Objective: To further assess the influence of the weight after TURBT as a predictive factor for recurrence and progression in NMIBC.Materials and methods: A cohort of patients with a first episode of NMIBC between 1999 and 2016 was analysed retrospectively. We studied the correlation between the tumour's size and weight, the time-dependent ROC curves for the optimal weight value for the prediction of recurrence and progression and their association with the risk of recurrence and progression at one and five years.Results: We analysed 470 patients who met inclusion criteria. Median (IQR) follow-up time was four years (2.2-6.7), 227 (48.3%) patients had a recurrence and 46 (9.8%) progressed. Median (IQR) weight after resection was 2 g (0.8-6) and its correlation with size was 0.56. The optimal value for the prediction of recurrence was 4 g. The RFS at one and five years with a weight <4 g was 77.7% and 53.5%, respectively, compared to 57.8% and 34.7% with higher weight (p < .001). PFS at one and five years was 98% and 92.7% for a weight <4 g compared to 91.4% and 83.1% for tumours >4 g, respectively (p = .02). On multivariate analysis, a higher weight was associated with an increased risk of recurrence: HR [95%:CI] = 1.52[1.05-1.86], and progression: HR[95%:CI] = 1.87[1.01-3.47] (p < .05).Conclusion: The weight of the specimen obtained after TURBT is a predictive factor of both recurrence and progression in NMIBC that may be more accurate than tumour size and easily and objectively measured. An increase of 52% and 87% in the risk of recurrence and progression, respectively, was found in tumours weighing more than 4 g.
Keywords: Weights and measures; disease progression; recurrence; urinary bladder neoplasms.