Thermography Offers Alternative in Breast Cancer Detection
by Lynda Wharton
[Article from the National Business Review – October 17, 2003]

Until a year ago, mammograms and ultrasound provided the only technological methods of screening for breast cancer (NBR Oct 10).

Now an additional screening method has become available. Digital Infrared Thermal Imaging (DITI) has finally arrived 20 years after it was first approved by the US Food & Drug Administration as an adjunctive diagnostic breast cancer screening procedure.

Thermography is an imaging technique that uses specialised infrared cameras to image the breast or other areas of the body.

The infrared camera can detect temperature patterns of heat emission from the skin surface to a depth of about 6mm.

Thermography is based on detecting physiological changes in the breast, which occur long before a physical mass or tumour develops.

Thermal patterns are displayed on the skin and detected by the infrared sensor camera. This temperature data is then transmitted to a computer where all the images are stored as a picture, where red means hot and blue means cold. A trained thermologist is then able to analyse the heat pictures and detect abnormal patterns that may indicate a potentially cancerous or precancerous condition. If any abnormality is detected, a mammogram is performed to investigate further. Thermography can detect an abnormality long before it becomes dense enough to be seen with ultrasound or mammograms, which can generally only detect masses when they are the size of a grape or larger.

Breast thermography has undergone extensive research since the late 1950’s, and has already been the subject of over 800 peer-reviewed studies, involving well over 300,000 women, some of whom were followed for up to 12 years.

The first recorded use of a primitive forerunner of modern thermography can be found in the writing of Hippocrates as early as 480BC. A slurry of mud was spread over the patient and observed for the areas that would dry first and was thought to indicate underlying organ pathology.

Modern day research has confirmed that certain temperatures related to the human body are indeed indicative of normal and abnormal physiology. In 1957 modern day thermography discovered the skin temperature over a cancer in the breast was higher than that of normal healthy breast tissue.

While a mammogram is an anatomical test that detects lumps, a DITI detects abnormal patterns of heat, and is classed as a physiological test. In a normal healthy breast the tissue has a blood supply that is controlled by a part of the nervous system known as the autonomic nervous system. This can either increase or decrease the blood flow to the cells. When cancerous or even pre-cancerous cells are present they secrete chemicals that override the regulation by the autonomic nervous system. The cancer cells thus ensure their own steady blood supply. A DITI is able to detect patterns of heat produced from the increased circulation produced by this abnormal metabolic activity of cancer cells. Breast thermography does not diagnose breast cancer perse; rather it detects they physiological changes in breast tissue that have been shown to correlate with the presence of cancer or pre-cancerous states.

First-line breast cancer detection still depends primarily on mammograms and physical breast examination by a doctor. DITI is not claimed to be a replacement for mammograms but rather an effective adjunctive tool to increase the accuracy of mammograms. Mammograms do not detect all breast cancers and have been shown to miss up to 30% of cancers in women under the age of 50. DITI is especially useful for overcoming this reduced accuracy in screening younger women. DITI combined with regular mammograms has been shown to increase accurate detection rates to 95%. DITI is also able to detect the first signs of breast cancer that may be forming up to 10 years before it can be detected by a mammogram or manual examination. Studies of large numbers of women who have been screened have found thermography is the sole early initial signal in 10% of breast cancers.

Long-term studies have shown thermography is able to detect extremely early warning signs of cancer, eight to 10 years before any other detection method.

In a woman with healthy breast, the thermographic image will remain surprisingly consistent from one screening to the next. It is recommended women have a DITI annually to look for changes in their usual thermographic picture. Any significant change from their norm should then be further investigated by a mammogram.

Often a DITI will show an altered picture long before a tumour can be detected by either mammogram or manual examination.

In these women, a persistently abnormal breast thermogram is considered to be the strongest possible risk factor for the future development of breast cancer, carrying with it a 22 times higher risk of future breast cancer. An abnormal thermogram is 10 times more significant as a future risk indicator for breast cancer than a close relative family history of the disease.

In one study a group of 1527 women with initially healthy breasts, but abnormal thermograms, were followed for 12 years. Within five years, 40% of them had developed cancerous breast tumours in the previously indicated region of the breast.

Sue Morgan, a thermographer at Auckland’s Meditherm NZ, says, “Women should consider thermography as an adjunctive screening tool to increase the chances of detecting breast cancers at their earliest stages”. She says DITI is a safe and effective screening tool for adult women of all ages but is especially useful for women otherwise poorly served by traditional mammograms, in the 30 - 50 age group.

These women can have dense breast tissue which increases the likelihood of mammograms missing abnormalities.” She says DITI is also an effective screening tool for women with small breasts or breast implants. The process is completely safe, with no radiation exposure such as occurs during a mammogram. The breasts are not compressed or touched in any way so it’s also a completely painfree and comfortable process.