to find out more about how well they work in different types of patients. Patient and public involvement A patient representative was involved in the preparation of this grant proposal; they will be involved in the research steering group and will help with writing the plain language report of the findings, disseminating the findings to patient groups and social media and in determining the design of future studies. Training and support (including payment and covering incidental expenses) will be provided. Dissemination We plan to publish our results in relevant, high quality medical journals and present the findings at international conferences.We also plan to speak to some organisations and associations directly to make our results easy for clinicians to access.We will also work with representatives from patient support groups, to communicate our findings to communities of patients and the public. £305,636.79