Bone Health Issues in Patients with Prostate Cancer: An Evidence-Based Review

Development and validation of two nomograms for predicting overall survival and Cancer-specific survival in prostate cancer patients with bone metastases: a population-based study

BACKGROUND

Prostate cancer with bone metastasis has significant invasiveness and markedly poorer prognosis. The purpose of this study is to establish two nomograms for predicting the overall survival (OS) and cancer-specific survival (CSS) of prostate cancer patients with bone metastasis.

METHODS

From January 2000 to December 2018, a total of 2683 prostate adenocarcinoma with bone metastasis patients were identified from the Surveillance, Epidemiology, and End Results Program (SEER) database. These patients were then divided into a training cohort and a validation cohort, with OS and CSS as the study endpoints. Correlation analyses were employed to assess the relationship between variables. Univariate and multivariate Cox analyses were utilized to ascertain the independent prognostic factors. Calibration curves and the area under the time-dependent receiver operating characteristic curve (time-dependent AUC) were employed to evaluate discrimination and calibration of the nomogram. DCA was applied to examine accuracy and clinical benefits. The clinical utility of the nomogram and the AJCC Stage System was compared using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Lastly, the risk stratifications of the nomogram and the AJCC Stage System were compared.

RESULTS

There was no collinearity among the variables that were screened. The results of multivariate Cox regression analysis showed that seven variables (age, surgery, brain metastasis, liver metastasis, lung metastasis, Gleason score, marital status) and six variables (age, surgery, lung metastasis, liver metastasis, Gleason score, marital status) were identified to establish the nomogram for OS and CSS, respectively. The calibration curves, time-dependent AUC curves, and DCA revealed that both nomograms had pleasant predictive power. Furthermore, NRI and IDI confirmed that the nomogram outperformed the AJCC Stage System.

CONCLUSION

Both nomograms had satisfactory accuracy and were validated to assist clinicians in evaluating the prognosis of PABM patients.

Prevalence and Prognostic Implications of PSA Flares during Radium-223 Treatment among Men with Metastatic Castration Resistant Prostate Cancer

Radium-223 (Ra233) prolongs the survival of men with symptomatic bone-predominant metastatic castration-resistant prostate cancer (mCRPC). However, prostate-specific antigen (PSA) response patterns are not closely associated with Ra223 therapy outcomes. Herein, we sought to analyze the impact of Ra223-induced PSA flares on patient outcome. Using a retrospective cohort study of Ra223 treatment in four Ontario/Canada cancer centres, we identified 134 patients grouped into sub-cohorts according to distinct PSA response patterns: (i) initial PSA flare followed by eventual PSA decline; (ii) PSA response (≥30% PSA decrease within 12 weeks of treatment); and (iii) PSA non-response. We analyzed patient characteristics and outcome measures, including overall survival (OS), using the Kaplan-Meier method and log-rank testing. PSA flares were observed in 27 (20.2%), PSA responses in 11 (8.2%), and PSA non-responses in 96 (71.6%) patients. Amongst PSA flare patients, 12 presented with post-flare PSA decreases below baseline and 15 with PSA decreases below the flare peak but above baseline. Although only six flare patients achieved ≥30% PSA decreases below baseline, the median OS of all flare patients (16.8 months, 95% CI 14.9-18.7) was comparable to that of PSA responders and non-responders (p = 0.349). In summary, around 20% of mCRPC patients experience Ra223-induced PSA flares, whose outcome is similar to that of men with or without PSA responses. Further studies are needed regarding suitable biochemical surrogate markers of response to Ra223.

Appropriateness and complications of androgen deprivation therapy for prostate cancer: Can we do better? A retrospective observational analysis from a referral center

INTRODUCTION

Androgen deprivation therapy (ADT) is the key of medical treatment for advanced prostate cancer (PCa), especially in elderly patients. However, the adherence of ADT prescription to current guidelines is not optimal and must be balanced against possible side effects. Aim of this study was to evaluate the prescriptive appropriateness of ADT and ADT-related adverse events in a referral center for PCa.

METHODS

Five hundred fifty six patients who received an outpatient prescription for ADT from 2014 to 2018 were retrospectively identified from an administrative database. Only standard ADT was considered, including GnRH agonists, GnRH antagonists, and antiandrogens. Prescriptive appropriateness was defined according to the last European Association of Urology (EAU) guidelines. Our cohort was stratified according to age categories and patient follow-up was updated.

RESULTS

Four hundred twenty five patients were available for analysis. Mean age was 80 years; 96.3% of our patients fell in the "elderly" category. There was a predominance of GnRH agonists over the antagonists (84.9% vs 13%). 15.5% of ADTs did not have an appropriate indication according to guidelines. Patient compliance to ADT was evaluated as good in 372 (87.5%) cases. ADT-related complications were detected in 166 (39%) patients: bone, cardiovascular, and other complications were reported in 7.3%, 8.9%, and 19% of patients. Progression of disease was noted in 165 (38.8%) cases during ADT. At last follow-up, 124 (30.1%) patients were deceased.

CONCLUSIONS

In a referral center, most ADT prescriptions followed EAU guidelines, but a non-negligible proportion still did not fall within these indications, exposing patients to unnecessary side effects. Compliance to ADT was generally good with a predominant use of GnRH agonists. Tolerance to ADT was fair, even if standardized reports were lacking.

The limitations of today’s clinical guidance: Atypical femoral fracture and long-term bone-modifying agents in the oncology setting

While bone-modifying agents such as bisphosphonates and denosumab are crucial to preventing skeletal-related events in patients with bone metastases, the optimal duration remains undefined. Extended duration may be associated with adverse effects such as osteonecrosis of the jaw and atypical femoral fracture. Although uncommon, atypical femoral fracture represents a serious consequence of prolonged bone-modifying agent use and are characterized by a prodrome and distinct radiographic findings. The oncology setting encompasses a unique set of atypical femoral fracture risk factors and considerations, with hormonal therapy in early stage disease, bone metastases in the advanced setting, and new targeted agents that may affect bone homeostasis. As outcomes in cancer treatment continue to improve, the questions of risks versus benefits of long-term bone-modifying agents and how to mitigate atypical femoral fracture risk become increasingly pertinent.