# Cytoreductive surgery

Source: https://onco.cc/terms/cytoreductive-surgery/  
OnCo record `cytoreductive-surgery` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cytoreductive surgery is an operation that strips every visible tumour deposit from the lining of the abdomen and from the organs it coats, often taking many hours. In bowel cancer that has spread only to that lining, it is the part of treatment that does the work: the heated chemotherapy added at the end of it was tested in a randomised trial and made no difference.

## Summary

What it involves. The surgeon removes the affected peritoneum and any organ or part of an organ carrying deposits, with the aim of leaving no visible disease. Completeness is scored: complete macroscopic resection, or resection leaving nodules under or over a size threshold. It is offered in a small number of specialist centres because the operation is long, the complication rate substantial, and case selection decisive.

What it achieves in bowel cancer. In the randomised trial that established the approach, 105 patients with peritoneal spread from colorectal cancer were assigned to systemic fluorouracil and leucovorin with or without palliative surgery, or to aggressive cytoreduction with heated intraperitoneal chemotherapy followed by the same systemic regimen; median survival was 12.6 against 22.3 months, with 8 percent treatment-related mortality in the aggressive arm, and survival depended sharply on how many of the seven abdominal regions were involved and on whether the cytoreduction was macroscopically complete (Verwaal 2003). Twenty years later PRODIGE 7 separated the two halves of that package: in 265 patients who had all achieved complete or near-complete cytoreduction, adding oxaliplatin hyperthermic intraperitoneal chemotherapy left median overall survival unchanged at 41.7 against 41.2 months and caused more late complications, so the surgery, not the heated chemotherapy, is the cornerstone (Quenet 2021).

How a patient reaches it. NICE NG151 (1.5.21) asks the multidisciplinary team to offer systemic anticancer therapy and to discuss referral to a nationally commissioned specialist centre for people whose metastases are limited to the peritoneum. Eligibility in PRODIGE 7 required a peritoneal cancer index of 25 or less, performance status 0 or 1, and fitness for six months of chemotherapy.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: CRS; peritonectomy; debulking surgery; complete cytoreduction; completeness of cytoreduction score
- Tags: gi; colorectal

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Debulking
- Verwaal, J Clin Oncol 2003: randomised trial of cytoreduction with hyperthermic intraperitoneal chemotherapy versus systemic chemotherapy and palliative surgery (105 patients): https://doi.org/10.1200/jco.2003.04.187
- Quenet, Lancet Oncol 2021: PRODIGE 7, cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases (265 patients): https://doi.org/10.1016/s1470-2045(20)30599-4
- NICE NG151: colorectal cancer, recommendations (Lynch 1.1, local disease 1.3, biomarkers 1.4, metastatic disease 1.5, ongoing care and support including follow-up 1.6): https://www.nice.org.uk/guidance/ng151/chapter/Recommendations

## Connected records

- cancers: [Appendiceal adenocarcinoma (mucinous and non-mucinous, including signet ring cell)](https://onco.cc/cancers/appendiceal-adenocarcinoma/), [Colon cancer (adenocarcinoma of the colon)](https://onco.cc/cancers/colon-cancer/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Peritoneal mesothelioma](https://onco.cc/cancers/peritoneal-mesothelioma/), [Rectal cancer](https://onco.cc/cancers/rectal-cancer/)
- technologies: [HIPEC / PIPAC (intraperitoneal chemotherapy)](https://onco.cc/technologies/hipec/)
- terms: [Peritoneal cancer index](https://onco.cc/terms/peritoneal-carcinomatosis-index/), [Peritoneal metastases from bowel cancer](https://onco.cc/terms/colorectal-peritoneal-metastases/), [Peritoneal metastasis](https://onco.cc/terms/peritoneal-metastasis/), [Resection margins (R0 / R1 / R2)](https://onco.cc/terms/resection-margins/)

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