2-weekly docetaxel in newly diagnosed high volume metastatic castration naïve prostate cancer

Abstract

Background: 3-Weekly Docetaxel improves overall survival when combined with Androgen Deprivation Therapy (ADT) in metastatic Castration Näive Prostate Cancer (mCNPC) but is associated with 30% incidence of grade 3-5 adverse events (CHAARTED Trial). 2-Weekly Docetaxel is better tolerated and results in improved overall survival compared to 3-weekly docetaxel in Castration Resistant Prostate Cancer (PROSTY Trial). We sought to determine the incidence of grade 3-4 toxicity and short term responses with 2-weekly docetaxel in high volume mCNPC patients. We also compared these outcomes to those achieved with 3-weekly docetaxel in CHAARTED Trial. Methods: 14 patients (median age 64 years) diagnosed with high volume mCNPC (CHAARTEDtrial criteria) between May-November 2016 were included. Histological diagnosis was established by TRUS guided prostate biopsy and staging was done using PSMA-PET scan in all patients. Docetaxel 50 mg/m2 every 2 weekly for 10 doses was given along with ADT. 13 patients received medical ADT and 1 patient underwent surgical castration. Patients were monitored every 2 weekly for clinical and biochemical adverse events (CTCAE 4.0). Treatment responses were evaluated clinically and serologically (serum PSA every 4-weekly). Results: Median PSA was95ng/ml (range 3.8-4000). ECOG performance status was 1 in 12 patients and 2 in 2 patients. Gleason score was 9, 8 and 7 in 4, 5 & 5 patients, respectively. Bone, lymph node and visceral metastasis were present in 13, 13 & 3 patients, respectively. All but one patient, who developed pulmonary tuberculosis after 6th cycle, completed the planned chemotherapy treatment. Treatment was well toler-ated & paronychia (2 patients) was the only grade 3 event reported in 2 patients (table). None of the patients developed grade 3-4 neutropenia or febrile neutropenia. PSA response and symptomatic improvement was seen in all patients (100%). Four (29%) patients achieved complete serological response (PSA<0.2ng/ml) which compares well with 32% reported inCHAARTED trial. Table: 271P Comparison of adverse events to CHAARTED Trial Conclusions: Within the limitations of a small retrospective study, we conclude that 2-weekly docetaxel is better tolerated and results in acceptable short term outcome meas-ures compared to standard 3-weekly docetaxel in metastatic castration naive prostate cancer.