Ultrasounds can detect breast cancer among those with dense breasts, as effectively as mammograms can, a study presented in the Journal of the National Cancer Institute has shown.
The findings, made public on Monday, December 28, were based on research led by Dr. Wendie Berg, professor of radiology at the University of Pittsburgh School of Medicine.
A group of 2,662 female participants were included in the American College of Radiology Imaging Network (ACRIN) protocol 6666, conducted across the United States, Argentina and Canada. The women hadn’t been diagnosed with breast carcinoma before they volunteered to be part of this research reviewing breast cancer screening methods.
However, their risk of developing the disease was believed to be high because their breast tissue was dense (which made breast cancer more likely and harder to detect), and there was also another contributing factor present alongside this prior one.
Throughout the trial, spanning across 3 years, the subjects had mammograms and ultrasounds on an annual basis, and this imaging was analyzed by different radiologists.
By the time the study had finished, 111 individuals had been told they suffered from breast cancer, and in around 4 out of 5 of the cases the condition proved to be invasive.
Overall, the disease had been diagnosed just almost just frequently using mammograms, as when employing ultrasounds.
The only difference was that the number of false positive results, which occurred when doctors wrongly presumed that a patient had a tumor, was more elevated when it came to ultrasounds, than when mammograms were performed.
More precisely, the percentage of women who had to take an ultrasound and were subsequently referred to more in-depth examinations, despite not actually having malignant tumors, was of around 32%.
In contrast, the proportion of female subjects who had worrisome mammograms that warranted more testing, although no cancer was eventually detected, was of approximately 23%.
On the other hand, ultrasounds proved more effective when it came to identifying node-negative invasive breast cancer, while mammograms detected a larger number of breast calcifications which are sometimes indicative of ductal carcinoma in situ (DCIS), the most prevalent type of non-invasive breast cancer.
As malignant breast tumors advance, the lymph nodes try to capture lymph fluid carrying cancer cells, to prevent it from affecting other parts of the body.
Therefore, when doctors discover cancerous cells in the lymph nodes located in the underarm, this suggests that breast cancer may be trying to spread: the higher the concentration of such cells, the greater the possibility of invasive cancer.
However, there is also the possibility that the tumor is node-negative, meaning that no traces of cancer can be found in the lymph node.
While the absence of cancer cells in the nodes isn’t always associated with a better prognosis, it’s still important to be aware of this particular aspect, and it appears that ultrasounds are more accurate when identifying node-negative malignant breast tumors that have actually spread past their original boundaries.
The results appear promising especially for patients from developing nations, where it is easier to get an ultrasound than a mammography exam, especially since the former has the advantage of being non-invasive also.
However, Dr. Lusi Tumyan, assistant clinical professor at the Department of Diagnostic Radiology, from the City of Hope cancer center, points out that ultrasounds shouldn’t be considered sufficient by themselves.
Instead, they should be employed as an additional method of screening, especially among those who face a higher risk of developing breast cancer.
All in all, study authors believe that mammograms and ultrasounds should both be performed on women with high breast density, in order to boost detection rates.
At the moment, recommendations issued by the American Cancer Society (ACS) specify that breast cancer tests should be taken into account starting from the age of 40, based on each person’s susceptibility to this disease.
Afterwards, women aged between 45 and 54 should have annual mammography exams, and starting from the age of 55 this type of screening should be repeated annually or once every two years.
Female patients who face a higher risk of breast cancer might also be advised to have MRIs so that the disease can be detected early enough.
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