Body mass index and risk of multiple myeloma: A meta‐analysis

Abstract

Excess body weight has been identified as a risk factor for a variety of cancer types. However, whether excess body weight increases the risk of multiple myeloma remains controversial. We conducted a meta-analysis to quantitatively summarize the evidence from epidemiologic studies of the associations of overweight and obesity with the risk of multiple myeloma. We searched the MEDLINE and EMBASE databases (1966 to May 2007) and the reference lists of retrieved articles. Cohort and case-control studies were included if they reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the relation between body mass index and multiple myeloma incidence or mortality. A random-effects model was used to combine study-specific results. A total of 11 cohort studies (involving 13,120 cases) and 4 case-control studies (1,166 cases and 8,247 controls) were included in the meta-analysis. Compared with individuals with normal weight, the risk of multiple myeloma was statistically significantly higher among those who were overweight (cohort studies: RR, 1.12, 95% CI, 1. Key words: body mass index; meta-analysis; multiple myeloma; obesity; review Multiple myeloma is a neoplasm of plasma cells of B lymphocyte origin. The prognosis of multiple myeloma is poor; only about one third of patients survive 5 or more years and 16% survive 10 years.1 Therefore, identification of risk factors amenable for modification could have marked impact on reducing morbidity and mortality from the disease. Little is known about the etiology of multiple myeloma. Suspected risk factors include chronic immune stimulation, autoimmune disorders, exposure to ionizing radiation, occupational exposure to pesticides or herbicides and prolonged use of hair dyes. 2Excess body weight has been recognized as a risk factor for a variety of malignancies, including cancer of the colon, breast (in postmenopausal women), endometrium, kidney, and esophagus (adenomcarcinoma).3 Overweight and obesity may also increase the risk of multiple myeloma, but findings from epidemiologic studies have been inconsistent. We therefore undertook a metaanalysis of cohort and case-control studies to quantitatively assess the associations of overweight and obesity, defined by body mass index (BMI), with risk of multiple myeloma. Material and methods Study selectionWe searched the electronic databases MEDLINE and EMBASE for studies on BMI and risk of multiple myeloma that were published from 1966 to May 2007, using the key words body mass index, BMI or obesity combined with myeloma or hematopoietic cancer. Furthermore, we reviewed the reference lists of retrieved articles to search for more studies. No language restrictions were imposed.To be included in our meta-analysis, a published study had to fulfill the following criteria: (i) cohort or case-control study in which multiple myeloma incidence or mortality was an outcome; and (ii) report relative risk (RR) estimates (odds ratios in casecontrol studies) with corresponding 95% confidence intervals (CIs) (or information...

Physical Activity in Relation to Risk of Hematologic Cancers: A Systematic Review and Meta-analysis

“…Physical activity may also increase the production of antioxidant enzymes, thereby improving DNA repair capacity (15,16). Finally, physical activity may indirectly decrease hematologic cancer risk by preventing adiposity and reducing body fat (13) because obesity represents a risk factor for nonHodgkin lymphoma, Hodgkin lymphoma, leukemia, and multiple myeloma (2)(3)(4).…”

“…Obesity has been suggested to be a risk factor for nonHodgkin lymphoma, Hodgkin lymphoma, leukemia, and multiple myeloma (2)(3)(4). Similarly, a deficient or suppressed immune system is a recognized risk factor common to non-Hodgkin lymphoma, Hodgkin lymphoma, multiple myeloma, and leukemia (5)(6)(7)(8).…”

Obesity and risk of monoclonal gammopathy of undetermined significance and progression to multiple myeloma: a population-based study

“…19,20 Obesity has been identified as a risk factor for MM, with 6,21,22 2 meta-analyses finding a 10% to 20% increased risk of MM for a 5 kg/m 2 increase in body mass index (BMI). 21,22 However, BMI is a limited measurement as it does not provide information on fat distribution, which is of importance as many of the complications associated with obesity have been shown to be closely related to abdominal obesity. 23,24 A recent pooled analysis of 20 prospective studies found that waist circumference is a risk factor for MM mortality and that BMI in early adulthood plays an important role later in life regarding MM mortality, particularly in women.…”

Anthropometric characteristics and non-Hodgkin's lymphoma and multiple myeloma risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)

“…[17][18][19][20][21][22][23][24][25][26] Results from a meta-analysis by Larsson et al indicate that excess body weight may be a risk factor for NHL and MM, 27,28 whereas a pooled analysis from the InterLymph Consortium found no evidence to support the hypothesis that obesity is a determinant of all types of NHL combined. 29 Of the 19 published reports, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] seven cohort studies focused on incident cases 10,[18][19][20][21][22]26 and two cohorts focused on mortality.…”