If you, or someone you love, have been diagnosed with lymphoma, you probably have many questions. Lymphoma is a complex disease, so here’s a brief overview to get you started.
What is lymphoma?
Lymphomas are cancers of the lymphatic system, which is part of your immune system. The lymphatic system includes the spleen, thymus, tonsils, and bone marrow; lymph fluid; lymph vessels; and lymph nodes, which filters lymph fluid and stores lymphocytes, a type of white blood cell. Most lymph nodes cluster together in the neck, abdomen, pelvis, groin, and armpits.
“For a variety of reasons, one cell within the lymph system may go rogue and start growing abnormally and that’s what becomes a cancer,” says Syed Rizvi, M.D., assistant professor at UT Southwestern Medical Center.
Types of lymphoma
Lymphomas are broadly divided into Hodgkin's lymphoma and non-Hodgkin's lymphoma, says Deepa Jagadeesh, M.D., an oncologist at the Cleveland Clinic.
Non-Hodgkin’s lymphomas are further divided into B cell lymphomas and T cell lymphomas. In fact, there are more than 60 subtypes of non-Hodgkin's lymphomas, says Dr. Rizvi, and “they all have different personalities and different flavors.”
Hodgkin’s lymphoma is also divided into two types, says Dr. Rizvi: classical (the most common) and nodular lymphocyte-predominant. According to the National Cancer Institute (NCI), the classical type has four subcategories: nodular sclerosing Hodgkin’s lymphoma, mixed cellularity Hodgkin’s lymphoma, lymphocyte depletion Hodgkin’s lymphoma, and lymphocyte-rich classical Hodgkin’s lymphoma.
According to the NCI’s Surveillance, Epidemiology, and End Results Program, there will be about 8,500 new cases of Hodgkin’s lymphoma and nearly 75,000 new cases of non-Hodgkin’s lymphoma in 2018.
Oncologists also describe non-Hodgkin’s lymphomas based on how aggressive they are.
“Not all lymphomas are extremely aggressive,” Dr. Rizvi tells HealthCentral. “At one end of the spectrum you have low-risk, low-grade lymphomas. They don’t require treatment up front.”
Examples of this category include follicular lymphoma, small lymphocytic lymphoma, and some marginal zone lymphomas.
Unlike advanced stage solid tumors (for example, breast or colon cancer) stage 4, low-grade lymphomas do not necessarily require treatment, says Dr. Rizvi. “The only reason to treat them is if the patient is having symptoms or damage to their organs. If none of that is present, there’s significant data that observation is a reasonable approach.”
At the other end of the spectrum, Dr. Rizvi says, are very aggressive lymphomas, such as Burkitt lymphoma or diffuse large B-cell lymphoma, the most common lymphoma in that category. “These require treatment right away,” Dr. Rizvi says. “We do not wait and observe these lymphomas. They are likely to be life-threatening if not treated.”
Risk factors for lymphoma
Males are more likely to develop lymphoma and, while it generally occurs in older adults, lymphomas do occur in children. Hodgkin’s lymphoma also occurs in young adults. Being infected with the Epstein-Barr virus or having a first-degree relative increases your risk for Hodgkin’s lymphoma. Risk factors for non-Hodgkin’s lymphoma include inherited immune or autoimmune disorders, certain infections (including HIV and H. pylori), and taking drugs that suppress the immune system.
Symptoms of lymphoma
Symptoms are generally the same, regardless of the type of lymphoma, says Dr. Jagadeesh, and include swollen lymph nodes, fever (usually at night), night sweats, and weight loss. “Patients can have all of these symptoms, or some of them,” she says.
Lymphoma may cause other symptoms, depending on where the tumor is located. “If it’s mostly in the chest, patients complain of cough and shortness of breath,” Dr. Jagadeesh says. “If it’s mostly in the abdomen and is a large mass, the patient may have abdominal pain or back pain. And, if it’s in the gastrointestinal tract, they may have nausea or vomiting.”
Diagnosis and staging lymphomas
Diagnosing lymphomas requires a physical exam, blood work — which includes checking blood counts, blood chemistry, and renal and liver function — and imaging studies, usually a CT scan. A pathologist will examine a small sample from the tumor (a biopsy) under the microscope to confirm a diagnosis of lymphoma.
Depending on the cancer, Dr. Jagadeesh says she may order a PET scan or bone marrow biopsy and may test the patient for HIV infection or hepatitis B.
Lymphoma treatment and prognosis
Treatment for lymphomas consists primarily of chemotherapy alone or in combination with radiation. It depends on the stage of the disease.
For early-stage Hodgkin's lymphoma, treatment may be chemotherapy with radiation. “If the disease is advanced, we usually only do chemotherapy,” Dr. Jagadeesh says.
“Treatment for non-Hodgkin lymphoma varies a lot because there are so many different subtypes,” Dr. Jagadeesh says. “If it’s low-grade lymphoma with no symptoms and the patient’s blood counts are okay, sometimes we don’t treat it because it’s not a curable disease. So, we’ll do something called wait and watch. We’ll monitor the disease and if the patient starts developing symptoms, then we would treat it.”
“The interesting thing about high-grade lymphomas,” says Dr. Rizvi, “is that they are aggressive and can be life threatening. However, given that chemotherapy relies on cell division as the point where it acts, it can be relatively easy to cure a high-grade or aggressive lymphoma when compared to a low-grade lymphoma.”
Other potential treatment options include stem cell transplants, biological therapies, and Chimeric Antigen Receptor T-Cell therapy, or CAR-T, a procedure that manipulates the patient’s own T cells to recognize the cancer as a foreign entity and to fight it. The Food and Drug Administration has approved CAR-T for diffuse large B cell lymphomas, or low-grade lymphomas that have transformed into large cell lymphomas, says Dr. Rizvi.
According to the NCI, these lymphoma treatments may cause other health problems down the line, including an increased risk for another cancer.
Cure rates for early stage Hodgkin's lymphoma average around 95 percent and advanced stage Hodgkin's lymphomas have cure rates of 70 to 80 percent, says Dr. Jagadeesh. Low-grade non-Hodgkin's lymphoma isn’t curable, but does not necessarily require treatment. Even aggressive diffuse, large B-cell non-Hodgkin's lymphoma has a cure rate of 50 to 70 percent, depending on the stage and risk features.
Dr. Jagadeesh encourages patients with rare diseases like T cell lymphoma to seek care at a tertiary care center that has specialists.
“They have experience taking care of [patients with] those diseases, which are not commonly treated at community hospitals,” she says.