SAN ANTONIO — Diabetes is believed to be a contributing factor to several types of cancer, and new research in San Antonio patients reveals an association with kidney cancer. The study of data records of 473 patients who underwent surgery for renal cell carcinomas found that 25 percent had a history of diabetes.
More than 60 percent of the patients were Hispanics, and men outnumbered women among the kidney cancer cases overall. However, 1.5 times more women with kidney cancer were diabetic, according to the analysis conducted at The University of Texas Health Science Center San Antonio. The kidney cancer cases covered the period from 1994 to 2009.
“The strong message is that if you’re diabetic, have your hemoglobin A1c tested every three months by a physician and keep your blood glucose level as normal as you can on a daily basis,” said lead researcher Samy L. Habib, Ph.D., assistant professor of cellular and structural biology in the School of Medicine. “This will prevent diabetes complications, including developing lesions such as renal cell carcinoma.”
A test for diabetes may also be a test for cancer
Hemoglobin A1c strongly predicts diabetes complications — keeping its level under 7 percent reduces blood vessel complications in diabetic patients. Dr. Habib suggested that hemoglobin A1c monitoring may be a useful marker for early detection of silent or small renal cell carcinomas before they manifest clinically.
Kidney cancer is the sixth-leading cause of cancer death in the U.S. Every year 40,000 Americans are diagnosed with kidney cancer and about 12,000 die. It is sometimes detected too late after it has spread to other parts of the body.
In Texas, a state of 25 million people, about 2 million have diagnosed diabetes. That’s 8 percent of the population. The percentage of diagnosed diabetes in Bexar County exceeds 9 percent. The incidence of diabetes among renal cell carcinoma patients is more than twice as high as the Bexar County and state average, therefore.
Majority of tumors were small and localized
The study shows that diabetes increases the incidence of the clear cell type of renal cell carcinoma from 80 percent to 92 percent. The majority of tumors tended to be small and localized, indicating a favorable response to therapy and survival. Some of the cancers were likely found when the patients underwent CT scans or magnetic resonance imaging (MRI) trying to diagnose other diabetic complications, Dr. Habib said.
The majority of diabetic patients diagnosed with kidney cancer were 50-59 years of age, whereas incidence of kidney cancer is more frequent in patients who are in their 60s.
Further studies are needed to evaluate the importance of hemoglobin A1c monitoring and blood glucose control on renal cell carcinoma outcomes, Dr. Habib said.
Liver, pancreatic cancers may also have strong links to diabetes
Dr. Habib will soon study the association of pancreatic, liver, breast and lung cancers with diabetes. He expects to find particularly strong links to diabetes in liver and pancreatic cancers.
Dr. Habib’s laboratory began this line of research in 2005, and he is studying the molecular and genetic factors by which diabetes enhances kidney cancer.
This work was supported by a grant from the American Diabetes Association and a Merit Review Grant from the U.S. Department of Veterans Affairs, South Texas Veterans Health Care System. Co-authors are Thomas Prihoda, Ph.D., associate professor of pathology; Maria Luna, M.D., clinical adjunct faculty; and Sherry Werner, M.D., professor of pathology and physician with UT Medicine San Antonio, the clinical practice of the School of Medicine.
The Journal of Cancer published the research in January, with e-publication ahead of print on Dec. 24, 2011.
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