Does nonmetastatic castration-resistant prostate cancer still exist?

Management of Patients with Nonmetastatic Castration-Resistant Prostate Cancer: Recommendations of a Multidisciplinary Panel of Experts from South America

Most prostate cancer patients who undergo androgen-deprivation therapy or orchiectomy will eventually develop castration-resistant prostate cancer (CRPC), often preceded by a nonmetastatic CRPC state known as M0CRPC. The recent development of second-generation antiandrogens provides clinicians with efficacious and safe treatments for M0CRPC. However, the complexity of these patients, who typically have to deal with underlying comorbidities and polypharmacy, often challenges therapeutic decisions in this setting. The recent development of novel imaging techniques also provides clinicians with tools for detecting metastases with high sensitivity and specificity. However, the lack of evidence on the early detection of metastases and the corresponding impact on therapeutic decisions makes these techniques a double-edged sword that must be managed appropriately. Here, we present the expert view of the rapidly evolving concept of M0CRPC and provide recommendations for the identification of these patients, the appropriate use of the emerging imaging modalities, and patients’ management, particularly considering their clinical complexity and the recent development of next-generation antiandrogens.

A framework for the development of effective anti-metastatic agents

Most cancer-related deaths are a result of metastasis, and thus the importance of this process as a target of therapy cannot be understated. By asking 'how can we effectively treat cancer?', we do not capture the complexity of a disease encompassing >200 different cancer types - many consisting of multiple subtypes - with considerable intratumoural heterogeneity, which can result in variable responses to a specific therapy. Moreover, we have much less information on the pathophysiological characteristics of metastases than is available for the primary tumour. Most disseminated tumour cells that arrive in distant tissues, surrounded by unfamiliar cells and a foreign microenvironment, are likely to die; however, those that survive can generate metastatic tumours with a markedly different biology from that of the primary tumour. To treat metastasis effectively, we must inhibit fundamental metastatic processes and develop specific preclinical and clinical strategies that do not rely on primary tumour responses. To address this crucial issue, Cancer Research UK and Cancer Therapeutics CRC Australia formed a Metastasis Working Group with representatives from not-for-profit, academic, government, industry and regulatory bodies in order to develop recommendations on how to tackle the challenges associated with treating (micro)metastatic disease. Herein, we describe the challenges identified as well as the proposed approaches for discovering and developing anticancer agents designed specifically to prevent or delay the metastatic outgrowth of cancer.