PRelationship Between Physical Activity and Cancer Ris
Condition: Cancer
Study type: Observational

Summary: 
      This protocol is a sub-study of the ongoing "Protect Health and Reduce Cancer Risk" study
      conducted in Shanghai, China, and sponsored by the Shanghai Cancer Institute, Vanderbilt
      University, and the National Cancer Institute. The parent study is designed to examine the
      relationship of diet, lifestyle, occupational, and environmental risk factors, as well as
      genetic variation, to cancer incidence in a large cohort of men in women between 40 and 70
      years of age. The current sub-study will assess the validity and reliability of a new
      physical activity questionnaire for use in the parent study and to evaluate whether different
      types of activity and the frequency, intensity, and duration of activity are associated with
      markers that have been linked to cancer risk, such as C-reactive protein, interleukin 6 and
      soluble tumor necrosis factor alpha.

      Participants in the current 12-month study are selected from among men and women
      participating in the "Protect Health and Reduce Cancer Risk" study. Participants keep a diary
      of their physical activity and complete two 30-minute interviews about their physical
      activity, one at the beginning and one at the end of the study period. Every 3 months for 7
      consecutive days, they wear a pager-sized activity monitor on their waist that records their
      physical activity patterns during that period of time. They provide blood and urine samples
      four times during the study and, at the end of the study, undergo a health examination that
      includes an electrocardiogram, body composition measurement, and physical fitness test. The
      fitness test is a step-test consisting of 3-minute stages in which the subject successively
      increases the stepping speed until reaching 85 percent of his or her predicted maximal heart
      rate.

      Blood and urine samples are analyzed for levels of nutrients and certain proteins, and are
      stored for future studies related to nutrition and physical activity and possibly for genetic
      studies related to health, nutrition, exercise, or disease.
    

Detailed description: 
      In the past decade, China has experienced fundamental decreases in the populations' physical
      activity levels, due to increasingly sedentary occupations and lifestyles. However, the
      transition to a Western lifestyle has not reached the entire Chinese population. The
      resulting wide range of between-person variation in physical activity provides an
      unparalleled opportunity for physical activity studies. Although physical activity
      measurement techniques have evolved considerably over the past years, the main obstacle in
      quantifying physical activity is the complexity of precisely measuring its individual
      components, particularly low to moderate-intensity activities.

      Recently, investigators at Vanderbilt University, the Shanghai Cancer Institute, and the DCEG
      initiated two prospective population-based cohort studies: the Shanghai Women's Cohort and
      the Shanghai Men's Cohort. The aim of these studies is to prospectively examine the relations
      of diet, lifestyle, occupational, and environmental risk factors, as well as genetic
      variation, to cancer incidence among 75,000 women and 73,000 men, aged 40 to 70 years old,
      and residing in Shanghai, China. We propose to conduct a study among 600 women and men
      participating in these two cohort studies. The specific objectives of the current study are
      to develop a comprehensive physical activity questionnaire and to assess the validity and
      reliability of this instrument in the Shanghai cohorts using objective measures of physical
      activity/physical fitness: activity monitors, and the Modified Canadian Aerobic Fitness Test.
      In addition, we intend to evaluate whether different types and parameters of physical
      activity are associated with circulating levels of specific inflammatory markers that have
      been linked to cancer risk. The specific markers are C-reactive protein (CRP), interleukin 6
      (IL-6), and soluble tumor necrosis factor alpha (TNF-a). The impact of potentially
      confounding variables of the association between physical activity and inflammatory markers,
      such as recent exercise, use of anti-inflammatory drugs, and current or recent infections,
      will be carefully accounted for in the analysis.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        community sample
      
Keywords: Physical Activity; Cancer Risk