Adult Preventive Health care

Explanation
Key Concept/Objective: To recognize that guidelines are established by expert panels charged with using available evidence to create explicit recommendations that are easy to follow in clinical practice

To avoid errors in judging the evidence and weighing benefi ts and harms, expert panels, as well as individual clinicians, should do the following: (1) use an independent systematic review to distinguish assertions based on evidence from those based on other grounds, (2) make the rationale for a recommendation explicit, and (3) be free from fi nancial and political confl icts of interest. Although the use of these measures does not guarantee a correct decision, they represent the best safeguards against bias. The USPSTF assigns an overall grade to each prevention service that refl ects the overall strength of evidence and the magnitude of benefit.

Explanation
Key Concept/Objective: To recognize that only two cancer screenings contain a grade A recommendation from the USPSTF, colon cancer screening and cervical cancer screening

Only two cancer screening tests meet the USPSTF criteria for a strong recommendation: (1) Papanicolaou (Pap) smears for cervical cancer and (2) fecal occult blood testing or endoscopic procedures for colorectal cancer. With both of these conditions, the aim of screening is to remove precancerous lesions, which prevents invasive cancer, saves the involved organ, and reduces disease-specifi c mortality. By contrast, the more controversial cancer screening tests, such as PSA and mammography, detect invasive cancers and lead to aggressive treatments (prostatectomy and mastectomy) that often destroy the involved organ and that have more substantial
morbidity than cone biopsy for cervical cancer and polypectomy for colorectal cancer.

Explanation
Key Concept/Objective: To understand that in breast cancer screening, false positives are common and to recall that there is no proven all-cause mortality benefi t to screening

In the trials, which involved nearly half a million women, mammography clearly had no effect on all-cause mortality. The USPSTF, although fully aware of this fact, chose to base their assessment of the benefi ts on the narrower grounds of breast cancer mortality. They chose to let women decide for themselves whether reducing the risk of dying of breast cancer was important to them. Judging from the trials, about 1,200 women 40 to 70 years of age must be invited to be screened four to fi ve times over 10 years to prevent one death from breast cancer. Of women 40 to 49 years of age, 1,792 (95% confi dence interval 764 to 10,540) must be invited to be screened to prevent one death from breast cancer. Women who get 10 annual mammograms have about a 50% chance that at least one of them is a false positive result; many of these false positive results necessitate a biopsy.

Explanation
Key Concept/Objective: To realize the confl icting information regarding prostate cancer screening in men < 75 and to understand that screening for men > 75 is not recommended

The USPSTF concluded that evidence was insuffi cient to recommend for or against prostate cancer screening in men younger than 75 years; the USPSTF recommends against screening for prostate cancer in men age 75 years or older. This conclusion was based on the following considerations: (1) there are no completed randomized, controlled trials of screening, although studies are ongoing in the United States and in Europe; (2) although prostate cancer is a major cause of cancer death in men, many cases are clinically indolent (in autopsy studies, the prevalence of histologic prostate cancer in men older than 50 years is about 30%, but only 3% of men die of prostate cancer); (3) the value of treatment for the localized cancers targeted by screening is unknown; the one randomized, controlled trial of radical prostatectomy, which found no improvement in the 15-year survival rates of patients undergoing surgery, has been criticized for methodological problems (another randomized, controlled trial comparing expectant management with radical prostatectomy for the treatment of localized cancer is under way); (4) aggressive treatments for localized disease are associated with signifi cant morbidity; and (5) mortality from prostate cancer has not declined in the United States despite 15 years of widespread use of PSA testing.

Explanation
Key Concept/Objective: To recognize that not all cancers have available screening tests, usually due to uncertain benefit and to the morbidity of diagnosis and treatment

The USPSTF recommended against screening for bladder, ovarian, pancreatic, and testicular cancers. In each case, the deciding factor was that screening and treatment caused serious, immediate harms, whereas evidence of a benefi t was inconclusive. As with mammography for breast cancer, screening for these cancers is aimed at detection of early invasive disease, and treatment has substantial morbidity. This degree of morbidity is in contrast to that associated with screening for colonic polyps or cervical dysplasia,for which treatment is relatively safe and is aimed at preserving, rather than removing, the involved organ.