Chemohormonal therapy beneficial for Chinese men with metastatic hormone-naïve prostate cancer
Adding docetaxel to androgen deprivation therapy (ADT) can prevent prostate-specific antigen (PSA) progression and delay the development of castration resistance in Chinese patients with metastatic hormone-naïve prostate cancer, a study by the Chinese University of Hong Kong (CUHK) has shown.
“The territory-wide study included data from all six public oncology centres in Hong Kong. Compared with age- and PSA-matched patients treated with hormonal therapy alone [n=32], those treated with chemohormonal therapy [n=32] had highly significant improvements in PSA progression-free survival and castration resistance-free survival,” reported investigator Dr Jeremy Teoh of the S. H. Ho Urology Centre, Department of Surgery, CUHK, who presented the findings at the Hong Kong Society of Uro-Oncology Annual Scientific Meeting 2018.
PSA progression-free survival, the primary outcome of the study, reached a median of 20.5 months in the chemohormonal therapy group compared with a median of 8 months in the hormonal therapy group (p=0.001).
Median castration resistance-free survival was 17.7 months in patients who received chemohormonal therapy vs 8 months in those who received hormonal therapy alone (p=0.002).
However, clinical progression-free survival was not significantly different between the two groups (p=0.66).
“The lack of significant difference in clinical progression-free survival can be explained by the retrospective nature of the study. As such, there were no standardized follow-up imaging protocols, and imaging was performed only when clinically indicated. The between-group difference in clinical progression-free survival might therefore have been underestimated,” explained Teoh.
In multivariate Cox regression analyses, the use of chemohormonal therapy was the only factor significantly associated with PSA progression (hazard ratio [HR], 0.31; p=0.008) and castration resistance (HR, 0.38; p=0.015). No significant associations were found between these endpoints and patient age, baseline PSA, Gleason score, presence of visceral metastasis, or presence of diabetes, hypertension or dyslipidaemia.
None of the above factors was found to be significantly associated with clinical progression.
In the retrospective cohort study, the 32 patients treated with ADT plus docetaxel were from a recent case series that represents the first real-life experience of chemohormonal therapy in metastatic hormone-naïve prostate cancer in Asia. [Asia Pac J Clin Oncol, in press] These patients were age- and PSA-matched to a historical cohort of 32 patients with metastatic hormone-naïve prostate cancer who were treated with hormonal therapy alone.
“Among patients treated with ADT plus docetaxel, the median time to castration-resistant prostate cancer and time to PSA nadir was 19.5 months and 7 months, respectively, after a median follow-up of 11.4 months,” reported Teoh. “PSA response was achieved in all patients, and the median maximal PSA response was 99.6 percent.”
“Grade 3/4 febrile neutropenia, neutropenia and anaemia occurred in 12.5 percent, 40.6 percent and 3.1 percent of patients who received ADT plus docetaxel, respectively,” he continued.
Docetaxel was given at the standard dose of 75 mg/m2 to 31 patients (96.9 percent), with 30 patients (93.8 percent) completing ≥6 cycles. Only one patient (3.1 percent) discontinued docetaxel due to toxicity.
“The rate of neutropenia in our cohort was higher than that in the CHAARTED and STAMPEDE trials, suggesting that tolerability of docetaxel may be different between Asians and other populations,” Teoh noted.