Cancer is the second leading cause of death in the United States, after cardiovascular disease, and research scientists and drug companies are looking hard for the next big breakthrough in cancer treatment.
Pharmaceutical companies spent more than $67 billion a year on research and investment last year, according to the Pharmaceutical Research and Manufacturers of America, and the government funds several billion dollars more.
Here are some of promising new approaches I learned about this year, while preparing the fourth edition of my book on chemotherapy treatment, Making the Chemotherapy Decision. They include telomerase inhibitors, stem cells, cancer vaccines, antineoplasteons and lifestyle modification.
1.Telomerase inhibitors — Attempts to break the seeming immortality of the cancer cell by agents called telomerase inhibitors are underway. The telomere is a sort of button on the end of each human chromosome composed of DNA, RNA, and certain proteins. In normal cells, the telomere shortens each time a cell divides, and when it disappears, the cell dies. This does not happen in cancer cells, it is believed, because an enzyme called telomerase, produced by a specific gene or set of genes, somehow inhibits the cancer cell aging process and allows cancer cells to keep dividing forever. Telomerase activity has been identified in the vast majority of cancers, according to a 1997 study published in the European Journal of Cancer.
The first telomerase inhibitor was produced in 1994. According to author Michael Fossel, M.D. PhD, a professor of clinical medicine at Michigan State University, this new class of anticancer agents could work against cancers that express telomerase, which are the more malignant cancers, and could probably limit the growth of the tumor mass to perhaps 4 grams (enough to fill a teaspoon), a manageable size in most locations of the body. Because normal cells don’t express this substance, researchers believe that detecting the presence of telomerase in the body could one day alert doctors to the onset of cancer before a tumor has even begun to form.
A telomere inhibiting drug, called Imetelstat or GRN163L, entered Phase 2 clinical trials in 2010 with patients with breast cancer, multiple myeloma or thrombocythemia.
2. Stem cells– Stem cells which can develop into other types of cells may someday have a major role in cancer treatment.
Stem cells are similar in some ways to cancer cells. Their only current approved use is in bone marrow transplants, which involves removing a patient’s own stem cells from bone marrow, then reinserting the stem cells into the body after high dose chemotherapy treatments. However, clinical trials are underway using a similar technique on people with lymphoma. Doctors are reinjecting lymphocyte stem cells from a doner after the patient’s own lymphocytes have been destroyed, in an attempt to beat the cancer.
More breakthroughs with stem cells in cancer treatment could be coming. In 2011, researchers at the University of California at Irvine transplanted neural stem cells into rats that had been exposed to radiation therapy, and reported that many of the stem cells survived and turned into brain cells, improving the cognitive function of the animals. And at the McGowan Institute for Regenerative Medicine in Pittsburgh, researchers used stem cells and chemicals to regrow a windpipe for a man whose cancerous trachea had been surgically removed.
Cancer stem cells, on the other hand, a small portion of cells in each cancer, are believed to be responsible for the metastatic spread of some cancers after treatment. Cancer stem cells are much more resistant to standard chemotherapy and radiation treatments than most cancer cells. Some research is targeting these cells with drugs and delivery methods which do not harm normal cells.
3. Cancer vaccines-The quest to develop vaccines that prevent the occurrence of cancer or cause its regression is much different than the quest to develop a polio vaccine, which targeted the polio virus. Many cancers are believed to originate within the human body. However, it has been estimated that between 10 and 25 percent of all neoplasms may be caused by or contributed to by viruses.
Scientists are using two main strategies to develop cancer vaccines. So-called prophylactic vaccines aim to prevent the development of cancers.while therapeutic vaccines are used to treat existing cancers.
Prophylactic vaccines have been approved against the human papillomavirus believed to cause 70 percent of cervical cancer. Although several vaccines for melanoma underwent testing in clinical trials, only one melanoma vaccine has been approved for use-and approved only in Canada, not in the U.S.
In 2010, Sipuleucel-T or Provenge was the first therapeutic vaccine approved for the treatment of metastatic prostate cancer. This drug, which costs an estimated $93,000 for a full course of treatment, according to The Economist magazine, can be customized to each patient’s cells.
According to the National Cancer Institute, clinical trials are now underway for vaccines to treat bladder cancer, brain tumors, breast cancer, cervical cancer, Hodgkin’s lymphoma, kidney cancer, melanoma, multiple myeloma, leukemia, lung cancer, Non-Hodgkin’s lymphoma, pancreatic cancer, prostate cancer, and solid tumors. Preventive vaccines for solid tumors and more vaccines for cervical cancer are also undergoing clinical trials.
The task of developing cancer vaccines is extraordinarily difficult, and many proposed vaccines have already been eliminated in clinical trials.
4. Antineoplastons are molecules, basically peptides and amino acid derivatives, that kill certain cancer cells without harming normal cells. Dr. Stanislaw Burzynski first identified antineoplastons in 1967. His clinic in Houston, Texas, is continuing his controversial work that has resulted in results superior to conventional cancer treatment in clinical trials involving certain types of malignant brain tumors and colon cancer which has spread to the liver. Since antineoplaston treatment is not FDA approved, it must be administered in the context of an approved clinical trial. Treatment is individualized, based on the identification of oncogenes in individual patients. Dr. Burzynski views cancer as a disease of the genes, and says he is trying to find keys which disable the network of genes which protects and nourishes various forms of cancer.
5. Prevention– The greatest reductions in cancer rates may well come from simple lifestyle modifications. Smoking and excessive drinking, for instance, increase the risk of contracting certain cancers, and curtailing these activities will increase your chances of avoiding them. According to the Centers for Disease Control, incidences of lung cancer have fallen in step with reductions in numbers of Americans smoking.
Obesity, too, is a recognized risk factor for some types of cancer. Regular physical exercise may help you lose weight and avoid cancer, too. Studies have shown that increased levels of physical activity help prevent many types of cancer including colon cancer and breast cancer.
An analysis of several hundred studies published in the Journal of the American Dietetic Association found that increased vegetable and fruit consumption resulted in lower rates of many forms of cancer. Research studies involving vitamin A, vitamin C, Vitamin E and other antioxidant vitamins found in plants are now underway. While the links between good nutrition and cancer prevention are increasingly apparent, the idea that vitamin supplements can help prevent or control cancer is still controversial.
According to the National Cancer Institute, several studies have suggested that taking a baby aspirin every day may help prevent incidences of hormone dependent breast cancer and colon cancer.
Reducing the incidence of cancer-causing chemicals and chemical combinations in our environment may also reduce or prevent the incidence of many types of cancer. The President’s Cancer Panel released a report in 2010 which called on President Obama to take action to reduce public exposure to carcinogenic chemicals in our food, water, and air that “needlessly increase health care costs, cripple our nation’s productivity, and devastate American lives.” Bisphenol A, radon, formaldehyde and benzene were among the chemicals specifically mentioned in the panel’s report.
In Europe, the European Directive for Registration, Evaluation and Authorization of Chemicals, or REACH, has already begun the process of banning and phasing out dangerous carcinogenic and mutagenic chemicals.