Saliva Cancer Clues for Prevention via Bio Markers
© 2014 Health Realizations, Inc. Update
Cancer is a disease that causes abnormal cells in your body to divide uncontrollably and then invade the healthy tissues nearby. Cancer cells can spread to other parts of your body using your blood or lymph systems as their vehicles. There are numerous kinds of cancer; over 71 types have been identified so far. With such high numbers, it is important for researchers to have options available for the early detection and accurate diagnosis of this disease.
One of the newest techniques available to doctors is saliva testing. This technique allows the doctor to separate and analyze each protein found in your saliva, revealing the biomarkers. A biomarker is a molecule found in your blood, other body fluid or tissue that signals a normal or abnormal condition or disease. Biomarkers can be used to identify cancer at the cellular level, determine the best treatment and monitor how your body is responding to treatment.
How Do Biomarkers Work?
The idea that cancer and other diseases can be detected at an early stage is one that is beyond important. If these diseases can be discovered, monitored or predicted through such a simple test, patients could potentially take action against illness before the physical symptoms ever appear, and this is often the key to a cure. Studies show that breast cancer, type 2 diabetes and Alzheimer's disease each leave their own specific signature in saliva.
Since saliva can be tested quickly and easily, it is often seen as the body fluid of choice for getting a look inside your body systems. The tests that are performed using saliva are relatively new and are still being perfected by scientists. However, such tests are able to identify certain shifts within the molecules that signal an abnormal transformation. Scientists can easily monitor the changes present in cells, ranging from pre-malignant to late stage cancer. Salivary biomarkers for the detection of oral and systemic disease is now coming of age, while testing blood samples for these kinds of markers lags behind.
In order to test for disease-related proteins, only a tiny sample of saliva is needed. One study found that there are changes in two specific proteins - myosin and actin - that occur during the very early transformation of healthy cells to diseased cells. These early biomarkers could be crucial to successfully treating diseases like oral cancer. This kind of transformation could allow doctors to watch a lesion that is premalignant and know exactly when to take action.
What Exactly Is Saliva?
Saliva is mostly made up of water, but its content does not come from the water you drink each day. Instead, the water comes from the three salivary glands on the bottom of your mouth and at the sides of your cheeks, along with the smaller glands in your mouth and throat. There are tiny capillaries that surround your salivary ducts that carry saliva into your mouth. Blood filters through these capillaries while specialized cells absorb water, proteins and various other molecules. Once this mixes with the fluid produced by the glands, you have saliva.
Once formed, saliva contains a multitude of proteins that can be screened for diseases. In the past, researchers have only tested the free-floating saliva protein. Since there are a huge number of proteins found in the oral cells, scientists developed another method to study these new proteins. They analyzed the saliva samples obtained from four patients with oral cancer and identified well over 1,000 different human proteins, including many of the known proteins already associated with cancer. They also separated protein from over 30 bacteria that had not previously been found in saliva, but may have possible links to cancer. This new technique provides the first data from the use of whole cells to identify large numbers of human and bacterial proteins contained within saliva. The data may also help to find new biomarkers that are associated with oral cancer and its progression.
The Fight Against Pancreatic Cancer
Cancer of the pancreas is often known as the "worst" cancer due to its mortality rate. Pancreatic ductal adenocarcinoma is the most common type of pancreatic cancer. It is also the most lethal. It has a mortality rate that is almost the same as the rate of incidence. More than 42,000 people were diagnosed with pancreatic cancer in 2009, while the mortality rate claimed over 35,000 lives. Pancreatic cancer is the fourth leading cause of cancer death in the United States. However, new research indicates that salivary testing may prove to be a very useful weapon in the fight against this particular form of cancer.
During one specific study of 90 people, researchers successfully linked changes in the molecules found in human saliva to the presence of early-stage pancreatic cancer. By simply analyzing the altered genes, biomarkers were identified that distinguished between pancreatic cancer patients and non-cancer patients. There are already plans to test the salivary biomarkers on a larger population in a multicenter study. The possibility of early detection is monumental for people who are diagnosed with pancreatic cancer when time is of the essence.
Pancreatic cancer presents typical symptoms of jaundice and abdominal pain, but only in the advanced stages of the disease. For this reason, it is very difficult to treat and fewer than 5 percent of people diagnosed with this type of cancer will live longer than five years. With pancreatic cancer being diagnosed at such a high rate, along with the fact that it is so deadly, there is an urgent need to find a reliable test to diagnose the disease at an early stage. If saliva testing can pave the way to implementing a safe and effective screening test, thousands of lives could be saved each year.
New Biological Tools for The Fight Against Lung, and Other, Cancers
Lung cancer is the leading cause of cancer death for men and women in the United States. In 2009, there were 219,440 new patients diagnosed in the United States alone. The main contributor to lung cancer is smoking. There are an estimated 45 million current smokers and another 45 million former smokers who are at risk for being diagnosed with lung cancer in the next 50 years.
Over 75% of all lung cancer cases are diagnosed in the late stages of the disease. Similar to pancreatic cancer, there has been no definitive method to test for the disease to determine who is at risk before symptoms appear. The treatment for lung cancer often has poor results, including the failure of chemotherapy and radiation treatment. Other problems include late diagnosis, progression of lesions and the lack of markers for early detection.
A new research project has confirmed that there are, in fact, biomarkers contained within saliva that have the capability of detecting lung cancer by using non-invasive biological samples. The research team is the leading team in salivary diagnostics and is charged with identifying these biomarkers.
Astonishingly, researchers have found that every systemic disease they studied yielded unique and discriminatory salivary biomarkers. These include pancreatic cancer, breast cancer, lung cancer, gastric cancer and ovarian cancer. Researchers also believe that their newly designed diagnostic tools played a large role in their ability to discover such links in salivary biomarkers. It is clear that more research must be done to further understand the association between oral and systemic health. The value of being able to identify a disease before its onset or progression is immeasurable. Adding to that value is the fact that salivary testing is non-invasive, non-painful, and non-embarrassing for patients. Saliva is an ideal body fluid for testing purposes, as well.
In April 2010, the U.S. Office of Science and Technology issued their Grand Challenges of the 21st Century for the biomedical research community. The first of these goals included the need of sequencing the DNA for every form of human cancer. Second was to develop therapeutic treatment options that target only the tumor cells, while sparing normal healthy cells (unlike chemotherapy and radiation, which kill healthy cells too). The third goal was to develop the ability to detect dozens of diseases by using a sample of saliva.
Working Toward the Future
Marching toward the goals that have been laid out for the medical community, researchers at Michigan State University are currently working to create a cost-effective test using salivary biomarkers to detect oral cancer. They believe they have discovered a way to utilize this new technology so that patients can avoid needles, biopsies and even reduce the mortality rate caused by this form of cancer.
Currently, around 100-120 patients are being recruited for testing purposes. Researchers are looking for signs of early malignancy, specifically the white lesions and growths that are found within the mouth and on the tonsils. The scientists will focus on the specific biomarkers that were formally identified by researchers who conducted another study for the presence of oral cancer. The biomarkers found in saliva will help doctors to identify patients in need of treatment for oral cancer, while also preventing others from experiencing the pain of invasive biopsies. Experts are optimistic that the saliva test for biomarkers will prove to be a milestone in the early detection and successful treatment of many different types of cancer, possibly in the near future.
The American Society for Biochemistry and Molecular Biology, Understanding Our Saliva
National Cancer Institute, Lung Cancer Topics
U.S. Office of Science and Technology Policy, Grand Challenges of the 21st Century
National Cancer Institute, Laboratory Tests that Detect Cancer