Page 43 Complete Your CE Test Online - Click Here assigned participants to one of two ways of detecting lung cancer: low-dose helical computed tomography (CT), also called spiral CT, and standard chest X-ray. Helical CT uses X-rays to obtain a multiple-image scan of the entire chest. A standard chest X-ray produces a single image of the whole chest in which anatomic structures overlie one another. Each participant had three annual exams with either helical CT or chest X-ray. The NLST had more than 53,000 US participants aged 55 to 74 who had smoked at least 30 pack-years but who were otherwise fairly healthy and had no signs, symptoms, or history of lung cancer. (Pack-years are calculated by multiplying the average number of packs of cigarettes smoked per day by the number of years a person has smoked.) The study findings revealed that participants who received low-dose helical CT scans had a 15% to 20% lower risk of dying from lung cancer than participants who received standard chest X-rays. This is equivalent to approximately 3 fewer deaths per 1,000 people screened in the CT group compared to the chest X-ray group over a period of about seven years of observation (17.6 per 1,000 in the CT group versus 20.7 per 1,000 in the chest X-ray group). On average over the three rounds of screening exams, 24.2% of the low-dose helical CT screens were positive and 6.9% of the chest X-rays were positive. In both arms of the trial, the majority of positive screens led to additional tests whether or not cancer was found. Adenocarcinomas and squamous cell carcinomas were detected more frequently at the earliest stage by low-dose helical CT compared to chest X-ray. Small cell lung cancers, which are very aggressive, were infrequently detected at early stages by low-dose helical CT or chest X-ray. Low-dose helical computed tomography to screen for lung cancer has been shown to reduce lung cancer deaths among current or former heavy smokers ages 55 to 74. Inclusion criteria more or less match those of the National Lung Screening Trial (NLST). In 2013, both the American Cancer Society (ACS) and the U.S. Preventive Services Task Force (USPSTF) made official recommendations to screen adults within the age range of the NLST who had a 30 pack-year history of smoking who still smoked or had quit within the previous 15 years. The USPSTF recommendations allow screening as late as age 80, although the ACS limits it to age 74 as in the original study. The USPSTF says that low-dose spiral CT should be stopped once the person has not smoked for 15 years or develops a health problem that limits life expectancy or the capacity to have lobectomy for lung cancer. Because the research to date has not yet addressed the potential for overdiagnosis and overtreatment, the possibility that this might occur is very real when screening for lung cancer with CT. Breast cancer screening for women 40 and older Mammography Screening mammograms are used to check for breast cancer in asymptomatic women, and usually involve two X-ray views of each breast. The X-ray images make it possible to detect tumors that are too small to be palpated. Screening mammograms can also find microcalcifications (tiny arrays of calcium deposits) that sometimes indicate the presence of breast cancer. Evidence-based practice! Asking patients what they have heard about mammography can help nurses address concerns. Mammographic screening for breast cancer has been shown to reduce mortality from the disease among women ages 40 to 74, especially those aged 50 or older. For asymptomatic women of average risk, the American Cancer Society (ACS) strongly recommends starting annual mammography at age 45, observing that the years of life gained through mammography screening are very similar between the ages of 45 and 49 to those gained between ages 50 and 54. Women age 45 to 54 should be screened annually and should transition to biennial screening at age 55 or opt to continue with annual screenings. The ACS recommends that mammography screening should continue until a woman is in poor health or has a life expectancy of less than 10 years rather than selecting a specific age to stop screening. The ACS further recommends that all women be familiar with the potential benefits, limitations, and harms of mammography. The ACS allows for women who value the potential benefit over potential risk to start screening at age 40, and for them to switch to biennial screening at age 55 or maintain an annual schedule with informed consent. The ACS has expressed concern about screening women who have serious or terminal health conditions, which still seems to be common practice, because of the low likelihood of improving life expectancy or other outcomes and possibility for potential harms. This recommendation is somewhat different from the U.S. Preventive Services Task Force, which recommends biennial mammography for asymptomatic women of average risk starting at age 50 and continuing through age 74. However, they are also careful to include the possibility that women may elect to begin as early as age 40 if they value the potential benefits more than they are concerned over potential harms. They further note that there is insufficient evidence of benefit in screening women aged 75 and older. Women at higher risk The American Cancer Society has an extra guidance for women at higher risk for breast cancer, recommending the addition of annual breast MRI (along with annual mammography) for women who have any of these factors that increase risk for breast cancer: ● ● BRCA gene mutation (personally or in a first-degree relative if the patient has not been tested). ● ● History of radiation therapy to the chest between ages 10 and 30. ● ● Cowden syndrome or Bannayan-Riley-Ruvalcaba syndrome (these two related genetic conditions are mutations in the PTEN gene and may be called PTEN hamartoma tumor syndrome) or Li-Fraumeni syndrome (personally or in a first-degree relative if the patient has not been tested). ● ● Lifetime breast cancer risk of 20% to 25% using models (such as the Claus model) that calculate breast cancer risk largely based on family history. The ACS recommends against MRI screening in women whose lifetime breast cancer risk is calculated to be less than 15%. The ACS further says that there is insufficient evidence to recommend for or against MRI screening for women who have had breast cancer, ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), or atypical ductal or lobular hyperplasia (ADH or ALH) and for women with dense breast tissue as seen on a mammogram. When following these recommendations, there is no particular mention of newer forms of mammography, which may have advantages. Digital mammography stores images as computer files, which allows for closer examination of suspicious areas without always necessitating the patient return for more X-rays. Digital screening has higher sensitivity in women with dense breasts and makes records easier to share. Three- dimensional (3D) mammography, also known as breast tomosynthesis, is a type of digital mammography in which X-ray machines are used to take pictures of thin slices of the breast from different angles, and computer software is used to reconstruct a 3-dimensional image. It is generally performed at the same time as standard mammography, with a slightly higher radiation dose. This has not been compared with 2D mammography in randomized studies, so researchers do not know if it is better or worse at avoiding false-positives or finding early cancers. Implants and mammography Women with breast implants should have mammograms on the same schedule as other women. A woman who had an implant following a mastectomy should ask her surgeon whether a mammogram of the reconstructed breast is necessary, as it might be if any breast tissue was left behind. It is important to let the mammography facility know about breast implants when scheduling a mammogram. The technician and radiologist must be experienced in performing mammography on women with breast implants. Implants can hide some breast tissue, making it more difficult for the radiologist to detect an abnormality on