Fluorine-18-Labeled Fluciclovine PET/CT in Clinical Practice: Factors Affecting the Rate of Detection of Recurrent Prostate Cancer.

OBJECTIVE. The purpose of this study is to show the performance and evaluate the factors influencing the positivity rate (PR) of commercially produced 18F-fluciclovine PET/CT in the detection of recurrent prostate cancer in clinical practice. MATERIALS AND METHODS. We performed a retrospective cohort study of 152 men who had suspected biochemical recurrence of prostate cancer after receiving initial treatment and underwent fluciclovine PET/CT. PRs were calculated for whole-body, prostate and prostate bed, and extraprostatic locations. The influence of different factors, such as the absolute prostate-specific antigen (PSA) level, PSA kinetics, the Gleason score, and Gleason grade groups, on the PR was evaluated. RESULTS. The overall PR was 81% (123/152) for the whole body, 61% (92/152) for the prostate and prostate bed, and 55% (83/152) for extraprostatic locations. There was a linear increase in the PR with an increasing PSA level (p < 0.001). For the whole body, the PR for PSA levels of less than 1 ng/mL, 1 to less than 2 ng/mL, 2 to less than 5 ng/mL, and 5 or more ng/mL were 58% (32/55), 87% (13/15), 100% (39/39), and 92% (35/38), respectively. No statistically significant linear trend was found between the PR and the PSA level doubling time (p > 0.05). In addition, no statistically significant linear trend was found between the PR and increasing Gleason grade group. However, for every 1-unit increase in a patient's Gleason score, the odds of a positive finding in the extraprostatic location increased by 49% (p < 0.05). CONCLUSION. Commercially produced fluciclovine PET/CT has a high PR for detection of prostate cancer recurrence and is positively correlated with increasing PSA levels. For extraprostatic disease, the PR increases with higher Gleason scores.

Active surveillance selection and 3-year durability in intermediate-risk prostate cancer following genomic testing.

BACKGROUND: Genomic testing can add risk stratification information to clinicopathological features in prostate cancer, aiding in shared medical decision-making between the clinician and patient regarding whether active surveillance (AS) or definitive treatment (DT) is most appropriate. Here we examined initial AS selection and 3-year AS durability in patients diagnosed with localized intermediate-risk prostate cancer who underwent Prolaris testing before treatment decision-making. METHODS: This retrospective observational cohort study included 3208 patients from 10 study sites who underwent Prolaris testing at diagnosis from September 2015 to December 2018. Prolaris utilizes a combined clinical cell cycle risk score calculated at diagnostic biopsy to stratify patients by the Prolaris AS threshold (below threshold, patient recommended to AS or above threshold, patient recommended to DT). AS selection rates and 3-year AS durability were compared in patients recommended to AS or DT by Prolaris testing. Univariable and multivariable logistic regression models and Cox proportional hazard models were used with molecular and clinical variables as predictors of initial treatment decision and AS durability, respectively. RESULTS: AS selection was ~2 times higher in patients recommended to AS by Prolaris testing than in those recommended to DT (p < 0.0001). Three-year AS durability was ~1.5 times higher in patients recommended to AS by Prolaris testing than in those recommended to DT (p < 0.0001). Prolaris treatment recommendation remained a statistically significant predictor of initial AS selection and AS durability after accounting for CAPRA or Gleason scores. CONCLUSIONS: Prolaris added significant information to clinical risk stratification to aid in treatment decision making. Intermediate-risk prostate cancer patients who were recommended to AS by Prolaris were more likely to initially pursue AS and were more likely to remain on AS at 3 years post-diagnosis than patients recommended to DT.

Metastatic Male Breast Cancer With Increased Uptake on 18F-Fluciclovine PET/CT Scan.

Prostate imaging with F-labeled 1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC, F-fluciclovine) PET/CT scan (Axumin) was recently approved by the US Food and Drug Administration for men with suspected prostate cancer recurrence based on elevated blood prostate-specific antigen levels following prior treatment. We present a rare case of a 77-year-old man with suspected recurrent prostate cancer with an incidental finding of advanced-stage breast cancer showing different degrees of F-fluciclovine uptake.