chemotherapy
Oncologists are testing a new technique called gene expression profiling that subtypes each breast cancer tumor by its genetic defects so that doctors can tailor their treatment to inhibit that particular tumor. The researchers believe the technique could spare millions of women from needlessly receiving toxic chemotherapy, and they are leading a national clinical trial to study gene profiling. "Currently, we have no predictive model to determine who will respond to hormonal therapies and who won't, so we prescribe chemotherapy as a backup measure to ensure the cancer's demise," said Matthew Ellis, M.D., Ph.D., director of the breast cancer program at Duke. "This one-treatment-fits-all approach leads to a huge amount of over treatment, with up to 50 percent of women unnecessarily receiving chemotherapy."
An international team of researchers has used a gene test to identify certain patients with adult T-cell acute lymphoblastic leukemia (ALL) who can be successfully treated with chemotherapy alone and should not be subjected to the rigors of bone marrow transplants. The researchers found that these patients survived for at least three years after being treated with intensive chemotherapy. It was previously known that only slightly over half of the patients with this disease could be cured with chemotherapy. Adult ALL patients often undergo transplants in an effort to beat back the stubborn disease. Until now there was no way to identify those who have a more favorable outlook and shouldn't undergo risky bone marrow transplantation.
An association between a common human virus and colon cancer has been established by a group of researchers in the U.S., suggesting a possible role for it in the development of cancer in the human intestinal tract. The so-called JC virus most likely infects humans through the upper respiratory tract and remains in a latent stage in most people throughout their lives, and, in some cases, causes minor sub-clinical problems. But in people whose immune systems are depressed, either through chemotherapy given to organ transplant recipients or an illness such as AIDS, JCV can become active and may contribute to cancer in the brain or cause the fatal demyelinating disease Progressive Multifocal Leukoencephalopathy (PML).
Surgeons in Philadelphia say they are finding success by combining light-based cancer therapy with surgery to treat patients with advanced lung cancer that has spread within the chest. While the number of patients treated to date is small, many patients are living three to four times longer than did those patients who did not receive the therapy. In photodynamic therapy (PDT), a nontoxic photosensitizing agent, photofrin, is injected into the bloodstream and absorbed by cells all over the body. These compounds tend to concentrate more in cancer cells than in normal cells. When the compound is exposed to a certain wavelength of light, it absorbs the light energy and produces a form of oxygen that kills the cells. The damage occurs only where the light is shined. In the study, each patient is given chemotherapy until the cancer stops responding, meaning the disease begins to grow again. If the cancer has not spread beyond the chest, the patient then receives photofrin 24 hours prior to surgery to remove the tumor. During surgery, he or she receives an appropriate dose of light therapy. Of the 16 patients evaluated to date, at least one-half have lived more than 23 months, which is between three and four times the usual time.
Today, even the best cancer treatments kill about as many healthy cells as they do cancer cells. But a St. Louis researcher has begun to lay the conceptual and experimental groundwork for a new strategy for chemotherapy -- one that turns existing drugs into medicinal "smart bombs." The approach is essentially a sophisticated drug releasing system, one that can recognize and use cancerous DNA sequences as triggering mechanisms for the drugs that fight them.
FROM THE TRENCHES: A consortium of scientists announced that it has deciphered the genetic code of the parasite that causes the deadliest form of Malaria, an illness that kills more than a million people a year in developing nations.
