Local surgical, ablative, and radiation treatment of metastases.

Because local therapies directed toward a specific tumor mass are known to be effective for treating early-stage cancers, it should be no surprise that there has been considerable historical experience using local therapies for metastatic disease. In more recent years, increasing interest in the use of local therapy for metastases likely has arisen from improvements in systemic therapy. In the absence of effective systemic therapies, such local treatments were often considered futile given both the difficulty in eliminating all sites of identifiable metastatic disease as well as realities regarding the rapid natural history of uncontrolled tumor dissemination. However, with a higher likelihood of patients surviving longer after effective systemic therapy, even if not cured, the goal of the eradication of residual metastases via potent local therapies can be rationalized. However, this rationalization should be evidence-based so as to avoid harming patients for no established benefit. Although surgical metastectomy remains the most common and first-line standard among local therapies, nonsurgical alternatives, including thermal ablation and stereotactic body radiotherapy, have become increasingly popular because they are generally less invasive than surgery and have demonstrated considerable promise in eradicating macroscopic tumor. Rather than eliminating the need for local therapies, improvements in systemic therapies appear to be increasing the prudent utilization of modern local therapies in patients presenting with more advanced cancer.