What are regional cancer treatments and how do they help?
Advanced cancer can be difficult to treat, especially when it has spread to vital organs that are essential to the body’s survival, such as the liver and lungs. The difficulty is not only to reach the tumor, but to treat it without damaging the affected vital organs and further harming the patient’s health. But a more targeted treatment approach offers these patients a potential option, allowing doctors to deliver high doses of chemotherapy or radiation directly to the tumor, without exposing the rest of the body to harmful levels of toxicity. Therapies, called organ-directed therapies or regional therapies, are a strategy for choosing a specific target, rather than delivering them throughout the body. “We work to manage a patient’s disease in a way that addresses where the cancer may have the worst impact in the body,” says Pragateshwar Thironavukarasu, MD, a surgical oncologist and liver and pancreatic biliary surgeon at our hospital in Tulsa.
Regional treatments first emerged in the 1950s, after surgeons realized the need for a safer alternative when surgery was too invasive or potentially harmful to patients, or in cases where the cancer could not be surgically removed. “Liver surgery is still considered the standard treatment when the goal of treatment is to remove all cancers and surgery for the cancer can be performed,” says Diego Muilenburg, MD, a surgical oncologist at our hospital near Phoenix. “Regional therapies are a good option when surgery is not an option for any reason.”
In the case of regional liver therapies, which are generally referred to as liver-targeted therapies, “it’s about organ preservation,” says Dr. Muilenburg. “We are trying to save as much healthy liver as possible while still killing the tumor.” The liver is a popular target for regional therapies because it is one of the most common sites for metastatic disease, has the ability to regenerate on its own, and can “take the blow,” says Dr. Muilenburg, which means irradiation of part of the organ generally does not. It does not cause the kind of damage radiation does to other organs.
Treatments that target the liver
Treatments that target the liver are offered in several ways. The most common are:
- Hepatic artery pump: The surgeon places a tube in the hepatic artery, the main blood vessel that supplies blood to the liver, and connects it to a small implanted pump that continuously delivers chemotherapy directly to the liver.
- Hepatic chemical embolism and radiation embolism: Through a minimally invasive catheter placed in the groin, small particles are injected into the liver’s arteries that block blood flow to the tumor, blocking off the source of oxygen and nutrients it needs for growth, while simultaneously delivering high-dose chemotherapy or radiation directly on the tumor.
- Radiofrequency hepatectomy and microwave resection: The oncologist uses heat, either from radiofrequency or a microwave power source, to burn the tumor.
Regional treatments also allow for a therapeutic method called hyperthermia, in which chemotherapy is heated. The increased temperature inside a tumor is designed to damage the parts of the cancer cells that cannot tolerate high temperatures as well as the healthy cells.
There may be several regional treatments available to treat some cancers, but it’s important that your oncologist knows how to conduct each and which option to use and when, says Dr. Thironavucarasu. For example, a liver pump cannot be used to treat a liver tumor after radiation embolization because the blood vessels that the pump will use to deliver chemotherapy will be blocked. “Treating all conditions with the same topical treatment is a unique approach to treating cancer, but cancer is not a one-size-fits-all,” says Dr. Thironavukarasu.
Cancer is not stagnant either. It evolves and so have regional treatments. Only two decades ago, in fact, regional therapies were considered experimental and most surgeons didn’t use them, says Charles Komen Brown, MD, PhD, medical director of surgery and a surgical oncologist at our hospital near Chicago. “If you think about where we were then compared to where we are now, where many regional therapies are accepted as the standard for care for some cancers, regional treatment has come a long way,” he says.
Regional Cancer Treatments
In addition to the liver, topical treatments are used to attack tumors in these areas of the body:
- The abdomen , a common site of malignancies on the surface of the peritoneum. Malignancies on the peritoneal surface involve the lining of the peritoneum, the thin, transparent membrane that lines the abdomen. Sometimes undetected tumors in the appendix, rectum, colon, stomach, ovary, or other organs spread to these surfaces.
- Lungs , which are common sites of metastases for colorectal cancer, melanoma and sarcoma. The lungs may be the target of some types of topical treatments like the liver, says Dr. Muilenburg.
- Organs , where topical treatments may be used to treat skin cancer. In isolated limb injections, a high dose of warm chemotherapy may be used to treat the leg or arm to avoid damaging the rest of the body.
Changes, in our understanding of cancer and the way regional therapies can be used to treat it, will continue to influence the way oncologists use treatment. In the future, Dr. Brown believes that cancer treatments that affect the body’s systems, such as chemotherapy and immunotherapy drugs that travel through the bloodstream and affect cells throughout the body, will increasingly be combined with regional therapies to treat cancer. “We’re already doing some of that, by combining liver radioembolization with systemic chemotherapy when treating cancer in the liver, and by combining high-temperature intraperitoneal chemotherapy (HIPEC), which is a type of brachytherapy, with systemic chemotherapy to treat tumors malignancy affecting the surface of the peritoneum. Dr. says. Brown. “I think that’s where the future will be.”
Of course, the end goal may be to completely eliminate topical treatments. “In the long term, it would be great if we didn’t have to do regional treatments because the systemic treatments work well enough that we no longer need them,” says Dr. Muilenburg. “Right now, we treat an area because that is the only place we see cancer. But in some cases, the cancer has already spread to other parts in microscopic amounts that cannot be detected with diagnostic tools. It would be better if we could treat the body systematically and target all the cancer cells.” metastasizing rather than targeting these localized areas, but for now, these treatments are limited to a few specific cancers.”
Learn more about liver cancer, a part of the body that is often treated with topical treatments.