Predictive value of stathmin-1 and osteopontin expression for taxan resistance in metastatic castrate-resistant prostate cancer

OBJECTIVE Several pathways are known to be activated during metastasis and treatment of cancer. We investigated the role of osteopontin (OPN) and stathmin-1 (STHMN1) in metastatic castrate-resistant (mCRPC). METHODS We included 30 patients who received at least 6 cycles of taxane regimen for metastatic mPC in the present study. For this study retrospective data was taken from Firat University, Faculty of Medicine, Medical Oncology Department between 2009 and 2015. OPN expression and STHMN1 expression were retrospectively evaluated by immunohistochemical staining in biopsy specimens. The relationship between the expression levels of OPN and STMN1 and the response to taxane based regimen and survival was analyzed. RESULTS There was mild or strong overexpression of OPN and STHMN1 in all the patients. STHMN1 expression was mildly positive (+2) in four of the cases (13.2%) while it was strongly positive (+3) in 25 (83.4%) cases. Similarly, OPN expression was mildly positive (+2) and strongly positive (+3) in five (16.6%) and 25 (87.4%) patients, respectively. There was no significant correlation between the expression levels of STHMN1 and OPN, survival, and response to taxane based regimen (p>0.05); however, OPN overexpression showed a significant correlation with lower Gleason scores (GS) (p:0.032). CONCLUSIONS STHMN1 and OPN may be prognostic markers although they are not predictive markers of response to treatment in mCRPC. The overexpression of OPN may help identifying patients with lower GS.