How would you manage sarcomatoid carcinoma of the prostate with poorly differentiated adenocarcinoma that is not amenable to surgery?

There is data on this rare histologic variant, albeit limited, and often in these situations we try to extrapolate from analogous areas with more data.

It is believed that the pathogenesis of these tumors, the epithelial and sarcomatoid components, arise from a single cell of origin, rather than separate cell types. As described above, this patient has both components, and most sarcomatoid tumors of the prostate have a previous diagnosis of acinar adenocarcinoma, favoring an epithelial-mesenchymal transition. Fitting with this, and hypothesized as a driver of this transition, genomic analyses specifically of prostatic sarcomatoid tumors reveal very high rates of TP53 (~90%) and RB1 (~50%) genomic alterations (Millis et al., Journal of Clinic...

Sarcomatoid carcinoma of the prostate is too rare an entity to have specific guidelines regarding radiotherapy dosing or technique. This histology has been documented to occur in prostate cancer patients who received prior radiotherapy, which has led some authors to imply the radiation may be causative in the development of sarcomatoid differentiation. Rather, I suspect those patients presented with an unrecognized mixed histology, and the sarcomatoid element proved more resistant to the radiation therapy. This leads me to suspect that this histology is more resistant to radiotherapy and may benefit from dose escalation. So, I would recommend dose escalation via external beam micro-boost technique (similar to the FLAME study, Kerkmeijer et ...