Can a biopsy spread cancer throughout the body? - Dr. Kust for Jutarnji list

Our oncologist Dr. Kust writes for Jutarnji list and Živim.hr. We are publishing the article in its entirety, and you can read the original at the link.

Biopsy is one of the most important diagnostic procedures in modern medicine. It allows doctors to make a precise diagnosis and make decisions about the best treatment for each individual patient. Despite its unquestionable importance, there is often a fear among patients that a biopsy could encourage the spread of cancer. Is this fear, although understandable, based on scientific evidence?

A biopsy involves taking a tissue sample from a suspicious lesion or organ in order to analyze its structure and cellular composition. There are several types of biopsies, including fine-needle aspiration biopsy, wide-needle biopsy, and surgical biopsy. The choice of method depends on the localization of the suspicious formation, its size, accessibility, and suspicion of a certain type of disease.

Fine needle aspiration (FNA) biopsy uses a very thin needle and is often performed under ultrasound or CT guidance. This method is rapid, minimally invasive, and suitable for lymph nodes, thyroid, and some superficial tumors. Although FNA allows cytological analysis of cells, it does not always provide sufficient information about tissue architecture, which may limit the possibility of a complete histological diagnosis.

Core needle biopsy uses a thicker needle to take a cylindrical sample of tissue. This method provides more information because it allows for an examination of the cellular arrangement within the sample, which is important for determining the degree of tumor differentiation and immunohistochemical analysis. Core biopsy is now the standard for suspicious changes in the breast, prostate, liver, and many other organs (Figure 1).

Figure 1. Breast biopsy with a wide needle.

For suspicious or difficult-to-reach lesions that are not adequately assessed by needle methods, surgical biopsy is resorted to. It can be excisional, where the entire suspicious formation is removed, or incisional, where only a part of the change is taken. Although surgical biopsy requires anesthesia and a somewhat longer recovery time, it provides the most complete sample for analysis and is often used when previous less invasive methods are insufficiently informative. Each of these techniques has its advantages and limitations, but the common goal of all is the same — to make an accurate diagnosis with minimal risk to the patient. Without a biopsy, it is impossible to definitively distinguish benign from malignant formations, determine the exact type of tumor and its degree of aggressiveness, and thus plan treatment correctly. For example, lung cancer can be small cell or non-small cell, and treatment differs significantly depending on the type. The same applies to breast tumors, where the subtype, hormonal status, and the presence of HER2 receptors determine the treatment strategy. In hematological malignancies, such as lymphoma, biopsy is indispensable because without detailed histological analysis it is not possible to choose the appropriate chemotherapy protocol.

Nevertheless, there is still a widespread belief that biopsy can lead to "breaking"the tumor and spreading cells to surrounding tissue or into the bloodstream. Fears of this type have some historical basis, as early attempts to sample tumors, before the development of today's technologically advanced methods, could theoretically increase the risk of disease spread. Today, however, thanks to significant advances in medical technology and standardized procedures, such a risk is almost negligible.

The needles used for biopsies are designed to minimally traumatize the tissue and reduce the possibility of cell dissemination. In most cases, biopsies are performed under the control of ultrasound, CT, or magnetic resonance imaging in order to precisely target the area of interest, thus further reducing the risk. Special techniques for processing the samples taken, as well as methods for closing the needle channel after the procedure, further contribute to the safety of the procedure. Although there was concern in the past that biopsy could encourage the spread of tumor cells, modern scientific research shows that this risk is extremely low and in most cases without clinical significance. Most large clinical studies and case analyses have not found an increased incidence of local recurrence or distant metastases after routine biopsies, including breast, lung, thyroid and lymph node biopsies.

Biopsy has numerous other advantages that far outweigh any minimal potential risks. A properly established diagnosis allows for a personalized approach to treatment, optimization of treatment plans and avoidance of unnecessarily aggressive or ineffective therapies. In modern oncology, a “one-size-fits-all” approach is no longer acceptable - therapies are now selected according to the precise biological characteristics of the tumor that can only be determined by biopsy.

An important aspect that is often overlooked is the psychological component. The unknown is what causes the most fear in patients, and it is precisely the biopsy that brings answers. After receiving clear results, patients and their doctors can plan further steps together, which brings a sense of control and reduces the level of anxiety. Waiting without a diagnosis, suspicion and speculation are often much more harmful to the patient's mental health than the knowledge of the nature of the disease itself.

It is also worth noting that there is increasing talk about liquid biopsy, a procedure that analyzes tumor cells or DNA fragments circulating in the blood. Although this method is still not a substitute for a classic biopsy, especially in making an initial diagnosis, it is increasingly used to decide on the choice of targeted therapy, monitor the response to therapy and detect early signs of recurrence.

Ultimately, biopsy is a safe and indispensable tool in cancer diagnostics. The risk of tumor spread due to biopsy is minimal and many times lower than the risk of not making a timely and accurate diagnosis. Fear of a biopsy should not be a reason to delay the examination, because it is quick diagnosis and timely treatment can make a crucial difference in the outcome of the disease.

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