Researchers at The University of Texas Health Science Center at Houston can identify and quantify specific protein markers in human saliva to provide an early, non-invasive diagnosis of breast cancer, according to a study published in the journal Cancer Investigation.

The study describes how the onset of breast cancer produces a change in the normal type and amount of proteins in glandular secretions from the salivary glands. The protein profile in a healthy person is altered by the presence of cancer.

Lead researcher Charles Streckfus, D.D.S., a University of Texas Dental Branch at Houston professor of diagnostic sciences with an expertise in salivary function and molecular epidemiology, collaborated on the groundbreaking study with William Dubinsky, Ph.D., a biochemist and professor of integrative biology and pharmacology at The University of Texas Medical School at Houston; and Lenora Bigler, Ph.D., clinical research professor with the UT Dental Branch.

“Why not the dentist?” said Streckfus. “Most folks, especially women and children, visit the dental office way more often than they ever see the physician. Saliva is a non-invasive, quicker way for detection.”

The study is being applied to a “lab-on-a-chip” technology platform developed by biochemists at The University of Texas at Austin. The ultimate goal is to bring this type of diagnostic test, which is capable of detecting the presence of cancer before a tumor forms, into the dental office or other health care facilities. The technology aims to improve the ease and effectiveness with which dental professionals and other health care providers can provide quick, accurate diagnostic information and physician referrals to their patients.

Dubinsky said saliva holds the codes to many medical secrets. “Saliva is a complex mixture of proteins. We go through a process that compares different samples by chemically labeling them in such a way that we can not only identify the protein, but determine how much of it is in each sample,” said Dubinsky. “This allows us to compare the levels of 150-200 different proteins in cancerous versus non-cancerous specimens to identify possible markers for disease.”

In the study, researchers analyzed saliva samples from 30 patients. They found 49 proteins that differentiated healthy patients from those with benign breast tumors and those with malignant breast tumors.

These findings suggest that patients can be tested for breast cancer by examining certain protein markers in their saliva during a visit to a dentist’s office or other health care facilities.

Streckfus said that being able to chemically distinguish between benign and malignant tumors through a saliva test eliminates possible false positive results. The supplemental chemical confirmation could allow experts to immediately determine the patient’s next treatment option, whether it be surgery, a biopsy or further testing.

SOURCES:
Cancer Investigation, January 10, 2008
University of Texas Health Science Center at Houston (http://www.uthouston.edu)