Obesity is very common and is a risk factor for breast cancer in postmenopausal women. One mechanism explaining why obesity is a risk factor is it may raise estrogen levels in women. In particular, one type of estrogen, serum estradiol, is a strong risk factor for breast cancer. Researchers studied a group of 151 African-Americans and 60 Caucasian premenopausal women. Adiposity was measured in two different ways: BMI= weight (kg)/height² (m²) and waist-hip ratio (WHR) = waist circumference/hip circumference. BMI is a measure of overall adiposity, whereas WHR is a measure of abdominal adiposity. In addition, a complete hormonal profile was obtained, including serum estradiol (ES_1).
Finally, other breast cancer risk factors were also assessed among these women, including:
1) Ethnicity (1 for African -American; 0 for Caucasian)
2) Age
3) Parity (# of total children)
4) Age at first birth
5) Any children (1 if yes; 0 if none)
6) Age when menstrual periods began
Exercise #1: Identify and explain at least two regression/correlation constructs in the case scenario. Then describe the steps you would take to analyze this scenario. Please explain each step by indicating your rationale.