June 10, 2005 ANN ARBOR, MI -- It's been five years since Dave Smethurst had 10 tumors removed from his liver. After surgery, three remained, too difficult for surgeons to safely remove.
The average patient lives less than six months with liver tumors that cannot be removed surgically. But after receiving a new type of treatment pioneered at the University of Michigan Comprehensive Cancer Center, Smethurst has reached the magical five-year mark.
"I guess I'm considered cured after five years -- that's kind of the gold standard for cancer patients. It's been five years now and I'm doing just fine," says Smethurst, 58.
The treatment, available only at U-M, involves an innovative method of delivering 400 times the normal amount of chemotherapy directly into the liver and combining that with state-of-the-art, specialized radiation therapy targeted directly at the tumors.
"On average, patients' lives are significantly prolonged, and I think, based on the evidence we have now, that some patients are cured. In the past, nobody was curable with unresectable disease," says Theodore Lawrence, M.D., Ph.D., Isadore Lampe Professor and Chair of Radiation Oncology at the University of Michigan Medical School.
Most often, liver tumors originate as cancer in another part of the body and spread to the liver. Primary liver cancer, or cancer that starts in the liver, is among the most serious and deadly types of cancer. Typically, it's not discovered till an advanced stage because it causes few distinct symptoms. About 17,500 people are expected to be diagnosed with primary liver cancer this year, and 15,420 will die from it, according to the American Cancer Society.
Standard treatment for tumors that cannot be removed through surgery has been traditional intravenous chemotherapy, which is delivered through a vein to the entire body. The drugs are drawn to rapidly dividing cells, including cancer cells. But cells that affect digestion and hair growth are also rapidly dividing and are affected as well, causing unpleasant side effects such as nausea and hair loss.
U-M researchers based their new treatment on the liver having two major blood supplies but needing only one. The tumor lives off one of the two blood supplies, and the artery feeding into the liver actually feeds the tumor's growth. With this treatment, the chemotherapy is infused directly into this artery so the drug goes directly to the tumors in the liver.
The liver is also where chemotherapy drugs are typically processed and removed from the blood supply. By targeting the drugs to the liver, very little of the drug travels throughout the body.
"With this approach, the tumor sees a much higher concentration of the drug. Despite the fact that we're giving a concentration of drug that's 400 times what the body would otherwise tolerate, the fact that the liver extracts or removes the drug means that the whole body sees a low concentration of drug," says William Ensminger, M.D., Ph.D., professor of internal medicine at the U-M Medical School and director of cancer pharmacology at the U-M Comprehensive Cancer Center.
For patients like Smethurst, that means minimal side effects, possibly nausea, diarrhea or a fever, but no hair loss.
The chemotherapy is given 24 hours a day for two weeks with twice-daily radiation treatments occurring at the same time. The patient then gets a two-week break before repeating the chemotherapy and radiation combination for another two weeks.
By carefully identifying through CT and MRI scans where the tumor is, radiation beams can be chosen that hit the tumor while sparing the normal liver tissue. A special planning technique is used that divides the liver into 2,000 to 2,500 small volumes and calculates the dose to each one that would result from a particular arrangement of radiation beams. This information is used to calculate the maximum safe dose of radiation that can be given. Because of its precision, Lawrence equates the technique to "surgery without a knife."
"We treat the tumor with cross-firing beams that build up the dose on the tumor but spare the surrounding tissues. We can calculate exactly how much radiation we're giving to the normal liver. We continue to refine our treatment until we've minimized the dose to the normal liver and to the other critical, normal structures, but we've maximized the dose to the tumor," Lawrence says.
For Smethurst, who remains cancer-free, the opportunity to be part of this novel technique fed his hopeful attitude and positive outlook throughout treatment.
"There's just tons of cancer research going on all over this country, and that really gives a lot of hope to cancer patients, knowing that literally tomorrow a drug may be approved for treatment that will save your life," he says.
Symptoms of liver cancer
Liver cancer is often not diagnosed till advanced stages because the symptoms are difficult to recognize. Some signs of liver cancer are:
* Pain, especially in the abdominal area or around the right should blade
* Unexplained weight loss
* Loss of appetite
* Pain or swelling in the upper right area of the abdomen
* Jaundice, or yellowing of the skin and whites of the eyes
U-M Comprehensive Cancer Center: http://www.cancer.med.umich.edu/learn/liver.htm
National Cancer Institute: http://www.cancer.gov/cancertopics/types/liver/
American Cancer Society: http://www.cancer.org/docroot/lrn/lrn_0.asp
U-M Cancer AnswerLine: 800-865-1125
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