To gather information, using a standardized database, seven institutions retrospectively collected data from January 1994 to September 2021 on patients with SUB, meeting the main inclusion criteria of BCa with soft tissue tumor histology and sarcomatoid differentiation.
The study evaluated 53 patients, with a median follow-up of 18 months (range 1-263 months). Median age at presentation was 69 years (range 16-89 years). Extra-vesical spread (T3/T4) was the most common presentation of the primary tumor in 59% of cases, and nodal metastases were identified in 35% of patients. Interestingly, unlike in urothelial carcinoma (UC) of the bladder, where distant recurrence is the primary pattern, this study reveals that rates of local and distant recurrences in SUB were 49% and 37%, respectively. Considering that around 60% of patients in this cohort showed extra-vesical spread, the high rates of local failures underscore the importance of optimizing local therapies, especially in this sub-group.
Historically, the treatment approach for SUB has been extrapolated from the management of UC of the bladder, with cystectomy and chemotherapy forming the core of a multimodality approach. Retroperitoneal sarcomas (RPS) exhibit a behavioral pattern that aligns more closely with the findings of this study, showing a higher incidence of local recurrence as the primary cause of mortality. Considering the high incidence of local recurrences following surgery, neoadjuvant radiotherapy has emerged as an attractive yet controversial option for RPS.
Despite the retrospective nature of this study, and therefore hampered by its intrinsic biases, the significant rate of local failures in this cohort leads to the hypothesis that neoadjuvant radiotherapy, as part of a multi-disciplinary approach, may play a crucial role in reducing loco-regional failure and potentially improving the survival of SUB patients, particularly in higher tumor stages (T3/T4) where achieving R0 surgery with wide margins is more challenging and outcomes are poorer.
In summary, primary SUB is a heterogeneous disease group that often appears at advanced stages with aggressive disease progression. Unlike UC, SUB tends to recur locally, suggesting the need for multimodal approaches. Continuous international collaborative efforts are necessary to offer guidance for personalized treatments based on SUB-specific indicators.
Written by: Piero Bettoli,1,2 ZhihuiAmy Liu,3 Natalia Jara,4 Federico Bakal,1 William Wong,5 Mario Terlizzi,6 Paul Sargos,6 Thomas Zilli,7 Juliette Thariat,8 Sebastian Sole,4,9 Guillaume Ploussard,10 Sharad Goyal,11 Peter Chung,3 Alejandro Berlin,3 Claudio V. Sole4,9
- Department of Radiation Oncology, Fundación Arturo López Pérez, Santiago, Chile.
- Facultad de Medicina, Universidad de Los Andes, Santiago, Chile.
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
- Department of Radiation Oncology, Instituto de Radiomedicina, Santiago, Chile
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, USA.
- Department of Radiation Oncology, Institute Bergonie, Bordeaux, France.
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
- Department of Radiation Therapy, Centre Francoise Baclese, Caen, France.
- Facultad de Medicina, Universidad Diego Portales, Santiago, Chile.
- Department of Urology, La Croix du Sud Hospital, Toulouse, France.
- Department of Radiation Oncology, George Washington University Hospital, Washington DC, USA.