Prognostic importance of concomitant non-regional lymph node and bone metastases in men with newly diagnosed metastatic prostate cancer.

OBJECTIVES: To evaluate the prognostic importance of concomitant non-regional lymph node (NRLN) and bone metastases in men with synchronous metastatic hormone-sensitive prostate cancer (mHSPC), and to determine whether M1b/M1c is the most appropriate M-stage and evaluate the additional importance to the distinction in low/high volume disease. PATIENTS AND METHODS: All men diagnosed with synchronous mHSPC from 2010 to 2018 in the Netherlands were identified in the Netherlands Cancer Registry. Men were categorised as having NRLN (M1a), bone (M1b), NRLN and bone (M1c), or visceral metastases (M1c). For men diagnosed since October 2015 disease volume could be determined. Analyses were performed in this cohort (>5600 men) and repeated in the 2010-2018 cohort (>14 000 men). The primary outcome measure in this observational cohort study was overall survival (OS) and Cox regression was used to calculate hazard ratios (HRs). RESULTS: Compared to men with NRLN and bone metastases (reference group), OS of men with only NRLN (HR 0.70, 95% confidence interval [CI] 0.55-0.88) was better. This was also true for men with only bone metastases in the low-volume subgroup (HR 0.75, 95% CI0.58-0.98), but not in the high-volume subgroup (HR 0.99, 95% CI 0.84-1.18). In contrast, the OS of men with visceral metastases was worse (HR 2.20, 95% CI 1.75-2.77 + 0.97/month, 95% CI 0.96-0.98). CONCLUSION: In men with low-volume synchronous mHSPC, presence of concomitant NRLN and bone metastases (currently classified as M1c), is a poor prognostic sign. However, survival of men with visceral metastases (M1c) is worse. Implying that classifying concomitant NRLN and bone metastases as M1c or M1b is not appropriate. Adding a fourth M1-category to the ninth edition of the Tumour-Node-Metastasis classification should be contemplated. Furthermore, definitions of metastatic burden need to be re-evaluated.

Impact of non-regional lymph node metastases accurately revealed on 18F-PSMA-1007 PET/CT in the clinical management of metastatic hormone-sensitive prostate cancer.

BACKGROUND: Non-regional lymph node (NRLN) metastases has shown increasing importance in the prognosis evaluation and clinical management of primary metastatic hormone-sensitive prostate cancer (mHSPC). Hence, this study aimed to investigate the concordance rates between 18F-PSMA-1007 PET/CT and conventional imaging (CI) in revealing NRLN metastases, and explore the impact of NRLN metastases on the management of primary mHSPC. METHODS: The medical records of 224 patients with primary mHSPC were retrospectively reviewed, including 101 patients (45.1%) only received CI for TNM classification, 24 patients (10.7%) only received 18F-PSMA-1007 PET/CT, and 99 patients (44.2%) received both 18F-PSMA-1007 PET/CT and CI. Among patients who received 18F-PSMA-1007 PET/CT and CI before initial treatment, the concordance rates between 18F-PSMA-1007 PET/CT and CI were analyzed. The high-volume disease was defined as the presence of visceral metastases and/or ≥ 4 bone metastases (≥ 1 beyond the vertebral bodies or the pelvis) based on the findings of 18F-PSMA-1007 PET/CT and/or CI. The primary endpoint was progression-free survival (PFS), and Cox regression analyses were performed to explore independent predictors of PFS. RESULTS: A total of 99 patients (44.2%) received both 18F-PSMA-1007 PET/CT and CI, the concordance rate in revealing NRLN metastases between 18F-PSMA-1007 PET/CT and CI was only 61.62%, and Cohen's kappa coefficient was as low as 0.092. Moreover, 18F-PSMA-1007 PET/CT detected an additional 37 of 94 (39.4%) patients with positive NRLNs who were negative on CI. Cox regression revealed that androgen deprivation therapy (ADT), N1, high-volume, NRLN and visceral metastases were associated with worse PFS (all P < 0.05) in 224 patients. Furthermore, in patients with low-volume disease, the median PFS of patients with NRLN metastases was significantly shorter than that of patients without NRLN metastases (19.5 vs. 27.5 months, P = 0.01), while the difference between patients with low-volume plus NRLN metastases and high-volume disease was not significant (19.5 vs. 16.9 months, P = 0.55). Moreover, early docetaxel chemotherapy significantly prolonged the PFS of these patients compared with ADT alone (20.7 vs. 12.3 months, P = 0.008). CONCLUSION: NRLN metastases could be accurately revealed by 18F-PSMA-1007 PET/CT, which should be considered a high-volume feature, especially concomitant with bone metastases. Furthermore, patients with low-volume plus NRLN metastases may be suitable for more intensive treatment, such as early docetaxel chemotherapy.