Clinical Considerations and Challenges in Treating Patients With Oligometastatic Prostate Cancer

One of the most challenging aspects of caring for patients with prostate cancer remains the heterogeneity of their disease. Patients invariably ask about prognosis and curability of their cancer. Use of nomograms and clinical trial data help to provide some relevant information in various disease states. Formany situations, the answer to such a question still remains difficult. A particularly difficult situation arises with patients with hormone-sensitive prostate cancer with oligometastatic disease. The excellent review by Clement and Sweeney sheds light on this clinically relevant population. What exactly is oligometastatic disease in patients with prostate cancer? There has not yet been a consensus definition, and this highlights the difficult nature of this disease state. Somestudieshaveconsidered patients with one to three metastases as having oligometastatic disease, whereas other studies have an expanded definition allowing one to five lesions. Current studies have tried to stratify disease as high volume versus low volume to tease out subgroups of patients with hormone-sensitive metastatic prostate cancer that would benefit from more aggressive therapy. Clinical outcomes and data show that patients with limited metastatic disease often do better than patients with high-volume metastases, regardless of treatmentmodality. This clinical phenomenon may account for the larger benefit of the chemohormonal therapy of androgendeprivationanddocetaxel inhighvolume disease but lack of a benefit in patients with low-volume disease. Multiple studies highlighted in the accompanying article by Clement and Sweeney are testing different initial androgen-deprivation therapy–based combination therapies in patients with oligometastatic disease. Unlike with docetaxel, an intense combinatorial approach may take advantage of the unique biology of patients with low-volume oligometastatic prostate cancer. There are challenging logistics and factors in caring for patients with oligometastatic prostate cancer. The role of definitive therapy for the primary site of disease in patients withmetastatic prostate cancer is unclear. Retrospective data show some clinical benefit with definitive therapy of the primary site of disease, both in men with lymph node–positive disease and in those with low-volume M1b disease. This included a longer period until castration resistance. Prospective studies are ongoing to help determine the role of local control by radiation or surgery in addition to androgen-deprivation therapy. Patients who have poor prognostic factors such as initial unresponsiveness to androgen-deprivation therapy or other adverse prognostic factors may not be candidates for local definitive therapy. General consensus from our group would not support routine local interventionwith curative intent in patients with metastatic