New study below [1].
Prednisone/Prednisolone & Dexamethasone are corticosteroids - steroid hormones that "have been used in the therapy for castration-resistant prostate cancer (CRPC) for decades, both as monotherapy and in combination with additional agents." [2]
"... prednisone is distinctly different from prednisolone, but is converted to prednisolone by hepatic enzymes."
A 2015 paper [2] details a Phase II study "among chemotherapy naïve CRPC patients who had not received prior abiraterone or enzalutamide therapy."
"In an intent-to-treat analysis 41% of patients in the dexamethasone arm achieved a PSA response, while only 22% of patients in the prednisolone arm achieved a PSA response."
"Interestingly, 23 of the 36 patients randomized to prednisolone crossed over to dexamethasone at PSA progression and 19 of those patients were evaluable for PSA response. Seven of these patients (37%) achieved a PSA response to dexamethasone, which suggests a potential role for dexamethasone even after progression on prednisone therapy."
The new study (U.K., Royal Marsden) involved "75 chemotherapy and abiraterone/enzalutamide-naive CRPC patients."
The Neutrophil to Lymphocyte Ratio [NLR] is a measure of inflammation. Markers of inflammation are associated with poorer oucome. {In every situation - even when disease has not been diagnosed. Chronic low-level inflammation is something that everyone should test for & treat IMO.}
"The median NLR for all evaluable patients was 2.6 at baseline; 2.9 at 6 weeks; and 4.0 at 12 weeks." i.e. treatment increased inflammation.
"A favorable baseline NLR (less than median) associated with a 5.5-fold higher odds of a PSA >50% response"
"Higher baseline NLR (log10) associated with a shorter time to PSA progression" - risk factor = 9.5.
"NLR at 6 weeks was also associated with duration of benefit; in the favorable NLR category time to PSA progression was 10.8 months, for those who converted to an unfavorable (greater than median) category 4.5 months, and for those remaining in a unfavorable category only 1.5 months"
"Overall survival was 33.1 months ... and 21.9 months ... for those with an favorable and unfavorable baseline NLR, respectively."
Inflammation kills. My contention is that, while the disease can ramp up inflammation (via NF-kB activation), inflammation can be treated, independentantly of the disease.
"Treatment-naive CRPC patients with a high baseline or during-treatment NLR appear not to benefit from low-dose corticosteroids. The immunological implications of an unfavorable NLR, and whether corticosteroids might drive prostate cancer progression in patients harboring a high NLR, warrant further study."
...
Zytiga is usually coupled with prednisone. I don't know if Zytiga has been studied with dexamethasone. We tend to forget that the corticosteroid also has anti-Pca activity.
-Patrick
