Physical activity and risk of breast cancer overall and by hormone receptor status: the European prospective investigation into cancer and nutrition.
Physical activity is associated with reduced risks of invasive breast cancer. However, whether this holds true for breast cancer subtypes defined by the estrogen receptor (ER) and the progesterone receptor (PR) status is controversial. The study included 257,805 women from the multinational EPIC-cohort study with detailed information on occupational, recreational and household physical activity and important cofactors assessed at baseline. During 11.6 years of median follow-up, 8,034 incident invasive breast cancer cases were identified. Data on ER, PR and combined ER/PR expression were available for 6,007 (67.6%), 4,814 (54.2%) and 4,798 (53.9%) cases, respectively. Adjusted hazard ratios (HR) were estimated by proportional hazards models. Breast cancer risk was inversely associated with moderate and high levels of total physical activity (HR = 0.92, 95% confidence interval (CI): 0.86-0.99, HR = 0.87, 95%-CI: 0.79-0.97, respectively; p-trend = 0.002), compared to the lowest quartile. Among women diagnosed with breast cancer after age 50, the largest risk reduction was found with highest activity (HR = 0.86, 95%-CI: 0.77-0.97), whereas for cancers diagnosed before age 50 strongest associations were found for moderate total physical activity (HR = 0.78, 95%-CI: 0.64-0.94). Analyses by hormone receptor status suggested differential associations for total physical activity (p-heterogeneity = 0.04), with a somewhat stronger inverse relationship for ER+/PR+ breast tumors, primarily driven by PR+ tumors (p-heterogeneity < 0.01). Household physical activity was inversely associated with ER-/PR- tumors. The results of this largest prospective study on the protective effects of physical activity indicate that moderate and high physical activity are associated with modest decreased breast cancer risk. Heterogeneities by receptor status indicate hormone-related mechanisms.
Unit of Physical activity and Cancer, Divisions of Environmental Epidemiology and Preventive Oncology, German Cancer Research Center, DKFZ, Heidelberg, Germany. k.steindorf@dkfz.de
Karen
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Steindorf
Rebecca
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Ritte
Piia-Piret
PP
Eomois
Annekatrin
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Lukanova
Anne
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Tjonneland
Nina Føns
NF
Johnsen
Kim
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Overvad
Jane Nautrup
JN
Østergaard
Françoise
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Clavel-Chapelon
Agnès
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Fournier
Laure
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Dossus
Birgit
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Teucher
Sabine
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Rohrmann
Heiner
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Boeing
Angelika
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Wientzek
Antonia
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Trichopoulou
Tina
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Karapetyan
Dimitrios
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Trichopoulos
Giovanna
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Masala
Franco
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Berrino
Amalia
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Mattiello
Rosario
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Tumino
Fulvio
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Ricceri
J Ramón
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Quirós
Noémie
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Travier
María-José
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Sánchez
Carmen
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Navarro
Eva
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Ardanaz
Pilar
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Amiano
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Bueno-de-Mesquita
Franzel
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van Duijnhoven
Evelyn
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Monninkhof
Anne M
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May
Kay-Tee
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Khaw
Nick
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Wareham
Tim J
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Key
Ruth C
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Travis
Kristin Benjaminsen
KB
Borch
Malin
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Sund
Anne
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Andersson
Veronika
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Fedirko
Sabina
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Rinaldi
Isabelle
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Romieu
Jürgen
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Wahrendorf
Elio
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Riboli
Rudolf
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Kaaks
D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009752:Nutritional Status; D011379:Prognosis; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012307:Risk Factors
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone