Lymphoma vs. Leukemia: Understanding the Difference

If you or a loved one have recently been diagnosed with leukemia or lymphoma, you may be confused about the difference between the two, given that they’re both cancers of the blood and can have overlapping secondary symptoms.

It’s true that both are blood cancers, but leukemia and lymphoma have some major differences you need to be aware of, as these cancers have different origins, primary symptoms, and associated age groups. The good news is that modern methods have rendered many blood cancers highly treatable, and new advances are being made every day.

Below, you’ll learn the key differences between leukemia and lymphoma, how each is diagnosed and treated, and the different roles of radiation therapy in treating each type.

What Is Leukemia?

Leukemia is a cancer of blood-forming tissues; that means the bone marrow, which is the spongy tissue inside your bones which produces all blood cells, and the blood cells themselves. Leukemia produces abnormal white blood cells that crowd out the healthy cells in your blood or bone marrow, causing abnormal blood-related symptoms.

There are four main types of leukemia:

• Acute lymphoblastic leukemia, or ALL
• Acute myeloid leukemia, or AML
• Chronic lymphoblastic leukemia, or CLL
• Chronic myeloid leukemia, or CML

The terms “chronic” or “acute” refer to how aggressive the type of leukemia is, with acute being the faster-growing type. “Myeloid” and “lymphoblastic” refer to the types of blood cells in which leukemia develops.

While leukemia is the most common type of cancer affecting children, it can and does affect both children and adults. In children, ALL and AML are the most common. In adults, CML and CLL are more common, typically affecting adults over 65.

Common symptoms of leukemia include frequent infections, easy bruising/bleeding, petechiae (small, non-raised blotchy red or purple spots), severe fatigue, bone pain, fever, night sweats, and weight loss. Some of these symptoms, such as fever, fatigue and weight loss, are also common in patients with lymphoma.

What Is Lymphoma?

Lymphoma is cancer of the lymphatic system, the network of lymph tissue and lymph nodes that exists throughout the body. The cancer originates in the lymphocytes, cells that populate the body’s lymphatic tissue.

The two main types of lymphoma are Hodgkin lymphoma, which occurs in around 10-15% of cases, and non-Hodgkin lymphoma, which accounts for the other 85-90%.

The key difference between non-Hodgkin and Hodgkin lymphomas is that Hodgkin lymphomas are diagnosed based on the presence of Reed-Sternberg cells, which are affected lymphocyte cells with a distinctive appearance under a microscope.

Hodgkin lymphoma is also considered more curable due to the predictable way this lymphoma spreads via the lymph nodes. By contrast, non-Hodgkin lymphoma has a less-predictable spread and can metastasize to other organs and bodily systems. Hodgkin lymphoma is also more common among young adults, whereas non-Hodgkin lymphoma typically affects adults 65 or older.

The first sign is often a painless swelling of one or more lymph nodes, particularly in areas such as the neck, armpits, or groin, which contain a higher concentration of lymph nodes. Secondary symptoms include weight loss, fatigue, fever, and night sweats, which are also common with other types of cancer, making it essential that patients see a medical professional to get the correct diagnosis.

Leukemia Diagnosis

A leukemia diagnosis often begins with a complete blood count (CBC) test, which checks for abnormal levels of red blood cells, white blood cells, or platelets. A person with leukemia will typically have either high or low white blood cells and low red blood cells.

The patient might also have a blood smear examination. This is also a blood test, but it’s manually done under a microscope in order to find and characterize abnormal cells, as opposed to the CBC, which is done via a computer. An oncologist might use a blood smear to get information about the leukemia that a CBC cannot provide, as the CBC only provides numerical data on the number of blood cells.

Further testing might include a bone marrow biopsy, as leukemia can originate in the bone marrow directly. Cytogenetic and molecular testing are sophisticated tests which identify abnormalities at the cellular and molecular level and can provide insight to the oncology team about the prognosis in cases of acute leukemia.

Because leukemia is a cancer of the blood and not a tumor-based cancer, leukemia typically does not follow the typical stages I-IV associated with other cancers. Instead, oncologists will classify leukemia based on its type—that is, acute vs. chronic and myeloid vs. lymphoblastic. This information is critical to creating a treatment plan.

Lymphoma Diagnosis

A lymphoma diagnosis frequently begins with a physical examination which looks for the presence of swollen lymph nodes; often, a patient will have already noticed the swelling in their neck, armpit, or groin.

A biopsy of the lymph node, in which a piece of the affected node is removed for testing either by using a needle or by excising a piece, is needed to definitively diagnose lymphoma.

From there, blood tests and imaging such as a CT, PET, or MRI may be necessary to determine the extent of the spread; depending on the type of lymphoma, a bone marrow biopsy may be necessary. The oncologists on the case use all this information to assign the lymphoma a stage from I-IV, with IV being the most serious.

Why An Accurate Diagnosis Matters

The treatment options for leukemia and lymphoma can vary drastically, and the specific subtype of cancer is often what determines a patient’s prognosis, which means that it’s essential that any patient gets the correct diagnosis.

Working with a hematologist-oncologist, a doctor who specializes in both cancer and blood disorders, can make an enormous difference when it comes to accurately diagnosing which specific type of blood cancer a patient has and developing the correct treatment plan.

Leukemia Treatment

The primary treatment for leukemia is often chemotherapy, a type of drug which kills both cancer cells and unaffected cells throughout the body. Because chemotherapy affects the whole body at once, it’s what’s called a systemic treatment.

A treatment plan may also include targeted therapy, which uses drugs to only kill targeted cells which have specific abnormalities. Depending on the location and severity of the leukemia, a patient may need a bone marrow transplant, which replaces affected bone marrow with cells from a donor. In order to kill the affected cancer cells in the bone marrow, radiation therapy may be used to prepare for the transplant. It can also be used in specific other situations where a targeted approach is necessary.

Acute leukemias are more likely to require a fast-acting, intensive approach, often combining chemotherapy and a bone marrow transplant, whereas chronic leukemias may require a less intensive course of treatment.

Lymphoma Treatment

Lymphoma treatment also frequently involves chemotherapy. It also involves radiation therapy more frequently than leukemia treatment does, particularly if the patient has been diagnosed with Hodgkin lymphoma, as radiation can target specific areas of lymphoma growth. Treatment may also involve immunotherapy drugs such as rituximab, targeted therapy, or a bone marrow transplant.

Some lymphoma types may require CAR T-cell therapy, a type of immunotherapy which weaponizes the body’s T-cells to fight cancer. This therapy is sometimes also used to fight acute lymphoblastic leukemia.

For slow-growing lymphomas, medical providers might opt for a watchful waiting approach, in which the lymphoma is monitored but not directly treated. This is common for pregnant patients for whom more intensive interventions may harm the fetus.

SERO’s Role

 SERO’s role in helping patients with lymphomas goes beyond just providing the highest quality radiation therapy; SERO’s team is also committed to human-centered, compassionate, safe care for patients with lymphoma, in addition to using the most advanced radiation techniques to tackle cancer.

Advances in the field of radiation oncology mean that the techniques for radiation in lymphoma cases are more sophisticated than ever. Whether the goal is curative or palliative, SERO’s team of top tier radiation oncologists in Charlotte provide a multidisciplinary approach to blood cancers, ensuring that radiation treatment is safe, effective, and in the patients’ best interest.

The prognoses for leukemia and lymphoma vary widely by specific type and stage; always consult with your doctor in order to receive the most accurate diagnosis and prognosis. Many factors can affect an individual’s prognosis beyond the type and stage of cancer, including age, overall health, response to treatment. Oncologists look at the overall picture of a patient’s health when determining a prognosis. Advances in technology and treatment, such as innovations in radiation therapy, are continuously improving health outcomes for cancer patients.

While leukemia and lymphoma are both blood cancers with overlapping symptoms, understanding the differences matters. Each has distinct origins, diagnostic methods, and treatment approaches, and accurate diagnosis is the critical first step toward effective treatment.

The good news: many blood cancers, including both Hodgkin and non-Hodgkin lymphoma, are highly treatable with modern therapies. Advances in radiation oncology have made treatment more precise and effective than ever before.

If you or a loved one has been diagnosed with lymphoma, SERO’s radiation oncology care specialists can help. Our team provides advanced radiation therapy as part of a comprehensive, multidisciplinary approach to blood cancer treatment. Contact us to learn how we can support your care.

Additional Resources

Leukemia and Lymphoma Society