Since the establishment of a dedicated MDT for complex pelvic surgery and PES service in September 2015, a total of 67 PES procedures have been performed. The majority of procedures were for primary locally advanced colorectal cancer with high complexity of cases as evidenced by high requirement for pelvic side wall dissection, bone resection and/or flap reconstruction. Despite this patients had acceptable short-term major complication rate and mortality rate. Oncological outcomes including R0 resection rates, five year DFS and five year OS compare favourably with published results.
Other published studies on PES have reported comparable outcomes to those within this study. In a similar sized cohort study of 61 patients over a five year period, Dickfos et al (Brisbane, 2018) demonstrated that radical resectional pelvic surgery can be safely performed with acceptable results during the establishment phase of a dedicated tertiary service.5 In their reviewed cases including 34 locally advanced, 25 recurrent pelvic tumours and two non-neoplastic pathologies, there was a 91.5% R0 resection rate, 52.5% overall complication rate, 26.2% rate of Clavien-Dindo IIIb complications, 3.3% 30-day mortality and 8% 12 month mortality rate.5 Traeger et al (Adelaide, 2022) in their cohort of 113 patients (between 2008 and 2021) also demonstrated improvement in outcomes post development of a dedicated pelvic exenteration service, including higher rates of R0 resection (93.9% versus 84.2%) and lower rates of Clavien-Dindo grade IV complications (8.5 versus 31.3%).6 Internationally, a Danish study of 90 patients undergoing PES between 2001 and 2010 (50 for primary advanced rectal cancer and 40 for locally recurrent rectal cancer) reported R0 resection rates of 68% for primary advanced (PARC) and 38% for locally recurrent rectal cancer (LRRC), major complication rate of 62% and 60% respectively, in hospital mortality of 2.2% overall, and 5 year DFS of 46% for PARC and 17% for LRRC.7 Oncological outcomes in this study including R0 resection rates, DFS and OS compare favourably with these published results.
Varying definitions of a major complication between studies makes it difficult to directly compare the results of this study with published results. The PelvEx Collaborative, which also defined major complications as Clavien-Dindo classification III or IV, reported that out of 1184 patients undergoing PES for locally recurrent rectal cancer, one third had a major complication and one fifth required either radiological or surgical re-intervention.8 In comparison, this study had a smaller cohort size and included eight patients who underwent PES with palliative intent, yet had a similar major complication rate of 34.3% and rate of reintervention of 31.3%. The role of palliative PES remains reserved for select patients where the benefits of palliative resection (such as fungating tumours, disabling pain or uncontrolled fistulas) may outweigh the potential morbidity of PES.9 Patients within this study who underwent PES with palliative intent were carefully selected and underwent a comprehensive MDT evaluation process prior to proceeding to surgery.
Clear operative margins (R0) following PES have been proven to be critical to improving survival.8,9,10 In many centres, expected inability to achieve an R0 margin is regarded as a contraindication to PES. 5 Surgical technical planning is crucial to achieving clear margins and dedicated pre-operative MDT review, along with interdisciplinary communication with gastrointestinal pathologists, have been suggested as important factors in achieving these outcomes. 11 Worldwide R0 resection rates for PES are reported to be 79.9%.12 The higher R0 resection rates within this study (92.2%) may be due to a higher proportion of primary to recurrent cancers, and the unit’s emphasis on careful pre-operative surgical planning and interdisciplinary communication during processing and assessment of pathology specimens within the Complex Pelvic Surgery MDT setting.
Limitations of this study include its retrospective nature, despite data being prospectively recorded, leading to potential for bias and missing data. Additionally, comparison of local outcomes to other published data is limited by the heterogeneity of the cohort of patients undergoing pelvic exenteration, including differences in patient characteristics, rates of neoadjuvant therapy, procedure performed (proportion of total, anterior and posterior exenterations, rate of bone resection and pelvic side wall dissection) and tumour histology.
In conclusion, the results of this study indicate that PES can be safely performed in a lower volume unit with a collaborative multidisciplinary team and careful pre-operative planning of surgical resection margins. Short-term outcomes are comparable to other published data with this data demonstrating favourable indicators of long-term oncological outcomes such as R0 resection rates.