Tumor Advances in Diagnosis and Removal

Tumor — the word alone is enough to send a shiver down the spine of the bravest. Diagnoses that would have been a death sentence 20 years ago are now treatable with procedures that result in brief recovery times and minimal scarring.

Cancer is the term used for more than 100 diseases characterized by the uncontrolled, abnormal growth of cells that can potentially spread throughout the body, according to a Web site sponsored by the American Society of Clinical Oncology. According to the site, “cancer begins when normal cells in the body live beyond their normal life cycle, enabling them to continue to divide and reproduce uncontrollably, invading and destroying healthy tissue.¹

In 2003, approximately 1,334,100 new cancer cases are expected to be diagnosed in the United States, and nearly 556,500 cancer deaths will occur. Cancer is the second leading cause of death in the United States — behind heart disease — and is responsible for one of every four deaths.

Cancer is best treated if it is discovered early. “Staging” estimates how large the primary tumor is, whether it has spread to lymph nodes and whether it has metastasized to other areas of the body.

Diagnosis

Diagnosis of cancer can be done by any number of procedures. These can involve:

• Ultrasound
• Computerized tomography (CT) scan
• Magnetic resonance imaging (MRI) scan
• Positron emission tomography (PET) scan
• Chest CT scan or chest X-ray
• Bone X-ray and bone scan
• Biopsy
• Bone marrow testing
• Bronchoscopy
• Pap smear
• Fecal occult blood test

Treatment

Novel therapies use the patient’s own immune system to counter cancer. These therapies can interfere with cell growth, help healthy immune cells control the cancer, or help repair normal cells damaged by other forms of cancer treatment, says the American Cancer Society (ACS).²

Immunotherapy is often used as an adjuvant therapy; according to the ACS, it is most often effective if used to treat small cancers and may not be as effective with advanced disease.

“Complementary” or “alternative” therapy may also be used — although some skeptics question its efficacy, others laud its benefits. These therapies can include treatments with hydrogen peroxide, hydrazine sulfate and essiac tea. Other options are relaxation massage and biofeedback, aromatherapy, art or music therapy, meditation, prayer, t’ai chi and yoga. Such therapies should be supervised by a physician and used in concert with medical interventions, says the ACS.

Chemotherapy is a third option; it can be used as a cure, to prevent spread, to slow cancerous growth, to kill cancer cells that have spread to other sites or to relieve cancer symptoms. Because chemotherapy travels through the bloodstream, it has the unique ability to attack cancer throughout the body. Side effects of the therapy, however, can be drastic — nausea, vomiting, hair loss, susceptibility to infection and fatigue.

Radiation therapy utilizes a stream of high-energy particles or waves to destroy or damage cancer cells; it is used in more than half of all cancer cases and is the primary treatment for some forms of cancer.

Radiofrequency Ablation

“The standard of care for liver tumors in providing surgical cure has been resection for many years. It’s the primary modality in giving a patient who has resectable disease the best chance of a cure,” says Stanley Rogers, MD, assistant professor of surgery at the University of California, San Francisco. “For other patients, there have been very poor other options available, including (for certain tumors) injection with ethanol, or cryoablation in other instances. Other treatment options include placement of hepatic pumps and systemic chemotherapy; those are probably the most common treatment options for patients who have liver tumors aside from resection. Radiofrequency ablation (RFA) is a new technique that’s become available; it allows a few modalities in its application, and specifically, that includes either an open procedure, a laparoscopic procedure or a percutaneous procedure.”

The radiofrequency treatment allows heat to build up from within the tumor to a temperature that produces cellular death, Rogers explains. “Our ability to now direct this heat — using catheters that have prongs at the tip that we can deploy into the tumor — allows us to sequentially increase the amount of heat distributed to a certain volume of tumor and provide cellular death and (hopefully) death of the tumor in whole or in part.”

Asked how effective RFA is, Rogers responds, “It works very well. Obviously, once you hit a certain temperature, cellular death is assured, and — different from certain chemotherapies that eradicate a certain percentage of large tumors — heat will kill a tumor completely within that certain volume. It’s really the best local treatment option other than resection that’s available today.”

As of yet, there have been no quality comparative studies of resection versus ablation. “Those will likely occur over the next few years,” Rogers says. “There are certainly case reports and cases where local cure has been obtained using RF thermal ablation techniques. In the right hands, RFA can be a modality that can provide a curative outcome for specific tumors in certain individuals.”

Radiofrequency ablation has been used in many other types of tumors; the technique was, in fact, first performed in prostate tumors and has been used in brain tumors as well. “More recently, it’s been used in tumors of the kidney, lung and breast, and it is used for some nonmalignant growths as well, including benign tumors of the liver that might be causing pain or might have a high risk of bleeding, or non-malignant tumors elsewhere,” says Rogers.

Many physicians who utilize RFA combine it with other modes of treatment to ensure complete eradication of the tumor. “For example, a patient who has one tumor in the right lobe [of the liver] and three tumors in the left lateral segment might undergo a resection of that left lateral segment and ablation of the tumor in the right lobe,” he adds. “It’s a modality that can be combined with resection; it can also be combined with pump placement or systemic chemotherapy. That’s actually the nice thing about RFA, that it’s relatively easy to perform, patients recover pretty quickly when it’s done percutaneously or laparoscopically, and that allows it to be combined with other treatment modalities. It’s a very aggressive approach to the liver tumors.”

The technology has been available for at least eight years, Rogers recalls, and he has been utilizing it since he was a laparoscopic fellow at University of California, San Francisco with Allen Siperstein. “He had just started doing these laparoscopically at that point and we brought this modality to become more accepted, and clearly to increase its use, both locally and nationally,” says Rogers.

Of course, RFA is strictly a local treatment; unlike chemotherapy, its effect is not system-wide. “In certain instances, for example, a small tumor, you can ablate the tumor and the surrounding normal tissue, so that the tumor is totally treated and does not recur,” he adds. “When you have a small tumor, the chance of a local cure is greater. The chance of it not allowing metastases elsewhere in the liver to blossom is not very good, unlike chemotherapy. When I say local, I mean a very focused treatment where that RF energy is released, as opposed to a more systemic treatment, in which the whole body is affected, or a regional treatment in which just the liver is affected, for example, with a liver pump.”

A liver pump works by distributing chemotherapy in a regional manner to only the liver. Its purpose is to decrease the systemic side effects that are so prevalent with general chemotherapy. “You can give a much higher concentration of chemotherapy to the liver or to the area where the pump is placed,” Rogers points out.

The pump can be installed using an open operation, but there are new approaches that allow it to be installed laparoscopically as well.

Typically, RFA is performed laparoscopically in the operating room in open surgery or using percutaneous techniques which can be done in an interventional radiology suite. “RFA of liver tumors is typically not done in an endoscopy suite,” Rogers says. “There are likely to be developed RF applications that will be performed endoscopically, like the [current] Stretta procedure, which is performed endoscopically and uses RF energy to provide very localized ablation of the smooth muscles of the lower esophagus in an attempt to prevent GERD.”

Endoscopy can be used for tumor removal; Rogers utilizes a combination laparoscopic/endoscopic approach to tumor removal. “For example, [I use it] in patients who have benign tumors of the stomach, or to debulk certain types of tumors in order to allow palliation — for example, debulking an esophageal tumor with laser treatment. But RF ablative therapy has not yet been developed to the point that it can be used endoscopically for those techniques that I’m aware of,” he says.

Radiofrequency interstitial tissue ablation (RITA) is a technology used to treat unresectable liver tumors by Philip L. Leggett, MD, of Northwest Medical in Houston. “Laparoscopically, you put a light inside the patient’s abdomen, and then you make another small hole and slip in an ultrasound probe and you ultrasound the liver to find the tumor target. Then you stick a needle in through the skin into the tumor under ultrasound guidance, and the needle has little wires that are deployed out. Then you deliver radiofrequency energy into the tumor to destroy it. Literally, you cook the tumor,” Leggett explains.

Leggett has been using the technology for three or four years. Like Rogers, he agrees that the treatment can be very effective in certain cases. “It depends on how many different tumors they have,” he observes. “Patients are deemed unresectable if they have lesions on both sides of the liver [or if they have] too many lesions.” The location of the lesions may also make resection impossible. “In some patients, I use a combination of resection of individual tumors, and cooking the ones that are nonresectable,” he confirms.

“If [tumors are] based in one lobe or the other, you can take out a whole lobe. Livers will actually regenerate,” he points out.

The key concern with using radiofrequency ablation instead of resection is leaving cancerous cells behind. “If I resect a tumor, I would usually cook (or RITA) the bed where the tumor came out in order to increase the area of tumor kill zone,” Leggett explains. “It depends on the size of the tumor; I try to cook another centimeter to two surrounding the area where I cut it out.”

The extra centimeters are to ensure that no malignant cells remain. “In some tumors, if I resect them, you can’t always tell what the microscopic margin is like until you get the report back two days later. It takes about two days to look at the tumor and make sure the edges have normal tissue around them, to make sure that you’re around it. So in a lot of cases now, I do a combination,” says Leggett.

The treatment is a valuable ally for surgeons. “In the old days, when you didn’t have any of this technology — if you had tumors of the liver that are metastatic from colon cancer, for example — 15 years ago, that was a death sentence. People died within six months, 15 or 20 years ago. Now we have the technology to do things like this,” Leggett exults.

The RITA process can be adjusted to ablate smaller or larger areas. “You can go up to seven centimeters in a cook,” he says. “You can deploy the wires out to get a seven-centimeter spherical kill zone, but you can go as small as one to seven centimeters.”

Works Cited

1. www.peoplelivingwithcancer.org/plwc/Shared/
plwc_ArticleViewPrint/1,1890,25793,pp.html 10/29/03

2. www.cancer.org/docroot/CRI/content/
CRI_2_4_4X_Biologic_Therapies.asp?sitearea=CRI 10/29/03