Core needle biopsy
The text contains relevant data and opinions about the core biopsy. However, we believe that for a patient with a suspicious breast finding, it is better to start the treatment with surgery without a core biopsy. Arguments for this position are given in the final part of the text. A “core needle” biopsy, or just a “core” biopsy as it is often called, involves taking a piece of tissue with a specially designed hollow needle to examine the tissue under a microscope. The tissue sample is taken out in the needle and extracted from the area of concern. It has a cylindrical (worm-like) shape, is usually 1-2 cm long, and about 2 mm in diameter. Usually, multiple samples (usually four) are taken during a biopsy. This amount of tissue is sufficient for complete histological and immunohistochemical analyses.
No type of breast cancer treatment can begin without a histological diagnosis.
A core biopsy is performed to make a histological diagnosis of breast changes. The previous, so-called clinical diagnosis, which consists of a clinical examination, mammography, ultrasound and possibly magnetic resonance imaging, gives a diagnosis that is not definitive. No matter how confident are we about the nature of the change based on these examinations, it is not considered an accurate diagnosis according to medical protocols. The correct diagnosis is obtained only after examining the tissue under a microscope.
This is especially true for cancer. No type of breast cancer treatment can begin without a histological diagnosis.
Core biopsy is the simplest way to obtain tissue for histological diagnosis. The tissue can also be obtained by surgical intervention under local or general anesthesia, when the affected area is cut out, partially or entirely, but this procedure is more complex, demanding, and expensive. Today, core biopsy is a widely adopted procedure in the world for all patients with suspected breast cancer based on previous diagnostics. The advantage of this approach is reflected primarily in the rationalization of surgical treatment by shortening the surgery time.
Another advantage is that preoperative determination of the histological and immunohistochemical tumor characteristics can reveal more biologically aggressive forms of cancer that will respond better to chemotherapy. These patients are often suggested to start the treatment with chemotherapy before surgery. However, this advantage is conditional because the administration of chemotherapy before or after surgery does not affect the prognosis (see Neoadjuvant chemotherapy).
The advantage of this approach is reflected primarily in the rationalization of surgical treatment by shortening the surgery time.
The disadvantages of core biopsy are subjective and largely depend on the expertise of the physician who determines the indication or performs the biopsy.
The first disadvantage refers to the indication of biopsy in cases where it is unnecessary. Biopsies that are often performed are those of changes in the breast that are clearly benign, most often fibroadenoma. Although this is not an absolute error, the appearance of a fibroadenoma is so characteristic that just based on clinical and ultrasound examinations we can be almost 100% sure that it is a fibroadenoma. This appearance can be atypical in sporadic cases, when a biopsy is warranted. In other cases, it is unnecessary trauma for the patient and a waste of time and money.
Another and much more dangerous disadvantage of core biopsy is the possibility of taking a sample from the wrong place. The frequency of this error directly depends on the expertise of the doctor performing the biopsy. In this case, a change in the breast can be perceived as benign when it is actually cancer. In this case, the correct diagnosis can be significantly delayed, and valuable time for treatment can be lost.
A disadvantage of a core biopsy can also be a situation when an adequate sample is obtained by biopsy, and histological analysis shows that it is benign, so surgical removal is no longer an option. These changes are indeed benign at the time of biopsy, but many of them may be sites where cancer develops in the future. By completely removing them, we would prevent the development of cancer.
There are opinions that core biopsy promotes the entry of tumor cells into the circulation and metastases by damaging the tumor tissue and the blood and lymphatic vessels in it. Although logical, this assumption has not been proven in clinical practice.
We cannot classify the complications of core biopsy as its disadvantages because they are unwanted phenomena that occur with practically all medical procedures.
We cannot classify the complications of core biopsy as its disadvantages because they are unwanted phenomena that occur with practically all medical procedures. This primarily includes profuse bleeding and the formation of large hematomas. Perforation of the chest wall is an extremely rare complication.
We believe that for a patient with suspected breast cancer, it is better to start the treatment with surgery without a core biopsy. In this case, the histological diagnosis is made during the surgery itself with a so-called “ex tempore” biopsy. The tumor is cut out entirely and sent for a histological examination, which lasts about twenty minutes, and after receiving the findings, a definitive surgical procedure is performed. This avoids damage to the tumor tissue and several days of waiting for histological findings. The only disadvantage is more extended surgery. This disadvantage is significant for large medical systems with a large number of patients, but for the individual patient, this approach is more natural and better.
A counterargument to our position is that some changes treated in this way will not be cancer. However, we reasonably claim that over 95% of the changes we suspect are cancer, based on previous diagnostics, are confirmed to be so by histological analysis. The remaining changes, which turn out to be non-cancerous, are removed by a small-scale surgery that does not leave any consequences. Very often, these are pathological lesions from which cancer develops in the future, so it is good that they were removed.