Cancer may become the leading cause of death by 2020

The Centers for Disease Control (CDC) looked at data for the five leading causes of death (heart disease, cancer, stroke, chronic lower respiratory diseases, and accidents) which together account for 63 percent of all deaths in the United States,. 

They used mortality data, population estimates and projections to estimate and predict heart disease and cancer deaths from 1969 through 2020.

The report indicates that fewer people died prematurely from cancer, stroke and heart disease between 2010 and 2014.

They predicted that from 1969 through 2020, the number of heart disease deaths would decrease 21.3% among men and 13.4% among women while the number of cancer deaths would increase 91.1% among men and 101.1% among women. They suggest that cancer would become the leading cause of death around 2016.

In 2014, more than 614,000 Americans died of heart disease and approximately 592,000 died of cancer that year.  However, in 2016, almost 601,000 Americans may die as a result of cancer, while more than 597,000 may die from heart disease.  Thus cancer could surpass heart disease as the leading cause of death among Americans this year, according to the report.

The authors conclude that the risk of death declined more steeply for heart disease than cancer over the past 4 decades. If current trends continue, cancer will become the leading cause of death by 2020.

Obesity linked to premature death

It is well known that being overweight can lead to health complications including diabetes, heart disease, stroke and cancer.

A recent study published in Lancet reports on a meta-analysis of 239 prospective studies published from 1970 to last year (median follow-up 13·7 years).  Of those 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died.   The investigators extracted their information from 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America.

They compared the risk of death to people's body mass index, or BMI, a measure of body fat that is calculated using height and weight.  They defined a BMI from 18.5 to 25 as normal, 25-30 as overweight, 30-35 as moderately obese and over 40 as severely obese.

In the study, the risk of dying before the age of 70 was 19 percent for men and 11 percent for women of normal weight.

But that risk jumped to 30 percent and 15 percent, respectively, for obese men and women.  The investigators found that overweight people die one year earlier than expected and that moderately obese people die up to three years prematurely.

The World Health Organization estimates that 1.3 billion adults worldwide are overweight, and 600 million more are obese. The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in all four continents. As common diseases such as heart disease, stroke, diabetes and cancer have been strongly associated to obesity, strategies to combat it are needed all around the globe.

Exercise linked to reduced risk of several cancers

Physical activity has been associated with lower risk of heart disease and all cause mortality, but its association with risk of cancer is not well understood.

Moore et al research published in JAMA Internal Medicine, suggests that exercise is a powerful cancer-preventive and found that physical activity drove down the rates of a broad array of cancers even among smokers, former smokers, the overweight and obese.

Researchers collected data from 12 prospective studies from the United States and Europe and analyzed associations between self-reported physical activities with the incidence of 26 types of cancer in the study period, which lasted 11 years between 1987 and 2004.

A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included. High versus low levels of physical activity were associated with lower risk of 13 cancers: esophageal adenocarcinoma, liver, lung, kidney, gastric, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast. The data indicated that a higher level of activity was tied to a 7 percent lower risk of developing any type of cancer. Individuals who were very active had a 20% lower risk of cancers of the esophagus, lung, kidney, stomach, endometrium compared with people who were less active.  The reduction was slightly lower for colon, bladder, and breast cancers.

Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. Leisure-time physical activity was associated with higher risks of malignant melanoma and prostate cancer.  Associations were generally similar between overweight/obese and normal-weight individuals. Smoking status modified the association for lung cancer but not other smoking-related cancers.

Health care professionals should emphasize that physical activity was associated with lower risks of many cancer types and most of these associations were evident regardless of body size or smoking history.

Cancer death rate has fallen in the United States

Each year, the American Cancer Society (ACS) estimates the numbers of new cancer cases and deaths that will occur in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival.

The ACS collects and reports data from several registries such as SEER, CDC, NPCR, NACCR and NCHS.  In 2016, 1,685,210 new cancer cases and 595,690 cancer deaths are projected to occur in the United States. Overall cancer incidence trends are stable in women, but declining by 3.1% per year in men (from 2009-2012), much of which is because of recent rapid declines in prostate cancer diagnoses. The cancer death rate has dropped by 23% since 1991, translating to more than 1.7 million deaths averted through 2012. The decline is attributed to decreasing smoking rates and advances in cancer detection, treatment and prevention.

Deaths from lung, breast, prostate, and colon/rectum cancers drove overall declines.  Death rates for female breast cancer have declined 36% from peak rates in 1989, while deaths from prostate and colorectal cancers have each dropped about 50% from their peak. Meanwhile, lung cancer death rates declined 38% between 1990 and 2012 among males and 13% between 2002 and 2012 among females, due to a decline in the use of tobacco.

In spite of this progress, death rates are increasing for cancers of the liver, pancreas, and uterine corpus. Among children and adolescents (aged birth-19 years), brain cancer has surpassed leukemia as the leading cause of cancer death because of the dramatic therapeutic advances against leukemia.  

Despite of these remarkable improvements cancer remains the leading cause of death in 21 states, primarily due to exceptionally large reductions in death from heart disease. Accelerating progress against cancer requires novel approaches in diagnosis, treatment and the application of existing cancer control knowledge across all segments of the population

CA: A Cancer J Clin Vol 66, 1, 7-30, Jan-Feb 2016

One in Two Americans will develop Cancer in their Lifetime

According to the American Cancer Society the lifetime risk of developing or dying from cancer refers to the chance a person has, over the course of his lifetime, of being diagnosed with or dying from disease. These risk estimates, like annual incidence and mortality data, provide another measure of how widespread cancer is in the United States.

The information is from the US National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) Database, and is based on incidence and mortality data for the United States from 2009 through 2011.

The risk is expressed both in terms of a percentage and as odds. For example, the risk that a man will develop bladder cancer during his lifetime is 3.83%. This means he has about 1 chance in 26 of developing bladder cancer (100/3.83 = 26.1). Put another way, 1 out of every 26 men in the United States will develop bladder cancer during his lifetime.

The risk for women of developing cancer at any site is 37.8% while their risk of dying due to cancer is 19.6%.  This means 1 in 3 women will develop cancer in their life while 1 in 5 will die from the disease.

The risk for females for developing breast cancer, the most common cancer in women, is 12.3%.   This means 1 in 8 women will develop the disease while the risk of dying form cancer is 2.7%, which means 1 in 37 will die from the disease.

The risk for men of developing cancer at any site is 43.3% while the risk of dying due to cancer is 22.6%.  This means 1 in 2 men will develop cancer in their life while 1 in 4 will die from the disease.

The risk for men to develop prostate cancer, the most common cancer in men, is 15%.   This means 1 in 7 men will develop the disease while the risk of dying is 2.6%, which means 1 in 38 will die from the disease.

According to a study published in the British Journal of Cancer, the odds of developing cancer over the course of one’s life in the UK has increased from 38.5% for men born in 1930 to 53.5% for men born in 1960. For women it increased from 36.7 to 47.5%.

Therefore according to the data for the United States and United Kingdom over half of people who are currently adults under the age of 65 years will be diagnosed with cancer at some point in their lifetime.