Stratification of patients with metastatic prostate cancer based on extent of disease on initial bone scan

A Prospective Study of the Relationship Between Clinical Outcomes After Enzalutamide and Serum Androgen Levels Measured via Liquid Chromatography-tandem Mass Spectrometry in Patients with Castration-resistant Prostate Cancer

Background

Enzalutamide (ENZ) is used to treat patients with castration-resistant prostate cancer (CRPC). However, the kinetics of serum androgens before and after ENZ treatment are unknown.

Objective

To elucidate the kinetics of serum androgens and explore the possibility of identifying a useful marker for predicting the effects of ENZ.

Design setting and participants

We conducted a prospective study from 2014 to 2018 at Gunma University Hospital and related facilities. Data were analyzed for 104 patients with CRPC treated with ENZ.

Outcome measurements and statistical analysis

We measured serum androgen levels using liquid chromatography-tandem mass spectrometry. Relationships with outcomes were assessed using multivariable Cox regression and log-rank analyses.

Results and limitations

The median age of the patients was 73 yr. Median serum testosterone, dihydrotestosterone (DHT), androstenedione, and dehydroepiandrosterone sulfate levels were 49.0, 5.8, 222.2, and 326.3 pg/ml, respectively. We performed multivariate analysis using Cox regression to predict prostate-specific antigen progression-free survival (PSA-PFS) and overall survival (OS). Hemoglobin level (≥12.5 vs <12.5 g/dl), docetaxel treatment history (no vs yes), and DHT level (≥5.9 vs <5.9 pg/ml) were significant predictors of PSA-PFS (p <  0.05). Eastern Cooperative Oncology Group performance status (0 vs. 1-2), hemoglobin level (≥12.5 vs <12.5 g/dl), presence of visceral metastasis (no vs yes), amount of bone metastasis (extent of disease 0-2 vs 3-4), and docetaxel treatment history (no vs yes) were significant predictors of OS (p <  0.05). Binomial logistic analysis of the predictors of any grade of anorexia, malaise, and fatigue showed that the presence of visceral metastasis and a low DHT level (<5.9 pg/ml) were significant.

Conclusions

Our results suggest that serum androgen levels before ENZ treatment may be useful for predicting efficacy, prognosis, and the incidence of adverse events.

Patient summary

We measured blood levels of testosterone and other male hormones before treatment with enzalutamide among men with prostate cancer resistant to castration. We found that the levels of these hormones may be useful for predicting the efficacy of enzalutamide treatment, prognosis, and the occurrence of adverse side effects.

Three-month early change in prostate-specific antigen levels as a predictive marker for overall survival during hormonal therapy for metastatic hormone-sensitive prostate cancer

Objective

To date, there are no useful markers for predicting the prognosis of metastatic hormone-sensitive prostate cancer (mHSPC). We evaluated the effect of early changes in prostate-specific antigen (PSA) levels after androgen deprivation therapy (ADT) on castration-resistant prostate cancer (CRPC) progression and overall survival (OS) in mHSPC patients.

Results

In 71 primary mHSPC patients treated with ADT, the median times to CRPC and OS were 15 months and 92 months, respectively. In multivariate analysis, a Gleason score of ≥ 8 (p = 0.004), an extent of disease value (EOD) of ≥ 2 (p = 0.004), and a 3-month PSA level > 1% of the pretreatment level (p = 0.017) were independent predictors of shorter time to CRPC. The area under the receiver operating characteristic curve was feasible at 0.822. A 3-month PSA level > 1% of the pretreatment level was an independent predictor of OS (p = 0.004). Three factors were independent predictors of shorter time to CRPC. A 3-month PSA level > 1% of the pretreatment level correlated with a poor prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05641-5.

Prognostic impact of bone metastatic volume beyond vertebrae and pelvis in patients with metastatic hormone-sensitive prostate cancer

BACKGROUND

Although bone metastasis beyond the vertebrae and pelvis has been a key factor in prognostic models of metastatic hormone-sensitive prostate cancer (mHSPC), the clinical significance of it is still unclear. The present study evaluated the prognostic impact of the volume of bone metastasis beyond the vertebrae and pelvis on the outcomes of mHSPC and created an ideal risk classification based on it.

METHODS

We retrospectively reviewed 197 patients with mHSPC who were treated with combined androgen blockade as the initial treatment between June 2003 and October 2019. We calculated the bone scan index (BSI), including the BSI beyond the vertebrae and pelvis (bBSI), using BONENAVI, and investigated the association between the BSI and the overall survival (OS) of mHSPC.

RESULTS

According to the CHAARTED criteria, 91 and 106 patients were classified into the low- and high-volume groups, respectively. Of the 79 patients who did not have visceral metastasis in the high-volume group, those with a bBSI ≤ 0.27 (n = 16) showed a favorable OS, as did those in the low-volume group. The modified CHAARTED high-volume group (presence of visceral metastases or 4 bone lesions with a bBSI > 0.27) showed a significantly shorter OS than others, with a hazard ratio (HR) of 4.69 (p < 0.001), which was higher than that observed with the original CHAARTED criteria (HR = 4.33).

CONCLUSIONS

Our data suggested that considering the volume of bone metastasis beyond the vertebrae and pelvis may help to improve the accuracy of risk classification. Further large-scale prospective studies are needed to validate our findings.

Impact of pretreatment anemia on upfront abiraterone acetate therapy for metastatic hormone-sensitive prostate cancer: a multicenter retrospective study

Background

Anemia has been a known prognostic factor in metastatic hormone-sensitive prostate cancer (mHSPC). We therefore examined the effect of anemia on the efficacy of upfront abiraterone acetate (ABI) in patients with mHSPC.

Methods

We retrospectively evaluated 66 mHSPC patients with high tumor burden who received upfront ABI between 2018 and 2020 (upfront ABI group). We divided these patients into two groups: the anemia-ABI group (hemoglobin < 13.0 g/dL, n = 20) and the non-anemia-ABI group (n = 46). The primary objective was to examine the impact of anemia on the progression-free survival (PFS; clinical progression or PC death before development of castration resistant PC) of patients in the upfront ABI group. Secondary objectives included an evaluation of the prognostic significance of upfront ABI and a comparison with a historical cohort (131 mHSPC patients with high tumor burden who received androgen deprivation therapy (ADT/complete androgen blockade [CAB] group) between 2014 and 2019).

Results

We found that the anemia-ABI group had a significantly shorter PFS than the non-anemia-ABI group. A multivariate Cox regression analysis showed that anemia was an independent prognostic factor of PFS in the upfront ABI group (hazard ratio, 4.66; P = 0.014). Patients in the non-anemia-ABI group were determined to have a significantly longer PFS than those in the non-anemia-ADT/CAB group (n = 68) (P < 0.001). However, no significant difference was observed in the PFS between patients in the anemia-ABI and the anemia-ADT/CAB groups (n = 63). Multivariate analyses showed that upfront ABI could significantly prolong the PFS of patients without anemia (hazard ratio, 0.17; P < 0.001), whereas ABI did not prolong the PFS of patients with anemia.

Conclusion

Pretreatment anemia was a prognostic factor among mHSPC patients who received upfront ABI. Although the upfront ABI significantly improved the PFS of mHSPC patients without anemia, its efficacy in patients with anemia might be limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08206-8.

Combined bone scintigraphy and fluorocholine PET/computed tomography predicts response to radium-223 therapy in patients with prostate cancer

Aim

To assess the value of bone scintigraphy and ¹⁸F-fluorocholine PET/computed tomography (CT) in predicting outcome in patients with prostate cancer and bone metastases treated with ²²³radium.

Materials & methods

Retrospective analysis of 48 patients that underwent ²²³radium therapy. End points were pain relief and overall survival.

Results

After therapy, pain relief was observed in 27 patients. Patients without pain relief had more bone lesions at PET/CT than at bone scintigraphy (pretherapy imaging mismatch). In 39 patients who completed treatment protocol, post-therapy alkaline phosphatase and pretherapy imaging mismatch were independent predictors of poor overall survival.

Conclusion

Patients with more lesions at ¹⁸F-fluorocholine PET/CT than at bone scintigraphy had a poor prognosis. The combined imaging approach could be useful to predict outcome after ²²³radium therapy.

Abiraterone acetate versus bicalutamide in combination with gonadotropin releasing hormone antagonist therapy for high risk metastatic hormone sensitive prostate cancer

The objective of this study was to compare the efficacy of abiraterone acetate with that of bicalutamide in combination with gonadotropin-releasing hormone (GnRH) antagonist treatment for patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). A total of 149 patients with mHSPC who underwent treatment at our hospital and affiliated hospitals between December 2013 and July 2020 were retrospectively identified. Fifty patients were administered abiraterone acetate (1000 mg/day) plus prednisolone (5 mg/day) with a GnRH antagonist (degarelix) (group A), and 99 patients were administered bicalutamide (80 mg/day) with a GnRH antagonist (group B). The prostate-specific antigen (PSA) progression-free survival (PSA-PFS) was significantly longer in group A than in group B. Abiraterone acetate therapy and Gleason score were significant independent factors of PSA-PFS. Using propensity score matching, 56 matched patients were obtained. The PSA-PFS (p < 0.001) and overall survival (OS) (p = 0.0071) of patients with high-risk mHSPC were significantly longer in group A of matched patients. Abiraterone acetate therapy and Gleason score were significant independent factors for PSA-PFS in matched patients. The PSA-PFS and OS of patients treated with abiraterone acetate in combination with a GnRH antagonist were significantly better than those treated with bicalutamide.

Radiotherapy in the Management of Metastatic Hormone-Sensitive Prostate Cancer: What Is the Standard of Care?

Systemic therapy has historically been the backbone of treatment for patients with metastatic disease. However, recent evidence suggests metastasis-directed therapy in those with oligometastatic disease (≤5 lesions) may improve progression-free and overall survival. Within prostate cancer-specific cohorts, metastasis-directed therapy also appears to delay the time to initiation of androgen deprivation therapy while also generally being associated with a mild toxicity profile and has thus garnered interest as a means to delay systemic therapy. Here we review the evidence surrounding the use of radiation therapy to metastatic sites in patients with metastatic hormone-sensitive prostate cancer.

Oligometastatic and Oligoprogression Disease and Local Therapies in Prostate Cancer

Our understanding of metastatic disease is rapidly advancing, with recent evidence supporting an oligometastatic state currently defined by patients having a limited (typically ≤5) number of metastatic deposits. The optimal management of these patients is also shifting toward increased integration of local therapies, with emerging evidence suggesting metastasis-directed therapy can improve overall survival. Additionally, the use of stereotactic ablative radiation therapy within castration-sensitive oligometastatic prostate cancer cohorts appears to forestall the need to initiate systemic therapy, which has unfavorable side effect profiles, such as androgen deprivation therapy, while itself being associated with little toxicity. We review the literature surrounding the use of metastasis-directed therapy in the treatment of oligometastatic prostate cancer by reviewing the evidence for its use within 3 subgroups: de novo synchronous, oligorecurrent, and oligoprogressive disease.

Differential prognostic factors in low- and high-burden de novo metastatic hormone-sensitive prostate cancer patients

Metastatic burden is a critical factor for therapy decision-making in metastatic hormone-sensitive prostate cancer. The present study aimed to identify prognostic factors in men with high- or low-metastatic burden treated with primary androgen-deprivation therapy. The study included 2450 men with de novo metastatic prostate cancer who were treated with primary androgen-deprivation therapy at 30 institutions across Japan between 2008 and 2017. We investigated the prognostic value of various clinicopathological parameters for progression-free survival (PFS) and overall survival (OS) in patients stratified by low- or high-metastatic burden. Among the 2450 men, 841 (34.3%) and 1609 (65.7%) were classified as having low- and high-metastatic burden, respectively. Median PFS of the low- and high-burden groups were 44.5 and 16.1 months, respectively, and the median OS was 103.2 and 62.7 months, respectively. Percentage of biopsy-positive core, biopsy Gleason grade group, T-stage, and N-stage were identified to be differentially prognostic. M1a was associated with worse PFS than was M1b in the low-burden group, whereas lung metastasis was associated with better PFS and OS than was M1b in the high-burden group. Differential prognostic factors were identified for patients with low- and high-burden metastatic prostate cancer. These results may assist in decision-making to select the optimal therapeutic strategies for patients with different metastatic burdens.

Machine Learning Algorithm Guiding Local Treatment Decisions to Reduce Pain for Lung Cancer Patients with Bone Metastases, a Prospective Cohort Study

INTRODUCTION

As life expectancy increases for lung cancer patients with bone metastases, the need for personalized local treatment to reduce pain is expanding.

METHODS

Patients were treated by a multidisciplinary team (MDT), and local treatment including surgery, percutaneous osteoplasty, or radiation. Visual analog scale (VAS) and quality of life (QoL) scores were analyzed. VAS at 12 weeks after treatment was the main outcome. We developed and tested machine learning models to predict which patients should receive local treatment. Model discrimination was evaluated by the area under curve (AUC), and the best model was used for prospective decision-making accuracy validation.

RESULTS

Under the direction of MDT, 161 patients in the training set, 32 patients in the test set, and 36 patients in the validation set underwent local treatment. VAS in surgery, percutaneous osteoplasty, and radiation groups decreased significantly to 4.78 ± 1.28, 4.37 ± 1.36, and 5.39 ± 1.31 at 12 weeks, respectively (p < 0.05), with no significant differences among the three datasets, and improved QoL was also observed (p < 0.05). A decision tree (DT) model that included VAS, bone metastases character, Frankel classification, Mirels score, age, driver gene, aldehyde dehydrogenase 2, and enolase 1 expression had a best AUC in predicting whether patients would receive local treatment of 0.92 (95% CI 0.89-0.94) in the training set, 0.85 (95% CI 0.77-0.94) in the test set, and 0.88 (95% CI 0.81-0.96) in the validation set.

CONCLUSION

Local treatment provided significant pain relief and improved QoL. There were no significant differences in reducing pain and improving QoL among training, test, and validation sets. The DT model was best at determining whether patients should receive local treatment. Our machine learning model can help guide clinicians to make local treatment decisions to reduce pain.

TRIAL REGISTRATION

Trial registration number ChiCRT-ROC-16009501.

Short-term outcomes of risk-adapted upfront docetaxel administration in patients with metastatic hormone-sensitive prostate cancer: a multicenter prospective study in Japan

We conducted a risk-adapted upfront docetaxel (DOC) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Here, we reported an interim analysis of the study. The study enrolled 68 patients with newly diagnosed mHSPC between 2016 and 2018. According to the presence of visceral metastasis, an EOD score ≥ 3, or prostate-specific antigen (PSA) level at 3 months of ≥ 1 ng/mL, patients were divided into low- and high-risk groups. Patients were treated with androgen deprivation therapy (ADT) with or without bicalutamide; those in the high-risk group received upfront treatment involving six cycles of DOC (70 mg/m²). Short-term treatment effect, adverse events, and quality of life (QOL) were evaluated. Fifty (73.5%) were classified in the high-risk group, and 46 (67%) received upfront ADT + DOC. In the ADT + DOC group, 43.5% (20/46) patients achieved a PSA level ≤ 0.2 ng/mL. PSA nadir and time to PSA nadir were 0.291 ng/mL and 288 days, respectively. In the ADT + DOC group, 76.1% (35/42) patients had adverse events (AEs) of grade ≥ 3. During a median follow-up of 18.5 months, 36.4% (8/22) patients in the ADT group and 43.5% (20/46) in the ADT + DOC group had CRPC. Two QOL scores including the physical status and appetite loss at 6 months significantly worsened in the ADT + DOC group but was resolved by 12 months. Upfront DOC achieved high PSA responses without long-term QOL deterioration. However, the short-term outcomes were limited. Longer follow-up is needed to determine the survival advantage.

Study of the Usefulness of Bone Scan Index Calculated From 99m-Technetium- Hydroxymethylene Diphosphonate (99mTc-HMDP) Bone Scintigraphy for Bone Metastases from Prostate Cancer Using Deep Learning Algorithms

BACKGROUND

BSI calculated from bone scintigraphy using ^99mtechnetium-methylene diphosphonate (^99mTc-MDP) is used as a quantitative indicator of metastatic bone involvement in bone metastasis diagnosis, therapeutic effect assessment, and prognosis prediction. However, the BONE NAVI, which calculates BSI, only supports bone scintigraphy using ^99mTc-MDP.

AIMS

We developed a method in collaboration with the Tokyo University of Agriculture and Technology to calculate bone scan index (BSI) employing deep learning algorithms with bone scintigraphy images using ^99mtechnetium-hydroxymethylene diphosphonate (^99mTc-HMDP). We used a convolutional neural network (CNN), enabling the simultaneous processing of anterior and posterior bone scintigraphy images named CNNapis.

OBJECTIVES

The purpose of this study is to investigate the usefulness of the BSI calculated by CNNapis as bone imaging and bone metabolic biomarkers in patients with bone metastases from prostate cancer.

METHODS

At our hospital, 121 bone scintigraphy scans using ^99mTc-HMDP were performed and analyzed to examine bone metastases from prostate cancer, revealing the abnormal accumulation of radioisotope (RI) at bone metastasis sites. Blood tests for serum prostate-specific antigen (PSA) and alkaline phosphatase (ALP) were performed concurrently. BSI values calculated by CNNapis were used to quantify the metastatic bone tumor involvement. Correlations between BSI and PSA and between BSI and ALP were calculated. Subjects were divided into four groups by BSI values (Group 1, 0 to <1; Group 2, 1 to <3; Group 3, 3 to <10; Group 4, >10), and the PSA and ALP values in each group were statistically compared.

RESULTS

Patients diagnosed with bone metastases after bone scintigraphy were also diagnosed with bone metastases using CNNapis. BSI corresponding to the range of abnormal RI accumulation was calculated. PSA and BSI (r = 0.2791) and ALP and BSI (r = 0.6814) correlated positively. Significant intergroup differences in PSA between Groups 1 and 2, Groups 1 and 4, Groups 2 and 3, and Groups 3 and 4 and in ALP between Groups 1 and 4, Groups 2 and 4, and Groups 3 and 4 were found.

CONCLUSION

BSI calculated using CNNapis correlated with ALP and PSA values and is useful as bone imaging and bone metabolic biomarkers, indicative of the activity and spread of bone metastases from prostate cancer.

Utility of whole-body diffusion-weighted magnetic resonance imaging in the management of treatment-related neuroendocrine prostate cancer

INTRODUCTION

Treatment-related neuroendocrine prostate cancer, a rare and aggressive malignancy that emerges during androgen deprivation therapy characterized by low serum prostate-specific antigen concentrations, is challenging to monitor because it is associated with predominantly visceral and lytic bone metastases.

CASE PRESENTATION

We describe the case of a 69-year-old man with treatment-related neuroendocrine prostate cancer in whom the treatment response could be monitored using whole-body diffusion-weighted magnetic resonance imaging in addition to serum concentrations of neuroendocrine markers. The patient responded well to platinum-based chemotherapy and achieved a complete response, as evidenced by these diagnostic modalities.

CONCLUSION

Our case suggests that whole-body diffusion-weighted magnetic resonance imaging is useful in disease management for treatment-related neuroendocrine prostate cancer as well as the potential evaluation of mixed responses and treatment resistance.

Assessment of a software for semi-automatically calculating the bone scan index on bone scintigraphy scans

AIMS

The incidence of bone metastases exceeds 85% in patients who die from prostate cancer. Bone scintigraphy is the most widely used method for the early detection of bone metastases in prostate cancer. We developed a software program that semi-automatically calculated the bone scan index (BSI) on technetium-99m hydroxymethylene diphosphonate bone scintigraphy scans with a computer-aided diagnosis system (CAD) and examined whether the BSI calculated using this software could replace the extent of disease (EOD) score.

METHODS

The subjects were 175 patients who were diagnosed with prostate cancer at our hospital and underwent bone scintigraphy. We analyzed receiver operating characteristic curves to determine the BSI cutoff value between EOD groups. The cutoff value was determined based on the maximum value of the sum of the sensitivity and specificity.

RESULTS

BSI cutoff values of 0.20, 1.56, and 4.56 were used to distinguish between EOD 0 and 1-4 (sensitivity [87.2%] and specificity [100.0%]), between EOD 0- and 2-4 (sensitivity [85.2%] and specificity [92.0%]), and between EOD 0-2 and 3-4 (sensitivity [88.4%] and specificity [99.2%]), respectively.

CONCLUSION

Our results suggest that this software can calculate BSI, and the software may play a role in predicting prognosis and selecting an appropriate treatment strategy. If a sufficient number of other nuclear medicine tests are performed, creating a similar CAD system is possible.

Bone scintigraphy as a gatekeeper for the detection of bone metastases in patients with prostate cancer: comparison with Ga-68 PSMA PET/CT

OBJECTIVES

Gallium-68-labeled prostate-specific membrane antigen (Ga-PSMA) positron emission tomography (PET)/computed tomography (CT) is a valuable diagnostic tool for the detection of bone metastases in patients with prostate cancer (PCa). However, bone scintigraphy (BS) with technetium-labeled diphosphonates is cheap and widely available for the same patient population. PSMA PET comes with a cost, and financial constraints in the present economic environment may require its more selective use. In this study, we aimed to compare the diagnostic performance of BS with Ga-PSMA PET/CT for the detection of bone metastases in patients with PCa and correlate the results with various clinical and biochemical variables.

MATERIALS AND METHODS

Ninety-five patients who underwent Ga-PSMA PET/CT and BS within 3 months for newly diagnosed or recurrent PCa were extracted from our database. Lesion, region and patient-based analyses were performed. Clinical and imaging follow-up was used as the reference test. Results were compared with tumor grade, serum prostate-specific antigen (PSA), and alkaline phosphatase (ALP) values.

RESULTS

On the patient-based analysis, 75% (42/56) and 98.2% (55/56) of the patients with bone metastases were correctly diagnosed by BS and Ga-PSMA PET, respectively. In 26/95 patients with equivocal lesions on BS, Ga-PSMA PET correctly reclassified skeletal involvement in 11 and excluded metastases in 15 patients BS missed bone metastases in 3 patients. The true-positive rate of BS in patients with serum ALP ≥ 120U/L and PSA ≥ 50 ng/ml was 95.8% and 87.5 respectively.

CONCLUSION

Ga-PSMA is superior to BS for the evaluation of metastatic disease in patients with PCa. However, BS can also detect bone metastases in patients with PCa with a minimum sensitivity of 75%. Biochemical data are helpful to select patients with a high pretest probability who should undergo BS first as a part of the initial workup from an economic point of view. Due to its higher cost, Ga-PSMA PET should be performed in a selective group of patients when BS results are inconclusive or metastasis-directed therapy is planned.

Efficacy of cabazitaxel and the influence of clinical factors on the overall survival of patients with castration-resistant prostate cancer: A local experience of a multicenter retrospective study

AIM

To date, the optimal sequencing of life-prolonging therapies for patients with metastatic castration-resistant prostate cancer (mCRPC) remains unclear owing to a lack of prospective trials. This study aimed to evaluate the efficacy and safety of cabazitaxel (CBZ) treatment and examine the prognostic factors for oncological outcomes in patients with mCRPC who received CBZ after docetaxel (DOC).

METHODS

This multi-institutional retrospective study included 44 patients with mCRPC who received CBZ. All enrolled patients had histologically confirmed prostate cancer (PCa) with distant metastases and had received DOC before CBZ administration. The primary endpoint was the oncological outcomes, including the overall (OS) and progression-free survival (PFS). The secondary endpoints were adverse events due to CBZ and rates of ≥30% reduction in prostate-specific antigen (PSA) levels.

RESULTS

The median follow-up period was 9.2 months (range, 0.2-34 months). During this time, 34 patients (77%) died of PCa. The median OS and PFS were 12.2 (range, 0.2-34 months) and 1.4 months (range, 0.4-17 months), respectively. According to the PSA decline rate, patients who achieved a ≥30% reduction in PSA levels had significantly longer OS than those who showed a <30% reduction in PSA levels (P = 0.002). Regarding the number of cycles of CBZ, patients who received ≥4 cycles of CBZ showed significantly longer OS than those who received <4 cycles of CBZ (P < 0.001). Patients who had visceral metastasis showed significantly shorter OS than those without visceral metastasis (P = 0.012).

CONCLUSION

This study demonstrated that CBZ was effective and safe in Japanese local patients in a real-world setting. Patients with mCRPC who received ≥4 cycles of CBZ showed a ≥30% reduction in the serum PSA levels, and did not have visceral metastasis might achieve longer OS.

The utility of a deep learning-based algorithm for bone scintigraphy in patient with prostate cancer

OBJECTIVE

Bone scintigraphy has often been used to evaluate bone metastases. Its functionality is evident in detecting bone metastasis in patients with malignant tumor including prostate cancer, as appropriate treatment and prognosis are dependent on the presence and degree of bone metastasis. The development of a deep learning-based algorithm in the field of information processing has been remarkable in recent years. We hypothesized that a deep learning-based algorithm is useful in diagnosing osseous metastases in patients with prostate cancer using bone scintigraphy. Thus, this study aims to examine the utility of deep learning-based algorithm in detecting bone metastases in patients with prostate cancer, as compared with nuclear medicine specialists.

METHODS

In total, 139 serial patients with prostate cancer, who underwent whole-body bone scintigraphy, were enrolled in this study. Each scintigraphy examination was evaluated visually and independently by nuclear medicine specialists; this was also analyzed using a deep learning-based algorithm. The number of abnormal uptakes was assessed by the nuclear medicine specialists and with a software which used the deep learning-based algorithm, and the per-patient detection rate and the per-region detection rate were then calculated. The software automatically analyzed bone scintigraphy for the presence or absence of osseous metastasis in individual patients, for the 12 body regions. The detection rates analyzed separately by the nuclear medicine specialists and using the software were then compared. The sensitivity, specificity, and accuracy by the specialist and with the software were calculated.

RESULTS

The sensitivity, specificity, and accuracy by the nuclear medicine specialists were 100%, 94.9% and 97.1%. On the other hand, they with the software were 91.7%, 87.3% and 89.2%. No statistically significant difference was determined between the per-patient detection rates assessed by the specialists versus the software. In regional assessment, there was also no statistically significant difference between most of the per-region detection rates (10 of 12 regions) by the specialists versus the results obtained by the software.

CONCLUSIONS

The software with the deep learning-based algorithm might be used as diagnostic aid in the evaluation of bone metastases for prostate cancer patients.

A novel prognostic model for Japanese patients with newly diagnosed bone‐metastatic hormone‐naïve prostate cancer

Objectives

To evaluate the prognosis of newly diagnosed patients with metastatic hormone‐naïve prostate cancer (mHNPC) and develop a novel prognostic model based on ChemoHormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) risk classifications.

Patients and methods

We retrospectively analyzed the data of 578 newly diagnosed mHNPC patients initially treated with androgen deprivation therapy. We evaluated three clinical factors, namely, CHAARTED risk classifications (high‐volume disease [HVD] vs low‐volume disease [LVD]), Gleason scores (GS, 9‐10 vs ≤8), and hemoglobin (Hb, ≤13.0 g/dL vs >13.0 g/dL), for their prognostic potential in predicting time to castration‐resistant prostate cancer (TTC) and overall survival (OS) of mHNPC patients by multivariate analysis. Moreover, we developed a novel prognostic model that consisted of significant prognostic factors.

Results

Of the entire cohort, the median TTC and OS values were 18.3 and 67.5 months, respectively. HVD, GS 9‐10, and Hb ≤13.0 g/dL were independent poor prognostic factors for both TTC and OS. We developed a novel prognostic model which could stratify mHNPC patients into four risk groups according to the numbers of poor prognostic factors: group 1, LVD with low‐risk (LVD patients without GS 9‐10 and Hb ≤13.0 g/dL); group 2, LVD with high‐risk (LVD patients with GS 9‐10, Hb ≤13.0 g/dL, or both); group 3, HVD with low‐risk (HVD patients without GS 9‐10 with or without Hb ≤13.0 g/dL); and group 4, HVD with high‐risk (HVD patients with GS 9‐10 with or without Hb ≤13.0 g/dL). The median TTC and OS of groups 1, 2, 3, and 4 were 124.8, 36.4, 17.9, and 11.2 months, and 117.2, 94.2, 67.9, and 46.2 months, respectively. A significant difference in TCC and OS was found between all groups.

Conclusion

We developed a prognostic model for mHNPC patients that consisted of CHAARTED risk classifications, GS, and Hb. Our prognostic model could significantly stratify the prognosis of patients with LVD and HVD into two groups each. This model might be a good reference for shared decision making between patients and physicians on the initial treatment for mHNPC.

Analysis of Bone Scans in Various Tumor Entities Using a Deep-Learning-Based Artificial Neural Network Algorithm-Evaluation of Diagnostic Performance

The bone scan index (BSI), initially introduced for metastatic prostate cancer, quantifies the osseous tumor load from planar bone scans. Following the basic idea of radiomics, this method incorporates specific deep-learning techniques (artificial neural network) in its development to provide automatic calculation, feature extraction, and diagnostic support. As its performance in tumor entities, not including prostate cancer, remains unclear, our aim was to obtain more data about this aspect. The results of BSI evaluation of bone scans from 951 consecutive patients with different tumors were retrospectively compared to clinical reports (bone metastases, yes/no). Statistical analysis included entity-specific receiver operating characteristics to determine optimized BSI cut-off values. In addition to prostate cancer (cut-off = 0.27%, sensitivity (SN) = 87%, specificity (SP) = 99%), the algorithm used provided comparable results for breast cancer (cut-off 0.18%, SN = 83%, SP = 87%) and colorectal cancer (cut-off = 0.10%, SN = 100%, SP = 90%). Worse performance was observed for lung cancer (cut-off = 0.06%, SN = 63%, SP = 70%) and renal cell carcinoma (cut-off = 0.30%, SN = 75%, SP = 84%). The algorithm did not perform satisfactorily in melanoma (SN = 60%). For most entities, a high negative predictive value (NPV ≥ 87.5%, melanoma 80%) was determined, whereas positive predictive value (PPV) was clinically not applicable. Automatically determined BSI showed good sensitivity and specificity in prostate cancer and various other entities. Particularly, the high NPV encourages applying BSI as a tool for computer-aided diagnostic in various tumor entities.

Clinical outcome of surgical management for symptomatic metastatic spinal cord compression from prostate cancer

BACKGROUND

Metastatic spinal cord compression (MSCC) from prostate cancer (PC) influences not only patients' prognosis but also their quality of life. However, little is known about the clinical outcome of surgery for MSCC from PC. We evaluated both the oncological and functional outcomes of decompression and reconstruction surgery for patients with symptomatic MSCC from PC.

METHODS

We assessed 19 patients who underwent decompression and reconstruction surgery for symptomatic MSCC from PC. Of these 19 patients, 8 had metastatic hormone-naïve PC (mHNPC) and 11 had metastatic castration-resistant PC (mCRPC).

RESULTS

The median age of the patients with mHNPC and mCRPC was 72 and 65 years, respectively. The median prostate-specific antigen level at the time of diagnosis of MSCC in patients with mHNPC and mCRPC was 910 and 67 ng/mL, respectively. Although two of eight patients (25.0%) with mHNPC were ambulatory preoperatively, six patients (75.0%) were ambulatory postoperatively. Among 11 patients with mCRPC, only 3 (27.3%) were ambulatory preoperatively, while 6 (54.5%) were ambulatory postoperatively. The median postoperative overall survival among patients with mHNPC and mCRPC were not reached and 8 months, respectively.

CONCLUSIONS

Decompression and reconstruction surgery for symptomatic MSCC from PC might contribute to a favorable functional outcome among men with mHNPC and mCRPC. However, its role in improving the oncological outcome remains unclear. The treatment strategy should be chosen by shared decision-making among patients, urologists, radiation oncologists, and orthopedic surgeons.

Prognosis and safety of radium‐223 with concurrent abiraterone acetate or enzalutamide use for metastatic castration‐resistant prostate cancer: Real‐world data of Japanese patients

Objectives

To evaluate the real‐world data on the efficacy and safety of a combination therapy with radium‐223 (Ra‐223) and second‐generation androgen‐receptor targeting agents (ARTAs), including abiraterone acetate (ABI) and enzalutamide (ENZ), among Japanese patients with bone metastatic castration‐resistant prostate cancer (CRPC).

Patients and methods

We retrospectively reviewed 79 patients with bone metastatic CRPC who were treated with Ra‐223. The number of patients with concurrent ARTA use was 24:17 receiving ABI and 7 receiving ENZ. We evaluated the overall survival (OS) according to ARTA use and compared the survival of patients treated with Ra‐223 with or without ARTA using multivariate analysis.

Results

The median survival in the entire cohort was 23.5 months. The patients receiving Ra‐223 combined with ARTA showed a tendency of better OS than patients treated with Ra‐223 alone, although no significant difference was observed (median OS, 26.5 vs 23.5 months; P = .115). A multivariate analysis showed that the extent of disease on bone scan (EOD) scores and pain at baseline were significant predictors of OS. The concurrent use of bone‐modifying agents (BMAs) was not significant for favorable OS (P = .050). However, the concurrent use of second‐generation ARTA was not a significant factor for OS. Regarding safety, a bone fracture occurred in only one (4.2%) of 24 patients treated with combined Ra‐223 and ARTA therapy.

Conclusion

Our real‐world data analysis suggested that Ra‐223 combined with a second‐generation ARTA is well tolerated in Japanese patients. The EOD score and pain at baseline are significant prognostic factors for OS, but the concurrent use of second‐generation ARTA has no influence on OS among men treated with Ra‐223. The concurrent use of BMA yields a marginally favorable OS.

Validation of the 3-variable prognostic score (3-PS) in mCRPC patients treated with 223Radium-dichloride: a national multicenter study

Objective

Radium-223 (²²³Ra) has been approved for treatment in patients with metastatic castration-resistant prostatic cancer (mCRPC) and bone metastasis. This α-emitting radionuclide has a beneficial effect on pain and is also capable to increase overall survival (OS). Several studies evaluated the prognostic value of different biomarkers at baseline, such as serum values, imaging parameters or pain. To date, however, clinicians lack a validated and simple system to assess which patients will most likely benefit from ²²³Ra treatment. The 3-variable prognostic score (3-PS), proposed in a single-center study in 2017 classifies patients in five prognostic groups with a specific OS. This study aims to validate the 3-PS in a larger multicenter population.

Methods

Four hundred and thirty mCRPC patients treated with ²²³Ra from six different centers were analyzed. The 3-PS score consists of the collection of baseline hemoglobin, prostatic specific antigen and Eastern cooperative oncology group performance status and was initially applied to the whole population (total group). The score was then validated on the 338 patient’s subgroup (clean group) obtained by subtracting the 92 patients enrolled for the original study of the 3-PS score. This purified group served as further validation evidence.

Results

Statistical analysis showed that the 3-PS score was valid on the total group as well as in the clean group as the AUC estimated (0.74) falls within the CI of the AUC calculated on the validation sample (95% CI 0.66–0.82).

Conclusion

This study confirms the validity of the 3-PS score for mCRPC patients. This score is simple, noninvasive and affordable and can be easily used to select patients that will most probably complete ²²³Ra treatment. In addition, this tool provides an exact estimate of life expectancy in terms of OS.

Size of pelvic bone metastasis as a significant prognostic factor for metastatic prostate cancer patients

INTRODUCTION

To investigate the potential prognostic value of image analysis of pelvic bone metastasis in newly diagnosed prostate cancer patients.

METHODS

Data from 69 patients with both bone scintigraphy and pelvic CT images were selected for this analysis. Open source software (3D Slicer version 4.8.1.) was used for image analysis. Metastatic pelvic bone lesions were manually contoured, and radiomic features were extracted. As risk factors for overall survival (OS) and cause-specific survival (CSS), 105 radiomic features and clinical risk factors including age, initial prostate-specific antigen, Gleason score, TNM stage, lactate dehydrogenase (LDH), hemoglobin (Hb), alkaline phosphatase, extent of disease, visceral metastases, and radiotherapy were assessed by uni- and multivariate analyses.

RESULTS

Median follow-up was 41 months (range 0-157 months). Five-year overall survival and cause-specific survival rate were 37.9% and 43.5%, respectively. After multivariate analysis, LDH, Hb, and "maximum 2D diameter" defined as maximum tumor size in the axial plane were detected as risk factors for OS. Gleason sum, LDH, and maximum 2D diameter were detected as risk factors for CSS.

CONCLUSION

Maximum 2D diameter was detected as a significant prognostic factor for metastatic prostate cancer patients.

Evaluation of bone metastasis burden as an imaging biomarker by quantitative single-photon emission computed tomography/computed tomography for assessing prostate cancer with bone metastasis: a phantom and clinical study

Metabolic bone volume (MBV), standardized uptake value (SUV), and total bone uptake (TBU) are new imaging biomarkers for quantitative bone single-photon emission computed tomography/computed tomography. The purpose of this study was to validate the quantitative accuracy and utility of MBV, SUV_mean, and TBU for the assessment of bone metastases in prostate cancer. We used a bone-specific phantom with four hot spheres (φ = 13, 17, 22, 28 mm) filled with different Tc-99 m activities to simulate uptake ratios of 3 and 7, corresponding to normal and metastatic values. We calculated the error ratio (%Error) by comparing MBV, SUV_mean, and TBU with true values for various parameters, including bone lesion size, uptake ratio, and SUV cut-off level. Differences for MBV, SUV_mean, TBU, and bone scan index (BSI) were calculated to verify their utility in assessing bone metastases. Receiver-operating characteristic curve (ROC) analysis was performed to calculate the area under the curve (AUC) for each biomarker. MBV, SUV_mean, and TBU were affected by lesion size, uptake ratio, and SUV cut-off level; however, TBU demonstrated the most stable %Error. The TBU %Error was within 15% in spheres 17 mm or larger when the SUV cut-off level was 7, regardless of the uptake ratio. The ROC analyses revealed the AUCs of BSI (0.977) and TBU (0.968). Additionally, TBU was able to assess bone metastasis when BSI provided false-negative results, but TBU also provided false-positive results by degenerative changes. The synergy between TBU and BSI could potentially improve diagnostic accuracy.

Blood platelet volume predicts treatment-specific outcomes of metastatic castration-resistant prostate cancer

BACKGROUND

In the present guidelines for the management of metastatic castration-resistant prostate cancer (mCRPC), it is unclear who benefits most from androgen receptor axis-targeted agents (ARATs) or docetaxel as the first-line treatment.

METHODS

We conducted a retrospective study to explore new treatment-specific biomarkers in mCRPC. A total of 211 patients with mCRPC who received either ARAT or docetaxel as first-line treatment were included. Patients were compared for radiographic progression and prostate-specific antigen (PSA) progression. Multivariable Cox regression models were used to assess the association between pretreatment biomarkers and risk of events. The statistical interaction between biomarkers and clinical outcomes was also evaluated.

RESULTS

Of all analyzed biomarkers, multivariable Cox regression models identified MPV [≤ median (9.7 fL)] as an independent prognostic factor of radiographic progression [hazard ratio (HR), 2.35; 95% confidence interval (CI), 1.15-4.80; P = 0.019] and PSA progression (HR, 1.96; 95% CI, 1.01-3.95; P = 0.048) in patients treated with ARAT, whereas such associations were not observed in those treated with docetaxel. Interaction analyses showed that those initially treated with docetaxel have lower risk of radiographic progression (HR, 0.33; 95% CI, 0.13-0.79; P = 0.014) and PSA progression (HR, 0.48; 95% CI, 0.23-0.98; P = 0.044) than ARAT when MPV was small.

CONCLUSIONS

The present study identified pretreatment MPV as a significant treatment-specific prognostic factor of PSA and radiographic progression in patients with mCRPC who received first-line treatment. Furthermore, our results suggested that those with small MPV may better be treated initially with docetaxel than ARAT.

The cytoreductive prostatectomy in metastatic prostate cancer: what the individual trials are hoping to answer

OBJECTIVE

To review the ongoing randomised trials of cytoreductive prostatectomy (CRP) in de novo hormone-sensitive metastatic prostate cancer (HSPC) in order to identify their goals and assess their strengths and weaknesses.

METHODS

PubMed, MEDLINE and clinical trials websites searches were performed to identify currently ongoing trials of CRP in de novo HSPC.

RESULTS

Nine randomised clinical trials in CRP were identified and included: Southwest Oncology Group (SWOG) 1802, Surgery in Metastatic Carcinoma of Prostate (SIMCAP), Adjuvant Treatments to the Local Tumour for Metastatic Prostate Cancer: Assessment of Novel Treatment Algorithms (IP2-ATLANTA), Testing Radical prostatectomy in men with prostate cancer and oligoMetastases to the bone (TRoMbone), Impact of Radical Prostatectomy as Primary Treatment in Patients with Prostate Cancer with Limited Bone Metastases (g-RAMPP), Cytoreductive Prostatectomy vs Cytoreductive Prostate Irradiation as a Local Treatment Option for Metastatic Prostate Cancer: a Multicentric Feasibility Trial (LoMP II), Androgen-Deprivation Therapy or Androgen-Deprivation Therapy Plus Definitive Treatment (Radiation or Surgery) (FUSCC-OMPCa), and the Testing Radical Prostatectomy in Chinese Men with Prostate Cancer and oligoMetastases to the Bone study. Each study was different; assessing various primary outcome measures including overall survival (OS), progression-free survival and feasibility to randomise between standard therapy and CRP or between radiation therapy and CRP in the metastatic setting. In the oligometastatic setting, the trials assess OS, feasibility to randomise and time to castration resistance. Similarly, a number of secondary endpoints ranging from cancer-specific outcomes to quality-of-life outcomes are being investigated. The inclusion criteria in these trials also varied in terms of volume of metastatic disease (oligometastatic to high-volume metastatic disease), diagnosis of metastases (imaging based vs biopsy confirmed), imaging modalities used (conventional to newer modalities), as well as outcomes and follow-up regimes.

CONCLUSION

While there are differences in each protocol, each trial aims to address different aspects of CRP in de novo HSPC. Therefore, the specific goals of each study and the limitations have to be taken into consideration when interpreting the results of these trials.

Fracture risk and survival outcomes in metastatic castration-resistant prostate cancer patients sequentially treated with abiraterone acetate and RADIUM-223

PURPOSE

To evaluate the fracture risk and survival outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC) who received sequentially abiraterone acetate (AA) and radium 223 [223Ra]RaCl₂ in the daily clinical practice.

MATERIALS

We retrospectively reviewed the records of mCRPC patients who received [223Ra]RaCl₂ immediately after progressing during an AA treatment line in everyday clinical practice.

RESULTS

We reviewed data of a consecutive series of 94 mCRPC patients. Most of the patients (85.1%) received [223Ra]RaCl₂ as second- or third-line treatment. [223Ra]RaCl₂ treatment was well-tolerated; there were only four cases of grade 3 anaemia, two cases of grade 3 leukopenia and one case of grade 3 neutropenia. The overall fracture rate is 2.1%; one fracture was recorded during the course of [223Ra]RaCl₂ treatment, and one was recorded 1 month after its end. The fractures both occurred at metastatic sites. Median OS from [223Ra]RaCl₂ start was more than 14 months regardless of the treatment line when [223Ra]RaCl₂ was administered.

CONCLUSION

The findings of this study show that the treatment with [223Ra]RaCl₂ immediately after AA was active and safe with a very low risk of a fracture. Thus, the present observational report makes a valuable contribution to the current debate concerning the risks and benefits of including [223Ra]RaCl₂ in the therapeutic algorithm.

How many bone metastases may be defined as high-volume metastatic prostate cancer in Asians: A retrospective multicenter cohort study

BACKGROUND

Recent landmark randomized trials (CHAARTED and LATITUDE studies) have highlighted potent upfront therapy for "high-volume" and "high-risk" metastatic castration-naïve prostate cancer (mCNPC). However, treatment response shows racial differences. We aimed to propose a novel definition for "high-volume" prostate cancer in Asians.

METHODS

We retrospectively pursued 426 patients with de novo mCNPC from multiple institutions between 1999 and 2017. All patients received androgen deprivation therapy alone as initial treatment. We evaluated the number of bone metastases at diagnosis to clarify the clinical significance for progression-free survival and overall survival (OS). Statistical analyses were conducted using the Mann-Whitney U test, Cox proportional hazard models, and Kaplan-Meier methods.

RESULTS

Median age and prostate-specific antigen level were 73 years and 266.2 ng/ml, respectively. Median OS was 55.5 months in patients who met the CHAARTED high criteria (vs 33.1 months in the trial). We evaluated 5 thresholds in the number of bone metastases (≥4, ≥6, ≥11, ≥16, and ≥21) to investigate the prognostic values. Patients with ≥11 bone metastases showed the highest HR for OS (2.766). Patients with 11 to 20 bone metastases had a significantly shorter OS than those with ≤10 metastases (P = .0001). We, therefore, proposed modified CHAARTED and LATITUDE high criteria (extending bone metastases ≥11). In multivariate analysis, the modified criteria were the only independent prognostic factors for OS (P = .0272 and P = .042, respectively). Conversely, no significant differences in OS were seen between patients with 1 to 3 bone metastases and 4 to 10 (P = .7513).

CONCLUSION

Our exploratory study suggested ≥11 bone metastases as a suitable definition for "high-volume" prostate cancer in Asians. A larger, prospective study is warranted to verify our findings.

Diagnostic performance of a computer-assisted diagnostic system: sensitivity of BONENAVI for bone scintigraphy in patients with disseminated skeletal metastasis is not so high

Purpose

Bone scintigraphy (BS) of disseminated skeletal metastasis is sometimes misinterpreted as normal. The use of computer-assisted diagnosis (CAD) may resolve this problem. We investigated the performance of a CAD system, BONENAVI, in the diagnosis of disseminated skeletal metastasis.

Methods

Cases of disseminated skeletal metastasis were selected from a BS log. These patients’ BSs were analyzed by BONENAVI to obtain an artificial neural network (ANN) and bone scan index (BSI). Clinical features (type of primary cancer, CT type, and BS type) were compared with the BONENAVI (ANN and BSI) results. The BS findings (diffuse increased axial skeleton uptake, inhomogeneity of uptake, proximal extremity contrast, and degree of renal uptake) and ANN or BSI were evaluated. Then, negative ANN patients were presented.

Results

Fifty-four patients were diagnosed as having disseminated skeletal metastasis. Regarding the primary cancers, 12 had prostate cancer, 16 gastric cancers, 16 breast cancers, and 10 miscellaneous cancers. Total sensitivity of ANN (≥ 0.5) was 76% (41/54). ANN values correlated with the BS type among clinical features. Diffuse increased axial skeleton uptake was mostly correlated with ANN of the BS findings.

Conclusion

The BONENAVI CAD system was partially helpful in diagnosing disseminated skeletal metastasis, but the sensitivity of BONENAVI was not sufficient and underestimated the disseminated skeletal metastasis. Further improvement of this CAD system is necessary to improve the detectability of disseminated skeletal metastasis.

Clinical outcomes and prognostic factors in patients with newly diagnosed metastatic prostate cancer initially treated with androgen deprivation therapy: a retrospective multicenter study in Japan

PURPOSE

Clinical outcomes of patients with newly diagnosed metastatic hormone-naïve prostate cancer (mHNPC) and initially treated with androgen deprivation therapy (ADT) were evaluated.

METHODS

The medical records of 605 consecutive mHNPC patients with initial ADT or combined androgen blockade (CAB) at nine study centers between 2008 and 2016 were retrospectively reviewed. Castration-resistant prostate cancer (CRPC)-free and overall survival (OS) were estimated by the Kaplan-Meier method. The association of pretreatment risk factors with CRPC-free survival and OS was evaluated by Cox proportional hazard models and differences in survival were classified by the number of risk factors.

RESULTS

Median follow-up was 2.95 years, median CRPC-free survival was 21.9 months and median OS was 5.37 years. Multivariable analysis found that four risk factors, a Gleason score ≥ 9, lymph node metastasis, an extent of disease score ≥ 2, and serum LDH of > 220 IU were independently associated with both CRPC-free survival and OS. Median CRPC-free survival of low-risk patients with no or one factor was 86.5 months, 17.9 months in intermediate-risk patients with two or three factors, and 11.0 months in high-risk patients with four factors. Median OS was 4.72 years in intermediate- and 2.44 years in high-risk patients. It was not reached in low-risk patients.

CONCLUSION

In this series, CRPC-free and OS of a subset of mHNPC patients in Japan who were treated with ADT or CAB had better CRPC-free and overall survivals in Japan. Risk-adapted treatment based on the presence of novel prognostic factors may be beneficial for selected mHNPC patients.

METastasis Reporting and Data System for Prostate Cancer as a Prognostic Imaging Marker in Castration-resistant Prostate Cancer

BACKGROUND

METastasis Reporting and Data System for Prostate Cancer (MET-RADS-P) has been proposed as a standard of data acquisition and interpretation for whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) performed in men with advanced prostate cancer. The aim of this study is to demonstrate the clinical significance of the scores in castration-resistant prostate cancer (CRPC).

MATERIALS AND METHODS

We retrospectively evaluated WB-DWI obtained from 72 patients with CRPC between 2014 and 2017, when disease progression was suspected at the time of starting a new line of anticancer therapy. Twenty-five (35%) and 30 (42%) patients had a treatment history that included taxane-based chemotherapy and new hormonal drugs, respectively.

RESULTS

Active bone metastases were identified in 60 patients (83%; number of bone metastasis = 0, 1-2, 3-5, 6-10, and > 10: n = 12 [17%], 20 [28%], 11 [15%], 1 [1%], and 28 [39%], respectively). Progressive lymph node and visceral metastases were identified in 10 (14%) and 4 (6%), respectively. During the median follow-up period of 24 months, 36 (50%) died of prostate cancer. Cancer-specific survival (CSS) was significantly stratified according to the MET-RADS-P scores of osseous metastatic burden and the presence of visceral metastasis (P < .0001). Multivariate analysis revealed that high osseous metastatic burden (> 10) and the presence of visceral metastasis were significant indicators of shorter CSS (P = .0036 and P = .0017, respectively).

CONCLUSIONS

The extent of bone metastasis and the presence of visceral metastasis on WB-DWI were associated with a shorter CSS in CRPC. MET-RADS-P score can be a prognostic imaging biomarker for CRPC.

Automated measurement of bone scan index from a whole-body bone scintigram

Purpose

We propose a deep learning-based image interpretation system for skeleton segmentation and extraction of hot spots of bone metastatic lesion from a whole-body bone scintigram followed by automated measurement of a bone scan index (BSI), which will be clinically useful.

Methods

The proposed system employs butterfly-type networks (BtrflyNets) for skeleton segmentation and extraction of hot spots of bone metastatic lesions, in which a pair of anterior and posterior images are processed simultaneously. BSI is then measured using the segmented bones and extracted hot spots. To further improve the networks, deep supervision (DSV) and residual learning technologies were introduced.

Results

We evaluated the performance of the proposed system using 246 bone scintigrams of prostate cancer in terms of accuracy of skeleton segmentation, hot spot extraction, and BSI measurement, as well as computational cost. In a threefold cross-validation experiment, the best performance was achieved by BtrflyNet with DSV for skeleton segmentation and BtrflyNet with residual blocks. The cross-correlation between the measured and true BSI was 0.9337, and the computational time for a case was 112.0 s.

Conclusion

We proposed a deep learning-based BSI measurement system for a whole-body bone scintigram and proved its effectiveness by threefold cross-validation study using 246 whole-body bone scintigrams. The automatically measured BSI and computational time for a case are deemed clinically acceptable and reliable.

Prognostic Value of Hemoglobin in Metastatic Hormone-sensitive Prostate Cancer: A Systematic Review and Meta-analysis

The purpose of this study was to assess the prognostic value of hemoglobin (Hb) in patients with metastatic hormone-sensitive prostate cancer (HSPC). The PUBMED, Web of Science, Cochrane Library, and Scopus databases were searched in December 2019 according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Studies were deemed eligible if they compared patients with HSPC with normal and low Hb levels to determine their ability to predict overall survival, cancer-specific survival, progression-free survival, and castration-resistant prostate cancer-free survival. Formal meta-analyses were performed for these outcomes. The systematic review identified 25 studies including 6614 patients; 21 studies comprising 5782 patients were eligible for meta-analysis. Low Hb levels were associated with worse overall survival (pooled hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.15-1.29), cancer-specific survival (pooled HR, 1.46; 95% CI, 1.24-1.72), progression-free survival (pooled HR, 1.21; 95% CI, 1.14-1.28), and castration-resistant prostate cancer-free survival (pooled HR, 1.37; 95% CI: 1.18-1.57). Subgroup analyses revealed that low Hb levels were also associated with poor overall survival in patients with both "high-volume" (pooled HR, 1.49; 95% CI, 1.29-1.72) and "low-volume" HSPC (pooled HR, 1.40; 95% CI, 1.13-1.73). This meta-analysis revealed that low Hb serum levels in patients with metastatic HSPC were associated with increased risks of overall mortality, cancer-specific mortality, disease progression, and biochemical recurrence. Furthermore, Hb levels were independently associated with overall survival in the "high-volume" and "low-volume" HSPC subgroups. Therefore, it might be useful to incorporate Hb testing into prognostic tools for metastatic HSPC.

Prognostic value of alkaline phosphatase in hormone-sensitive prostate cancer: a systematic review and meta-analysis

Purpose

To assess the prognostic value of alkaline phosphatase in patients with hormone-sensitive prostate cancer.

Methods

A systematic review and meta-analysis was performed using the PUBMED, Web of Science, Cochrane Library, and Scopus in April 2019 according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Studies were deemed eligible if they compared hormone-sensitive prostate cancer patients with high vs. low alkaline phosphatase to determine its predictive value for overall survival, cancer-specific survival, and progression-free survival. We performed a formal meta-analysis of these outcomes.

Results

42 articles with 7938 patients were included in the systematic review and 28 studies with 5849 patients for the qualitative assessment. High alkaline phosphatase was associated with worse overall survival (pooled HR 1.72; 95% CI 1.37−2.14) and progression-free survival (pooled HR 1.30; 95% CI 1.10−1.54). In subgroup analyses of patients with “high-volume” and “low-volume”, alkaline phosphatase was associated with the overall survival (pooled HR 1.41; 95% CI 1.21−1.64 and pooled HR 1.64; 95% CI, 1.06−2.52, respectively).

Conclusions

In this meta-analysis, elevated serum levels of alkaline phosphatase were associated with an increased risk of overall mortality and disease progression in patients with hormone-sensitive prostate cancer. In contrast, those were not associated with an increased risk of cancer-specific mortality. Alkaline phosphatase was independently associated with overall survival in both patients with “high-volume” and “low-volume” hormone-sensitive prostate cancer. Alkaline phosphatase may be useful for being integrated into prognostic tools that help guide treatment strategy, thereby facilitating the shared decision making process.

Cytoreductive treatment strategies for de novo metastatic prostate cancer

In the past decade, a revolution in the treatment of metastatic prostate cancer has occurred with the advent of novel hormonal agents and life-prolonging chemotherapy regimens in combination with standard androgen-deprivation therapy. Notwithstanding, the use of systemic therapy alone can result in a castrate-resistant state; therefore, increasing focus is being placed on the additional survival benefits that could potentially be achieved with local cytoreductive and/or metastasis-directed therapies. Local treatment of the primary tumour with the established modalities of radiotherapy and radical prostatectomy has been explored in this context, and the use of novel minimally invasive ablative therapies has been proposed. In addition, evidence of the potential clinical benefits of metastasis-directed therapy with ionizing radiation (primarily stereotactic ablative radiotherapy) is accumulating. Herein, we summarize the pathobiological rationale for local cytoreduction and the potentially systemic immunological responses to radiotherapy and ablative therapies in patients with metastatic prostate cancer. We also discuss the current evidence base for a cytoreductive strategy, including metastasis-directed therapy, in the current era of sequential multimodal therapy incorporating novel treatments. Finally, we outline further research questions relating to this complex and evolving treatment landscape.

Changes in conditional net survival and dynamic prognostic factors in patients with newly diagnosed metastatic prostate cancer initially treated with androgen deprivation therapy

BACKGROUND

The purpose of this study was to identify predictive factors associated with conditional net survival in patients with metastatic hormone-naive prostate cancer (mHNPC) initially treated with androgen deprivation therapy (ADT).

METHODS

At nine hospitals in Tohoku, Japan, the medical records of 605 consecutive patients with mHNPC who initially received ADT were retrospectively reviewed. The Pohar Perme estimator was used to calculate conditional net cancer-specific survival (CSS) and overall survival (OS) for up to 5 years subsequent to the diagnosis. Using multiple imputation, proportional hazard ratios for conditional CSS and OS were calculated with adjusted Cox regression models.

RESULTS

During a median follow up of 2.95 years, 208 patients died, of which 169 died due to progressive prostate cancer. At baseline, the 5-year CSS and OS rates were 65.5% and 58.2%, respectively. Conditional 5-year net CSS and OS survival gradually increased for all the patients. In patients given a 5-year survivorship, the conditional 5-year net CSS and OS rates improved to 0.906 and 0.811, respectively. Only the extent of disease score (EOD) ≥2 remained a prognostic factor for CSS and OS up to 5 years; as survival time increased, other variables were no longer independent prognostic factors.

CONCLUSIONS

The conditional 5-year net CSS and OS in patients with mHNPC gradually increased; thus, the risk of mortality decreased with increasing survival. The patient's risk profile changed over time. EOD remained an independent prognostic factor for CSS and OS after 5-year follow-up. Conditional net survival can play a role in clinical decision-making, providing intriguing information for cancer survivors.

Treatment strategy for metastatic prostate cancer with extremely high PSA level: reconsidering the value of vintage therapy

The prognostic significance of initial prostate-specific antigen (PSA) level for metastatic prostate cancer remains uncertain. We investigated the differences in prognosis and response to hormonal therapies of metastatic prostate cancer patients according to initial PSA levels. We analyzed 184 patients diagnosed with metastatic prostate cancer and divided them into three PSA level groups as follows: low (<100 ng ml⁻¹), intermediate (100–999 ng ml⁻¹), and high (≥1000 ng ml⁻¹). All patients received androgen deprivation therapy (ADT) immediately. We investigated PSA progression-free survival (PFS) for first-line ADT and overall survival (OS) within each of the three groups. Furthermore, we analyzed response to antiandrogen withdrawal (AW) and alternative antiandrogen (AA) therapies after development of castration-resistant prostate cancer (CRPC). No significant differences in OS were observed among the three groups (P = 0.654). Patients with high PSA levels had significantly short PFS for first-line ADT (P = 0.037). Conversely, patients in the high PSA level group had significantly longer PFS when treated with AW than those in the low PSA level group (P = 0.047). Furthermore, patients with high PSA levels had significantly longer PFS when provided with AA therapy (P = 0.049). PSA responders to AW and AA therapies had significantly longer survival after CRPC development than nonresponders (P = 0.011 and P < 0.001, respectively). Thus, extremely high PSA level predicted favorable response to vintage sequential ADT and AW. The current data suggest a novel aspect of extremely high PSA value as a favorable prognostic marker after development of CRPC.

Prognostic significance of early changes in serum biomarker levels in patients with newly diagnosed metastatic prostate cancer

We evaluated the impact of early changes in serum biomarker levels on the survival of patients with metastatic hormone-sensitive prostate cancer (mHSPC) who were initially treated with androgen deprivation therapy (ADT). We retrospectively investigated 330 patients with mHSPC whose serum maker levels were at baseline and at 2–4 months. An optimal Cox regression model was established with the highest optimism-corrected concordance index based on 10-fold cross-validation. The median cancer-specific survival (CSS) and overall survival (OS) were 7.08 and 6.47 years (median follow-up, 2.53 years), respectively. In the final optimal Cox model with serum biomarker levels treated as time-varying covariates, prostate-specific antigen (PSA), hemoglobin (Hb), and alkaline phosphatase (ALP) significantly increased the risk of poor survival in the context of both CSS and OS. Kaplan–Meier curves stratified by the three risk factors of high PSA, low Hb and high ALP desmondtated that median OS were not reached with none of these factors, 6.47 years with one or two factors, and 1.76 years with all three factors.Early changes in serum biomarker levels after ADT may be good prognostic markers for the survival of patients with mHSPC.

Bone Scintigraphy in Staging of Newly Diagnosed Prostate Cancer in Regard of Different Risk Groups

Objectives

Prostate cancer (PC) is the most common cancer in men over 50 years of age. Bone scintigraphy is still performed in many institutions at the time of primary diagnosis. We aimed to evaluate the role of bone scan in the primary staging of PC in regard of different risk groups.

Methods

A retrospective analysis of bone scans in 296 patients (mean age 64±6 y) acquired at the time of primary diagnosis was performed in our institution. The median prostate specific antigen (PSA) was 6.73 ng/ml, all patients had a Gleason score of >5.

Results

Only 11/296 patients had a positive bone scan, 1 being in the intermediate risk group, 10 in the high-risk group and none in the low-risk group according to D'Amico classification.

Conclusion

Our results support the few published studies that less than 10% of patients with newly diagnosed PC by biopsy would develop bone metastasis, all in the intermediate or high-risk groups. Therefore, a staging by bone scan can only be recommended in patients with intermediate or high-risk, or symptomatic patients only.

Fully automated analysis for bone scintigraphy with artificial neural network: usefulness of bone scan index (BSI) in breast cancer

OBJECTIVE

Artificial neural network (ANN) technology has been developed for clinical use to analyze bone scintigraphy with metastatic bone tumors. It has been reported to improve diagnostic accuracy and reproducibility especially in cases of prostate cancer. The aim of this study was to evaluate the diagnostic usefulness of quantitative bone scintigraphy with ANN in patients having breast cancer.

PATIENTS AND METHODS

We retrospectively evaluated 88 patients having breast cancer who underwent both bone scintigraphy and ¹⁸F-fluorodeoxyglucose (FDG) positron-emission computed tomography/X-ray computed tomography (PET/CT) within an interval of 8 weeks between both examinations for comparison. The whole-body bone images were analyzed with fully automated software that was customized according to a Japanese multicenter database. The region of interest for FDG-PET was set to bone lesions in patients with bone metastasis, while the bone marrow of the ilium and the vertebra was used in patients without bone metastasis.

RESULTS

Thirty of 88 patients had bone metastasis. Extent of disease, bone scan index (BSI) which indicate severity of bone metastasis, the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and serum tumor markers in patients with bone metastasis were significantly higher than those in patients without metastasis. The Kaplan-Meier survival curve showed that the overall survival of the lower BSI group was longer than that with the higher BSI group in patients with visceral metastasis. In the multivariate Cox proportional hazard model, BSI (hazard ratio (HR): 19.15, p = 0.0077) and SUVmax (HR: 10.12, p = 0.0068) were prognostic factors in patients without visceral metastasis, while the BSI was only a prognostic factor in patients with visceral metastasis (HR: 7.88, p = 0.0084), when dividing the sample into two groups with each mean value in patients with bone metastasis.

CONCLUSION

BSI, an easily and automatically calculated parameter, was a well prognostic factor in patients with visceral metastasis as well as without visceral metastasis from breast cancer.

Management of Metastatic Hormone-Sensitive Prostate Cancer (mHSPC): an Evolving Treatment Paradigm

OPINION STATEMENT

Combination systemic therapy is now standard of care for all men with metastatic, hormone-sensitive prostate cancer (mHSPC). Patients with mHSPC should be treated with standard androgen deprivation therapy (ADT) and abiraterone acetate with prednisone or docetaxel (chemohormoanl therapy) unless there are contraindications to combination therapy. Based on the Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) study subgroup analysis, chemohormonal therapy may be most beneficial in men with high-volume disease burden, as men with low-volume metastatic disease do not appear to experience a survival benefit with chemohormonal therapy, while abiraterone in combination with ADT appears to be beneficial across both disease volume subgroups. Decisions regarding whether to use chemohormonal therapy or abiraterone and ADT for men with mHSPC should integrate consideration of volume of disease burden, quality of life effects, duration of therapy, and patient preferences for treatment as there is no formally powered prospective head-to-head comparison of these options demonstrating superiority of one approach over the other. Treatment of the primary tumor with radiation should be considered in men with de novo low-volume metastatic disease as radiation is associated with prolonged survival and a tolerable toxicity profile. Men with de novo high-volume metastatic disease do not appear to have improved survival with radiation of the primary tumor. Numerous clinical trials are ongoing to evaluate treatment approaches that may benefit men with mHSPC. Radical prostatectomy in men with mHSPC in combination with optimal systemic therapy is currently being assessed in a clinical trial, but should not be considered outside of a clinical trial. Metastasis-directed therapy with radiotherapy directed at metastatic lesions is still investigational, but can be considered in clinical trials in men with oligometastatic disease. Multiple studies are enrolling worldwide for men with mHSPC, and these should be considered for all interested patients.

Impact of Anatomic Location of Bone Metastases on Prognosis in Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Whole-body assessments of ¹⁸F-NaF positron emission tomography (PET)/computed tomography (CT) provide promising quantitative imaging biomarkers of metastatic castration-resistant prostate cancer (mCRPC). This study investigated whether the distribution of metastases across anatomic regions is prognostic of progression-free survival.

PATIENTS AND METHODS

Fifty-four mCRPC patients with osseous metastases received baseline NaF PET/CT. Patients received chemotherapy (n = 16) or androgen receptor pathway inhibitors (n = 38). Semiautomated analysis using Quantitative Total Bone Imaging software extracted imaging metrics for the whole, axial, and appendicular skeleton as well as 11 skeletal regions. Five PET metrics were extracted for each region: number of lesions (N_L), standardized maximum uptake value (SUV_max), average uptake (SUV_mean), sum of uptake (SUV_total), and diseased fraction of the skeleton (volume fraction). Progression included that discovered by clinical, biochemical, or radiographic means. Univariate and multivariate Cox proportional hazard regression analyses were performed between imaging metrics and progression-free survival, and were assessed according to their hazard ratios (HR) and concordance (C)-indices.

RESULTS

The strongest univariate models of progression-free survival were pelvic N_L and SUV_max with HR = 1.80 (N_L: false discovery rate adjusted P = .001, SUV_max: adjusted P = .001). Three other region-specific metrics (axial N_L: HR = 1.59, adjusted P = .02, axial SUV_max: HR = 1.61, adjusted P = .02, and skull SUV_max: HR = 1.58, adjusted P = .04) were found to be stronger prognosticators relative to their whole-body counterparts. Multivariate model including region-specific metrics (C-index = 0.727) outperformed that of whole-body metrics (C-index = 0.705). The best performance was obtained when region-specific and whole-body metrics were included (C-index = 0.742).

CONCLUSION

Quantitative characterization of metastatic spread by anatomic location on NaF PET/CT enhances potential prognostication. Further study is warranted to optimize the prognostic and predictive value of NaF PET/CT in mCRPC patients.

Feasibility of local administration of chemotherapeutic drugs as an effective adjuvant therapy in primary, recurrent and metastatic extradural tumours of the spine-review

Present day multimodality treatment with advances in systemic chemotherapy and radiotherapy has increased the survival of patients significantly even in those primary tumours which were once considered to have a poor prognosis. However, local recurrence can severely jeopardise the quality of life and even reduce survival. Hence local recurrence is considered as the worst complication in the management of spinal tumours and the need to achieving adequate local tumour control cannot be overemphasised. Techniques like en bloc resections which significantly reduce the chances of local recurrence are always not possible due to anatomical and technical reasons and sometimes, not feasible in debilitated patients. Local administration of chemotherapeutic drugs has already been recognised as a treatment strategy in the management of bladder and brain tumours. In this literature review, an attempt is made to explore the available evidence in the English literature for local administration of chemotherapeutic drugs in the surgical management of primary, recurrent and metastatic spinal tumours.

Bone scan index as metastatic bone disease quantifier and predictor of radium-223-dichloride biochemical response

OBJECTIVES

This work aims to assess whether the biochemical response of radium-223-dichloride treatment can be predicted based on the pretherapy bone scan, and consequently if bone scan index (BSI) and maximum lesion intensity have a place as alternatives or as complements to extent of bone disease (EOBD) scoring in predicting biochemical response to treatment. Many cases of advanced prostate cancer have evidence of bone metastasis. Accurate EOBD quantification could help predict the response to radium-223-dichloride therapy. Current EOBD score is simple to use but does not consider size, intensity or localisation of lesion BSI might be more suitable for stratification of bone metastases.

PATIENTS AND METHODS

Bone scans (n=20) preceding radium-223-dichloride treatment for prostate cancer were assessed retrospectively using automated BSI software (EXINI) and by assessing maximum counts per lesion. Results were then compared to total alkaline phosphatase (ALP) as a measure of biochemical response to therapy using linear regressions and to their EOBD scores using box plot analysis.

RESULTS

Moderate correlation was found between ALP response and maximum lesion intensity (R=0.41) and BSI (R=0.46). Strong correlation (R=0.71) was found between baseline ALP and BSI and between lesion number and BSI (R=0.60). Visual assessment of EOBD score was found to correlate well with baseline ALP and maximum ALP response.

CONCLUSION

BSI is a useful asset in stratification of patients with metastatic bone disease. It may also have a place in prediction of biochemical response.

Oligometastatic Prostate Cancer: A Shrinking Subset or an Opportunity for Cure?

Oligometastatic prostate cancer (OMPC), generally defined by presence of five or fewer metastatic sites on imaging, represents a transitional state between localized and widespread metastatic disease and encompasses a wide spectrum of disease biologies and clinical behaviors. A collaborative effort is ongoing to determine the genomics of OMPC. The prevalence of OMPC varies significantly in the literature and is likely to change further as substantial improvements in imaging improve our ability to reclassify a subset of patients with biochemical recurrence by conventional imaging as OMPC and another subset from OMPC to polymetastatic disease. The mainstay of OMPC treatment remains systemic therapy, either with androgen-deprivation therapy (ADT) alone or in combination with other agents (docetaxel, abiraterone, etc.). Focal therapies, including resection or radiotherapy (RT), to the primary tumor have demonstrated an improvement in outcomes, including failure-free survival in several retrospective studies. RT to the prostate has specifically demonstrated an overall survival (OS) advantage in patients with low-volume disease in a clinical trial. Improvement in outcomes has been observed with focal therapies for retroperitoneal and more distant metastatic sites in retrospective studies. Advancements in our understanding of the biology, imaging modalities, and treatments may allow for aggressive multimodality therapies in an effort to obtain deeper responses and, potentially, cures for selected patients with OMPC with favorable clinicopathologic characteristics. Participation in clinical trials or institutional registries is strongly encouraged for patients with OMPC who opt for an aggressive multimodality approach.