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Prevention Studies for a Cancer-free Tomorrow

The American Cancer Society conducts long-term studies that help us better understand the causes of cancer and how to prevent the disease. These studies have shown how lifestyle, medical, environmental, and genetic, and other factors relate to cancer risk and and how they ultimately plated a role in the 29% drop in cancer death rates between 1991 and 2017.

How Do We Conduct Cancer Prevention Studies?

We deliver lifesaving research by collecting biospecimens and survey data from large groups of cancer-free adults and monitoring their health status over time.

What Are Some of Our Studies’ Findings and Their Impact?


The 1964 Surgeon General’s landmark report concluded that smoking causes lung cancer.  This finding was based, in part, on our early studies linking smoking with death from lung cancer and other health dangers. Since then, adult smoking rates have declined from over 40% in the mid-1960s to 14% in 2017.

Excess Body Weight

Cancer Prevention Study-I (CPS-I) revealed the first epidemiologic evidence that excess body weight increases the risk of premature death. Findings from CPS-II contributed to the International Agency for Research on Cancer's conclusion in 2016 that excess body fatness increases the risk of 13 different cancers..


CPS-II was the first prospective study to find a link between regular aspirin use and lower risk of colorectal cancer, opening the door to more research on aspirin and its effect on the risk of other cancers.

Diet & Exercise

CPS-II findings provided evidence that adhering to cancer prevention guidelines for body weight, diet, physical activity, and alcohol intake is associated with lower risk of premature death from cancer, cardiovascular disease, and other causes.


Data and biospecimens from CPS-II have contributed to the identification of most of the known genetic susceptibility variants associated with breast, prostate, and pancreatic cancer. This work has led to a better understanding of the role family history plays in these cancers.

Who Has Participated in Our Studies?

1952 to 1955: The Hammond-Horn Study

22,000 volunteers helped recruit 188,000 participants from 9 states who were between the ages of 50 and 69

1959 to 1972: The CPS-I Study

68,000 volunteers helped recruit 1,000,000 participants from 25 states with an average age of 52 at enrollment

1982 to the present: The CPS-II Study

77,000 volunteers helped recruit 1,200,000 participants across all 50 states, plus Washington, DC, who were an average age of 57. These participants have provided 110,000 biospecimens. 

2006 to the present: The CPS-3 Study

30,000 volunteers helped recruit 304,000 participants across all 50 states, plus Washington, DC, and Puerto Rico, with an average age of 47.  These participants have provided 300,000 biospecimens. 

What’s Next for The Cancer Prevention Studies?

Tissue Specimens

We are collecting tumor tissue specimens to study specific molecular subtypes of colorectal, prostate, blood, ovarian, and breast cancers.

Diet & Cancer

We're examining dietary patterns throughout life, including meal timing, binge drinking, blood biomarkers of diet, and the gut microbiome (as measured by stool samples) to advance our understanding of how diet influences cancer risk.

Activity, Sleep, & Cancer

We're collecting survey and activity monitor-based physical activity data to study the role of different intensities of physical activity, patterns of sedentary behavior, and sleep (including light at night) in relation to cancer risk.

Infection & Cancer

We will assess the role viral and bacterial infections play in altering the risk of leukemia and lymphoma development by studying CPS-II and CPS-3 blood samples.

Smoking & Cancer

We will investigate how e-cigarette use may influence the smoking habits and quit rates of adults who smoke regular cigarettes.


Using information collected both before and after a cancer diagnosis, we will study factors associated with improved quality of life, with the goal of better understanding the unique health effects of cancer among cancer survivors.

Fighting Cancer on All Fronts

The American Cancer Society is the nation's preeminent cancer-fighting organization. Our mission is to save lives, celebrate lives, and lead the fight for a world without cancer.

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