A new study confirms that low pre-treatment serum testosterone levels significantly predict poor survival after primary treatment with androgen deprivation therapy (ADT) for metastatic, castration-resistant prostate cancer (mCRPC).
Akira Yokomizo, MD, PhD, and colleagues of Kyushu University in Fukuoka, Japan, examined the relationship of various parameters to prognosis for 56 patients with mCRPC treated with primary ADT at their institution from 2000 to 2012. These factors included pre-treatment serum testosterone, body mass index (BMI), PSA level at diagnosis, pathologic Gleason score, clinical stage, and age.
Corroborating previous research, the new study, which was published online in Anticancer Research, found that low pre-treatment serum testosterone predicted poor overall, cancer-specific, and progression-free survival after primary ADT. The median serum testosterone level was 397 ng/dL. The median overall, cancer-specific, and progression-free survival rates were 68.1, 68.9, and 23.2 months, respectively. Men with higher testosterone levels in the second to fourth quartiles showed similar survival.
“Therefore, pre-treatment testosterone may reflect the nature of how much the tumor is dependent on androgens,” the investigators suggested. “Accordingly, low serum testosterone may mean less dependency on androgen.” It is also possible that low testosterone is a cause of prostate cancer progression.
Although BMI previously has been reported to be associated with serum testosterone, the investigators found no correlation. Ethnic differences in obesity may play a role.
In the future, adding useful biomarkers, including serum testosterone level, before treatment into the J-CAPRA score system may improve its accuracy, the researchers suggested. In this study, men with low serum testosterone level had a worse prognosis from the time of development into CRPC. Novel therapies, including early use of chemotherapy and combination treatments, could be helpful.
The investigators noted the small number of participants and lack of ethnic diversity among the study’s limitations.
- Shiota M, Takeuchi A, Sugimoto M, et al. Prognostic Impact of Serum Testosterone and Body Mass Index Before Androgen-deprivation Therapy in Metastatic Prostate Cancer. Anticancer Research 35:6925-6932.