LEXINGTON One in eight women will develop breast cancer within their lifetime. With these daunting statistics, it is no wonder that Chad Harston, MD, is so passionate about his position as lead physician with the Lexington Clinic Center for Breast Care, where he has been focusing exclusively on his specialty, breast imaging, since 2011. “I have been doing breast imaging almost 100 percent of the time for more than 10 years now. That is hundreds of thousands of mammograms.”
After joining and subsequently receiving a scholarship from the United States Air Force, Harston received his medical degree from Baylor College of Medicine in Houston, Texas. After a transitional internship at Wilford Hall Medical Center, he moved into his residency in diagnostic radiology at San Antonio Uniformed Services Health Education Consortium.
Periodically, the Air Force determines which sub-specialties will be in the highest demand. During his service, they concluded that women’s imaging was most needed, so Harston became a Women’s Imaging Fellow at Brigham and Women’s Hospital and Harvard Medical School in Boston, Mass. Soon, he realized it was an excellent fit. “I felt I was making a difference in the lives of women by detecting cancers early so they could be treated more successfully,” says Harston.
Following his fellowship, Harston returned to San Antonio to fulfill his commitment to the Air Force and spent the next four years overseeing the instruction of nearly 70 residents and medical students, as well as treating women that were both active and retired from the military. His last six months of duty were spent in Iraq performing “battlefield radiology.”
The Mammography Quality Standards Act was enacted by congress in 1992, and since that time, mammography has been heavily regulated by the federal government. As the designated lead physician, Harston must ensure Food and Drug Administration guidelines are met in accordance with the law. This includes regulations regarding image quality and image interpretation, among others. While federal standards require that mammography results be sent to women within 30 days, the Lexington Clinic Center for Breast Care offers to provide results to patients before they leave the facility, usually within 10–15 minutes. Occasionally, this immediate service may not be possible when old mammograms are required for comparison and must be mailed from another facility. If screening images show a possible abnormality, further testing is immediately offered, including special mammographic views and breast ultrasound.
Harston has a simple mission. “My goal is to find breast cancers when they’re as small as possible.” He adds, “If we can find cancers when they are less than one centimeter in size and there are no metastases to lymph nodes, then the statistics show there is 100 percent survival.”
In order to accomplish this, Lexington Clinic offers not only traditional mammograms, but tomosynthesis, otherwise known as 3-D mammography, contrast-enhanced digital mammography (CEDM), ultrasound, MRI, and image-guided needle biopsies. Recent breakthroughs in technology have decreased radiation, improved sensitivity for malignancy, and decreased false positives.
Tomosynthesis supplies a more comprehensive view by providing one-millimeter virtual slices of the breast. This is especially effective for evaluating the dense glandular tissue that is common in premenopausal women. Prior studies have shown that the sensitivity of traditional mammograms falls as breast density increases. However, this can be overcome to a significant degree with the new 3-D technology. In regards to the benefit of tomosynthesis, Harston elaborates, “In fact, recent research has shown that 3-D mammography helps in all women. It has improved sensitivity across all breast density categories, but especially for those with moderately dense tissue.”
Currently, the Lexington Clinic Center for Breast Care is the only site in central Kentucky to offer CEDM, which uses iodinated IV contrast dye in conjunction with mammograms. This allows the radiologist to see areas in the breast with abnormal blood flow, an attribute of cancer that is not visible on a regular mammogram. On a regular mammogram, the fatty tissue is black, while glandular tissue and cancers both show up as white. Patients with areas of predominantly glandular tissue are described as having dense breasts. In these women it can be difficult to distinguish a tumor growing in a background of dense glandular tissue because both appear white. However, CEDM reveals cancers that are obscured by dense tissue by highlighting areas with abnormal blood flow. Harston explains, “If there is a tumor, it lights up like a light bulb in a dark room on a contrast-enhanced mammogram. This is because computer processing darkens the dense background tissue and reveals areas with abnormal contrast accumulation. CEDM is as sensitive as breast MRI and has the additional benefits of being faster, less expensive, and more accommodating for patients with claustrophobia and large body habitus.”
The American Cancer Society (ACS) recommends extra screening with breast MRI for high-risk patients. Contrast-enhanced mammography is the next best option for women who cannot undergo MRI. To determine who meets ACS high-risk criteria, the Center for Breast Care offers a complimentary breast cancer risk assessment using several scientifically validated mathematical models that take into account genetic predisposition and personal history. A few of the other factors that influence risk include number of pregnancies, breast-feeding history, and use of hormone replacement therapy. The assessment, administered by Debbie Stakelin, MSN, RN, GN-BC, CN-BN, determines if the patient meets the threshold of 20 percent or higher lifetime chance of developing breast cancer. If so, she is classified as high-risk and will receive a recommendation for adjunctive screening. Women with extremely dense breast tissue are also at a disadvantage because their cancers are much more likely to be obscured on a mammogram. About 70 percent of missed breast cancers occur in women with dense tissue. These women should also consider undergoing contrast-enhanced mammography.
When it comes to mammograms of all types, Harston is adamant on one point – every woman should begin screenings at age 40 and continue to get them yearly. He explains, “Breast cancers that are detected when they are still one centimeter or less have the best prognosis. Yearly screening mammography is hands-down the best way to find cancers this early. The average size of cancers discovered with screening mammography is 1.1 cm. In contrast, the average breast cancer discovered on a clinician’s physical exam is around 2.6 cm and those discovered by patients are around 3.6 cm.”
Harston elaborates, “We know that smaller cancers are easier to treat and cure. We also know that mortality is directly related to the size of the cancer at the time it is discovered; so, the larger the cancer is when it’s discovered, the more likely the woman will die from it.” He adds, “If you want to improve your odds, don’t skip years between screenings. Without any doubt, a regimen of yearly screening beginning at age 40 will save the most lives.”
Aside from ordering yearly screening mammograms, Harston urges primary physicians to advise women on the role lifestyle plays in their risk for breast cancer. “It is helpful to advise patients to stop smoking, to drink little or no alcohol and to pursue a healthy lifestyle including a diet and exercise program that will keep body weight in the normal range. Smoking, alcohol, being overweight, and obesity are all risk factors for breast cancer.”
If we can find cancers when they are less than one centimeter in size and there is no metastasis to the lymph nodes, then the statistics show that there is 100 percent survival. — Dr. Chad Harston