Biopsy and Pathology: The Foundation of Personalized Medicine

In the era of modern medicine, the diagnosis and treatment of diseases are no longer limited to standardized treatment protocols. Personalized Medicine is gradually becoming a major trend, in which every treatment decision is based on the unique biological characteristics of each individual.

To achieve this, biopsy and histopathological analysis performed by pathology specialists play a crucial role, providing in-depth information about the nature of a disease and thereby paving the way for more effective and precise treatment.

1. What Is Personalized Medicine?

1.1. Definition and Importance

Personalized medicine, also known as precision medicine, is an approach to disease treatment and prevention based on each individual's genetic differences and specific lifestyle. Instead of applying a standard treatment protocol to all patients with the same disease, personalized medicine focuses on tailoring treatment approaches to best match each patient's individual biological characteristics. This helps optimize treatment effectiveness, minimize side effects, and improve patients' quality of life.

2. Biopsy: A Technique for Collecting Valuable Information

2.1. What Is a Biopsy?

A biopsy is a medical procedure in which a small tissue or cell sample is removed from the body for examination under a microscope. Its primary purposes are to diagnose diseases, particularly cancer, determine the extent of disease spread, or identify important biomarkers. This process plays an extremely important role in establishing an accurate diagnosis and guiding appropriate treatment.

2.2. Common Types of Biopsy

There are several biopsy techniques, depending on the location and type of tissue to be sampled [4]:

• Fine Needle Aspiration (FNA): Uses a very fine needle to aspirate a small amount of cells from a tumor or suspicious area. This minimally invasive method is commonly used for the rapid diagnosis of superficial masses, such as those in the thyroid, breast, or lymph nodes.
• Core Needle Biopsy (CNB): Uses a larger hollow needle to obtain a cylindrical tissue sample. It is often performed under imaging guidance (ultrasound or CT) to ensure accuracy, particularly for deeper tumors [3], [5].
• Punch Biopsy: Uses a sharp, circular instrument to obtain a cylindrical tissue sample from the skin or other surfaces and is commonly used in dermatology.
• Excisional Biopsy: A surgical procedure to remove an entire tumor or area of abnormal tissue. This method is commonly used for small lesions or when complete removal of the tumor is required for both diagnosis and treatment.
• Endoscopic Biopsy: Performed during endoscopy (e.g., gastroscopy, colonoscopy, or bronchoscopy) using small instruments to obtain tissue samples from the mucosa of hollow organs. In some cases, when a tumor is located deep within the body, particularly in the pancreas, ultrasound may also be used to perform a biopsy through the stomach or duodenum, a technique known as Endoscopic Ultrasound (EUS).
• Bone Marrow Biopsy: A procedure to obtain a bone marrow sample and a small piece of bone from the pelvis to diagnose blood disorders, lymphoma, or other conditions affecting the bone marrow.
• Liquid Biopsy: A less invasive method that collects circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA) from blood or other body fluids [2]. This method is useful for disease monitoring, detecting recurrence, or evaluating treatment effectiveness.

2.3. When Is a Biopsy Needed?

A doctor may recommend a biopsy when an abnormal area of tissue is detected through imaging tests (such as X-ray, ultrasound, CT, or MRI) or clinical examination. The main purposes of a biopsy are to:

• Determine whether a tumor is benign or malignant (cancerous).
• Accurately diagnose the type of cancer or other disease.
• Determine the extent of invasion or stage of the disease.
• Identify specific biomarkers or genetic mutations to guide treatment.
• Evaluate the causes of inflammatory or autoimmune conditions.

2.4. The Role of Biopsy in Personalized Medicine

Biopsy provides important information and serves as a foundation for decision-making in personalized medicine:

• Definitive Diagnosis: Biopsy is the gold standard for diagnosing many diseases, particularly cancer, helping determine histological type and the degree of cellular differentiation.
• Molecular Profiling: Analysis of biopsy specimens can identify genetic mutations, abnormal protein expression, or other biomarkers. This information is essential for gaining a better understanding of the biological characteristics of the disease.
• Guiding Targeted Therapy Selection: Based on the molecular characteristics identified, doctors can select appropriate targeted therapies or immunotherapies, potentially providing greater effectiveness and fewer side effects than traditional chemotherapy.
• Monitoring Treatment Response: Biopsies may be repeated during treatment to evaluate the effectiveness of the treatment regimen and detect drug resistance or disease recurrence at an early stage.

3. Pathology: The “Brain” Behind Biopsy Analysis

3.1. What Is Pathology?

Pathology is a medical specialty that studies diseases through the examination of tissues, cells, and body fluids. Pathologists do not directly examine patients but play a central role in diagnosis, prognosis, and treatment guidance by analyzing specimens obtained from biopsies, surgery, or autopsies. They are experts in identifying pathological changes at the microscopic level.

3.2. Specimen Processing at the Department of Pathology

After a biopsy specimen is collected, it undergoes a rigorous processing procedure at the Department of Pathology to ensure the quality of analysis:

• Specimen Reception and Assessment: The specimen is received, patient information is recorded, and gross examination is performed. For tissue specimens (such as core needle biopsies or excisional biopsies), their size and shape are described. For cell specimens (such as FNA), the quantity and quality of the specimen are assessed.
• Tissue Specimen Processing (Tissue Biopsy): Tissue specimens are immediately fixed in formalin to preserve cellular architecture and are then embedded in paraffin to form a solid block (FFPE) [1]. The paraffin blocks are cut into extremely thin sections (approximately 3–5 micrometers) using a specialized microtome. These sections are then placed on glass slides and stained with Hematoxylin and Eosin (H&E) to highlight cellular structures for microscopic examination.
• Cell Specimen Processing (Fine Needle Aspiration – FNA): Aspirated cell samples are spread directly onto glass slides or processed using liquid-based cytology. The slides are then also stained for microscopic examination.
• Microscopic Examination and Analysis: Pathologists examine the slides under a microscope, identify pathological findings and abnormal cellular features, and establish the final diagnosis. In some cases, additional tests such as immunohistochemistry or molecular testing may be required to clarify the diagnosis or identify therapeutic biomarkers.

4. Challenges and Prospects

4.1. Challenges in Specimen Management and Analysis

Although biopsy and pathology play major roles, several challenges remain. Ensuring the quality of biopsy specimens (quantity, size, and fixation time) is extremely important; insufficient or damaged specimens may affect analytical results [1]. In addition, integrating large amounts of data from multiple tests and interpreting them accurately is also a challenge for pathologists.

4.2. Future Directions for Biopsy and Pathology

The future of biopsy and pathology promises many breakthroughs:

• Liquid Biopsy and Its Complementary Role: Liquid biopsy will be increasingly applied, particularly for disease monitoring, early detection of recurrence, and evaluation of treatment effectiveness when tissue biopsy is not feasible or is too invasive [2]. It will complement traditional biopsy rather than completely replace it.
• Artificial Intelligence (AI) in Pathology Analysis: AI and machine learning are being studied to support pathologists in analyzing histological images and detecting features that are difficult to identify with the naked eye, thereby improving diagnostic accuracy and efficiency.
• Optimization of the Pre-Analytical Process: Research is focusing on standardizing and optimizing the pre-analytical steps of specimen handling (collection, fixation, and processing) to ensure the highest possible specimen quality for complex molecular testing [1].

5. Conclusion

Biopsy and pathology are two indispensable pillars of modern medicine, particularly in the era of personalized medicine. From tissue collection to in-depth analysis at the cellular and molecular levels, these processes provide important information that enables doctors to make accurate diagnoses, select optimal treatment regimens, and monitor treatment effectiveness for each patient. The continuous development of biopsy and pathology techniques, together with the support of advanced technologies, is opening up a promising future for personalized treatment and improved healthcare.

6. References

• [1] Ricella Souza da Silva et al. (2022). Tissue management in precision medicine: What the pathologist needs to know in the molecular era. https://pmc.ncbi.nlm.nih.gov/articles/PMC9644376/
• [2] Lynette M Sholl et al. (2020). Traditional Diagnostics versus Disruptive Technology: The role of the pathologist in the era of liquid biopsy. https://pmc.ncbi.nlm.nih.gov/articles/PMC8290882/
• [3] Miyuki Sone et al. (2022). Role of Image-Guided Percutaneous Needle Biopsy in the Age of Precision Medicine. https://pubmed.ncbi.nlm.nih.gov/35362826/
• [4] Mayo Clinic (2022). Biopsy: Types of biopsy procedures used to diagnose cancer. https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/biopsy/art-20043922
• [5] Mayo Clinic (2022). Needle biopsy. https://www.mayoclinic.org/tests-procedures/needle-biopsy/about/pac-20394749

The information above is for reference purposes only and is not intended as medical advice. Please contact your doctor for detailed medical consultation.