Cancer is defined as the rapid production of abnormal cells that have the potential to spread in other parts of the body . This disease is the result of a combination of genetic and environmental factors, such as exposure to physical carcinogens (e.g. UV radiation), chemical carcinogens (e.g. asbestos), and biological carcinogens (e.g. infection by virus) . According to the Center of Disease Control & Prevention (CDC), cancer is a leading cause of mortality in the United States, second only to heart disease . Fortunately, cancer death rates in the United States are on a downward trend, reducing by 27% between the years of 2001 and 2020 . Within this timeframe, males experienced a larger decrease in cancer death rates (30%) than females (25%) . The cancers leading in death rates are respectively: lung, colorectal, pancreatic, breast, and prostate . This recent decline in cancer mortality can be attributed to several factors including: a reduction in smoking habits from targeted public health tobacco prevention campaigns, cancer vaccines, cancer screening tests, and new cancer treatments . Thus, close to a third of global cancer deaths can be attributed to “tobacco use, high body mass index, alcohol consumption, low fruit and vegetable intake, and lack of physical activity” .
Although the rate of cancer deaths is on the decline due to the aforementioned factors, the rate of cancer incidence is currently on the rise. Some of the rise can be attributed to the aging global population. The likelihood of cancer diagnosis increases with age due to a combination of factors . For one, risk factors and behaviors associated with cancer accumulate with age . Secondly, our body’s cellular mechanism deteriorates with age, thereby increasing the chance of having errant cells within the body . Life expectancy has improved in recent decades with the onslaught of improved hygiene and sanitation practices, modern medicine, and technology . Due of these advances, whereas a century ago the main causes of death were communicable (infectious) diseases, the majority of deaths today globally can be attributed to non-communicable (noninfectious) diseases such as cancer . Thus, because cancer is more common among older populations, and more people around the world are living to older age today, cancer rates are understandably higher today than they were at times with lower life expectancies.
Although the improvements in lifestyle over the past century and a half have led to an increase in life expectancy, they have also resulted in an increase in unhealthy behaviors that increase risk for cancer. Rapid economic growth and industrialization around the world have prompted the widespread adoption of unhealthy daily habits and practices, namely: poor eating habits due to the globalization of the Western diet, less exercise due to a lesser need for physical labor, and increased alcohol and tobacco consumption due to more disposable income and leisure time . Combined, these lifestyle factors increase the likelihood of cancer as well as other noncommunicable diseases. Middle-to-low-income countries are more prone to cancers caused by the pathogen infection associated with poor hygiene and sanitation . Thus, in less developed countries, cancers caused by infections such as HPV and hepatitis constitute approximately 30% of total cancer rates .
Another cause of the rise in cancer diagnoses pertains to the improvement in cancer screening techniques and technologies. For example, between the years of 1989 and 1991, there was a 40% increase in the incidence of prostate cancer . It can be reasonably inferred that the true rate of prostate cancer incidence did not increase by 40%; rather, evidence shows that “increased medical surveillance and more aggressive detection”  were cause for this dramatic increase in a two-year span . Early detection of cancer allows for of better health outcomes overall because of the ability to attempt more treatment options. Thus, the increase in the incidence of cancer rates from improved screening practices contribute to the declining cancer mortality rates.
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Author: Keeana Bacchus
Editor: Sara Giarnieri
Health scientist: Keeana Bacchus