Researchers noted a 20.1 percent incidence of bone-only metastasis in a cohort of men with castration-resistant prostate cancer, according to findings from research presented at the recent Society for Nuclear Medicine and Molecular Imaging (SNMMI) conference.
Approximately 20 percent of men with castration-resistant prostate cancer may have bone-only metastasis, which was associated with a higher likelihood of N1 and M1 cancer presentations, according to positron emission tomography (PET) research presented at the recent Society for Nuclear Medicine and Molecular Imaging (SNMMI) conference.
For the retrospective multicenter study, researchers reviewed data from restaging PET exams, performed between January 2019 and December 2019, for 179 patients with castration-resistant prostate cancer (CRPC).
The researchers found that 36 patients (20.1 percent) had bone-only metastasis. While half of these patients had focal PSMA uptake in three or less bone segments, 15 patients (41.7 percent) had uptake in more than three bone segments and three patients (8.33 percent) exhibited diffuse bone marrow prostate-specific membrane antigen (PSMA) uptake, according to the study.
“In this retrospective study, the incidence of PSMA PET/CT bone-only disease in a CRPC population was 20%. All the lesions detected showed a quite high uptake of PSMA, indicating eligibility of bone-directed and PSMA-directed therapy,” wrote study co-author Stefano Fanti, M.D., a professor in the Department of Medical and Surgical Sciences, and director of the Nuclear Medicine Division at the University of Bologna in Italy, and colleagues. “The half of the patients (who) showed oligo(metastatic) disease in bone … may benefit from a bone metastasis directed therapy.”
(Editor’s note: For related research and interviews from the 2023 SNMMI conference, click here.)
For the patients with bone-only metastasis, the study authors pointed out that a median of six years had elapsed from the time of primary treatment and the PET scan.
The researchers noted these patients had a median prostate-specific antigen (PSA) doubling time (PSAdt) of 2.8 months, a median PSA velocity (PSAvel) of 8.4 ng/mL/year and a median International Society of Urological Pathology (ISUP) grade of 4.
“At the univariate analysis, patients with bone only PSMA uptake were more likely to be N1 or M1 at presentation … if compared with other CRPC patients,” said Fanti and colleagues.
1. Serani F, Castellucci P, Fendler W, et al. A retrospective multicenter analysis of the incidence of bone only disease at PSMA PET/CT in castration resistant prostate cancer (CRPC) patients. Poster abstract presented at the 2023 Society for Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting, June 24-June 27, Chicago. https://am.snmmi.org/iMIS/SNMMI-AM