by Wesley W. Wilson, MD
Artwork: Medical caduceus
NOTE: If you have any questions for "Ask the Doctor," please send
them to the Voice editorial office. The only questions Dr. Wilson will
be able to answer are the ones used in this column.
Wesley W. Wilson, MD has retired as an Internal Medicine practitioner at the Western Montana Clinic in Missoula, Montana. Dr. Wilson was diagnosed with type 1 diabetes in 1956, during his second year of medical school. He remains interested and involved in diabetes education for patients and professionals.
Q: After eight years with type 1 diabetes, my son recently died at age 25 from
a malignant brain tumor. He'd been taking many medications, including chemotherapy
meds, insulin, tegretol, captopril, phenobarbital and others. Could any of these
meds, alone of in combination, have caused his tumor to form?
A: Dear concerned, You have my condolences for your son's illness and death.
I can understand your wish to know why he developed diabetes, and what caused
the brain tumor. It is appropriate to ask if any of the drugs he used contributed
to the tumor formation.
Some agents, for example cigarettes and lung cancer, are associated, but the
cause of most cancers remains unknown. A few medicines may increase the risk
of cancer, but the vast majority of drugs do not. Interestingly, some chemotherapy
drugs increase cancer risk, but these agents do so only after prolonged or repeated
exposure. I presume the chemotherapy drugs were given to treat the brain tumor—thus
they could not have been responsible for its formation.
Phenobarbital and Tegretol are used to control seizures—and seizures are often seen with brain tumors—so they were probably given after the tumor began. Neither of these drugs, nor insulin, nor captopril have a reputation for causing tumors. I find no evidence that the drugs you listed caused the brain tumor. Age 25 seems inappropriate for cancer, but a three year-old in our church has been troubled by a brain tumor for the last two years.
Type 1 diabetes is perhaps a bit better understood. Some type of immune dysfunction causes an antibody attack of the insulin-producing beta cells of the pancreas, and the ability to produce insulin is destroyed. We used to think that type 1 diabetes began suddenly, but it is now evident there is a slow destruction of beta cells that proceeds for months or years before beta cell destruction becomes so severe that blood sugar rises and insulin must be given. That there is a long period of slow destruction before overt diabetes appears is important, since it allows us to hope that something can be done during this "development stage" to stop further beta cell destruction, and prevent or minimize diabetes. This is very important, since in the British publication LANCET, for Nov. 24, 2001, researchers reported that in a small group of persons with recently diagnosed diabetes, treatment with a peptide halted the progressive destruction of beta cells. This seemed to occur without the general blocking of immune function that causes so much trouble for folks who must take "immunosuppresive" drugs to prevent rejection of transplanted organs such as kidneys. These were folks with outright type 1 diabetes, but the question is: can we detect persons early in the pre-diabetic state and then halt the beta cell destruction?
There are now two reports of persons at high risk of type 2 diabetes treated with ½ hour exercise (walking) daily, and modest weight reduction, who were able to either prevent or delay appearance of diabetes. The weight loss was about 10 pounds for a 200 pound person. Those goals seem easy to achieve, especially since it was so effective in reducing diabetes.
It is an exciting time to be aware of developments in diabetes and it seems we should be ready to block the epidemic of type 2 diabetes now ongoing in the United States and other countries where the living is too easy and too good. I have been heartened to hear U.S. Secretary of Health and Human Services Tommy Thompson kick off a new program that will try to prevent diabetes by encouraging more healthful lifestyles.
I'm sorry to have not answered your questions and hope you will forgive my
enthusiasm about new developments that I feel show great promise.