PD48-05 METRIC SUB-STAGE ACCORDING TO MICRO AND EXTENSIVE LAMINA PROPRIA INVASION IMPROVES PROGNOSTICS IN T1 BLADDER CANCER

cancer. Even though a reTUR is recommended, this practice is not widely established. We have previously shown that substaging HGT1 according to the depth of lamina propria (LP) invasion allows identification of patients at low (T1a) and high (T1b) risk of progression. Herein we present the mature results of the first 200 cases treated with this optimized approach, at 5years median follow up. The main objective was the assessment of recurrence and progression rates and the secondary objective was to evaluate prognostic factors. METHODS: Since 2005, patients diagnosed at initial TUR of HGT1 have been assigned -according on the depth of invasion of muscularis mucosaeto BCG plus conventional follow up (HGT1a) or BCG followed by 2ndTUR (HGT1b) (all patients received immediate post-TUR mitomycin-C). Recurrence, time to disease recurrence, progression and time to progression, were documented. Clinical and histological features that may be associated with recurrence and progression were assessed using Cox regression in univariate analysis. RESULTS: Median age at diagnosis was 71y; 90% were males, with 89 (44.5%) cases being T1a and 111(55.5%) T1b. At a median follow up of 50m, 70 (35%) patients experienced disease recurrence or progression and the median time to disease recurrence/progression has not been reached. 41 patients (21%) had recurrent disease with both tumor size and age being significantly related to recurrence. Disease progression was observed in 29 (14.5%). 29 patients died (10 of their diseases, 8 of other cancers and 10 of other causes). Hazard ratios for progression of the variables of interests are presented in the attached Table. CONCLUSIONS: HGT1 cases invading the muscularis mucosae (HGT1b) showed an increased in risk of progression. The proposed strategy of diferring the 2ndTUR after induction of BCG and doing so only in T1b cases, allows for a global low progression rate. Besides, almost half of HGT1 cases -T1a cases-, can safely forgo a reTUR. We also confirm that tumor pattern, size and associated CIS are significantly associated with progression. Microstaging, should be encouraged to be evaluated by pathologists and contemplated in treatment strategies.