A recent study joins a body of evidence suggesting that long-term, regular aspirin use is associated with a reduced risk for cancer, with the most dramatic reduction being seen in colorectal cancer incidence. The research was presented at the 2015 AACR Annual Meeting.

“Previous studies of aspirin and cancer have been limited in terms of their size, length of follow-up, or ability to examine aspirin use in the context of other lifestyle factors,” Yin Cao, MPH, ScD, a research fellow in the Department of Nutrition at the Harvard School of Public Health, said in a statement. “Our research provides critical information regarding the full constellation of potential benefits of aspirin use, at a range of doses, timing, and duration of use, within a large population of individuals.”

For the study, data were collected on aspirin use, cancer diagnoses, and other risk factors every other year from 82,600 women participating in the Nurses’ Health Study and 47,651 men from the Health Professionals Follow-up Study. After 32 years of follow-up, 27,985 incident cancers were recorded.

Study participants who had two or more aspirin tablets per week had a 5% lower risk for cancer, compared with non-regular aspirin users. In gastrointestinal (GI) cancers, the risk was lowered by 20%, including a 25% reduction in colorectal cancers and a 14% reduction in gastroesophageal cancers. No association was found between regular aspirin use and a decreased risk for breast, lung, or advanced prostate cancers.

Significant risk reduction was seen only after 16 years of aspirin use and was no longer evident within 4 years of discontinuing use. The risk reduction was similar for women and men and not affected by the individual’s race, history of diabetes, family history of cancer, body mass index, and smoking history.

Previous studies have shown that long-term use of aspirin has lowered the risk of cardiovascular events, including heart attack and stroke. Senior study author Andrew T. Chan, MD, MPH, director of the Gastroenterology Training Program at Massachusetts General Hospital, who presented the study at AACR, said that these most recent findings suggest that even for those individuals who may not need the cardiovascular protective benefits of aspirin, the cancer prevention effect would make consumption worthwhile, and more research is warranted.

“Based on these data, there is the possibility that aspirin could have a significant clinical benefit for many individuals, since both cardiovascular disease and cancer are leading causes of death in the United States,” Chan explained. “The next step is to confirm these findings in additional populations and conduct further studies examining the potential impact of novel biomarkers which can be used to better personalize who should be treated.”

In that vein, Chan is also giving a plenary talk at the AACR meeting on molecular risk stratification for aspirin chemoprevention. He is an investigator on a recently published international 

 which found that the preventive benefit of aspirin and NSAIDS may be linked to variations in an individual’s DNA.2

Analyzing data from 10 large population-based studies, researchers found that although regular use of aspirin and NSAIDs was associated with an overall reduction in the risk of colorectal cancer, no protective effect was seen among about 9% of the participants who had genetic variations on chromosome 15. Additionally, approximately 4% of participants with variations on chromosome 12 were found to be at increased risk of colorectal cancer.

Coa cautioned against general aspirin use for cancer prevention, primarily because there are risks with aspirin, such as GI bleeding. A more tailored approach, including using biomarker research Chan mentioned, may turn out to be best.

			Cao Y, Nishihara R, Wu K, et al. Long-term aspirin use of aspirin and risk of cancer. Presented at: 2015 AACR Annual Meeting; April 18-22; Philadelphia, PA. Abstract 3197.

			Nan H, Hutter CM, Lin Y, et al. Association of aspirin and NSAID Use with risk of colorectal cancer according to genetic variants. 

View more from the 2015 AACR Annual Meeting

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A recent study joins a body of evidence suggesting that long-term, regular aspirin use is associated with a reduced risk for cancer, with the most dramatic reduction being seen in colorectal cancer incidence.

Long-term Aspirin Use Decreases Risk of GI Cancers, Especially Colorectal

 Each year, the American Cancer Society publishes its annual cancer statistics, highlighting gains as well as areas that need continued focus. For 2015, the organization's report shows a 22% decrease in cancer death over the past 20 years, equating to more than 1.5 million lives saved—a positive trend seen for the past few years.

The data, compiled from the National Cancer Institute, the Centers for Disease Control and Prevention and the National Center for Health Statistics, can be reviewed in two reports: Cancer Statistics 2015, published in CA: A Cancer Journal for Clinicians, and Cancer Facts & Figures 2015, which includes information on survivorship issues, side effects and patient resources.

The decline in cancer mortality appears across the country, largely due to a sharp decrease of tobacco-related lung cancer incidence that peaked in the early 1990s, as well as other advances in prevention, detection strategies for early-stage cancers and treatment. With data examined across disease sites, age ranges, geographical locations and other factors, the ACS has been able to show important gains, including a 55% decrease in cancer death among black men in their 40s.

The number of cancer survivors, not including those with non-melanoma skin cancer and non-invasive breast cancer, grew to 14.5 million, up from 13.7 million at the beginning of 2013. In 20 years, that number is expected to rise to nearly 20 million.

Predictions for 2015 include 1.6 million new cases of cancer, with 589,000 cancer deaths. The incidence of thyroid cancer has increased 4.5% from 2007 to 2011, which experts attribute partly to higher screening rates. Incidence rates for liver cancer are also increasing, as well as for melanoma, esophageal cancer and head and neck cancer caused by the human papillomavirus (HPV).

While declines have been seen across all states, the South shows the smallest decline. Survival rates also remain lower for minorities, particularly those with oral, uterine and bladder cancers. The authors acknowledge that further progress can be made by emphasizing prevention, early detection and access to treatment for those in low socioeconomic groups and in other disadvantaged populations.

“The continuing drops we’re seeing in cancer mortality are reason to celebrate, but not to stop,” John R. Seffrin, chief executive officer of the American Cancer Society, said in a statement. “Cancer was responsible for nearly one in four deaths in the United States in 2011, making it the second leading cause of death overall. It is already the leading cause of death among adults aged 40 to 79, and is expected to overtake heart disease as the leading cause of death among all Americans within the next several years.”

This year’s Cancer Facts & Figures also includes a special section on non-invasive breast cancer, separated sections for ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). It is estimated that non-invasive breast cancers will account for about 20% of breast tumors diagnosed in women. Prior to 1980, non-invasive breast cancers were rarely detected. 

Predictions for 2015 include 1.6 million new cases of cancer, with 589,000 cancer deaths. 

Report Shows Cancer Deaths Continue to Decline

The Centers for Medicare & Medicaid Services (CMS) announced that the agency plans to cover lung cancer screening using low-dose computed tomography (LDCT) for certain former and current smokers, a decision that could affect an estimated 4 million people.

The federal agency issued a draft guidance on November 10 that outlined annual lung cancer screenings with LDCT and counseling about the process, as a preventive service for individuals aged 55 to 74 years old with no signs of lung disease. The guidance is meant for individuals with a history of smoking at least one pack per day for 30 years and former smokers who have quit within the past 15 years.

“Tens of thousands of lives will be saved by providing America’s seniors with fair and equitable access to the same lifesaving lung cancer screening that is now being offered to those with private insurance,” Fenton Ambrose, president and CEO of the Lung Cancer Alliance, said in a statement issued by the organization. "Now, we will focus our attention on making sure those who would benefit most from this screening actually get screened.”

The decision follows the recommendation by the United States Preventive Services Task Force this last December for high-risk individuals to receive lung cancer screening, which ultimately made it a requirement for private insurers to cover the service in 2015. In April, a Medicare advisory committee voted against recommending lung cancer screening with LDCT out of concern that risks, such as false positives, unnecessary needle biopsies, and risky surgery would outweigh potential benefits. In response, more than 175 members of Congress signed letters this past September urging CMS to cover LDCT.

Richard C. Wender, MD, chief cancer control officer with the American Cancer Society, said the society, along with many other organizations, has been working with Medicare on a plan to cover the practice.

“We had the very interesting possibility that if Medicare did not provide coverage, you’d be covered (under private insurance) until you hit Medicare—and as your risk gets higher as you get older, you’d no longer be covered,” he said. “We like the way it turned out.”

While Medicare plans to cover screening for high-risk individuals, it will only occur at accredited facilities. In addition, data from each lung cancer screening performed under Medicare will be collected for a national registry to produce additional research regarding the preventive practice.

“We’ve learned a lot since when mammography was first recommended,” Wender says. “This really reflects a modern-day screening decision that recognizes from the outset how important it is to do it right.”

In addition to the evidence gathered from multiple lung cancer screening studies, guidelines also have narrowed in on a high-risk group and highlighted the importance of screening at accredited facilities. Because the number of these facilities may be limited, one goal is to broaden accessibility, says Wender.

“First priority is to build capacity to make sure the centers can meet specific quality program requirements,” he says. “Right along the same time will be some broad public education about who should consider screening, which (may involve) a large learning curve…that this is really only for people who have a very high risk of lung cancer.”

James L. Mulshine, MD, vice president and associate provost for research at Rush University Medical Center in Chicago, worked on the International-Early Lung Cancer Action Project, one of the lung cancer screening trials that provided evidence of benefit. The CMS ruling presents an opportunity to not only cure lung cancer in high-risk individuals, he says, but also motivate current smokers to quit.

“We now have to work to make sure that broad access to high-quality screening service with informed decision making and access to smoking cessation occurs for those at highest risk for this cancer,” Mulshine says.

Providing coverage for screening, as well as the discussion around it and smoking cessation, will be key for patients, but also for primary-care physicians and internists, who will be recommending the screening for their patients.

“This was a critical step. We can’t do anything without coverage, but in some respects, we recognize that the hard work is just starting—to create national capacity to reach as many people as possible with high-quality screening,” Wender says.

Elizabeth Whittington

Articles

Long-term Aspirin Use Decreases Risk of GI Cancers, Especially Colorectal

Report Shows Cancer Deaths Continue to Decline

CMS Will Cover Screening for Lung Cancer With LDCT