SIU 2017: MP15 – 03- EMT And CD133 Expression of Circulating Tumor Cell in Predicting Prognosis and Docetaxel-Based Treatment Effect in Metastatic Castration-Resistant Pro State Cancer

Lisbon, Portugal ( Although circulating tumor cell (CTC) enumeration in peripheral blood has already been validated as a reliable biomarker in predicting prognosis in metastatic castration-resistant prostate cancer (mCRPC), patients with favorable CTC counts (CTC < 5/7.5 ml) still experience various survival times. 

In this study, the authors attempted to explore EMT and CD133 expression of CTCs in predicting prognosis and treatment effect in mCRPC.

From January 2015 to October 2016, peripheral blood from 50 mCRPC patients treated by docetaxel based chemotherapy was collected. In addition CTC counts were performed in these blood samples using Can PatrolTM System. RNA in Situ Hybridization (RNA-ISH) was performed with epithelial tumour cells (E+) specific probes on isolated CTCs cells. PSA progression-free survival (PSA-PFS) and treatment response status were recorded in the follow-up.

Confirmed PSA response was observed in 27 (54.0%) patients treated by docetaxel based chemotherapy. The confirmed PSA response rate in M+CTCs patients was 33.3% (8/24), which was significantly lower than that of E--/E/M+CTCs patients 73.1% (19/26) (p =0.005). Moreover, patients with high/middle-level CD133 expression had a lower PSA response rate (29.4%, 5/17) compared with patients with non/low-level CD133 expression (66.7%, 22/33; p = 0.017). Also, there were significantly different PSA-PFS between M+CTCs and E--/E/M- subpopulation (2.5 vs. 7.3months, p = 0.008). High/ middle-level CD133 expression indicated poor PSA-PFS in mCRPC patients when compared to non/low-level CD133 expression (2.8 vs. 6.9 months p = 0.043).

In conclusion, detection of peripheral blood EMT and CD133 gene expression could predict PSA-PFS and docetaxel-based treatment effects in mCRPC patients.

Presented by: Li, G.

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre.Twitter: @GoldbergHanan at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal