Survival Rates and Factors That Affect Prognosis (Outlook) for Non-Hodgkin Lymphoma

Survival rates can give you an idea of what percentage of people with the same type and stage of cancer are still alive a certain amount of time (usually 5 years) after they were diagnosed. Survival rates can’t tell you how long you will live, but they may help give you a better understanding of how likely it is that your treatment will be successful.

Keep in mind that survival rates are estimates and are often based on previous outcomes of large numbers of people who had a specific cancer, but they can’t predict what will happen in any particular person’s case. These statistics can be confusing and may lead you to have more questions. Ask your doctor, who is familiar with your situation, how these numbers may apply to you.

What is a 5-year relative survival rate?

A relative survival rate compares people with the same type and stage of non-Hodgkin lymphoma (NHL) to people in the overall population. For example, if the 5-year relative survival rate for a specific stage of NHL is 70%, it means that people who have that cancer are, on average, about 70% as likely as people who don’t have that cancer to live for at least 5 years after being diagnosed.

Where do these numbers come from?

The American Cancer Society relies on information from the Surveillance, Epidemiology, and End Results (SEER) database, maintained by the National Cancer Institute (NCI), to provide survival statistics for different types of cancer.

The SEER database tracks 5-year relative survival rates for NHL in the United States, based on how far the cancer has spread. The SEER database, however, does not group cancers by the Lugano classification (stage 1, stage 2, stage 3, etc.). Instead, it groups cancers into localized, regional, and distant stages:

• Localized: The cancer is limited to one lymph node area, one lymphoid organ, or one organ outside the lymph system.
• Regional: The cancer reaches from one lymph node area to a nearby organ, it’s found in two or more lymph node areas on the same side of (above or below) the diaphragm, or it’s considered bulky disease.
• Distant: The cancer has spread to distant parts of the body, such as the lungs, liver, or bone marrow, or to lymph node areas above and below the diaphragm.

5-year relative survival rates for NHL

The overall 5-year relative survival rate for people with NHL is 74%. But it’s important to keep in mind that survival rates can vary widely for different types and stages of lymphoma.

Below are the 5-year relative survival rates for the two most common types of NHL in the United States – diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) – based on people diagnosed between 2012 and 2018.

Diffuse large B-cell lymphoma

SEER stage	5-year relative survival rate
Localized	73%
Regional	74%
Distant	58%
All SEER stages combined	65%

Follicular lymphoma

SEER stage	5-year relative survival rate
Localized	97%
Regional	91%
Distant	87%
All SEER stages combined	90%

Understanding the numbers

• These numbers apply only to the stage of the lymphoma when it is first diagnosed. They do not apply later on if the cancer grows, spreads, or comes back after treatment.
• People now being diagnosed with NHL may have a better outlook than these numbers show. Treatments have improved over time, and these numbers are based on people who were diagnosed and treated at least 5 years earlier.
• These numbers don’t take everything into account. Survival rates are grouped based on how far the cancer has spread, but your age and overall health, the type of NHL you have, how well it responds to treatment, and other factors (see below) can also affect your outlook.

Prognostic factors for non-Hodgkin lymphoma

For some types of lymphoma, the stage isn’t too helpful in determining a person’s prognosis (outlook). In these cases, other factors can give doctors a better idea about a person’s prognosis.

International Prognostic Index (IPI)

The International Prognostic Index (IPI) was first developed to help doctors determine the outlook for people with fast-growing (aggressive) lymphomas. However, it has proven useful for most other lymphomas as well (other than slow-growing [indolent] follicular lymphomas, which are discussed below). The IPI allows doctors to plan treatment better than they could just based on the type and stage of the lymphoma. This has become more important as new, more effective treatments have been developed that sometimes have more side effects. The index helps doctors figure out whether these treatments are needed.

The index depends on 5 factors:

• The patient’s age
• The stage of the lymphoma
• Whether or not the lymphoma is in organs outside the lymph system
• Performance status (PS) – how well a person can do normal daily activities
• The blood level of lactate dehydrogenase (LDH), which goes up with the amount of lymphoma in the body

Good prognostic factors	Poor prognostic factors
Age 60 or below	Age above 60
Stage I or II	Stage III or IV
No lymphoma outside of lymph nodes, or lymphoma in only 1 area outside of lymph nodes	Lymphoma is in more than 1 organ of the body outside of lymph nodes
PS: Able to function normally	PS: Needs a lot of help with daily activities
Serum LDH is normal	Serum LDH is high

Each poor prognostic factor is assigned 1 point. People without any poor prognostic factors would have a score of 0, while those with all poor prognostic factors would have a score of 5. The index divides people with lymphomas into 4 risk groups:

• Low risk (0 or 1 poor prognostic factor[s])
• Low-intermediate risk (2 poor prognostic factors)
• High-intermediate risk (3 poor prognostic factors)
• High risk (4 or 5 poor prognostic factors)

Follicular Lymphoma International Prognostic Index (FLIPI)

The IPI is useful for most lymphomas, but it’s not as helpful for follicular lymphomas, which tend to be slower growing. Doctors have developed the Follicular Lymphoma International Prognostic Index (FLIPI) specifically for this type of lymphoma. It uses slightly different prognostic factors than the IPI.

Good prognostic factors	Poor prognostic factors
Age 60 or below	Age above 60
Stage I or II	Stage III or IV
Blood hemoglobin 12 g/dL or above	Blood hemoglobin level below 12 g/dL
4 or fewer lymph node areas affected	More than 4 lymph node areas affected
Serum LDH is normal	Serum LDH is high

Patients are assigned a point for each poor prognostic factor. People without any poor prognostic factors would have a score of 0, while those with all poor prognostic factors would have a score of 5. The index then divides people with follicular lymphoma into 3 groups:

• Low risk: no or 1 poor prognostic factor(s)
• Intermediate risk: 2 poor prognostic factors
• High risk: 3 or more poor prognostic factors

For both the IPI and FLIPI, people in the low-risk group tend to have a better prognosis than those in the high-risk group.