Hematological Cancers And The Role Of Genetic Testing - Dr Suruchi Aggarwal

Hematological cancers, often referred to as blood cancers, are a group of malignancies that affect the blood, bone marrow, and lymphatic system (group of organs, tissues and vessels that keep body fluids in balance and protect the body against infection).

These cancers originate from abnormal growth and division of blood cells, and they can impact the production and function of blood components such as red blood cells, white blood cells, and platelets.

Hematological cancers are a diverse group of diseases, including leukemia, lymphoma, and myeloma, each with unique characteristics and challenges. Early detection is crucial for successful treatment, and genetic diagnostics play a pivotal role in understanding the genetic basis of these cancers.

Symptoms of Hematological Cancers

The symptoms of hematological cancers can vary depending on the specific type and stage of the disease. However, there are some common signs and symptoms that individuals should be aware of:

Fatigue: Persistent and unexplained fatigue is a common symptom across all hematological cancers due to disruptions in normal blood cell production.

Weight loss: Rapid, unexplained weight loss can be a sign of more advanced disease stages.

Frequent infections: Hematological cancers can lead to a weakened immune system, making individuals more susceptible to infections.

Bruising and bleeding: Reduced platelet counts can result in easy bruising, nosebleeds, or prolonged bleeding from minor cuts or injuries.

Swollen lymph nodes: Enlarged lymph nodes, often painless, may be a sign of lymphoma or leukemia.

Bone pain: Myeloma, a type of hematological cancer, can cause bone pain or fractures due to the weakening of bones.

Shortness of breath: Anaemia, a condition where there are too few red blood cells, can lead to shortness of breath and pale skin.

Early Detection: Early detection of hematological cancers is crucial for a better prognosis and more effective treatment. Diagnostic methods include:

Blood tests: Routine blood tests can detect abnormal levels of blood cells and other markers, which may prompt further investigation.

Bone marrow biopsy: This procedure involves the removal of a small sample of bone marrow to assess the presence of cancer cells.

Imaging studies: X-rays, CT scans, MRIs, and PET scans can help identify enlarged lymph nodes, tumors, or bone abnormalities.

Lymph node biopsy: Removing and examining lymph node tissue can provide information about the type and stage of lymphoma.

The Role of Genetic Diagnostics

Genetic testing has revolutionized the field of hematological cancer research and management. Understanding the genetic mutations and alterations associated with these cancers is essential for diagnosis, prognosis and treatment. Several ways in which it can help:

1. Accurate Diagnosis: Genetic tests help in precise diagnosis by identifying specific genetic mutations or chromosomal abnormalities associated with different hematological malignancies. This ensures that the appropriate treatment is administered.

2. Early Intervention: Genetic testing can detect mutations or abnormalities before clinical symptoms appear. This early detection allows for prompt intervention and potentially better treatment outcomes.

3. Prognostic Information: Genetic testing provides valuable prognostic information, helping clinicians predict the course of the disease and the patient's likely response to treatment. This guides treatment decisions and helps tailor therapies to individual patients.

4. Treatment Selection: Genetic testing assists in selecting targeted therapies. Some hematological malignancies, such as chronic myeloid leukemia (CML), are driven by specific genetic mutations like the BCR-ABL fusion gene. Identifying these mutations allows for the use of targeted drugs like imatinib, which can be highly effective.

5. Monitoring Disease Progression: Genetic testing can be used to monitor the progression of the disease and detect any emerging mutations that may lead to resistance to treatment. This allows for timely adjustments in the treatment plan.

6. Risk Assessment: Genetic testing can identify inherited genetic predispositions to hematological malignancies, such as certain types of leukemia and lymphoma. This information can be used for screening and preventive measures in individuals with a higher genetic risk.

7. Clinical Trials: Many clinical trials for hematological malignancies involve targeted therapies that require specific genetic mutations for eligibility. Genetic testing helps identify suitable candidates for these trials, expanding treatment options for patients.

8. Personalized Medicine: Hematological malignancies are highly heterogeneous, and genetic testing enables personalized treatment approaches. Tailoring therapies based on the genetic profile of the patient and their disease can lead to better outcomes and fewer adverse effects.

9. Minimal Residual Disease (MRD) Monitoring: Genetic tests can be used to monitor how a patient is responding to treatment or in case of relapse, can detect minimal levels of residual disease after treatment. This is critical for assessing treatment response and making decisions regarding further therapy or monitoring.

There are various genetic testing methods to detect different types of genetic aberrations and one or in combination is used for complete molecular workup in clinics:

1. Flow Cytometry

2. Karyotyping

3. Real-time PCR (RT-PCR)

4. Fluorescent In-Situ Hybridization (FISH)

5. Next-generation Sequencing (NGS)

6. Sanger Sequencing

7. Multiplex Ligation-dependent Probe Amplification (MLPA)

8. Fragment Analysis

In summary, genetic testing in hematological malignancies is of paramount importance as it aids in accurate diagnosis, treatment selection, and monitoring. By understanding the genetic basis of these cancers, healthcare professionals can provide more personalized and effective treatment options, ultimately enhancing the quality of life for individuals affected by these diseases.