Tuesday, May 29, 2012

Lung Cancer and Cigarette Smoke

     I read a paper studying the correlation between rates of cigarette smoking and lung cancer incidence in the United States.  It seems pretty common knowledge today that cigarettes contribute to cancer, but this paper offered some insights into the issue I had previously not thought of.  The paper, found here, analyzes these two things based on different birth cohorts and provides figures showing lung cancer incidence from the early 20th century, lung cancer based on different cohorts and smoking rates in teenagers. However, the figures offer an overly specific analysis with too narrow of a date ranges to show the change in lung cancer incidence in relation to change in smoking rates nationally. In order to get a better visual of how the rates mimic each other I decided to create a figure presenting smoking rates and lung cancer incidence for both males and females in the United States from 1965-2005. The data for smoking came from the CDC and the data for lung cancer came from the American Lung Association.

Here are the figures I used before I combined the lines.

First the lung cancer figure from the American Lung Association:

And here is the smoking figure from the CDC:

Here is my figure I created by combining the data from the two figures:
The X axis is the date and the Y axis has no numerical significance; the figure is just used to show the relationship between the two figures better. The blue line represents the smoking rate in males, and the red line is for females. The green line represents male lung cancer incidence and the yellow is for females.

As expected, the data from my figures matches the results presented in the paper. In both males and females there has been a decrease in smoking rates. In 1965 about 52% of the male population smoked cigarettes and about 34% of females smoked. In 2005 the rate of male smokers had dropped to 25% and females to 19%. In regards to lung cancer, since 1985, there has been a steady decrease in the rates of lung cancer for males. In 1985 100 in 100,000 people showed incidence of cancer. By 2005 that had dropped to 72 in 100,000 incidence of cancer. The disturbing trend is seen with females, despite the decrease in cigarette smoking, the rate of female lung cancer incidence continues to climb to todays rate of 50 in 100,000. The paper offers analysis of these trends, but my created figure helps to illustrate the trends in relation to each other as well as show more recent data (the data from the paper stops around 1970). The paper attributes the decrease in smoking and cancer trends to aggressive campaigning against smoking directed towards the younger generations.  However, despite the decrease in lung cancer rates, the paper still urges us to address this problem further to help continue the decrease of this disease.