Prognostic factors in metastatic castration resistant prostate cancer patients treated with radium-223: a retrospective study

BACKGROUND

Our study aims to identify baseline prognostic factors in metastatic castration resistant prostate cancer (mCRPC) patients treated with radium-223.

METHODS

Data about demographics, ECOG performance status, lymph node (LN) involvement, local treatment for prostate cancer, previous systemic treatments, cells blood count, PSA, ALP, albumin, LDH, bone protecting agents use (BPA), analgesic use and survival were collected. Univariable and multivariable analyses were performed.

RESULTS

Seventy-five men received radium-223 between September 2013 and December 2019. Median age was 73 years. Thirty-four (45.3%) had ECOG PS 0, 41 (54.7%) PS 1-2. In univariable analysis, LN involvement (HR 1.68, 95% CI 1.01-2.80, P=0.047), absence of local treatment on primary tumor (HR 1.93, 95% CI 1.13-3.29, P=0.016), baseline strong opioidsuse (HR 1.82, 95% CI 1.08-3.06, P=0.024), high platelets to lymphocyte ratio (PLR) (HR 1.91, 95% CI 1.06-3.45, P=0.03), high baseline ALP (HR 1.81, 95% CI 1.10-2.99, P=0.019) and high baseline LDH (HR 3.86,95% CI 2.01-7.41, P<0.001) were significantly associated with worst OS. At multivariable analysis, LN involvement, strong opioids use, baseline ALP, LDH and PLR levels were significantly associated with outcome.

CONCLUSIONS

In mCRPC patients treated with Radium-223, baseline ALP, LDH, strong opioid use, PLR, LN involvement and treatment on primary site are associated with different OS.

Role of radium-223 discontinuation due to adverse events in castration-resistant prostate cancer patients. A retrospective monocentric analysis

Background:

Radium 223 (Ra-223) was approved for the treatment of metastatic castration resistant prostate cancer (mCRPC) patients with bone-only disease, following demonstration of significant improvement in overall survival (OS). To date, there are no validated prognostic factors useful in predicting outcome of mCRPC patients treated with Ra-223. Our retrospective study aims to evaluate the prognostic role of treatment discontinuation due to adverse events in mCRPC patients treated with Ra-223, and to identify which factors correlate with the toxicity onset.

Methods:

We performed a retrospective analysis of all consecutive mCRPC patients treated with Ra-223 from September 2013 to December 2019 at our institute. Patients were divided in 2 groups according to the reason of Ra-223 therapy discontinuation: toxicity versus other causes. Outcome measures were progression-free survival (PFS) and OS.

Results:

In the overall population (75 patients) median PFS and OS were 5.46 months and 11.15 months respectively. Patients who discontinued treatment due to toxicity had a lower median PFS (3.49 vs 5.89 months, HR: 1.88, 95% CI: 1.14-3.12, p = 0.014) and OS (8.59 vs 14.7 months HR: 3.33, 95% CI: 1.85-6.01, p < 0.001) than patients who discontinued therapy due to other causes. The risk of Ra-223 discontinuation due to toxicity correlates with the number of previous treatments ( p = 0.002), previous chemotherapy treatment ( p = 0.039), baseline LDH ( p = 0.012), Hb ( p = 0.021) and platelet-to-lymphocyte ratio ( p = 0.024).

Conclusions:

Discontinuation due to toxicity is associated with worse outcomes in mCRPC patients treated with Ra-223. To reduce the risk of developing toxicities that may compromise treatment efficacy, Ra-223 should be used early in mCRPC patients.