Table 1.

Characteristics of the 15 cohort studies and eight case–control studies of physical activity and hematologic cancer risk included in the meta-analysis

Authors, year, gender	Study region	Subjects	Cases	Hematologic cancer subtype	PA: domain, timing in life	RR (95% CI), high vs. low PA	Low PA defined as	High PA defined as	Adjustment factors (excluding sex)	QS (%)
Cohort studies (N = 15)
Birmann et al., 2007
Men	North America	46,960	86	MM	RPA, consistent	0.80 (0.50–1.50)	<2 h/wk PA	≥7 h/wk PA	Updated age, BMI	73
Women		89,663	129			0.50 (0.20–1.40)				73
Blair et al., 2005
Women	North America	37,083	95	MM	RPA, recent	0.88 (0.51–1.49)	Low PA	High PA	—	48
Cerhan et al., 2002 Women	North America	37,932	252	NHL	RPA, past	0.83 (0.59–1.11)	Low PA	High PA	Age	60
			61	Leukemia		0.91 (0.45–1.67)				60
Hofmann et al., 2013
Men	North America	291,471	319	MM	RPA, recent	1.10 (0.82–1.48)	<16.25 MET-h/wk	≥50 MET-h/wk	Age (at baseline), race, age-specific BMI	65
Women		193,578	152	MM		1.43 (0.90–2.26)				65
Kabat et al., 2012
Women	North America	157,852	285	CLL/SLL	RPA, recent	1.03 (0.70–1.51)	0 h/wk strenuous PA	≥2 h/wk strenuous PA	Age, smoking, servings of alcohol per week, education, ethnicity, BMI enrollment in the observational study, treatment arm assignment in the clinical trials	82
			1,071	NHL		0.97 (0.79–1.20)				82
			286	DLBCL		0.89 (0.59–1.36)				82
			205	FL		1.25 (0.81–1.94)				82
Kabat et al., 2013
Men and women combined	North America	493,188	178	Leukemia	TPA, recent	0.70 (0.49–0.99)	<1 time/wk VPA	≥3 times/wk VPA	Age, BMI, smoking intensity, years of education	62
Khan et al., 2006
Men	Asia	46,157	35	MM	RPA, recent	0.44 (0.21–0.93)	<30 min walking/d	≥1 hour walking/day	Age	64
Women		63,541	31	MM		0.58 (0.26–1.27)				64
Lim et al., 2007
Men and women combined	North America	465,858	234	CLL/SLL	TPA, recent	0.80 (0.51–1.25)	PA <1 time/wk	PA ≥5 times/wk	Age, race, education, BMI, caloric intake	65
			1,340	NHL		0.97 (0.81–1.16)				65
			343	DLBCL		0.87 (0.61–1.25)				65
			257	FL		0.96 (0.63–1.46)				65
			56	HL		1.60 (0.72–3.54)	PA <1 time/wk	PA 3–4 times/wk		65
Lu et al., 2009
Women	North America	121,216	124	CLL/SLL	RPA, recent	1.50 (0.86–2.63)	0–0.50 h/wk/y strenuous PA plus MPA	≥4 h/wk/y strenuous PA plus MPA	Age, height, weight at cohort entry, age at menarche long-term strenuous PA plus MPA	61
			574	NHL		1.11 (0.86–1.44)				61
			155	DLBCL		1.00 (0.62–1.62)				61
			121	FL		1.01 (0.57–1.79)				61
Ma et al., 2010
Men and women combined	North America	491,163	338	Leukemia	RPA, recent	1.09 (0.84–1.41)	<3 times/mo VPA	≥3 times/wk VPA	Age, smoking status, total energy intake	69
Paffenbarger et al., 1992
Men and women combined	North America	56,683	86	NHL	RPA, past	0.67 (0.40–1.13)	<5 hours of VPA per week	≥5 hours of VPA per week	Age	57
			52	HL		0.73 (0.38–1.39)				57
			81	Leukemia		0.84 (0.45–1.58)				57
Pukkala et al., 2000
Men	Europe	2,269	6	NHL	OPA, past	0.78 (0.29–1.70)	General population	Inclusion in athletic group	5-year age groups	57
			3	HL		1.33 (0.27–3.88)				57
			5	Leukemia		0.51 (0.17–1.19)				57
			7	MM		1.39 (0.56–2.85)				57
Soll-Johanning et al., 2004
Men	Europe	14,568	44	Leukemia	OPA, past	1.08 (0.78–1.45)	Copenhagen population	Mail carrier	Age, calendar period	45
Teras et al., 2012
Men	North America	69,849	271	CLL/SLL	RPA, recent	0.95 (0.62–1.46)	≤0 MET-h/wk	≥17.5 MET-h/wk	Age at baseline, family history of hematopoietic cancer, education, smoking status, alcohol intake, BMI, height, sitting time	65
			1,139	NHL		1.02 (0.82–1.26)				65
			238	DLBCL		1.14 (0.70–1.88)				65
			143	FL		0.86 (0.49–1.51)				65
			211	MM		0.99 (0.60–1.64)				65
Women		77,001	211	CLL/SLL		0.73 (0.44–1.20)				65
			863	NHL		0.69 (0.54–0.89)				65
			197	DLBCL		0.71 (0.44–1.16)				65
			137	FL		0.77 (0.41–1.43)				65
			132	MM		0.54 (0.28–1.04)				65
van Veldhoven et al., 2011
Men	Europe	127,353	373	NHL	OPA, recent	1.05 (0.46–2.41)	Sedentary activities	Manual/heavy manual activities	Age, center, hypertension, hyperlipidemia, education, diabetes	67
				NHL	RPA, recent	1.11 (0.49–2.52)	<14.25 MET-h/wk	≥45.75 MET-h/wk		71
			45	DLBCL	TPA, recent	2.03 (0.38–10.79)	Inactive	Active		75
			45	FL		2.82 (0.52–15.23)				75
			77	MM		0.34 (0.05–2.14)				75
Women		216,403	402	NHL	RPA, recent	1.25 (0.49–3.16)	<14.25 MET-h/wk	≥45.75 MET-h/wk		71
				NHL	OPA, recent	2.06 (0.65–6.51)	Sedentary activities	Manual/heavy manual activities		67
			49	DLBCL	TPA, recent	5.03 (1.19–21.33)	Inactive	Active		75
			49	FL		2.59 (0.54–12.38)				75
			88	MM		0.65 (0.14–3.16)				75
Case–control studies (N = 8)
Brownson et al., 1991
Men	North America	17,147	462	NHL	OPA, recent	0.80 (0.60–1.30)	PA required <20% of the time	PA required >80% of the time	Age, smoking	45
			376	Leukemia		0.90 (0.60–1.40)				45
Cerhan et al., 2005
Men and women combined	North America	864	458	NHL	RPA, recent	0.83 (0.50–1.38)	<30 METs/wk	>1,080 METs/wk	Age, race, study center, alcohol use, height, BMI	58
			458	NHL	OPA, recent	0.98 (0.55–1.74)	Mostly sitting	Mostly exercise		49
Kasim et al., 2009
Men	North America	2,032	390	Leukemia	RPA, recent	1.31 (0.93–1.85)	<5.9 MET-h/wk	≥38.8 MET-h/wk	10-year age group, BMI, educational years, total fruits and vegetables consumption, occupational exposure to benzene and ionizing radiation	58
Women		1,727	263	Leukemia		0.97 (0.66–1.42)	<5.6 MET-h/wk	≥38.8 MET-h/wk		58
Keegan et al., 2006
Women	North America	441	187	HL	RPA, recent	0.56 (0.37–0.86)	Nonparticipation in ≥2 times/wk strenuous PA for ≥1 mo	≥2 times/wk strenuous PA for ≥1 mo	Age, race/ethnicity, education, Jewish upbringing, having a single room at age 11 years, living in a single family home at age 8 years, living in a rented family home at age 8 years, having ever nursed children, number of miscarriages, smoking status 1 year before diagnosis/interview, history of first or second degree relative with lymphoma	63
Kelly et al., 2012
Men	North America	758	184	CLL/SLL	RPA, recent	1.71 (1.08–2.70)	<615 METs/wk	≥2,701 METs/wk	Age, country of residence	58
			516	NHL		1.37 (0.98–1.92)				58
			88	DLBCL		1.19 (0.64–2.21)				58
			113	FL		0.96 (0.53–1.72)				58
Women		591	94	CLL/SLL		0.53 (0.27–1.06)				58
			358	NHL		0.71 (0.47–1.07)				58
			79	DLBCL		0.80 (0.38–1.69)				58
			109	FL		0.90 (0.49–1.67)				58
Pan et al., 2005
Men	North America	2,211	569	NHL	RPA, recent	0.79 (0.59–1.05)	<6.4 MET-h/wk	≥37.4 MET-h/wk	Age, province, education, smoking, alcohol drinking, exposure to certain chemicals, occupational exposure, BMI, total caloric intake, MPA	67
Women		1,925	461	NHL		0.59 (0.42–0.81)	<6.1 MET-h/wk	≥31.4 MET-h/wk		67
Parent et al., 2011
Men	North America	748	215	NHL	RPA, past	1.17 (0.81–1.69)	Sports or outdoor activities <1 time/wk	Sports or outdoor activities ≥1 time/wk	Age, SES, educational level, ethnicity, respondent status, smoking, BMI, sports, outdoor activities	75
			54	HL		0.97 (0.45–2.08)				75
			215	NHL	OPA, consistent	0.56 (0.26–1.20)	≤1.5 MET (at least 75% of work years in sedentary jobs)	≥4 METs (at least 75% of work years was spent in very active jobs)		66
			54	HL		0.84 (0.17–4.23)				66
Zahm et al., 1999
Men	North America	3,856	985	NHL	OPA, recent	1.00 (0.70–1.30)	Energy expenditure <8 kJ/min	Energy expenditure >12 kJ/min	Age, state of residence	51
Women		854	180	NHL		1.70 (0.20–11.50)	Energy expenditure <5 kJ/min	Energy expenditure >8 kJ/min		51

Abbreviations: CLL/SLL, chronic lymphocytic lymphoma/small lymphocytic lymphoma; DLBCL, diffuse large B-cell lymphoma; FL, follicular lymphoma; HL, Hodgkin lymphoma; MM, multiple myeloma; MPA, moderate physical activity; NHL, non-Hodgkin lymphoma; OPA, occupational physical activity; PA, physical activity; QS, quality score; RPA, recreational physical activity; SES, socioeconomic status; TPA, total physical activity; VPA, vigorous physical activity.