(UroToday.com) The 2023 ASCO annual meeting included a bladder cancer session, featuring a presentation by Dr. Fortis Gaba discussing results from the RESECT study assessing tumor factors and the variation in non-muscle invasive bladder cancer (NMIBC) recurrence after transurethral resection surgery between sites. Quality transurethral resection (TURBT) for urothelial carcinoma is a vital component of appropriate staging of patients prior to embarking on treatment for either non-muscle or muscle invasive disease. As such, the objective of this study from Dr. Gaba and colleagues was to determine if there is significant variation in early recurrence after TURBT surgery between sites taking part in the RESECT study (NCT05154084) after accounting for tumor characteristics.
RESECT is an international, multi-center, observational study. A mixed effects logistic regression model with tumor size, tumor number, tumor grade, tumor stage as fixed effects and site as a random effect was fitted. Cases with first, presumed NMIBC undergoing TURBT were included, and cases were excluded if first check follow up had not been completed. Furthermore, sites were excluded if they did not have at least 10 cases with first assessment follow up:
After exclusions, 186 sites (80 in the UK, 59 in Europe, 18 in North America, 17 in Asia, 7 in Africa, 3 in South America, and 2 in Oceania), contributing a total 4,597 cases (average 25 cases) were included:
Initial analysis of surgical and peri-operative practice showed wide variation, mean 75% (IQR 66-92) cases per site had detrusor muscle resection and 42% (IQR 17-58) had use of single instillation of intravesical chemotherapy. The median recurrence rate per site was 12% (IQR 0-22) for low-grade tumors and 27% (IQR 13-42) for high grade tumors:
After controlling for tumor size, number, stage and grade there was significant residual variation attributable to site (p<0.0001, intra-class correlation, 0.1). Furthermore, adjustment for sites improved the regression model from an area under the receiver operating characteristic curve of 0.66 to 0.74.
Dr. Gaba concluded his presentation discussing results from the RESECT study assessing tumor factors and the variation in non-muscle invasive bladder cancer recurrence after transurethral resection surgery between sites with the following take-home points:
- There is significant variation in the early recurrence rate of NMIBC after TURBT surgery between sites that could not be explained by currently understood tumor features such as size, number, stage and grade
- This study identified differences in surgical technique and perioperative practice that may impact this and further investigation is warranted to understand how these factors impact recurrence rates
- There is ongoing investigation to determine reasons for this variation and to determine if audit and feedback can improve early recurrence rates
Presented by: Fortis Gaba, MD, Department of Health Policy and Management, Harvard School of Public Health, Boston, MA
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, Chicago, IL, Fri, June 2 – Tues, June 6, 2023.