Treating Cancer with RFA

• Strategies for Cancer Treatment

• Types of Cancer Treated with RFA

Liver (primary and secondary hepatic cancers)
Breast (combined with surgery to treat early stage cancers)
Other Cancers (kidney, adrenal, lung, bone, prostate)

Strategies for Cancer Treatment

Most cancer cells develop in a primary tumor site such as the breast, colon or lung. Cells from these cancers can spread, or metastasize, to other parts of the body where they may form new tumors. There are two basic strategies to treat cancer:

Local treatments attack cancer at a specific site. Surgery to remove tumors is the most common local treatment. Radiation therapy is a local treatment when it is delivered through radioactive particles, seeds or rods implanted directly into a tumor. This type of radiation treatment is called brachytherapy. RFA and other interventional radiology catheter ablation procedures are a new type of local treatment that is especially promising for patients whose cancers cannot be treated surgically. RFA does not rule out other options, and it can be used before or after surgery or radiation therapy, or in addition to systemic treatments.

Systemic treatments attempt to destroy cancer cells at the primary site or that have traveled to other parts of the body. Chemotherapy and other cancer-fighting substances that are infused through a blood vessel and circulated throughout the body are systemic treatments. Radiation therapy is a systemic treatment when it is administered from outside the body (external beam radiation). This type of radiation therapy affects healthy tissues near the treatment site as well as the tissues through which it must pass to reach its target.

Local treatments have an advantage of killing cancer cells without harming healthy cells. Sometimes chemotherapy or other systemic treatments cannot be given in doses high enough to kill all cancer cells because of intolerable or life-threatening side effects.

Also, chemotherapy and other cancer-fighting substances pass through many types of tissue in the body. These tissues have different capacities to absorb and retain cancer drugs, so it is impossible to deliver an equal dose to every cell. Cancer cells that travel to the brain, for example, are sheltered from the full effects of chemotherapy by the “blood-brain barrier.” This built-in defense protects the brain by blocking potentially dangerous “invaders” – including many drugs –before they can reach the tissues of this vital organ.

The Role of RFA in Cancer Therapy

Most modern cancer treatments are customized for individuals depending on the size, location and type of tumor and the general health of the patient. RFA may be used alone, or in combination with other treatments, including surgery, chemotherapy and chemoembolization. RFA is not a cure for cancer, although some patients have remained disease free for two or more years after the treatment. Current strategies for using RFA include:

• Provide a local treatment option when surgery is not possible or too risky;
• Shrink large tumors to a size that makes it possible to remove them surgically;
• Relieve pain and other side effects to reduce suffering and improve the quality of life for people with cancer.

RFA and Liver Cancer

According to the American Cancer Society, about 14,000 cases of primary liver cancer are diagnosed each year. The most common form is hepatocellular carcinoma. This is a tumor that begins in the main cells of the liver (hepatocytes). Primary liver cancer is twice as common in men as in women.

Patients with other types of cancer also are at risk for liver cancer. The liver serves as a way-station that cleans out many of the waste products circulating in the blood – including cancer cells. These cells may grow and form tumors in the liver. It is estimated that as many as 70 percent of all people with uncontrolled cancer will eventually develop secondary liver tumors, or metastases (tumors formed by primary cancer cells that have spread from other cancer sites).

Cancer in the liver usually is not detected until it reaches an advanced stage, and most liver cancers cannot be treated with surgery. This is because the tumor may be too large, or have grown into blood vessels or other vital structures. Sometimes, many small tumors are spread throughout the liver, making surgery too risky or impractical. In fact, surgical removal is not possible for more than two-thirds of primary liver cancer patients and 90 percent of patients with secondary liver cancer.

Until recently, systemic treatment was the only option for patients with inoperable liver cancer. Unfortunately, chemotherapy and other systemic treatments usually cannot be given in doses high enough to control most liver cancers because of their toxic effects, many of which are life-threatening.

RFA may be the only local treatment option for many cancers that cannot be surgically removed, and does not have the unpleasant side effects of systemic options.

Because it does not have bad side effects, RF energy can be given without affecting the patient’s overall health or quality of life. Although RFA is not considered a cure for liver cancer, preliminary research has shown that it can prolong and improve the quality of life. In one study, 169 liver tumors were treated in a total of 123 patients. The great majority (98 percent) of the tumors were destroyed by RFA. None of the tumors had returned after an average follow up of 15 months. More than one-fourth (28 percent) of patients developed tumors elsewhere, however. In an Australian study of 489 tumors treated in 304 patients, cancers treated with RFA returned in 27 patients (9 percent) after an average follow up of 10 months.

RFA and Breast Cancer

Cancer of the breast is the most common cancer of women in the U.S. Approximately 180,000 new cases are diagnosed in the U.S. each year. Thanks to the widespread use of mammography to screen for the disease, two-thirds of all breast cancers are now diagnosed in an early, curable stage. Local treatment with surgery is accepted as the best first-line defense against early stage breast cancer. Depending on the patient and the type of cancer, the surgeon may remove the entire breast (mastectomy) or only the tumor and the tissue surrounding it (lumpectomy).

Systemic treatment of early stage breast cancer usually includes radiation therapy after surgery. This precaution is taken to destroy any cancer cells that have been left behind or that may have spread during the operation. In some cases, chemotherapy also may be recommended following surgery.

RFA is still an experimental breast cancer treatment, but the results of early clinical trials are promising. In a pilot study, RFA was performed before surgery in 26 women with early stage breast cancer. After surgery, laboratory tests were conducted to determine the effectiveness of RFA. No living cancer cells could be detected in the tumors of 25 (96 percent) of the 26 women in the study. Although more studies on larger numbers of women are needed, researchers are encouraged that RFA may significantly improve breast cancer treatment. Most doctors do not envision that RFA will take the place of other treatments – at least not in the immediate future – but adding RFA with other therapies will improve patient care by:

Destroying small cancers before surgery. Treating tumors with RFA before a lumpectomy reduces the bulk of the tumor to be removed, so operations may be less risky and disfiguring. After RFA, the surgeon can remove a small, dead tumor rather than living tissue made up of countless active cancer cells. This reduces the odds that the surgery itself will disrupt cancer cells, causing them to separate from the tumor and “escape” through the lymphatic or circulatory system.

Shrinking tumors to avoid mastectomy. RFA also may help patients with larger tumors that require the removal of the entire breast (mastectomy). RFA may shrink some tumors so they are small enough to be treated with lumpectomy - removal of the cancerous area.

Reduce need for harsh systemic treatments. In the future, pre-surgical RFA may make chemotherapy or radiation therapy unnecessary for some patients, or allow milder doses that avoid intolerable or life-threatening side effects.

RFA in the Treatment of Other Cancers

Studies are under way to determine the potential benefits of RFA as a treatment for a variety of cancers. In general, RFA is being tested for cancers that cannot be removed by surgeons because of their size or location, or because the patient is not healthy enough to have open surgery. RFA also is used to relieve pain and suffering for patients with a variety of cancers. These studies include cancers of the:

Kidney. In an early study sponsored by the National Institutes of Health (NIH), 18 patients with kidney cancer were treated with RFA. The treatment successfully destroyed tumors in the majority of the patients (72 percent). After follow up of at least five months, X-rays could not detect any sign of tumor in these patients. One patient remained cancer-free two years after the treatment.

Adrenal Glands. In another NIH study of 15 patients with adrenal tumors, 10 patients (67 percent) showed no sign of active disease after treatment with RFA. The other patients had some tumor remaining that could be seen by X-rays, but in every case the treatment had killed most of the tumor.

Lung, Bone and Prostate Cancer. RFA shows promise in shrinking lung cancers that obstruct the bronchial tubes, making breathing difficult for patients. Early research also suggests the technique may be helpful for bone and prostate cancer. More studies are needed to confirm these early results.

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