Metastasis-directed therapy alone may delay initiation of systemic therapy in select men with a solitary metastasis after hormone-sensitive prostate cancer recurrence, a new retrospective study suggests.
Among 124 patients with solitary oligorecurrent metastases observed on C-11 choline positron emission tomography (PET), 67 received surgical excision and 57 received stereotactic body radiation therapy (SBRT) as metastasis-directed therapy (MDT), without concurrent androgen deprivation therapy (ADT) or systemic therapy. Surgery was mostly recommended for lymph node metastasis. Radiation therapy was mostly recommended for bone metastasis.
PSA decline of more than 50% occurred in 80.5% of the surgery group and 40.3% of the SBRT group, Jack R. Andrews, MD, of Mayo Clinic Arizona in Phoenix and colleagues reported in The Journal of Urology. The 3-year radiographic progression-free survival rate was 29% in the surgery group and 16.5% in the SBRT group.
In a subset, surgery was associated with a median 14.9-month delay in radiographic progression and a median 18.5 month delay in initiation of systemic therapy, the investigators reported. SBRT was associated with a median 12-month delay in radiographic progression and a median 17.8 month delay in initiation of systematic therapy.
“This study represents the first reported series of MDT without ADT in patients with solitary metastatic prostate cancer,” the authors wrote. “These results suggest that MDT without ADT can delay systemic therapy and likely has a role in the treatment algorithm for oligometastatic prostate cancer.”
Dr Andrews’ team noted that neither the American Urological Association nor the National Comprehensive Cancer Network® (NCCN) recommends MDT as part of guideline-based care. However, the NCCN “has recently allowed for consideration of MDT to improve progression-free survival.”
They added that their report, along with upcoming clinical trials such as the STORM trial (ClinicalTrials.gov identifier: NCT03569241) “suggests a revision of the guidelines to allow for MDT in carefully selected patients.”
The investigators pointed out that the natural history of prostate cancer differs for lymph vs bone metastasis. Patients selected for surgery vs radiation also differed in other ways, precluding a direct comparison of the treatments. More research is warranted.
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Andrews JR, Ahmed ME, Sharma V, et al. Metastasis-directed therapy without androgen deprivation therapy in solitary oligorecurrent prostate cancer. J Urol. 208(6):1240-1249. doi:10.1097/JU.0000000000002898