Some patients simply do not respond to chemotherapy. Others suffer a recurrence despite treatment, or later develop a second cancer, which might be related to previous chemotherapy treatment. Chemotherapy also harms healthy cells, often producing significant side effects.
Chemotherapy is a category of extremely potent drugs that destroy rapidly growing cancer cells. According to experts at the Fred Hutchinson Cancer Research Center (FHCRC), the major clinical reason chemotherapy ultimately fails in advanced cancers is because the doses required to wipe out the cancer are also lethal to patients. That's why oncologists typically administer chemotherapy cyclically in small amounts: It gives normal cells a chance to recover between doses.
Why Chemotherapy May Fail
There are multiple reasons why chemotherapy may fail, and oncologists are challenged to circumvent these obstacles.
Some patients may not respond to chemotherapy because of a biological mechanism that causes these drugs to "jam" before they take effect. Researchers at The Rockefeller University found certain proteins that control other tumor-suppressing proteins are also involved in a second biological pathway in which they push cells to grow uncontrollably, negating the effect of chemo.
In blood cancers, researchers have found a set of cells that don't grow and spread as rapidly as regular cancer cells. They survive chemotherapy and then give rise to new, rapidly growing cells called cancer stem cells.
Experts at FHCRC also found that normal cells living near tumors might sustain DNA damage when exposed to chemotherapy. These damaged cells stimulate cancer growth by producing high levels of a protein that enables cancer cells to grow, invade nearby tissue, and resist chemotherapy.
Different Point of View on Chemotherapy
Not everyone believes chemotherapy is a suitable treatment for cancer. For example, in 1956, Hardin B. Jones, Ph.D., a top statistician in the cancer field and former professor of medical physics and physiology at the University of California, Berkeley, had this to say about chemotherapy.
"My studies have proved conclusively that untreated cancer victims live up to four times longer than treated individuals. If one has cancer and opts to do nothing at all, he will live longer and feel better than if he undergoes radiation, chemotherapy or surgery, other than when used in immediate life-threatening situations."
Most medical interventions carry risks and clearly, chemotherapy is an imperfect solution. However, by fully understanding the pros and cons, you can make informed decisions about your cancer treatment.
Sources:
Woodward, Kristen. "Cancer Chemotherapy Resistance: Hutchinson Center Team Discovers New Mechanism."
Fred Hutchins Cancer Research Center. Press Release. Web. 6 August 2012
http://www.fhcrc.org/en/news/center-news/2012/08/peter-nelson-lab-chemotherapy-resistance-mechanism.html
National Cancer Institute. "Chemotherapy and You: Support for People With Cancer." Web. 29 June 2007.
http://www.cancer.gov/cancertopics/coping/chemotherapy-and-you
Twombly, Renee. "Why chemotherapy fails." The Rockefeller University Scientist. Web. 16 July 2004. Web.
http://www.rockefeller.edu/pubinfo/news_notes/rus_071604_a.php
Wiezmann Wonder Wander. "Why Chemotherapy Fails." Wiezman Institute of Science. Web. 29 May 2012.
http://wis-wander.weizmann.ac.il/why-chemotherapy-fails
Hardin B. Jones, Ph.D. "Cancer Industry Critics." Web.
http://www.whale.to/cancer/jones_h.html
People Against Cancer. "The Failed War on Cancer." Web. 12 July 2008.
http://www.peopleagainstcancer.net/pdfs/news/20080916n2.pdf
