How Do You Get Non-Hodgkin’s Lymphoma?

The exact cause of Non-Hodgkin’s lymphoma is unknown. However, a variety of conditions act as risk factors in the development of Non-Hodgkin’s lymphoma are a family history of lymphoma and more.

Non-Hodgkin lymphoma (NHL) is cancer that affects the lymphatic system, a part of the body’s immune system.  The lymphatic system helps in filtering foreign cells and microorganisms. The lymphatic system is comprised of lymph fluid, lymph nodes, tonsils, thymus, and the spleen.

Non-Hodgkin’s lymphoma usually originates in the lymph nodes and other lymph tissue, although the skin may also be affected. 

Lymph tissues are present in:

• Spleen
• Bone marrow
• Thymus
• Tonsils
• Digestive tract

Approximately 74,200 people in the United States were diagnosed with Non-Hodgkin's lymphoma in the year 2019, as reported by the American Cancer Society. It is the seventh most commonly occurring cancer among all cancers.

Lymphomas are of two types, Non-Hodgkin’s lymphoma, and Hodgkin’s lymphoma.

• Non-Hodgkin’s lymphoma is more common than Hodgkin’s lymphoma.
• Physicians distinguish the lymphomas by the presence of Reed-Sternberg cells, which are absent in Non-Hodgkin’s lymphoma.
• Reed-Sternberg cells are giant cells present in the lymph fluid that are easily detectable under the microscope.

Non-Hodgkin’s lymphoma has two types: indolent lymphomas and aggressive lymphomas.

Non-Hodgkin’s lymphoma involves the abnormal production of white blood cells (lymphocytes) affecting the immune system. These lymphocytes are of two types:

• B lymphocytes (B cells): B cells protect the body from foreign microbes by producing antibodies
• T lymphocytes (T cells): T cells primarily modify the activities of cells of the immune system

Based on the rate of disease progression, Non-Hodgkin’s lymphoma can be classified as:

• Indolent lymphomas: The rate of growth and spreading is slow. The most common type of lymphoma is follicular lymphoma.
• Aggressive lymphomas spread rapidly and require immediate treatment. The most common type is diffuse large B cell lymphoma.

There are some cancers such as mantle cell lymphoma, which do not fall into either category. 

Like most cancers, the exact cause of Non-Hodgkin’s lymphoma is unknown. However, a variety of conditions act as risk factors in the development of Non-Hodgkin’s lymphoma:

• Family history of lymphoma
• Psoriasis
• Inherited immune-deficiency disease
• Helicobacter pylori infection associated with stomach cancer
• Viral infections such as HIV, Epstein-Barr virus, and hepatitis C virus
• Autoimmune disorders such as Rheumatoid arthritis, Sjogren’s syndrome and Hashimoto’s thyroiditis
• Inflammatory bowel disease
• Exposure to radiation and chemotherapy
• Exposure to various chemicals present in the herbicides, pesticides, solvents, and preservatives
• Genetic disorder such as Down syndrome
• Celiac disease: inability to digest gluten
• Chromosomal abnormalities 
• Age above 60 years
• Obesity
• Women with breast implants
• Alcohol intake
• Diets high in fat and meat products
• Ultraviolet exposure

Non-Hodgkin’s lymphoma exhibits different signs and symptoms. Many other conditions may also exhibit similar symptoms. Some of the most common symptoms of Non-Hodgkin’s lymphoma observed are:

1. Swollen lymph nodes
2. Enlarged abdomen
3. Chills
4. Weight loss
5. Chest pain or discomfort
6. Shortness of breath or cough
7. Easy bruising or bleeding
8. Frequent and severe infections
9. Fatigue
10. Abdominal fullness
11. Fever without an infection
12. Abnormal night sweats
13. Abdominal pain
14. Nausea or vomiting
15. Headache
16. Difficulty concentrating
17. Seizures
18. Double vision
19. Facial numbness
20. Slurring speech
21. Itchy skin
22. Red or purple lumps under the skin

The doctor uses a variety of tests and examinations to diagnose Non-Hodgkin’s lymphoma:

• Medical history and physical exam: Complete medical history of the signs and symptoms. The physician will examine some swelling and infection of the lymph nodes. Some blood tests will be used to rule out infection.
• Biopsy: A biopsy will be suggested if the size, texture, location, or presence of other symptoms strongly suggest a Non-Hodgkin’s lymphoma. The biopsies usually performed to diagnose Non-Hodgkin’s lymphoma include:
  • Excisional or incisional biopsy: Excisional biopsy involves the removal of the entire lymph node for diagnosis. An incisional biopsy involves the removal of a small part of the tumor.
  • Needle biopsy: A less invasive procedure as compared to an excisional biopsy, but less accurate.
  • Bone marrow aspiration: These are done to confirm if the lymphoma has involved the bone marrow.
  • Lumbar puncture: This test detects lymphoma cells in the brain.
  • Pleural or peritoneal fluid sampling: Lymphoma, if spread to the chest and abdomen, can be detected using this method.
• Laboratory tests involve flow cytometry and immunohistochemistry in which the biopsy samples are treated with antibodies.
• Imaging tests such as chest X-ray, computed tomography (CT) scan, ultrasound, positron emission tomography (PET) scan, and a bone scan helps in diagnosing Non-Hodgkin lymphoma and its extent.
• Blood tests, such as complete blood cell count, blood chemistry tests, and lactate dehydrogenase, tests also help in diagnosing the extent of the disease.

Oncologists classify the stages of Non-Hodgkin’s lymphoma based on the extent of the spread of the disease. The current staging system in adults (known as Lugano classification) is:

• Stage I: The cancer is present in only one of the organs inside the lymphatic system (such as in tonsils) or one organ outside the lymphatic system (such as lung or bone marrow).
• Stage II: Lymphomas may be present in two lymph node areas on the same side, or above or below the diaphragm, which is a thin band of muscle separating the chest and abdomen. The lymphoma may also be present in one organ and the lymph nodes in the nearby area.
• Stage III: The lymphoma is in the lymph node area, which may be above or below the diaphragm.
• Stage IV:  Lymphomas have spread to several organs and tissues.

The various treatment options include:

• Chemotherapy: Physician administers this drug via oral or injection route.
• Radiation therapy: A high dose of radiation terminates the cancer cell.
• Stem cell transplant: Physician injects healthy stem cells taken from the donor before the treatment.
• Biological drugs: Certain drugs such as Rituxan (rituximab) and Gazyva (Obinutuzumab) enhance the immune system’s ability to combat cancer cells.
• Targeted therapy drugs: Certain drugs such as Velcade (bortezomib) target the growth of lymphoma cells.
• Surgery may be preferred if the lymphomas are present in the spleen or stomach, and have not spread beyond that.

The five-year survival rate of patients suffering from NHL is 72%, which means 72% of the patients with Non-Hodgkin’s lymphoma will live for five years or more (data from 2009-2015). It is, however, important to keep in mind that the survival rate depends on the types and stages of the lymphoma. The outcome of the treatment depends on:

• Cancer stage
• Patient’s age
• Performance status

In recent decades, the survival rate for Non-Hodgkin lymphoma has improved progressively. The risks, outcomes, and complications of the treatment should be discussed with the treating physician.