Variations in pelvic lymph node dissection in invasive bladder cancer: A Dutch nationwide population-based study during centralization of care

Abstract

Objectives: To assess temporal trends in radical cystectomy (RC) and pelvic lymph node dissection (PLND) and the effect of centralization of care in the Netherlands between 2006 and 2012.

Patients and methods: This nationwide population-based study included 3524 patients from the Netherlands Cancer Registry who underwent RC as the primary treatment for cT1-4a, N0 or Nx, M0 urothelial carcinoma. Annual application rates of PLND, median LNC, and rates of node-positive disease (pN+) were compared by linear-by-linear association. Multivariable logistic regression was performed to identify patients׳ and hospital characteristics associated with PLND and LNC≥10, and to study associations between LNC and pN+disease.

Results: In total, 3,191 (91%) patients had PLND during RC and the use increased from 84% in 2006 to 96% in 2012 (P<0.001). Owing to centralization of care in 2010 (at least 10RCs/y/hospital), significantly more patients were treated in high-volume hospitals (≥20RC per year) in 2011 and 2012. PLND use was highest in males, younger patients and in academic, teaching, and high-volume hospitals (≥20RC per year). In 2012, PLND application rates were comparable for academic, teaching, and nonteaching hospitals (P = 0.344). Median LNC increased from 7 in 2006 to 13 in 2012 (P<0.001), 55% had an LNC≥10 (63% in 2012). Furthermore, lymph node count (LNC)≥10 was associated with cT3-4a and, pN+disease, R0 and treatment in academic, teaching, or high-volume hospitals (≥20RC per year). Rate of pN+disease increased from 18% to 24% between 2006 and 2012 (P = 0.014). This trend was significantly associated with increased LNC on a continuous scale (odds ratio = 1.03).

Conclusions: After centralization of care, PLND during RC for cT1-4a, N0 or Nx, M0 urothelial carcinoma has become standard in all types of Dutch hospitals. The increase in LNC between 2006 and 2012 was associated with a higher incidence of pN+disease and suggests more adequate template extension and adherence to contemporary guidelines in recent years.

Keywords: Bladder cancer; Centralization; Lymph node count; Lymph node dissection; Population-based; Staging.