Apparent Diffusion Coefficient Value can Predict Poor Bacillus Calmette-Guérin Responders in T1HG/NMIBC: Prospective Cohort Study.

BACKGROUND: Prediction of recurrence and progression and the choice of type of management are largely based on stage and grade; however, these prognostic features are limited in the prediction of clinical outcomes. The objective was to investigate the relation between the apparent diffusion coefficient (ADC) value and recurrence and progression of T1G3 of urothelial carcinoma after transurethral resection of the bladder tumor (TURBT) and Bacillus Calmette-Guérin instillation.

MATERIALS AND METHODS: This prospective study included 65 patients with single bladder mass T1G3 less than 3 cm without carcinoma in situ or lymphovascular invasion. Mean ADC values of the tumors were compared between patients with and without recurrence and progression following TURBT. The relation of ADC value and other factors were determined by univariate and multivariate analyses. The following tests were used to test differences for significance: difference and association of qualitative variable by χ2 test; differences between quantitative independent groups by t-test or Mann-Whitney U test; survival by Kaplan-Meier; Cox regression (or Cox proportional hazards model) was used to analyze the effect of several risk factors on time until event (recurrence and progression); correlation by Pearson or Spearman, and we calculated the most suitable cutoff and validity by receiver operating characteristic curve.

RESULTS: In relation to recurrence, smoking, nonpapillary shape and higher size, and lower ADC were significant predictors for recurrence. In relation to progression, female sex, nonpapillary shape, and lower ADC were significant predictors for progression. Multivariate analysis showed that ADC < 1.09 was the only significant independent predictors for recurrence. Also, it showed that ADC < 0.98 was the only significant independent predictors for progression.

CONCLUSION: Low ADC value group of T1G3 bladder cancer showed significant recurrence and progression than high ADC value group of T1G3 bladder cancer. ADC value in conjunction with other risk stratifications will have a promising role in stratifying patients with T1G3 who need to proceed to early radical cystectomy versus conservative treatment.