Biopsy in Breast Cancer Diagnosis: Advantages, Limitations and Alternatives

Biopsy, a procedure of extracting a small tissue sample from the body to provide doctors with material for examination, has been part of medical practice long before modern medicine. Biopsy procedures have been referenced as far back as the eleventh century, but the term ‘biopsy’ itself was coined by Ernest Besnier in 1879.

According to a 2005 population-based study on breast biopsy utilization conducted by a team of prominent physicians, oncologists, and researchers, including Dr. Karthik Ghosh, M.D., and Dr. L. Joseph Melton III, M.D., from the Mayo Clinic, breast biopsies revealed cancer in 20% to 42% of patients, depending on their age.

Despite the high accuracy of biopsy, especially with excisional biopsies that remove the entire lump and have a false-negative rate of just 0.1-0.3%, the procedure has several limitations, spurring an active search for better alternatives. This article will present you with the positive and negative sides of biopsy in breast cancer diagnosis and its potential options, including biomarker testing.

The Role of Biopsy in Breast Cancer Diagnosis

As mentioned earlier, biopsy, particularly excisional biopsy, can significantly enhance the precision of cancer diagnosis. This is possible because biopsy provides doctors with direct tissue samples for accurate examination. The tissues affected by cancer naturally serve as a great source of information about the disease, helping doctors determine its type, grade, and stage. Additionally, the samples can be used to detect genetic mutations in patients.

These insights into the disease are instrumental in selecting the appropriate cancer treatment and determining its intensity. Doctors can also monitor the progress or failure of medical procedures by repeating biopsies.

Limitations of Biopsy in Breast Cancer Diagnosis

One of the greatest concerns related to biopsy is the probability of false-negative results.

As mentioned earlier, the high accuracy of excisional biopsy is due to the large tissue samples collected during the procedure, which are often sufficient to exclude the possibility of cancer in healthy patients.

Vacuum-assisted biopsy (VAB) is slightly less precise, with a false-negative rate of 0.5-1%. However, it still collects a larger amount of tissue compared to less invasive techniques such as fine needle aspiration (FNA), stereotactic biopsy, and core needle biopsy (CNB), the latter of which has a false-negative rate of up to 4%.

This trend stems from the fact that less-invasive biopsy procedures are more likely to collect samples from parts of the tumor that do not contain cancer cells.

As a result, the more tissue collected during a biopsy, the more painful the procedure, the longer the recovery time required, and the higher the risks of infection and bruising. Surgical biopsies, such as excisional biopsy, require anesthesia and patient hospitalization. At the same time, individuals diagnosed with invasive breast cancer often need a separate surgical biopsy for lymph nodes after a breast biopsy.

Biomarker Testing and Other Breast Cancer Diagnostics Techniques

While biopsy remains a dominant technique for breast cancer diagnosis, its limitations have encouraged researchers to explore alternative methods. These include biomarker testing and innovative but insufficiently studied techniques, such as the non-invasive capture of cancer-derived particles known as exosomes in a patient’s urine or blood.

Non-invasive imaging tests such as MRIs, PET and CT scans, X-rays, and ultrasound examinations also support breast cancer diagnosis. Still, they are often insufficient for precise detection and are usually followed by biopsy.

Meanwhile, biomarker testing techniques analyze chemical substances that can signal the general presence of cancer in the body and specific details such as its growth, division, and spread. Furthermore, biomarker testing can help doctors assess receptors for hormones that can guide the selection of more effective treatments. The biomarkers based on hormonal receptors include progesterone receptor (PR) status and estrogen receptor (ER) status, which are positive in tumors likely to respond effectively to hormone therapy.

Although the detection of many cancer biomarkers, for instance, the cancer proliferation biomarker Ki67, requires a biopsy to provide doctors with the material for evaluation, there are also biomarkers, such as thymidine kinase, that can be found in the blood of individuals suffering from proliferating cancer. Further research into such biomarkers has great potential for developing efficient non-invasive techniques for cancer detection and continuous monitoring of the individual’s response to treatment.

Final Thoughts

Due to its high accuracy, biopsy is currently used as the primary technique for breast cancer diagnosis. However, it does not guarantee 100% precision and can be invasive, especially in the case of complete lump removal. Many alternative techniques, including imaging, are often combined with biopsy as most of them cannot provide detailed information about the disease, unlike the studies of the tissue samples collected during biopsy.

Even though many biomarker testing techniques are applied to tissue samples obtained through biopsy, some biomarkers, such as thymidine kinase, can be detected in the blood, eliminating the need for a biopsy.