In 2010, experts predict that 4,400 fewer Americans will be diagnosed with colon and rectal cancer than in 2009.

According to new American Cancer Society statistics for 2010, 142,570 people will hear the difficult words, “You have colorectal cancer”, down from 146,970 in 2009.

Still, 51,370 families will get painful news when loved ones die from colorectal cancer.

Continuing this year, African Americans are more likely to develop colorectal cancer than whites and other races, to die of it, and to have poorer survival at every stage of the disease.

Each year the American Cancer Society estimates the number of new cases and deaths from cancer expected in the United States in that year.  They study trends in cancer rates and look at the impact of various types of cancer.

In 2010 colorectal cancer will again be the third most commonly diagnosed cancer in men and women and the second most common cause of cancer death.

2010 Colon and Rectal Cancer

Incidence

• In 2010, 102,900 new cases of colon cancer and 39,670 cases of rectal cancer will be diagnosed for a total of 142,570.
• This is a reduction of 4,400 new cases over last year’s estimate of 146,970.
• 72,090 men will be diagnosed with colorectal cancer (9 percent of all cancers) and 70,480 women (10 percent of the total).
• Incidence rates are projected at 59.0 per 100,000 men and 43.6 per 100,000 women – a decrease from 61.2 for men and 44.8 for women in 2009.
• Over a lifetime, 1 in 19 men and 1 in 20 women will develop colon or rectal cancer.

Deaths

Although the number of deaths from colorectal cancer are expected to increase in 2010, rates for both new cases and deaths continue to go down. As the American population grows and ages, more people are vulnerable to colorectal cancer.

• 51,370 deaths from colorectal cancer are expected in 2010, up 1,450 from 49,920 in 2009.
• 26,580 men and 24,790 women will die.
• After all cancer rates peaked for men in 1990, colorectal cancer death rates dropped by 10.27  per 100,000 men from 30.77  to 20.51, accounting for a third of the decrease in all cancers.
• For women, cancer rates peaked in 1991.  Since then women’s colorectal cancer death rates have dropped from 20.30 to 14.53, accounting for about 30 percent of the overall cancer death rate decrease.

Five year survival

• In the years between 1975 and 1977, just over half of people with colorectal cancer lived five years past diagnosis (52 percent).
• By 1999 through 2005, two out of three would live those five years (66 percent).

African American Disparities

Incidence Rates Per 100,000 by Race and Ethnicity

Five-Year Survival Percentages by Race

2010 Overall Cancer Burden

• 1,529,560 new cases of cancer are expected in 2010.
• 569,490 people will die of cancer.
• Incidence rates (rates per 100,000 people) have been going down 1.3 percent each year for men in the years 2000 through 2006.
• For women, incidence decreased by 0.5 percent each year from 1998 through 2006.

Although the rates of new cancers and cancer deaths are going down, cancer remains the leading killer of people under the age of 85 in the United States.

One in four deaths is due to cancer.

In 2010, 1,529,560 people will be diagnosed with cancer and 569,490 will die.

In reporting cancers statistics for 2010, the ACS team wrote,

Although progress has been made in reducing incidence and mortality rates and improving survival, cancer still accounts for more deaths than heart disease in persons younger than 85 years. Further progress can be accelerated by applying existing cancer control knowledge across all segments of the population and by supporting new discoveries in cancer prevention, early detection, and treatment.

SOURCE: Jemal et al., Cancer Statistics, 2010, CA: A Cancer Journal for Clinicians, published online July 7, 2010.

For comparisons to 2009, see Jemal et al., Cancer Statistics 2009, CA: A Cancer Journal for Clinicians, Volume 59, Number 4, July/August 2009.

Image: Figure #3: Jemal, Cancer Statistics 2009,  CA Cancer J Clin 2010, online July 7, 2010.

The percentage of colorectal cancer deaths prevented by colonoscopy may be overestimated.

While still very effective in preventing colorectal cancer and deaths from the disease, limits of the test may be larger than previously thought.  Patients need to know that having colonoscopy does not guarantee that they won’t get colorectal cancer.

Experts now say that screening colonoscopy may reduce death from colorectal cancer by 60 to 70 percent and may not keep patients from dying from cancers on the right side of their colons at all.

A new Canadian study found that some people who died of colorectal cancer had a colonoscopy in the years before their cancer diagnosis.  A previous completed colonoscopy reduced chances of dying from colorectal cancer by two thirds in patients with cancers on the left side of their colons but did not decrease risk of death among those with right-sided cancers.

Working from the Ontario Cancer Registry, researchers identified 10,300 people who died from colorectal cancer in the seven years between 1996 and 2003.  They included only people aged 52 to 90 to ensure that the study would cover patients who had been eligible for colorectal cancer screening in the time before their diagnosis.

They then matched them to 51,500 controls, similar in age, sex, and social economic status, in order to perform a case-control study to determine how much colonoscopy decreased risk of death from colorectal cancer.

Among the 10,300 people who died from colorectal cancer, 719 or 7 percent had a colonoscopy 6 months or more before they were diagnosed with cancer.  Eight in ten of those colonoscopies were complete in reaching the cecum at the top of the colon, one in four included removal of polyps.  Among the 51,500 controls, 4000 or 9.8 percent had a colonoscopy, 1 in 5 had polyps removed.

Patients with previous colonoscopy whose cancers were on the left side of their colons had a 65 percent reduction in the risk of dying from their cancer, but there was no similar reduction in right-sided cancer death.

In analyzing their results, the researchers speculated that some reasons for colonoscopy not reducing risk for deaths from cancers on the right side of the colon were:

• Poor bowel cleansing before colonoscopy.
• Not completely evaluating the entire right colon.
• Different biology for right-sided lesions including more flat or sessile polyps.
• Different molecular basis for the cause and development of right-sided cancer.

Nancy Baxter, M.D., and her colleagues concluded,

Our study and others like it provide unique insight into colonoscopic approaches to prevent CRC death. In an Ontario-wide sample, colonoscopy is associated with a reduced risk for death from CRC arising from the left colon but not from the right colon. Although improvements in the quality of screening colonoscopy may narrow this difference, differences in tumor biology may limit the potential to prevent right-sided colon cancer deaths with current endoscopic technology.

In an associated editorial, David Ransohoff M.D. discussed the study, its limitations, and what it may mean as doctors talk to patients.  He recognized the problems with case control studies and the fact that medical records were not available to assess bowel preparation and colonoscopy completions.  However, he was also concerned that patients may be misled into thinking that colonoscopy protects more than it actually does.  He wrote,

These concerns and the authors’ results should make us worry that we might mislead our patients (and ourselves) by saying that colonoscopy reduces the risk for CRC death by 90%. Based on the considerations discussed earlier on case–control studies of sigmoidoscopy and randomized clinical trials of fecal occult blood testing that show CRC mortality reduction after colonoscopy (done because of a positive fecal occult blood testing result), a reasonable estimate—and what we should probably tell our patients—might be closer to a 60% to 70% reduction of the risk for death from CRC with high-quality colonoscopy. A 60% to 70% mortality reduction is not as good as 90%, but it should not be considered disappointing. It would be remarkably high compared with screening for other types of cancer, such as breast (with a 25% cancer mortality reduction at best) or prostate (with no proven cancer mortality reduction) cancer.

A video from the Annals of Internal Medicine explains the study and discusses the results with Dr. Baxter and Dr. Ransohoff.

SOURCE: Baxter et al., Annals of Internal Medicine, Early Release Article, December 16, 2008.

What This Means for Patients

New results from the Canadian study should not keep you from having a screening colonoscopy.

Colonoscopy does prevent death from colorectal cancer.  However, it has limits.  Colonoscopy will not completely protect you from getting colorectal cancer or dying from it.

Protect yourself further:

• Be aware of the symptoms of colon and rectal cancer and insist on having them evaluated with another colonoscopy even if you have had a clear one in the past.
• Follow colonoscopy prep instructions carefully and contact your doctor if the prep is not working.  Some gastroenterologists recommend splitting the prep into two parts — and doing the second part the day of the colonoscopy procedure to be sure the right colon is fully cleaned.
• Choose an experienced gastroenterologist to do your colonoscopy, one who does several procedures a day and spends at least eight minutes withdrawing the scope.  If your doctor doesn’t find polyps in 25 percent of men and 15 percent of women examined, you may want to look for a more skilled doctor.

Led by dropping rates of lung, breast, and colorectal cancer, the incidence rate of all new cancers in the United States is falling for the first time.  While overall cancer death rates have been decreasing since the early 1990′s, this is the first time that rates of new cancer diagnoses are also declining.

In the Annual Report to the Nation, the rate of newly diagnosed cancer fell 1.7 percent per year between 2001 and 2005.  Death rates for all cancers combined fell 1.8 percent annually during the same time period.

Both incidence of new colorectal cancers and colorectal cancer death rates continued to decline with the new report.  Between 1998 and 2005, incidence rates for men fell 3 percent annually while rates for women declined 2.4 percent.  Death rates fell 4.3 percent between 2002 and 2005 for both sexes.

The Annual Report to the Nation is yearly collaboration among the American Cancer Society, the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR). It provides updated information on cancer trends in the United States.

Colorectal cancer incidence rates declined for all races for both men and women.  Overall, 61 of every 100,000 men and 45 in 100,000 women were diagnosed with colon or rectal cancer in the United States.  Twenty-three men and 16 women per 100,000 Americans died from the disease.

The Report believes that the growing reduction in the incidence of colorectal cancer may be associated with increased screenings. In 1987 a little over 1 in every 4 Americans over age 50 (27 percent) were screened for colorectal cancer.  By 2005 half (50 percent) reported having been screened for the disease.  While use of fecal occult blood testing (FOBT) fell from 17 percent to 12 percent between 2000 and 2005, colonoscopy screening increased from 20 percent to 39 percent.

Commenting on the reduced rates for both incidence and mortality for colorectal cancer, John L. Petrini, MD, FASGE, president of the American Society for Gastrointestinal Endoscopy said,

This report demonstrates the importance of colorectal cancer screening beginning at age 50., Individuals with other risk factors, including a family history of colon cancer or polyps, and African Americans, may need screening at an earlier age. This disease is largely preventable and curable when diagnosed in its early stages. While we are encouraged by this excellent news, far too few people are getting screened. ASGE recommends colonoscopy screening beginning at age 50 and repeating every 10 years after a normal exam. Colonoscopy plays a very important role in colorectal cancer screening and prevention because it is the only method that allows for the detection and removal of precancerous polyps during the same exam and before the polyps turn into cancer.

In addition to reporting cancer incidence and death rates and trends, the Annual Report this year looked at lung cancer across states and among sex and age groups.  They found a wide difference in lung cancer rates between states where smoking is more common and states with lower smoking prevalence.  Lung cancer rates among women have just begun to level off, driven by older women who began smoking after World War II and lower “quit rates” among older women.

Concluding, Ahmedin Jemal, Ph.D., from the American Cancer Society, and his colleagues wrote,

Although the decrease in overall cancer incidence and death rates is encouraging, large state and regional differences in lung cancer trends among women underscore the need to maintain and strengthen many state tobacco control programs.

SOURCE: Jemal et al., Journal of the National Cancer Institute, Volume 100, Number 23, December 3, 2008.

For people from 25 to 64, U. S. death rates from the four major cancers — lung, breast, prostate, and colorectal — have decreased steadily from the early 1990′s.  However, with a single exception, those declines have been limited to people with at least 12 years of education.

For colon and rectal cancer, death rates for those with at least 16 years of education declined significantly for men and women, both black and white.  However, death rates did not change at all for white men, white women or black women who had less than a high school education.  Death rates for black men with less than 12 years of education actually increased by 2.7 percent each year.

During the same period of time, college-educated black women with lung cancer had death rates remain stable, the only group of college-educated people whose cancer deaths did not decline.

Among people with less than a high school education, only black women with breast cancer had a decrease in death rates (1.7% per year).  White women with lung cancer experienced at 1.4 percent increase in deaths in addition to the 2.7 percent increase in colon cancer deaths in black men.

Researchers at Emory University in Atlanta and the American Cancer Society studied cancer death trends from 1993 through 2001 using information from the National Center for Health Statistics, education level as recorded on death certificates, and population data from the US Bureau of Census Current Population Survey.

They found decreases in death rates grew more rapidly over time for each additional year of education.

Tracy Kinsey and Ahmedin Jemal and their colleagues concluded,

Recent declines in death rates from major cancers in the United States mainly reflect declines in more highly educated individuals.

They believe that other factors associated with cancer death rates such as smoking, screening, and access to treatment may also be linked to educational achievement.

SOURCE: Kinsey et al., Journal of the National Cancer Institute, Advanced Access, July 8, 2008.

More information about the study: Memo to the Media, Journal of the National Cancer Institute, July 8, 2008.