Cancer-Specific Survival of Patients with Non-Muscle-Invasive Bladder Cancer: A Population-Based Analysis - Beyond the Abstract
Surveillance, Epidemiology, and End Results (SEER) database was queried to identify patients with NMIBC. Our analysis included a substantial cohort of 98,238 patients who underwent transurethral resection of the bladder tumor (TURBT) and were diagnosed with NMIBC between 2004 and 2015. The study's findings reveal significant disparities in CSS across different NMIBC stages. Notably, T1HG and Tis were associated with the highest cancer-specific mortality (CSM) rates within the observed follow-up of 124 months (IQR 81-157), reaching 19.52% and 15.56% respectively. The study also highlighted the relatively high risk of CSM for rarely diagnosed T1LG and TaHG tumors, approximately 10%, contrasting with a favorable outcome for TaLG tumors (3.76%).
We developed a predictive nomogram utilizing Cox regression analysis, encompassing a range of risk factors such as tumor T category and grade, patient's age, tumor size, tumor histology and location, recurrent character, race, marital, and socioeconomic status. The nomogram demonstrated strong predictive capabilities, with a concordance index of 0.795 in the validation cohort, indicating its efficacy in estimating 5-year CSS. Decision curve analysis confirmed its clinical utility across the whole range of threshold probabilities as compared to using tumor grade and T stage alone.
The study's strengths lie in its utilization of a large population-based cohort with an extended follow-up period, providing valuable insights into real-world survival outcomes and prognostic factors for NMIBC. Focus on CSS, an often understudied endpoint in NMIBC research, contributes to the understanding of the disease's clinical course and long-term patient outcomes. Our findings emphasize the critical significance of considering both clinical and pathological factors when assessing prognosis. The alarming discrepancy in NMIBC prognosis between individuals with higher and lower socioeconomic status urgently demands attention and should be a pivotal point for discussion among healthcare policymakers and authorities.
Regarding such unfavourable long-term CSM outcomes in T1HG, the debate on the indication for radical cystectomy in those patients should be continued. Our data underscore the need for careful management of “forgotten” and relatively rare TaHG and T1LG which are also deadly tumours (up to 10% CSM). On the other hand, the significant burden of other-cause-specific mortality among all stages of NMIBC emphasizes the importance of considering comorbidities during clinical decision-making. Consequently, improved risk-stratification and taking comorbidities into consideration are obligatory to avoid over- and undertreatment in NMIBC.
Overall, this manuscript provides a real-world report on NMIBC cancer-specific survival and its prognostic indicators. Tumor T stage, grade, and patient’s age remain the key risk factors for CSM in NMIBC. Emphasis on the role of sociodemographic factors in prognosis further underscores the disparity in healthcare access. The development of a robust prognostic nomogram adds a valuable tool to for counseling patient survival outcomes but still requires external validation.
Written by: Aleksander Ślusarczyk, MD, PhD, Department of General, Oncological and Functional Urology, Medical University of Warsaw, Poland
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