Extent of Pelvic Lymph Node Dissection at Partial Cystectomy: Effect on Cancer-Specific Mortality.

Area of Science:

• Urology
• Oncology
• Surgical Oncology

Background:

• Partial cystectomy (PC) is a treatment option for select bladder cancer patients.
• The extent of pelvic lymph node dissection (PLND) during PC and its impact on outcomes require further investigation.
• PC eligibility is defined by tumor stage (≤cT2), size (≤3 cm), and resectability.

Purpose of the Study:

• To assess the extent of PLND performed in partial cystectomy (PC) patients.
• To evaluate the association between PLND extent and cancer-specific mortality (CSM) in PC patients.
• To analyze these associations based on PC eligibility criteria.

Main Methods:

• Utilized the SEER database (2004-2021) to identify patients who underwent PC with PLND.
• Tabulated the number of lymph nodes (LNs) removed, stratified by PC eligibility.
• Employed multivariable Cox-regression models to determine the effect of PLND extent on CSM, adjusting for covariates.

Main Results:

• Of 1017 PC patients, 19.4% were eligible and 80.6% were ineligible for standard PC criteria.
• Mean LNs removed increased over time in both eligible and ineligible groups.
• In all patients, greater PLND extent correlated with lower CSM (mHR: 0.99, p=0.036).
• In PC-ineligible patients, greater PLND extent was associated with lower CSM (mHR: 0.99, p=0.043), but not in eligible patients (mHR: 0.96, p=0.2).

Conclusions:

• Increased extent of PLND is associated with improved cancer-specific survival in all partial cystectomy patients.
• The benefit of extensive PLND on cancer-specific survival is particularly evident in patients ineligible for standard partial cystectomy criteria.
• These findings underscore the prognostic significance of lymph node dissection completeness in bladder cancer management.