Locoregional therapy is a specialized cancer treatment approach that focuses intently on a defined, limited area of the body. This strategy treats the primary tumor and any immediately surrounding tissues or nearby lymph nodes where cancer cells may have spread. Unlike treatments that circulate throughout the entire body, locoregional therapy allows physicians to deliver highly concentrated doses directly to the disease site. This targeted focus is significant in managing solid tumors, where achieving local control is often the primary goal for cure and long-term disease management.
Defining Locoregional Treatment vs. Systemic Therapy
The distinction between locoregional and systemic therapy lies in their scope of action and delivery method. Locoregional treatment is a localized intervention, aiming to eradicate or control the disease precisely at its site of origin and the adjacent tumor bed. This approach focuses on achieving a cure or preventing complications by eliminating the bulk of the cancer.
Systemic therapy, conversely, treats the whole body, as agents travel through the bloodstream to reach cancer cells wherever they may be. Examples include traditional chemotherapy, targeted therapies, and immunotherapy. While systemic therapies are the mainstay for widespread or metastatic disease, locoregional therapies are often the first line of defense for solid tumors confined to a specific area. Locoregional techniques can prevent the need for more aggressive systemic treatments or enhance their effectiveness against residual disease.
Core Locoregional Modalities: Surgery and Radiation
Surgery remains one of the oldest and most definitive forms of locoregional therapy, physically removing the tumor from the body. The goal of surgical resection is to excise the visible tumor and remove a margin of healthy tissue around it to ensure the complete removal of cancer cells. Surgeons also use this procedure for diagnostic purposes, obtaining tissue samples and assessing the extent of the disease for accurate cancer staging.
Radiation therapy is another widely used locoregional technique that uses high-energy beams to damage the DNA of cancer cells, preventing them from growing and dividing. External beam radiation therapy (EBRT) delivers radiation from a machine outside the body, precisely targeting the tumor while minimizing exposure to surrounding healthy structures. A more localized approach is brachytherapy, which involves placing radioactive sources directly inside or next to the tumor, either temporarily or permanently.
Advanced and Targeted Local Interventions
Beyond traditional surgery and radiation, advanced interventional techniques offer highly targeted, minimally invasive locoregional options. Ablation therapies destroy tumor tissue by applying extreme temperatures directly to the cancer site. Radiofrequency ablation (RFA) and microwave ablation (MWA) use heat generated by radio waves or electromagnetic energy to destroy tumor cells. Conversely, cryoablation uses an inserted probe to deliver extreme cold, which freezes and destroys the targeted tissue.
Embolization, often used for liver cancers, involves blocking the blood flow to the tumor. Transarterial chemoembolization (TACE) combines this blockage with the localized delivery of chemotherapy drugs. A catheter guides tiny particles loaded with chemotherapy directly to the tumor’s arterial supply, starving the tumor while delivering a high concentration of medication. Radioembolization, or Selective Internal Radiation Therapy (SIRT), uses micro-beads loaded with a radioactive isotope, such as yttrium-90, to deliver targeted radiation from within the blood vessel. These image-guided procedures allow for shorter recovery times and can be an option for patients who are not candidates for open surgery.
Strategic Roles in Cancer Treatment Planning
Locoregional therapies are integrated into a patient’s overall cancer strategy with varying intentions depending on the disease stage. For small, early-stage tumors, locoregional treatment may serve as the sole curative treatment, aiming for complete disease elimination. This is common for localized solid tumors confined to the organ of origin.
Locoregional therapies also play a significant role in multidisciplinary care by modifying the tumor burden before or after other treatments. When used before systemic therapy or surgery (neoadjuvant setting), treatment can shrink a tumor to make subsequent surgical resection more feasible. In the adjuvant setting, it eliminates any remaining microscopic disease in the local area after primary treatment. When a cure is no longer possible, locoregional interventions are used for palliation, managing symptoms like pain, bleeding, or obstruction to improve the patient’s quality of life.