Regional variance in treatment and outcomes of locally invasive (T4) rectal cancer in Australia and New Zealand: analysis of the Bi‐National Colorectal Cancer Audit

Abstract

Backgrounds: Locally invasive T4 rectal cancer often requires neoadjuvant treatment followed by multi-visceral surgery to achieve a radical resection (R0), and referral to a specialized exenteration quaternary centre is typically recommended. The aim of this study was to explore regional variance in treatment and outcomes of patients with locally advanced rectal cancer in Australia and New Zealand (ANZ). Methods: Data were collected from the Bi-National Colorectal Cancer Audit (BCCA) database. Rectal cancer patients treated between 2007 and 2019 were divided into six groups based on region (state/country) using patient postcode. A subset analysis of patients with T4 cancer was performed. Primary outcomes were positive circumferential resection margin (CRM+), and positive circumferential and/or distal resection margin (CRM/DRM+). Results: A total of 9385 patients with rectal cancer were identified, with an overall CRM+ rate of 6.4% and CRM/DRM+ rate of 8.6%. There were 1350 patients with T4 rectal cancer (14.4%). For these patients, CRM+ rate was 18.5%, and CRM/DRM+ rate was 24.1%. Significant regional variation in CRM+ (range 13.4-26.0%; p = 0.025) and CRM/DRM+ rates (range 16.1-29.3%; p = 0.005) was identified. In addition, regions with higher CRM+ and CRM/DRM+ rates reported lower rates of multi-visceral resections: range 24.3-26.8%, versus 32.6-37.3% for regions with lower CRM+ and CRM/DRM+ rates (p < 0.0001). Conclusion:Positive resection margins and rates of multi-visceral resection vary between the different regions of ANZ. A small subset of patients with T4 rectal cancer are particularly at risk, further supporting the concept of referral to specialized exenteration centres for potentially curative multi-visceral resection.

Establishing a state‐wide pelvic exenteration multidisciplinary team meeting in South Australia

“…18 The high positive margin rates in patients with T4 rectal cancers undergoing multi-visceral resection highlights the need for this type of discussion to improve outcomes for an at-risk patient group. 16 MDT discussion facilitates careful selection of patients to undergo pelvic exenteration and, with thorough surgical planning, may reduce the risk of positive resection margins known to negatively impact disease prognosis and survival outcomes. 19,20 While the long-term impact of patient discussion at the dedicated SA state-wide pelvic exenteration MDT is yet to be determined, the role of specialized MDT meetings in cancer patient management undoubtedly improves surgical outcomes and R0 resection rates, resulting in better patient satisfaction and ultimately overall survival.…”

“…Importantly, the development of a formal referral system for discussion at a state‐wide MDT offers facilitated and improved decision making, particularly important for patients with these less common locally advanced cancers 18 . The high positive margin rates in patients with T4 rectal cancers undergoing multi‐visceral resection highlights the need for this type of discussion to improve outcomes for an at‐risk patient group 16 . MDT discussion facilitates careful selection of patients to undergo pelvic exenteration and, with thorough surgical planning, may reduce the risk of positive resection margins known to negatively impact disease prognosis and survival outcomes 19,20 .…”

“…However, as patient numbers increased, it was recognized that there was a need to further clarify the management and referral pathways of these uncommon and complex patients, with the goal of improving patient outcomes. 16 This was further galvanized by a reduction in free movement of patients between states due to the Covid pandemic. In parallel with this, a dedicated pelvic exenteration service was being established at the Royal Adelaide Hospital, with work progressing on this since 2017, and volumes of exenteration surgery being done locally increasing rapidly as the resource matured.…”

“…In South Australia, pelvic exenteration surgery was historically not centralized, with appropriate reliance on interstate referrals for specialist multidisciplinary team (MDT) input. However, as patient numbers increased, it was recognized that there was a need to further clarify the management and referral pathways of these uncommon and complex patients, with the goal of improving patient outcomes 16 . This was further galvanized by a reduction in free movement of patients between states due to the Covid pandemic.…”

Minimally invasive surgery for maximally invasive tumors–pelvic exenterations for rectal cancers: are we prepared?

“…They reported an overall complication rate of 28.2% with a 7.3% circumferential resection margin positivity and with no distal margin involvement, with local recurrence rate of 8.1% and overall survival of 85.2% by 2-year follow-up. The latest review by Dinger et al [ 7 ] in 2022 on outcomes of locally invasive T4 rectal cancer in Australia and New Zealand reported an overall circumferential/distal margin positive rate of 24.1% and an overall complication rate of 31.2%, together with a variation in results of different locality in the region. This is partly explained by the heterogeneity of patients, operative approach, and practice in different centers and regions.…”