Wednesday, April 25, 2007
American Cancer Society Guidelines for the Early Detection of Cancer
American Cancer Society Guidelines for the Early Detection of Cancer Pt.5
At present, no organization recommends testing for early lung cancer detection in asymptomatic individuals at risk for lung cancer. However, the growth in the use of spiral computed tomography (CT) to test for early lung cancer detection in former and current smokers, as well as the more common use of chest x-ray, led the ACS to update its narrative about lung cancer testing in 2001 emphasizing the importance of informed decisions among individuals at risk who seek testing.2 The ACS historically has maintained that patients at high risk of lung cancer due to significant exposure to tobacco smoke or occupational exposures may decide to undergo testing for early lung cancer detection on an individual basis after consultation with their physicians.21
The circumstances leading to individual decision making are more challenging today because of growing evidence indicating a possible benefit from testing for early lung cancer detection with spiral CT22,23 and increased discussion of the potential benefits associated with early detection during media coverage of lung cancer diagnoses in well-known individuals.24 Favorable findings from investigations using low-dose helical CT for testing for early lung cancer detection25 led to a large prospective trial evaluating the relative efficacy of low-dose spiral CT versus chest radiography for the early detection of lung cancer in current and former smokers,26 as well as direct promotion to the public of spiral CT for early lung cancer detection. The NCI estimates that the trial may produce end results that could inform policy decisions as early as 2009.
In its narrative, the ACS emphasized the importance of informed decision making for individuals who elect to be tested for early lung cancer detection, and recommend that testing should be done only in experienced centers characterized by multidisciplinary specialty groups with experience in testing, diagnosis and follow-up. Current smokers should be informed that the more immediate preventive health priority is the elimination of tobacco use altogether, because smoking cessation offers the surest route at this time to reducing the risk of premature mortality from lung cancer.27
American Cancer Society Guidelines for the Early Detection of Cancer Pt.4
ACS guidelines for screening and surveillance for the early detection of adenomatous polyps and colorectal cancer were updated in 2001 (Table 1), and the recommendations for stool blood testing were modified in 2003 by adding fecal immunochemical tests.2,5 There are a number of options for colorectal screening, which may be chosen based on individual risk, personal preference, and access. The ACS recommends that average-risk adults begin colorectal cancer screening at age 50 years, with one of the following options: (1) annual fecal occult blood test (FOBT) or fecal immunochemical test (FIT); (2) flexible sigmoidoscopy every 5 years; (3) annual FOBT or FIT, plus flexible sigmoidoscopy every 5 years; (4) double contrast barium enema (DCBE) every 5 years; or (5) colonoscopy every 10 years. Other tests currently are being evaluated in experimental settings, and also available to a limited degree to the public, are stool DNA testing and computed tomography exams of the colon, also referred to as virtual colonoscopy. While not recommended at this time, the ACS is carefully monitoring the accumulation of evidence related to these tests.5
The ACS recommends more intensive surveillance for individuals at higher risk for colorectal cancer. Individuals at higher risk for colorectal cancer include individuals with a history of adenomatous polyps, individuals with a personal history of curative-intent resection of colorectal cancer, individuals with a family history of either colorectal cancer or colorectal adenomas diagnosed in a first-degree relative before age 60 years, or individuals at significantly higher-risk due to a history of inflammatory bowel disease of significant duration, or individuals at significantly higher-risk due to a family history or genetic testing indicating the presence of one of two hereditary syndromes, such as hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP).2 For these individuals, increased surveillance generally means a specific recommendation for colonoscopy, if available, and may include more frequent exams and beginning exams at an earlier age.2
Recently, several research reports revealed that there is reason to be concerned about the quality of FOBT testing in the United States. In the recent comparison of stool DNA testing with FOBT, Imperiale and colleagues observed that one-time FOBT testing using the take-home method was only 13% sensitive for cancer, with poorer performance in part attributable to in-office processing of test results.12 Further, in a study of veteran males reported earlier, Collins et al examined the performance of a single sample, in-office FOBT following digital rectal examination (DRE).13 The sensitivity for advanced neoplasia of a one time FOBT when done properly is very low,14 which is why there is a strong emphasis on the importance of annual testing for patients who chose to be screened for colorectal cancer with stool blood tests. Collins and colleagues observed that when procedure is done in the office following a rectal exam, the sensitivity for advanced neoplasia was only 4.9%.13 In an accompanying article in the same journal, Nadel et al reported on a national population-based survey of primary care providers, among which one-third reported that this was the only method of stool blood testing that they used, and an additional 41% reported using both the in-office and take home methods.15 These findings provide sobering evidence that millions of FOBTs done each year literally are worthless, and according to Sox in an accompanying editorial, provide at least indirect evidence for one reason that colorectal cancer mortality hasn’t dropped more despite the volume of stool blood testing.15,16
Many physicians take the opportunity to do FOBT with stool acquired during a DRE, having little confidence that the patient will complete the preferred at-home method. However, it is clear from this evidence that in-office testing for fecal occult blood not only is wasteful of time and resources, but a negative result also provides false reassurance to the patient. While convenient, one-sample FOBT for colorectal cancer screening with stool collected during a DRE is not recommended16 and has been discouraged in previous guidelines.2
Additional data from Nadel et al reveals further problems with stool blood testing, specifically that follow up of positive FOBTs commonly is inappropriate.15 Nearly one in three physicians surveyed reported repeating the FOBT if the first test was positive, and a higher percentage reported follow up with flexible sigmoidoscopy rather than colonoscopy. One third of adults in the National Health Interview Survey (NHIS) who reported having had a positive FOBT reported that they received no follow up.15
The findings on inappropriate testing with FOBT, as well as inappropriate follow up of a positive FOBT, indicate the need for a highly focused educational campaign to help clinicians understand that FOBT testing should follow manufacturer’s instructions, and that positive tests should be followed up with colonoscopy.
American Cancer Society Guidelines for the Early Detection of Cancer Pt.3
ACS guidelines for breast cancer screening were last updated in 2003 (Table 1).4 Guidelines for the early detection of breast cancer in average risk women emphasize a process that begins after a woman is 20 years of age and consist of a combination of clinical breast examination, counseling to raise awareness of breast symptoms, and regular mammography beginning at age 40.
Between the ages of 20 to 39 years, women should undergo clinical breast examination every 3 years, and annually after age 40 years. This exam should take place during periodic health examinations, and provides an opportunity for health care professionals to update a woman’s family history of breast cancer, discuss the importance of early breast cancer detection, discuss the importance of regular mammography after age 40 years, and answer any questions women may have about their own risk, new early detection technologies, or other matters relating to breast disease. During these discussions, health care professionals can play a key role in raising awareness about the importance of recognizing symptoms of breast cancer and developing a heightened awareness about breast changes. Although the ACS no longer recommends that all women conduct regular breast self-examination (BSE), women should be informed about the potential benefits, limitations, and harms associated with BSE. Women may then choose to do BSE regularly, occasionally, or not at all. If a woman chooses to perform periodic BSE, she can receive instructions in the technique and/or have her performance reviewed. The guidelines update in 2003 placed a strong emphasis on the health care professional’s role in raising and regularly reinforcing awareness about breast cancer, early breast cancer detection, the importance of prompt reporting of any new symptoms, and most important, regular screening with mammography after age 40 years.
The ACS recommends that average-risk women should begin annual mammography at the age of 40 years. Women also should be informed about the scientific evidence demonstrating the value of detecting breast cancer before symptoms develop, and the importance of adhering to a schedule of regular mammograms. Benefits include a reduction in the risk of dying from breast cancer, less aggressive therapy, and a greater range of treatment options. Women also should be told about the limitations of mammography, specifically that mammography will not detect all breast cancers, and some breast cancers detected with mammography may still have poor prognosis. Further, women should be informed about the potential harms associated with mammographic screening, including false positives, biopsy for abnormalities that prove to be benign, and the short period of anxiety that naturally would accompany a period where there was uncertainty about the presence of a malignancy.
There is no set age at which mammography screening should be discontinued. Rather, the ACS recommends that the decision to stop mammography screening should be individualized considering the potential benefits and risks of screening in the context of overall health status and anticipated longevity. As long as a woman is in good health and would be a candidate for breast cancer treatment, she should continue to be screened with mammography.
The 2003 update of the breast cancer screening guidelines also addressed issues related to screening high-risk groups. Although there is not sufficient data to recommend a specific surveillance strategy for high-risk women, including women younger than age 40 years at significantly elevated risk, the ACS guidelines state that women at significantly increased risk for breast cancer may benefit from earlier initiation of screening, screening at shorter intervals, and the screening with additional modalities such as ultrasound or magnetic resonance imaging.4 As noted above, an update of these recommendations for high risk women is currently underway.
In 2005, the first results of the Digital Mammographic Imaging Screening Trial (DMIST) were published.7 The goal of the study was to determine in a large prospective study whether digital technology improved diagnostic accuracy over screen film mammography. The study was conducted at 33 sites in the United States and Canada, and included 49,528 asymptomatic women who presented for screening mammography. Women who agreed to be in the study were screened for breast cancer with both digital and screen-film mammography, and the exams were interpreted independently by two radiologists. As part of the study, women were expected to return for an additional screening examination after 1 year, or if they received an examination at a nonparticipating site, to have the results sent to the study coordinator.
Previous studies comparing digital mammography to screen-film mammography have not found digital mammography to be significantly more accurate than screen-film mammography in the detection of breast cancer, although there was some suggestion that digital mammography offered advantages over screen-film mammography by reducing the proportion of women recalled for further evaluation for positive findings.8 This advantage primarily is due to the ability of digital technology to manipulate the contrast in the image, as well as magnify areas that warranted closer evaluation. In the first report of findings from the trial, Pisano et al reported that there was no overall difference in diagnostic accuracy between digital mammography and screen-film mammography in the entire study group, but that the accuracy of digital mammography was significantly better than screen-film mammography in three distinct subgroups of women–women under the age of 50 years, premenopausal or peri-menopausal women, and women with heterogeneously dense or extremely dense breasts on mammography examination.8 The authors concluded that the apparent advantage evident with digital mammography likely was due to the ability to take the fullest advantage of the available contrast through digital manipulation in subgroups of women with a higher prevalence of dense breast tissue, a circumstance that makes mammography more challenging and is associated with a higher rate of errors.
While the apparent implication of these findings is that younger women and women with dense breast tissue should chose digital mammography over screen-film mammography, a change in policy related to the application to specific technologies to specific groups of women faces unique challenges. First, and perhaps foremost, is the fact that digital mammography is not widely available. Second, there likely will be interest in seeing if these results can be duplicated in additional studies. Third, given the relative scarcity of digital mammography at this time, further clarification of the advantages of digital over screen-film in these three groups would provide greater guidance to policy makers, which are the advantages of digital over screen-film attributable mostly to age, density, or both? However, given the unique advantages of digital mammography over screen-film mammography in terms of electronic storage, teleradiology, and image manipulation, these findings suggest that both the technology and the ability to effectively use the technology is maturing and, over time, that it offer an improvement over conventional imaging for some groups of women.
American Cancer Society Guidelines for the Early Detection of Cancer Pt.2
Intoduction:
In 2000, the American Cancer Society (ACS) began a yearly report on its cancer detection guidelines, current issues related to screening and/or testing for the early detection of cancer, and updates on cancer screening rates.1 These annual reports provide a regular, yearly source for ACS guidelines related to cancer screening, or guidance to the public about testing for early detection for select cancers where mass screening is not recommended. The first report also included a description of the ACS process for the development or update of a cancer screening guideline.1
In 2001, the ACS published revisions in the early detection guidelines for colorectal cancer, endometrial cancer, and prostate cancer, and an updated narrative related to testing for early lung cancer detection.2 Guidelines for cervical cancer screening were most recently updated in 2002.3 In 2003, guidelines for the early detection of breast cancer were updated, and a technology update related to colorectal cancer screening also was published, resulting in the addition to immunochemical stool blood testing to the recommendations for colorectal cancer screening.4,5 The annual guideline reviews, as well as the more detailed guideline updates published as stand-alone articles, are available online at http://Caonline.AmCancerSoc.org.
At this time, several guidelines reviews and updates are in progress. The ACS is updating recommendations for the prevention and early detection of skin cancer, and conducting technology updates for (1) breast cancer screening in women at known or suspected inherited risk for breast cancer, and (2) testing stool for colorectal cancer. Furthermore, in the coming year we will publish an update on the recommendations for postpolypectomy and postcolorectal cancer resection follow up, which was done as a collaborative review with the U.S. Multisociety Task Force on Colorectal Cancer.6
American Cancer Society Guidelines for the Early Detection of Cancer Pt.1
Dr. Smith is Director of Cancer Screening, Cancer Control Science Department, American Cancer Society, Atlanta, GA.
Dr. Cokkinides is Program Director for Risk Factor Surveillance, Department of Epidemiology and Research Surveillance, American Cancer Society, Atlanta, GA.
Dr. Eyre is Executive Vice President for Research and Medical Affairs, American Cancer Society, Atlanta, GA, and Editor in Chief of CA.
Abstract:
Each January, the American Cancer Society (ACS) publishes a summary of its recommendations for early cancer detection, including guideline updates, emerging issues that are relevant to screening for cancer, and a summary of the most current data on cancer screening rates for US adults. In 2005, there were no updates to ACS guidelines. In this issue of the journal, we summarize the guidelines, discuss recent evidence and policy changes that have implications for cancer screening, and provide an update of the most recent data pertaining to participation rates in cancer screening by age, sex, and insurance status from the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System.
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