Radium-223 Treatment in Castration-Resistant Bone Metastatic Prostate Cancer

[Balsam01]

TAKE-HOME MESSAGE

•Radium-223 (223Ra) is indicated for patients with bony metastatic castrate-resistant prostate cancer. It is not known whether treatment of the primary tumor confers benefit. In this study, the authors reviewed outcomes in patients receiving 223Ra on the basis of prior radical prostatectomy (n = 16) or not (n = 28), including radiation therapy (n = 5) or no primary tumor treatment (n = 23). Demographics were similar between the two groups, including age and performance status. Fewer patients in the prostatectomy group had to interrupt therapy (25% vs 41%; P=.044), and mortality was much lower among those without a prostate at last follow-up (6% vs 43%; P=.04; median follow-up was 18 months).

•These data suggest that those with prior prostatectomy fare better with 223Ra treatment than those without prior prostatectomy, a finding that requires validation but may enhance our knowledge of prognosis and improve clinical decision-making.

– Joshua Cohn, MD

INTRODUCTION

Radium-223 (223Ra) improves symptoms and survival in patients with bone metastatic castration-resistant prostate cancer (mCRPC).

STUDY AIM

To evaluate the impact of a previous radical prostatectomy (RP) on the outcome of 223Ra therapy in mCRPC patients. The primary prostate tumor left untreated could progress during 223Ra treatment.

MATERIALS AND METHODS

mCRPC symptomatic patients treated with 223Ra were enrolled. Luteinizing Hormone-Releasing Hormone analogue was maintained. No other anticancer therapy was given. 223Ra was administered i.v. at the dose of 55 kBq/kg every 4 weeks for 6 cycles. Patients were stratified according to previous RP or not. Hematological toxicity was monitored. Statistical analysis of 223Ra discontinuations, progressions, and deaths were performed.

RESULTS

Forty-four patients were enrolled, 16 (36.4%) previously received RP, 5 (11.3%) prostate radiotherapy and 23 (52.3%) maintained the primary prostate tumor after local treatment. All patients presented only bone metastases, 24 patients (54.5%) had more than 20. Twenty-six (59.1%) patients were treated after first or second line systemic chemotherapy. Treatment interruptions occurred in 14 patients (50%) with prostate and in 4 (25%) without (P = 0.04). After a median follow-up of 18 months (6-30 months), 15 (53.6%), and 7 (43.7%) progressions (P = 0.34) and 13 and 1 (6.2%) deaths (P = 0.04) occurred in patients with and without prostate respectively.

CONCLUSION

The presence of the primary prostate tumor seems to play a detrimental role in mCRPC patients undergoing 223Ra treatment in absence of other concomitant anticancer therapy. On the other hand a previous RP might play a protective role.

Urologic Oncology: Seminars & Original Investigations

Radium-223 Treatment in Castration-Resistant Bone Metastatic Prostate Cancer. Should Be the Primary Tumor Always Treated?

Urol. Oncol 2019 Oct 07;[EPub Ahead of Print], V Serretta, MR Valerio, R Costa, V Tripoli, A Morabito, A Princiotta, C Scalici Gesolfo, N Borsellino, F Verderame, V Gebbia, M Licari, C Sanfilippo

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

[Fairwind]

While R-223 works better than nothing, a newer, more advanced radiopharmaceutical is available overseas. This compound is Lu-177 and it's undergoing trials in the U.S. but has not been approved by the FDA yet. Unlike Radium, it can attack both bone mets and soft tissue mets at the save time, giving it a considerable advantage.. Lu-177 has been used overseas for several years by thousands of patients with good results and few serious problems. Why the FDA is dragging their feet approving it in this country is a mystery.