4.2.3 Emerging therapies
Multiple agents are being developed and will be considered in the systemic treatment of these patients.
Therapies that show promise for treatment of prostate cancer include novel hormonal and targeted therapies, immunotherapies, combination therapies and radiopharmaceuticals (Sonnenburg & Morgans 2018).
For certain classes of drugs under investigation (e.g. PARP inhibitors), germline or somatic genomic testing (e.g. defects in genes involved in DNA repair) may help predict the patient’s treatment response.
Theranostics is an emerging treatment using radioactive substances that are taken into sites of prostate cancer spread, enabling high doses of radiation to be delivered to tumour sites. Examples are radioactive molecule lutetium-177 (Lu-177) labelled to a small molecule targeting prostate-specific membrane antigen (PSMA) and radium 223.
Radiation therapy is also emerging as an additional promising treatment for patients with oligometastatic prostate cancer. There are multiple ongoing trials evaluating the benefit of metastasis-directed therapy using conventional and stereotactic body radiation therapy (SBRT) to treat patients with oligometastatic or oligoprogressive disease (Palma et al. 2019). The rationale for metastasis-directed therapy is to either delay the need for additional systemic therapies or to use in combination with systemic therapies to further improve progression-free survival.
The key principle for precision medicine is prompt and clinically oriented communication and coordination with an accredited laboratory and pathologist. Tissue analysis is integral for access to emerging therapies and, as such, tissue specimens should be treated carefully to enable additional histopathological or molecular diagnostic tests in certain scenarios.