Breast, Colorectal, and Lung Cancer Screening Guidelines Explored

TON - June 2013, Vol 6, No 5 — July 10, 2013

Evidence-based guidelines translate research into practice and are intended to reduce variations in cancer care and promote excellence. However, it can be daunting to sift through the wealth of available guidelines for early detection of cancer, as existing guidelines from different agencies are not in agreement. At the 38th Annual Congress of the Oncology Nursing Society (ONS), 2 experts reviewed screening guidelines for common cancers and what nurses need to know about them.

“Nurses are the most trusted profession. Patients often come to us for advice. We need to educate ourselves so we can educate the public. It is important for us to know the cancer screening guidelines as well as the standard of care at your own facility. Also, know the population you serve and their particular needs. There are a number of good resources for nurses to get reliable information on screening. Communicate the message to patients effectively,” advised Joanne Ebner, RN, BSN, of Anne Arundel Medical Center at the DeCesaris Cancer Institute. Ebner reviewed screening guidelines for breast and colorectal cancer. Her colleague, Judith Smith, MSN, RN, AOCN, of the Division of Cancer Prevention at the National Cancer Institute (NCI), reviewed lung cancer screening guidelines.

Resources for current screening guidelines include websites for the NCI, US Preventive Services Task Force (USPSTF), the National Guideline Clearinghouse of the Agency for Healthcare Research and Quality, and ONS.

Breast Cancer

Breast cancer is the second leading cause of cancer death in women in the United States, accounting for 14% of those deaths. Mortality from breast cancer had decreased by 30% since 1989, which has been attributed to widespread screening along with treatment advances. However, reservations about film mammography include whether finding cancers earlier actually reduces mortality or just delays it. Mammography can cause psychological harm and increase the use of healthcare resources, owing to false-positive findings resulting in unnecessary tests and biopsies.

Considering these concerns, the USPSTF recommended against routine screening for women aged 40 to 49 years at average risk, and recommended biennial screening for average-risk women aged 50 to 74. Furthermore, USPSTF guidelines state that there is insufficient evidence to recommend clinical breast examination, breast self-examination, and digital mammography for women at average risk.

The American Cancer Society guidelines promote annual mammography for average-risk women beginning at age 40, and magnetic resonance imaging (MRI) for high-risk women. Other organizations, including the American Medical Association, the American Academy of Family Physicians, and the American Congress of Obstetricians and Gynecologists, have variations on these guidelines.

Emerging technology for breast screening includes digital mammography, contrast-enhanced digital mammography, MRI, tomosynthesis, MRI spectroscopy, diffusion-weighted MRI, and positron emission mammography. These technologies may be useful in high-risk women, but will increase the cost of screening.

Colorectal Cancer

Colorectal cancer is the second leading cause of cancer-related deaths in men and women in the United States. Over the past 30 years, the incidence of colorectal cancer has declined, largely because of colonoscopy.

“Colorectal cancer is the only cancer that we agree can absolutely be prevented. But only 60% of insured adults undergo screening,” Ebner said. Barriers to screening include fear, the unpleasant preparation for colonoscopy, no insurance, and lack of awareness.

There are several screening tests for colon cancer, including guaiac-based fecal occult blood testing, exfoliated DNA testing, sigmoidoscopy, colonoscopy, and virtual colonoscopy.

Most guidelines from professional societies and the USPSTF agree that colonoscopy should be initiated at age 50 and repeated every 10 years in those with an average risk, at age 45 in African Americans, and at age 40 (or 10 years younger than age of an affected relative) in high-risk individuals. Colonoscopy should be stopped after age 75 or when life expectancy is less than 10 years, according to most guidelines.

Lung Cancer

Lung cancer is the leading cause of cancer-related deaths for both men and women. Nearly 90% of all lung cancers are smoking related. Screening of asymptomatic individuals with no smoking history requires consideration of harms versus benefits. Potential harms include false-negative results, false-positive results setting into motion unnecessary use of resources, and detecting a lethal cancer without changing outcomes.

Several large clinical trials have shown that routine chest x-ray screening of the general population does not prevent lung cancer–related mortality. “The bottom line is that chest x-ray does not lower lung cancer mortality rates,” stated Smith.
The low-dose computed tomography (CT) scan, formerly called spiral CT, holds promise for screening patients at higher risk due to a history of smoking cigarettes. When the large, randomized National Lung Screening Trial (NLST) compared low-dose helical CT with chest x-ray in more than 50,000 current or former smokers, the study was halted early because low-dose CT was found to be superior to chest x-ray in preventing lung cancer mortality. People who received low-dose CT had a 20% lower risk of dying of lung cancer than those who received a chest x-ray.

“NLST was a game-changer,” said Smith. New guidelines from a number of organizations are consistent and state that high-risk patients should be screened with low-dose CT. Caveats are that the screened population should fulfill the eligibility criteria of the NLST (ie, aged 55-74 years, asymptomatic or former smoker with at least a 30-pack-year history and no other cancers), and that the technique be performed at medical centers with special expertise in lung cancer screening and treatment. More recently, the National Comprehensive Cancer Network modified the recommendation to encompass a lower age limit and lower pack-year history, and stipulated that one risk factor be added.

The USPSTF has yet to weigh in on lung cancer, but new guidelines are expected in 2014. “Why should we care what USPSTF says? Money. If they recommend it, low-dose CT will be reimbursed with no copay,” Smith explained.

Summary

Nurses have an important role to play in advising patients about cancer screening. “Nurses need to know the research findings, the controversies, and the differences between guidelines. The more you know, the more you can teach patients. It is helpful to have copies of the guidelines on hand for patient discussions,” Smith advised.

Reference
Ebner J, Smith J. Cancer screening guidelines: clarity and controversy. Presented at: 38th Annual Congress of the Oncology Nursing Society; April 26, 2013; Washington, DC.

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