ASCO GU 2018: Clinical Outcomes of Patients with Histologic Variants of Urothelial Carcinoma Treated with Tetra-Modality Bladder-Sparing Protocol Incorporating Consolidative Partial Cystectomy

San Francisco, CA (UroToday.com) Tri-modal therapy (TMT) enabling bladder-sparing has become an accepted treatment for selected patients with muscle-invasive bladder cancer (MIBC). As some of the histologic variants of urothelial carcinoma (VUC) are more resistant to chemotherapy and radiotherapy compared with pure urothelial carcinoma (PUC), it is still unclear whether bladder-sparing therapy provides comparable disease control in VUC. The authors report on development of a tetra-modality bladder-sparing therapy, consisting of maximal transurethral resection (TUR), chemoradiotherapy (CRT), and consolidative partial cystectomy, which has theoretical advantage in locoregional control by surgically eliminating chemo- and radio-resistant cells.

Methods:

After maximal TUR and CRT (40Gy + cisplatin), treatment response was evaluated by cytology, imaging and tumor-site re-biopsy. Complete responders were candidates for consolidative partial cystectomy, while radical cystectomy was recommended for non-responders. All VUCs identified in maximal TUR samples were categorized according to the 2004 World Health Organization Classification. Response rate to CRT, MIBC recurrence-free survival and cancer-specific survival (CSS) were compared between patients with PUC and VUC.

Results:

Between 1997 and 2016, 153 consecutive patients with cT2-3N0M0 bladder cancer (median age 69, female/male = 33/120, cT2/3 = 99/54) entered tetra-modality bladder-sparing protocol. VUC was identified in 37 (24%) of the patients, including glandular in 12 (8%), squamous in 11 (7%), micropapillary in 8 (5%), sarcomatoid in 2 (1%), microcystic in 2 (1%), and lymphoepithelioma-like in 1 (0.7%). There was no difference in the response rate to CRT between PUC and VUC (71% vs 84%, p = 0.13). Among the patients with PUC (n = 75) and VUC (n = 31) who underwent partial cystectomy, 5-yr MIBC recurrence-free rates were 92% and 100% (p = 0.21), and 5-yr CSS rates were 93% and 94% (p = 0.64), respectively.

Conclusions:

The authors concluded that tetra-modality bladder-sparing therapy incorporating partial cystectomy could provide favorable locoregional control and survival for patients with VUC.

Presented by: Toshiki Kijima, Tokyo, Japan

Co Authors: Soichiro Yoshida, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Kazutaka Saito, Kazunori Kihara, Yasuhisa Fujii; Tokyo Medical and Dental University Graduate School, Tokyo, Japan

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA

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