Table 2. Studies on micropapillary UC reporting outcomes with either neoadjuvant chemotherapy or upfront radical cystectomy.
| Author (year) | Pathologic complete response | Pathologic downstaging | Median follow up after cystectomy | Survival outcomes after cystectomy | Major independent factor(s) other than histologic phenotype affecting response/outcomes analyzed | Comments |
|---|---|---|---|---|---|---|
| Meeks (10) (2013), n=44 (VH n=44) | Comparing those who received NAC with those who did not, pCR occurred in 45% vs. 13% (P=0.049) | Comparing those who received NAC with those who did not, pathologic downstaging was achieved in 35% vs. 47% (P=0.4) | 24 months | Patients with p T0 disease had improved survival outcomes after cystectomy at 24 months follow up. Higher survival rates (25 vs. 92%) with a longer mean time to death [72 (95% CI: 55–90) vs. 29 (95% CI: 22–37) months, P=0.004] and lower rates of disease recurrence (21 vs. 79%) with longer time to recurrence [73 (95% CI: 56–90) vs. 26 (95% CI: 17–35) months, P=0.03] | Pathologic T stage was associated with worse survival outcomes | |
| Mitra (17) (2019), n=1,497 (VH n=151) | 10.7 years for conventional UC group, 7.8 years for micropapillary VH | Inferior 5-year RFS (70% vs. 44%; P<0.01) and OS (61% vs. 38%; P<0.01) compared to conventional UC. No association with risk of recurrence or mortality on multivariable analysis | Pathologic T stage, tumor grade and lymphovascular invasion were associated with worse survival outcomes | |||
| Kamat (15) (2007), n=100 (VH n=100) | 14 of 23 patients (61%) achieved pathologic downstaging with NAC | Patients alive at 5 yrs follow up were 32% for NAC group and 71% among those treated with initial cystectomy. Median OS was 43.2 for the 23 patients in NAC group. The median survival had not been reached at time of last follow up for the 32 patients treated with initial cystectomy | In this study, 55 patients underwent RC for surgically resectable disease-≤c T4A. In this subgroup, 23 received NAC and 32 had initial cystectomy. | |||
| Fairey (22) (2014), n=1,380 (VH n=33) | 10 years | Comparing patients with conventional UC and micropapillary UC, predicted five-year OS (61% vs. 67%, log rank P=0.96) and RFS (69% vs. 58%, log rank P=0.33). Micropapillary histologic subtype was not independently associated with OS on multivariable analysis (HR 0.91, 95% CI: 0.55–1.49, P=0.70) or RFS (HR 0.97,95% CI: 0.55–1.73, P=0.92) | Controlling for clinical and pathologic factors, survival outcomes of micropapillary histologic subtype were similar to conventional UC after radical cystectomy | |||
| Compérat (23) (2010), n=72 (VH n=72) 57 patients were treated with RC stratified into three groups based on % histologic variant on TURB1. <10%2. 10–50%3. >50% |
Comparison of groups stratified based on % of micropapillary variant, mean survival was 18 months, 16.8 months and 12.1 months for <10%, 10–50% and >50% groups respectively. | Percentage of histologic variant was analyzed. Tumors with a higher percentage of histologic variant had higher likelihood of disease recurrence and death (P=0.04 and P=0.009). Pathological T stage was predictive of disease specific survival both in univariate and multivariate analysis (P=0.01 and P=0.04, respectively) | The presence of micropapillary histologic subtype in any amount including CIS had impact on clinical outcomes | |||
| Wang (27) (2012), n=821 (VH n=73) | 9.6 years | Comparing UC with micropapillary VH with conventional UC, 10-year cancer specific survival was 31% vs. 53%; P=0.001. No significant difference was noted between groups after being stage matched for 10-year RFS (62% vs. 69%; P=0.87) or CSS (31% vs. 40%; P=0.41) | Percentage of histologic variant had no correlation with worse survival outcomes | When matched to persons with conventional UC, UC with micropapillary VH was observed not to have increased rates of local/distant disease recurrence or inferior CSS after RC |
UC, urothelial carcinoma; VH, variant histology; NAC, neoadjuvant chemotherapy; pCR, pathologic complete response; RFS, recurrence free survival; RC, radical cystectomy; CSS, cancer specific survival; OS, overall survival; CIS, carcinoma-in-situ; TURB, transurethral resection of bladder tumor.