# The Preoperative Prognosticators of Surgical Margins (R0 vs. R1) in Pelvic Exenteration—A 14-Year Retrospective Study from a Tertiary Referral Centre

## TL;DR

This study identifies factors that help predict successful cancer removal during a complex pelvic surgery for gynaecological cancers.

## Contribution

The study provides new insights into preoperative predictors of achieving R0 resection in pelvic exenteration after radiotherapy.

## Key findings

- R0 resection was achieved in 77.8% of patients undergoing pelvic exenteration.
- Younger age, cervical cancer origin, and smaller tumor size were associated with better resection outcomes.
- Intraoperative and postoperative complications occurred in nearly one-third and one-fifth of cases, respectively.

## Abstract

Pelvic exenteration is one of the most extensive operations performed for gynaecological cancers that return or persist after radiotherapy. It involves removing the cancer along with nearby pelvic organs, followed by reconstructive surgery. The main aim is to achieve “R0 resection,” meaning all visible and microscopic cancer is removed, which offers the best chance of long-term survival. We looked at 27 women who had surgery at Oxford University Hospitals between 2011 and 2024, after radiotherapy. Their cancers started in the cervix, uterus, vagina, or vulva. The average age was 63. Surgeons achieved complete removal in almost 80% of cases. Complications happened during surgery in about one in three women, and serious post-surgery problems in about one in five. Younger patients, with smaller tumour size, and those with cervical cancer and reduced blood loss during surgery were more likely to achieve full removal.

Background/Objectives: Pelvic exenteration is a complex surgery considered for locally advanced or recurrent pelvic malignancies, entailing a radical en-block resection of multiple adjacent pelvic organs, followed by reconstructive surgery. Achieving R0 resection (complete removal of macroscopic and microscopic disease) is critical for improving survival outcomes. This study aimed to define patient, tumour, and surgical predictors of R0 resection in an irradiated field, thereby optimising patient selection and establishing a surgical roadmap for pelvic exenterations. Methods: Our retrospective observational cohort study includes consecutive patients undergoing exenteration post-radiotherapy for non-ovarian gynaecological malignancies at Oxford University Hospitals between 1 January 2011 and 31 December 2024. The primary outcome was margin status. Secondary outcomes were intraoperative and postoperative complications. Results: Twenty-seven patients were identified, with a median age of 63 years (range 41–81) and median BMI of 27 (range 17–45). Primary tumour sites included the vulva (11.1%), vagina (14.8%), cervix (40.7%), and uterus (33.3%). R0 was achieved in 77.8% (n = 21) of cases. Intraoperative complications occurred in 29.6%, and significant postoperative complications (Clavien-Dindo IIIA/IIIB) in 22.2% of patients. R0 resection was significantly associated with younger age (median 61 vs. 70 years, p = 0.035) and primary cervical tumours (p = 0.036). On univariable logistic regression, tumour size on imaging (p = 0.038, OR 2.9) and on histology (p = 0.020, OR 2.01), and estimated blood loss (p = 0.048, OR 1.002) were significant predictors of R0 resection. None of these variables retained significance in multivariable logistic regression. Conclusions: Tumour size, primary tumour site, and patient age should be considered when selecting patients for pelvic exenteration following radiotherapy, and blood loss should be kept minimal in order to maximise the chances of achieving R0 resection.