Both as a preventive measure and to confirm a possible case of cancer or tumor, a biopsy is one of the fundamental tests performed in response to any possible alert. However, depending on the suspicion held by the doctors, one type or another may be performed. The biopsy does not end there, as once the tissue is obtained, it is time to analyze it and perform the relevant tests. Only in this way can we obtain a result and subsequently work on finding the best treatment for the problem.
Today we will talk about biopsy as a means of cancer detection, its types, and liquid biopsy, a new discovery and improvement in precision medicine. Does it have more advantages than disadvantages? Is this new technique practical?
How does a biopsy work?
A biopsy is a procedure used to detect problems or tumors by extracting a sample of tissue or cells from a specific area of the body for analysis. This procedure is usually performed when imaging tests, such as CT scans or MRIs, cannot differentiate between tumor cells and non-cancerous cells. In fact, in many cases where cancer is suspected, a definitive diagnosis can only be obtained through a biopsy, as it allows a detailed examination of the extracted cells.
The pathologist will be responsible for examining the sample obtained from the biopsy by healthcare professionals. They will need to do so with a microscope to prepare a pathology report. This highly technical report will use terms aimed at other medical professionals and pathologists.
Generally, the pathologist will describe the types of cells present, their organization, their normality or abnormality, and other characteristics that are relevant to the diagnosis of that particular case. There are occasions when a second sample may even be required to complete it (this will be indicated in the report).
The biopsy result will include a diagnosis based on the general examination, processing, and microscopic analysis of the tissue. This report will indicate the organ or tissue from which the sample was taken, the specific part it comes from, the biopsy procedure used, the specific findings in the tissue, and any other additional tests that may be necessary. It is important to mention that before the procedure, a local anesthetic is administered to the patient to numb the biopsy area and minimize pain.
Types of biopsy
Depending on the suspected tumor, the patient’s condition, and the severity of the situation, there are various types of procedures for sample extraction
Needle
As its name suggests, this type of biopsy uses a special needle, which is inserted through the skin to extract cells from an area suspected of having cancerous cells. Doctors often call it percutaneous tissue biopsy.
It is usually used in areas where the doctor has noticed something suspicious by feeling through the skin (lumps in the breast, enlarged lymph nodes…). When combined with imaging techniques, needle biopsy can also be used to extract cells from areas that cannot be felt. Within this type of biopsy, there are several ways to proceed:
Fine needle aspiration
A long, thin needle is inserted into the suspicious area, and a syringe is used to extract fluid and cells for later analysis.
Core needle biopsy
A larger needle with a cutting tip is needed to extract a column of tissue from the suspicious area.
Vacuum-assisted biopsy
A suction device is added to the needle to increase the amount of fluid and cells extracted, reducing the need for more insertions to obtain a valid sample.
Image-guided biopsy
This method combines imaging techniques with needle biopsy. This allows better access to suspicious areas that cannot be felt (liver, lungs, prostate, etc.). We ensure that the needle reaches the exact point thanks to real-time images.
Endoscopic
In this case, the procedure for obtaining a sample is similar to an endoscopy. For a biopsy, the same thin, flexible tube with a light at one end is used to help analyze structures within the body. The difference is that special tools are passed through the tube to collect a small sample of the tissue, which will be analyzed later.
This method is usually chosen depending on the location of the suspicious area. The endoscope can only be inserted through the mouth, rectum, urinary tract, or a small incision in the skin, so it is not always the most practical and least painful option for the patient.
Some common types of endoscopic biopsies include cystoscopy (tissue is extracted from inside the bladder), bronchoscopy (tissue is extracted from inside the lung), or colonoscopy (for tissue from inside the colon). Depending on the type of endoscopic biopsy performed, the patient may be given a sedative or anesthetic before the procedure.
Skin biopsy
When there are suspicions of a possible skin cancer, such as melanoma, this type of biopsy is used. In it, cells are obtained from the surface of the skin. As we have indicated, it is only used if there are suspicions of skin cancer or similar, and if the size of the suspicious cells makes it possible. It can be performed by shaving, punching (removing a small section of the deeper layers of the skin), through an incision, or by excision (completely removing the suspicious lump). Since these procedures can cause pain to the patient, a local anesthetic will always be applied to numb the area.
Bone marrow biopsy
Depending on the patient’s blood test results or if there is suspicion that the tumor may affect the bone marrow, the medical team may recommend this type of biopsy. The bone marrow is the spongy tissue located inside some of the longer bones of the spine where blood cells are produced. Analyzing a sample can provide answers to the patient’s blood problems derived from a possible tumor (leukemia, lymphoma, and multiple myeloma) of the area or of another type that originated in another part of the body but has spread to the bone marrow.
For this, a bone marrow sample from the back of the hip bone is needed, which will be obtained with a long needle. There are situations in which the sample can be collected from other bones in the body, but this is not usually common. The patient will receive a local anesthetic or another medication to reduce discomfort during the procedure.
Surgical biopsy
The last type of biopsy we will discuss is one that is performed when cells cannot be accessed through other types of biopsies or if their results have not been conclusive. It will be performed by a surgeon through an incision in the skin, through which the suspicious area will be accessed. Some examples of surgical biopsies are the removal of a breast nodule to diagnose possible breast cancer or the removal of a lymph node to diagnose possible lymphoma.
Surgical biopsy can be used to remove part of the suspicious area or to remove all abnormal cells. It is normal to administer some local anesthetic to numb the area. However, some require general anesthesia to induce a sleep-like state. Depending on the procedure and its complexity, the patient may need to stay a few nights in the hospital for observation.
Liquid biopsy, a novelty in the field of cancer detection
We did not want to end this article without mentioning a novelty in the field of biopsies. The liquid biopsy is an innovative procedure and its main difference is that it is non-invasive. It is used to detect and analyze tumor cells, free tumor DNA fragments, and other biomolecules present in body fluids (such as blood, for example). Unlike traditional biopsies, which require the extraction of solid tissue, the liquid biopsy only needs a blood sample or other body fluid for analysis. Its operation is as follows:
Sample extraction
A small amount of blood is drawn from the patient, usually through a vein in the arm, similar to a routine blood test. The fact that only this procedure is needed makes this type of biopsy so pioneering and safe for the patient.
Processing
The sample is then processed in the laboratory to separate the different components, mainly the plasma, which contains cfDNA and circulating tumor cells (CTCs).
Molecular analysis
Advanced genetic sequencing and molecular analysis techniques are used to identify mutations, genetic alterations, and other biomarkers associated with cancer.
Uses
This type of biopsy can be used for multiple purposes and situations, including:
Early cancer detection
It can help detect cancer at early stages, even before it is visible in traditional medical imaging.
Disease monitoring
It allows doctors to track the tumor’s progress and evaluate the response to treatment without the need for more invasive procedures.
Detection of relapses
It can identify signs of cancer recurrence faster than conventional techniques, allowing for earlier intervention to address it.
Identification of mutations
It helps identify specific mutations in the tumor that can guide the selection of targeted and personalized therapies.
Advantages and disadvantages
In addition to being a non-invasive procedure, the liquid biopsy also has a number of advantages that make it a very benign process for the patient. However, it is also necessary to mention some limitations that we, as medical professionals, may encounter when dealing with liquid biopsy:
Advantages
Non-invasive
This is the main reason for its use, as it avoids the need for surgical procedures and reduces the risk of complications.
Multiple repetitions
Its characteristics allow it to be performed more frequently, enabling continuous and real-time monitoring of cancer status.
Speed
Results can be obtained faster compared to traditional biopsies.
Limitations
Sensitivity and specificity
Although analysis techniques are advanced, the amount of cfDNA and CTCs in the blood can be very low, making detection difficult in some cases.
Not for all types of cancer
Its effectiveness can vary depending on the type of cancer and its stage, being more effective for some cancers than for others.
Although liquid biopsy still has a long way to go to perfect its process and make it valid for all types of tumors, it is a magnificent and noteworthy advance in the field of cancer detection and treatment. At Ambar Lab we are always up to date with any new developments in the medical sector and seek to apply any new discoveries in our own laboratory.
That is why we are able to offer more than 3,000 laboratory tests, support in managing your business, and the development of new projects. If you have any questions or are looking for a specific service, do not hesitate to contact our team so that we can provide you with a more personalized response.
