BMI in Lymphoma: 2 Different Meanings

BMI and Lymphoma. Doctor and patient talking. Caiaimage/Martin Barraud/OJO+/Getty Images

Two very different uses of BMI may come up in articles about lymphoma. Here, we’ll define each and give a brief overview of how they relate to lymphoma.

BMI = Body Mass Index

BMI = Bone Marrow Involvement

1. Body Mass Index

The BMI that people can relate to more readily is the body mass index. Body mass index is a measure of body fat -- it is an estimation of the body fat based on your height and weight and whether you are a man or a woman.

BMI Categories:

Underweight = <18.5

Normal weight = 18.5–24.9

Overweight = 25–29.9

Obesity = BMI of 30 or greater

You can calculate your BMI by plugging in your weight and height using any number of different online calculators, such as this one from the Cleveland Clinic.

Keeping fit to avoid overweight and obesity has long been known to ward off many different chronic diseases, but the link between BMI and your risk for non-Hodgkin lymphoma, or NHL, is a more recent one. The two basic categories of lymphoma are Hodgkin and non-Hodgkin lymphoma. Non-Hodgkin’s lymphoma is more common and represents a long list of different diseases with differing behaviors, treatments and prognoses.

BMI and Risk of NHL

Higher body weight and taller height during adolescence were recently associated with increased risk for non-Hodgkin lymphoma, according to a study published in Cancer.

Researchers from Sheba Medical Center in Ramat Gan, Israel, found that, adolescents who were overweight and obese had an increased risk for non-Hodgkin lymphoma.

They looked at health-related data on 2,352,988 Israeli adolescents, aged 16 to 19 years, who were examined between 1967 and 2011.

The strongest links for overweight/obesity were seen for marginal zone lymphoma, primary cutaneous lymphoma, and diffuse large B-cell lymphoma; the strongest associations for height were seen for diffuse large B-cell lymphoma and primary cutaneous lymphoma.

While this kind of a study suggests height and weight might be associated with a modest increase in risk, more research is necessary to understand the nature of this relationship and the mechanisms that might be involved.

NHL and Risk from BMI

In people who already have NHL, obesity -- as well as being underweight -- may be associated with worse survival. Obesity has been shown to decrease survival several malignancies, but for non-Hodgkin lymphoma (NHL) the association between body mass index (BMI) and survival is not as clear. In one study, obese patients (BMI ≥30.0 kg/m2) had higher all-cause and NHL-specific mortality compared to patients with high-normal BMI (22.5–24.9 kg/m2). More research is needed to understand the relationship between BMI and survival in patients with different types of NHL.

2. Bone Marrow Involvement

The other BMI in lymphoma refers to bone marrow involvement. It's pretty common for lymphoma to be diagnosed and for there to be bone marrow involvement at the time of diagnosis.

Bone marrow involvement in lymphoma is not the same thing as bone metastasis in other cancers.

Lymphoma is a cancer of the lymphocytes, a type of white blood cell. Your body has these lymphocytes as part of the immune system. They are in the blood stream, but they also go in and out of organs -- they are found in high concentrations in lymphoid organs such as lymph nodes and the spleen, but they are also found normally around the body – in the tonsils, scattered throughout the digestive and respiratory systems and the bone marrow. Often lymphoma cells can be found in the bone marrow even though the malignancy started somewhere else.

  • BMI involvement at diagnosis is present in the majority of indolent or slow-growing B-cell lymphomas.
  • BMI has been reported to occur in about 10 to 15 percent of diffuse large BCL (DLBCL) cases.

Lymphoma in the marrow can be treated just as well as lymphoma cells that accumulate in lymph nodes. Depending on the type of lymphoma, sometimes information about the lymphoma cells in the bone marrow can give you additional information about the disease, and sometimes this can be used to predict a more or less favorable prognosis.

There is also something called discordant bone marrow involvement, which means 2 distinct laboratory-determined subtypes coexist in at least 2 separate sites – one of the sites being the bone marrow. If the types found in the bone marrow are the same as the types in the other site, then the bone marrow involvement is concordant. In one very specific type of NHL, nodal follicular lymphoma (FL), concordant bone marrow involvement has been associated in worse survival. Making sense of discordant and concordant bone marrow involvement and what that actually means for patients, however, is an active area of research.

Sources

American Cancer Society. Normal bone marrow, blood, and lymphoid tissue. Accessed February 2016.

Chung R, Lai R, Wei P, et al. Concordant but not discordant bone marrow involvement in diffuse large B-cell lymphoma predicts a poor clinical outcome independent of the International Prognostic Index. Blood. 2007;110(4):1278-1282.

Brudno J, Tadmor T, Pittaluga S et al. Discordant bone marrow involvement in non-Hodgkin lymphoma. Blood. 2016;127(8):965-70.

Solal-Céligny P, Roy P, Colombat P, et al. Follicular lymphoma international prognostic index. Blood 2004;104(5):1258-1265.

Leiba M, Leiba A, Keinan-Boker L, et al. Adolescent weight and height are predictors of specific non-Hodgkin lymphoma subtypes among a cohort of 2,352,988 individuals aged 16 to 19 years. Cancer. 2016. Online ahead of print, February 2016.

Leo QJN, Ollberding NJ, Wilkens LR, et al. Obesity and Non-Hodgkin Lymphoma Survival in an Ethnically Diverse Population: The Multiethnic Cohort Study. Cancer causes & control : CCC. 2014;25(11):1449-1459.

 

 

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