This week I’m starting off with a new MOOC in Coursera – Data Visualization and Management by Wesleyan University. The course is part of a four-course specialization that will help me catching up with Python for data analysis, combining the capabilities that I already have using other statistical software together with a great open-source programming language. This blog post is part of the assignment that I have to submit for week 1 of the course and is also the foundation of the whole course structure.
Drinking alcoholic beverages like wine, beer, whisky and liquor among women is a commonplace sight at work related parties or just for recreation. Several research studies in the past have shown that consumption of alcoholic beverages “increases a woman’s risk of hormone-receptor-positive breast cancer”. The National Toxicology Program of the US Department of Health and Human Services lists consumption of alcoholic beverages as a known human carcinogen. In a meta-analysis of 53 epidemiological (which included a total of 58,000 women with breast cancer) showed that women who drank more than 45 grams of alcohol per day (approximately three drinks) had 1.5 times the risk of developing breast cancer as non-drinkers (a modestly increased risk) (Hamajima et al, 2002).
When we drink alcohol (chemical name ethanol), it is converted into a toxic chemical called acetaldehyde. This chemical causes the reduction of blood levels in the vitamin folic acid. Folic acid plays an important role in copying and repairing the DNA. Low levels of folic acid may render the DNA being incorrectly copied when cell division occurs. Such errors in DNA replication may lead the cells to become cancerous (8).
Epidemiological studies have shown that alcohol consumption in women leads to increased chances of breast cancer risk (Longnecker, 1994), (Smith-Warner et al, 1998),(Li CI et al, 2008),(Cotterchio et al, 2003),(Suzuki et al, 2005). In experimental studies conducted on human subjects the consumption of alcohol is shown to affect the plasma estrogen causing an increased risk of breast cancer in women. In a decade long study conducted on 39,876 US female health professionals aged 5 years or older by (Zhang et al, 2007) it was found that approximately 13.4% of women drank at least 10g/day of alcohol. It was found that the risk of breast cancer existed in 1.84% of women who consumed ≥10g/day of alcohol.
For this research study, I have chosen the “Gapminder Codebook”. It combines longitudinal survey data on respondents’ social, economic, psychological and physical well-being with contextual data on the family, neighbourhood, community, school, friendships, peer groups, and romantic relationships, providing unique opportunities to study how social environments and behaviours in adolescence are linked to health and achievement outcomes in young adulthood.
After studying the Gapminder Codebook, I have decided that I am particularly interested in determining if alcohol consumption can increase the risk of breast cancer.
I therefore, add to my codebook the following two variables
a. ‘alcconsumption’ – 2008 alcohol consumption per adult (age 15+), litres Recorded and estimated average alcohol consumption, adult (15+) per capita consumption in litres pure alcohol
b. ‘breastcancerper100TH’- 2002 breast cancer new cases per 100,000 female Number of new cases of breast cancer in 100,000 female residents during the certain year.
I now need to find if there are any other variables that directly or indirectly contribute to breast cancer risk. So, in a second review of the Gapminder Codebook, I think that working women are prone to a greater risk of breast cancer. So, the second topic that I would like to explore in this study is the association between breast cancer in female employee. So the third variable will be ‘femaleemployrate’ given as;
c. ‘femaleemployrate’- 2007 female employees age 15+ (% of population) Percentage of female population, age above 15, that has been employed during the given year.
So now that I have chosen the three variables for this study, I now derive the various hypotheses;
H0 (Null Hypothesis) = Breast cancer is not caused by alcohol consumption
H1 (Alternative Hypothesis) = Alcohol consumption causes breast cancer
H2 (Alternative Hypothesis) = Female employee are susceptible to increased risk of breast cancer.
Note: This post will be continued…
- Longnecker MP. Alcoholic beverage consumption in relation to risk of breast cancer: meta-analysis and review. Cancer Causes Control 1994;5:73–82.
- Smith-Warner SA, Spiegelman D, Yaun SS, et al. Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA 1998;279:535–40.
- Li CI, Malone KE, Porter PL, et al. The relationship between alcohol use and risk of breast cancer by histology and hormone receptor status among women 65–79 years of age. Cancer Epidemiol Biomarkers Prev 2003;12:1061–6.
- Cotterchio M, Kreiger N, Theis B, et al. Hormonal factors and the risk of breast cancer according to estrogen- and progesterone-receptor subgroup. Cancer Epidemiol Biomarkers Prev 2003;12:1053–60.
- Suzuki R, Ye W, Rylander-Rudqvist T, et al. Alcohol and postmenopausal breast cancer risk defined by estrogen and progesterone receptor status: a prospective cohort study. J Natl Cancer Inst 2005;97:1601–8.
- Zhang, Shumin M., et al. “Alcohol consumption and breast cancer risk in the Women’s Health Study.” American Journal of Epidemiology 165.6 (2007): 667-676.
- Hamajima N, Hirose K, Tajima K, et al. Alcohol, tobacco and breast cancer–collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease. British Journal of Cancer 2002;87(11):1234-1245. [PubMed Abstract]
- Cancer Research UK. 2014. How alcohol causes cancer. [ONLINE] Available at: http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/alcohol-and-cancer/how-alcohol-causes-cancer. [Accessed 03 January 16]