A Groundbreaking Approach to Breast Cancer Diagnostics
Enhancing Precision in Cancer Diagnostics
Microcalcifications, tiny calcium deposits, often signal breast cancer but more often indicate a benign condition. A novel diagnostic method developed by researchers at MIT and Case Western Reserve University could help doctors pinpoint cancerous and noncancerous cases more accurately.
Currently, when microcalcifications are found through mammography, doctors perform a follow-up biopsy to remove the questionable tissue. Regrettably, in 15 to 25 percent of these cases, the tissue containing the calcium deposits can't be retrieved, leading to an inconclusive diagnosis. As a result, the patient must endure a more invasive surgical procedure.
This new method, utilizing a unique type of spectroscopy, can locate microcalcifications during the biopsy, potentially reducing the inconclusive diagnosis rate by 97 percent, according to the researchers. Their findings were published in the Proceedings of the National Academy of Sciences the week of Dec. 24.
The spectroscopic approach could seamlessly integrate into the existing biopsy procedure, says Ishan Barman, an MIT postdoc and one of the paper's lead authors. This rapid technique could be a game-changer, sparing patients from unneeded surgeries and reducing radiological exposure.
A Simplified and Speedy Method
Microcalcifications form from calcium in the bloodstream depositing onto degraded proteins and lipids left behind by injured and dying cells. Although frequently found in breast tumors, microcalcifications are seldom seen in other types of cancer. Calcification is also a key factor in hardened arteries associated with atherosclerosis.
Among women with microcalcifications detected during a mammogram, only approximately 10 percent will have cancer, making the follow-up biopsy crucial. During this procedure, the radiologist first takes X-rays from various angles to locate the microcalcifications, then inserts a needle into the tissue and removes five to ten samples.
If the pathologist fails to find microcalcifications in these samples, the radiologist tries again, taking new X-rays. Unfortunately, the second attempt is rarely successful, says Maryann Fitzmaurice, senior research associate and adjunct associate professor of pathology and oncology at CWRU.
"If they don't get them on the first pass, they usually don't get them at all," she says. "It can become a prolonged and grueling procedure for the patient, with excessive X-ray exposure, and in the end, they still don't get what they're after, in one out of five patients."
For several years, the MIT and CWRU team has been developing a spectroscopic technique that could analyze the tissue the radiologist is about to biopsy, providing an instant analysis of whether that tissue truly contains microcalcifications.
Initially, the researchers focused on Raman spectroscopy, which uses light to measure energy shifts in molecular vibrations, thereby revealing precise molecular structures. Since Raman spectroscopy offers such granular information about a tissue's chemical composition, it is highly accurate in identifying microcalcifications. However, the equipment is costly, and the analysis takes a long time.
In the new study, the researchers discovered that another technique, known as diffuse reflectance spectroscopy, yields results comparable to Raman spectroscopy, offering information within seconds, allowing the radiologist to adjust the needle position before taking any samples.
Distinctive Signatures
Diffuse reflectance spectroscopy functions by sending light toward the tissue, then capturing and analyzing the light after its interaction with the sample. In this study, the researchers examined 203 tissue samples from 23 patients, within minutes of their removal. Each of the three types of tissue (healthy, lesions without microcalcifications, and lesions with microcalcifications) has subtle yet discernible differences in its spectrographic signature, which can be used to differentiate among them.
By analyzing these patterns, the researchers created a computer algorithm that can identify the tissues with a success rate of 97 percent. The changes in tissues' light absorption are likely due to altered levels of specific proteins (elastin, desmosine, and isodesmosine) often cross-linked with calcium deposits in diseased tissue, Jaqueline Soares explains.
Clinically, a radiologist would perform spectroscopy just after inserting the needle to provide real-time guidance for the current biopsy procedure. The researchers are now planning for a study in which they will test their needle and spectroscopy setup in patients during biopsies.
James Tunnell, an associate professor of biomedical engineering at the University of Texas, considers the findings a promising first step toward creating a system that could significantly impact breast cancer diagnosis. "This technology can be integrated into the system already used for biopsies. It's a simple technology providing the same level of accuracy as more intricate systems, like Raman spectroscopy," says Tunnell, who was not involved in the study.
The research was funded by the National Institutes of Health, the National Institute of Biomedical Imaging and Bioengineering, and the National Cancer Institute.
- This novel diagnostic method developed by researchers could help doctors more accurately distinguish cancerous and noncancerous cases, potentially reducing inconclusive diagnoses by 97%.
- The spectroscopic approach developed by MIT and Case Western Reserve University researchers could integrate into the existing biopsy procedure, sparing patients from unnecessary surgeries and reducing radiological exposure.
- Among women with microcalcifications detected during a mammogram, only approximately 10% will have breast cancer, making the follow-up biopsy crucial.
- The spectroscopic technique being developed by the MIT and CWRU team aims to analyze the tissue the radiologist is about to biopsy, providing an instant analysis of whether that tissue truly contains microcalcifications.
- In the new study, the researchers discovered that diffuse reflectance spectroscopy yields results comparable to Raman spectroscopy, offering information within seconds.
- The changes in tissues' light absorption are likely due to altered levels of specific proteins, which are often cross-linked with calcium deposits in diseased tissue, according to the researchers.
