Research table: Body weight and breast cancer survival

This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.

Introduction: After treatment for breast cancer, being overweight is linked to an increased risk of:

• Breast cancer recurrence (a return of breast cancer)
• Breast cancer-specific mortality (death from breast cancer)
• Overall mortality (death from any cause, not necessarily breast cancer)

This means women who are heavier after treatment for breast cancer are more likely to have their breast cancer return compared to those who are thinner after treatment. And they are also more likely to die from breast cancer or other causes.

Body weight is also linked to breast cancer risk (see our summary research table on body weight and breast cancer risk).

Learn more about body weight, weight gain and breast cancer survival.

Learn about the strengths and weaknesses of different types of studies.

Study selection criteria: Prospective cohort studies with at least 3,000 participants, pooled analyses and meta-analyses.

Table notes: In the studies below, researchers used a measure called body mass index (BMI) to estimate body fat. BMI takes into account a person’s height and weight. Calculate your BMI.

Unless noted, studies measured BMI at the time of breast cancer diagnosis.

Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.

Studies of women with stage IV (4) breast cancer are not included because stage IV breast cancer can cause weight loss.

Study	Study Population (number of women with stage I-III breast cancer)	Follow-up (years)	Levels of Body Mass Index (BMI) Compared	Breast Cancer-Specific Mortality RR (95% CI)	Overall Mortality RR (95% CI)
Prospective cohort studies
Korean Breast Cancer Registry [1]	41,021	8	25.0-29.9 vs. 18.5-24.9	1.13 (1.04-1.22)	1.15 (1.07-1.23)
			30 or more vs. 18.5-24.9	1.21 (1.02-1.43)	1.29 (1.13-1.48)
Ewertz et al. [2]	18,967	11	25-29 vs. Less than 25	1.26 (1.09-1.46)
			30 or more vs. Less than 25	1.38 (1.11-1.71)
Majed et al. [3]	14,709	8	30 or more vs. Less than 30	1.35 (1.19-1.54)	1.43 (1.28-1.60)
Jiralerspong et al. [4]	6,342	5	30 or more vs. Less than 25	1.23 (1.00-1.52)	1.24 (1.04-1.48)
NSABP B-30 [5]	5,265	6	30 or more vs. Less than 25		1.18 (1.02-1.35)
Nurses’ Health Study [6]	5,204	9	More than 30 vs. 21-22	1.09 (0.80-1.48)	1.20 (0.95-1.52)*
NSABP B-38 [5]	4,860	6	30 or more vs. Less than 25		1.11 (0.82-1.35)
Eastern Cooperative Oncology Group [7]	4,770	8-14	30 or more vs. Less than 25		1.23 (1.08-1.40)
BIG 1-98 [8]	4,760	9	30 or more vs. Less than 25	1.01 (0.84-1.23)	1.19 (0.99-1.44)
Collaborative Women’s Longevity Study [9]	3,993	6	30 or more vs. 18.5-24.9†	2.28 (1.43-3.64)	1.27 (0.99-1.64)
Cancer Prevention Study II – Nutrition Cohort [10]	3,689	13	30 to less than 35 vs. Less than 25	Among women ages 46-64: 0.64 (0.34-1.23) Among women 65 and older: 1.24 (0.22-1.88)	Among women ages 46-64: 0.50 (0.32-0.79) Among women ages 65 and older: 0.82 (0.68-1.00)
			35 or more vs. Less than 25	Among women ages 46-64: 0.73 (0.32-1.68) Among women 65 and older: 2.11 (1.27-3.52)	Among women ages 46-64: 1.08 (0.66-1.76) Among women ages 65 and older: 1.26 (0.97-1.63)
NSABP B-34 [5]	3,311	6	30 or more vs. Less than 25		1.03 (0.80-1.32)
Women’s Healthy Eating and Living Study [11]	3,088	7	30 or more vs. 18.5-24.9†		1.28 (0.97-1.70)
Pooled and meta-analyses
Protani et al. [12]	36 studies		30 or more vs. Less than 25‡		1.33 (1.21-1.47)
	19 studies		30 or more vs. Less than 25‡	1.33 (1.19-1.50)
Niraula et al. [13]	21 studies		30 or more vs. 25 or less‡	1.43 (1.21-1.69)	1.25 (1.16-1.35)
After Breast Cancer Pooling Project [14]	9,513 women		25-29.9 vs. 18.5-24.9	1.05 (0.90-1.22)
			30.0-34.9 vs. 18.5-24.9	1.04 (0.86-1.27)
			35 or more vs. 18.5-24.9	0.95 (0.74-1.20)
Pajares et al. [15]	5,683 women	8	35 or more vs. 18.5-24.9	1.32 (1.01-1.72)	1.47 (1.16-1.85)
Ladoire et al. [16]	4,996 women	6	30 or more vs. Less than 30		1.27 (0.98-1.63)
Chan et al. [17]	2 studies		25-29.9 vs. 18.5-24.9	1.37 (0.96-1.95)
	2 studies		30 or more vs. 18.5-24.9	1.68 (0.90-3.15)
	4 studies		25-29.9 vs. 18.5-24.9		0.98 (0.86-1.11)
	5 studies		30 or more vs. 18.5-24.9		1.21 (1.06-1.38)

NS = Results are not statistically significant.

Sig = Results are statistically significant.  

* Among never smokers, women with higher BMI (and those who gained weight after diagnosis) were at increased risk of breast cancer recurrence, breast cancer-specific mortality and overall mortality. 

† Body weight measured after treatment completed.

‡ Most common comparison of BMI measures used in studies. 

References

1. Jeon YW, Kang SH, Park MH, Lim W, Cho SH, Suh YJ. Relationship between body mass index and the expression of hormone receptors or human epidermal growth factor receptor 2 with respect to breast cancer survival. BMC Cancer. 15:865, 2015.
2. Ewertz M, Jensen MB, Gunnarsdóttir KA, et al. Effect of obesity on prognosis after early-stage breast cancer. J Clin Oncol. 29(1):25-31, 2011.
3. Majed B, Moreau T, Senouci K, Salmon RJ, Fourquet A, Asselain B. Is obesity an independent prognosis factor in woman breast cancer? Breast Cancer Res Treat. 111(2):329-42, 2008.
4. Jiralerspong S, Kim ES, Dong W, Feng L, Hortobagyi GN, Giordano SH. Obesity, diabetes, and survival outcomes in a large cohort of early-stage breast cancer patients. Ann Oncol. 24(10):2506-14, 2013.
5. Cecchini R, Swain SM, Costantino JP, et al. Body mass index at diagnosis and breast cancer survival prognosis in clinical trial populations from NRG Oncology/NSABP B-30, B-31, B-34, and B-38. Cancer Epidemiol Biomarkers Prev. 25(1):51-9, 2016.
6. Kroenke CH, Chen WY, Rosner B, Holmes MD. Weight, weight gain, and survival after breast cancer diagnosis. J Clin Oncol. 23(7):1370-8, 2005.
7. Sparano JA, Wang M, Zhao F, et al. Obesity at diagnosis is associated with inferior outcomes in hormone receptor-positive operable breast cancer. Cancer. 118(23):5937-46, 2012.
8. Ewertz M, Gray KP, Regan MM, et al. Obesity and risk of recurrence or death after adjuvant endocrine therapy with letrozole or tamoxifen in the breast international group 1-98 trial. J Clin Oncol. 30(32):3967-75, 2012.
9. Nichols HB, Trentham-Dietz A, Egan KM, et al. Body mass index before and after breast cancer diagnosis: associations with all-cause, breast cancer, and cardiovascular disease mortality. Cancer Epidemiol Biomarkers Prev. 18(5):1403-9, 2009.
10. Maliniak ML, Patel AV, McCullough ML, et al. Obesity, physical activity, and breast cancer survival among older breast cancer survivors in the Cancer Prevention Study-II Nutrition Cohort. Breast Cancer Res Treat. 167(1):133-145, 2018.
11. Flatt SW, Thomson CA, Gold EB, et al. Low to moderate alcohol intake is not associated with increased mortality after breast cancer. Cancer Epidemiol Biomarkers Prev. 19(3):681-8, 2010.
12. Protani M, Coory M, Martin JH. Effect of obesity on survival of women with breast cancer: systematic review and meta-analysis. Breast Cancer Res Treat. 123(3):627-35, 2010.
13. Niraula S, Ocana A, Ennis M, Goodwin PJ. Body size and breast cancer prognosis in relation to hormone receptor and menopausal status: a meta-analysis. Breast Cancer Res Treat. 134(2):769-81, 2012.
14. Nelson SH, Marinac CR, Patterson RE, et al. Impact of very low physical activity, BMI, and comorbidities on mortality among breast cancer survivors. Breast Cancer Res Treat. 155(3):551-7, 2016.
15. Pajares B, Pollán M, Martín M, et al. Obesity and survival in operable breast cancer patients treated with adjuvant anthracyclines and taxanes according to pathological subtypes: a pooled analysis. Breast Cancer Res. 15(6):R105, 2013.
16. Ladoire S, Dalban C, Roché H, et al. Effect of obesity on disease-free and overall survival in node-positive breast cancer patients in a large French population: a pooled analysis of two randomised trials. Eur J Cancer. 50(3):506-16, 2014.
17. Chan DS, Vieira AR, Aune D, et al. Body mass index and survival in women with breast cancer-systematic literature review and meta-analysis of 82 follow-up studies. Ann Oncol. 25(10):1901-14, 2014.

Updated 06/05/24