White House Press Secretary Tony Snow has bad news. His colon cancer, which was treated two years back, has sadly resurfaced.
Snow was treated with chemotherapy in 2005 after doctors removed his colon in order to prevent satellite growths of tumors that could be metastatic. Yet after recent surgery to remove a growth in the pelvic area, doctors discovered additional tumors in his liver.
AdvertisementThough patients often can be cured of their original tumors, cancers that grow back are much harder to eradicate, says Leonard Saltz, a colorectal cancer expert at New York's Memorial Sloan-Kettering Cancer Center.
Most relapses occur within 2½ to 3 years after the original tumor. If a tumor doesn't return within five years, many doctors consider the patient cured.
Says Dr. Raymond DuBois of MD Anderson Cancer Center that this relapse is not an unusual thing.
"Any time a patient comes in with a big tumor, we always worry about micrometastatic lesions somewhere else in the body," DuBois said.
"Once you have a tumor anywhere in the body, there is a chance that little seeds of metastasis may crop up later."
The good news is that more effective and better-tolerated drugs are now available. Such drugs help by blocking the tumor's ability to garner growth factors that enable its survival.
The Food and Drug Administration has approved five new colorectal cancer drugs since 1996: Camptosar, Eloxatin, Erbitux, Avastin and Vectibix.
In order to test for recurrent growths, vital to the prevention of colon cancer relapse, doctors rely on PET and MRI scans.
Yet the drawback of PET scans is that they rely on the tumors' voracious appetite for glucose. Hence, only tumors big enough, and thereby at a later stage, can be detected.
Technology is fortunately on to develop tests that detect certain biomarkers; proteins believed to be released by such tumors, in the blood. In such case, a simple blood test to identify these proteins will do the trick.
Yet doctors stress, prevention is always better than cure, and one of the most important methods is colon screening.
Colon screening performed via a test called the colonoscopy should be mandatory for all persons above 50, say doctors.
"Everybody is supposed to get screened for colon cancer right after they reach the age of 50," says DuBois, "because the risk of cancer started increasing dramatically after that. Colonoscopy is very effective; mortality rates from colon cancer have been going down in the last couple of years probably because the idea that people need to be screened is finally getting out there."
When caught early, DuBois notes, malignant growths still contained in the intestine can be removed with surgery, and 50 percent of patients are cured this way.
" Yet, about 30 percent of colon cancer patients, however, are diagnosed with the disease after it has progressed to more advanced stages, and spread to other organs such as the liver ", DuBois adds.
For people at average risk, the American Cancer Society recommends screening at age 50. People are advised to avoid tobacco, keep a healthy weight and exercise regularly.
Robert Mayer, an expert at Boston's Dana-Farber Cancer Institute, says deaths from the disease, the world's second most deadly cancer, have fallen nearly 9 percent since 1990.
Mayer gives most of the credit to screening, along with better treatments, such as treating earlier cancers with both surgery and chemotherapy.