Econstudentlog

Cancer statistics, 2011

“Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths expected in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival based on incidence data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. A total of 1,596,670 new cancer cases and 571,950 deaths from cancer are projected to occur in the United States in 2011. Overall cancer incidence rates were stable in men in the most recent time period after decreasing by 1.9% per year from 2001 to 2005; in women, incidence rates have been declining by 0.6% annually since 1998. Overall cancer death rates decreased in all racial/ethnic groups in both men and women from 1998 through 2007, with the exception of American Indian/Alaska Native women, in whom rates were stable. African American and Hispanic men showed the largest annual decreases in cancer death rates during this time period (2.6% and 2.5%, respectively). Lung cancer death rates showed a significant decline in women after continuously increasing since the 1930s. The reduction in the overall cancer death rates since 1990 in men and 1991 in women translates to the avoidance of about 898,000 deaths from cancer. However, this progress has not benefitted all segments of the population equally; cancer death rates for individuals with the least education are more than twice those of the most educated.”

Link to the publication. Some more data (click to view full size):

Sex differences matter a lot for some types of cancers and the differences between the genders are quite significant. Breast cancer cases make up ~30% of all new cancer cases for women and prostate cancer cases make up a similar proportion  of new male cases. Note that it makes a lot of sense to report the ‘new cases’-metric rather than the ‘total people afflicted’ if you want to know about the risk of getting the disease; some types of cancers are much more aggressive than others and death rates vary a lot, and so if you looked at a metric like ‘people afflicted’, relatively harmless cancers (e.g. (some types of) prostate cancer) would in some sense be ‘overrepresented’. As the report puts it, “the lifetime probability of being diagnosed with an invasive cancer is higher for men (44%) than women (38%) […] However, because of the earlier median age of diagnosis for breast cancer compared with other major cancers, women have a slightly higher probability of developing cancer before age 60 years.”

Looking just at the death rate, there’s some variation here; spanning from Utah’s very low death rate of just 135.7 (most likely caused by environmental factors – smoking and drinking in particular) to Kentucky’s 216.5 – the report mentions specifically later on that “lung cancer shows by far the largest geographic variation in cancer occurrence”, which I do not find surprising. Even though the two states mentioned have very different death rates, far most states are in the 170+ range so most inter-state differences aren’t that large especially considering how many different factors impact a variable like this.

When looking at the next table remember to look at the actual percentages as the proportions given are only very rough measures. I think it’s interesting that they included the latter, but it’s probably not a bad idea; to a lot of math-challenged individuals such a fraction may convey significantly more information than do the percentage estimates, and the seemingly much greater degree of ‘precision’ of the probability estimates should not make us forget that these are in fact just that, estimates:

Again, recall that these are averages and averaging can hide important variation in the data. For example, the 6-7% lifetime risk of lung- and bronchial cancers is an measure which both includes heavy smokers and non-smokers. A smoker should rationally assume his risk to be significantly higher than that, and a non-smoker would on the other hand probably get a more accurate risk assessment if he assumes that his/her risk of getting that type of cancer is quite a bit lower than the full-sample estimate.

“Cancer replaced heart disease as the leading cause of death among men and women aged younger than 85 years in 1999 (Fig. 6). The overall cancer death rate decreased by 1.9% per year from 2001 through 2007 in males and by 1.5% in females from 2002 through 2007, compared with smaller declines of 1.5% per year in males from 1993 through 2001 and 0.8% per year in females from 1994 through 2002 (Table 5). Notably, the lung cancer mortality rate in women has begun to decline for the first time in recorded history and more than a decade later than the decline began in men.”

There’s more at the link.

July 14, 2012 - Posted by | cancer, data, health, medicine

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