Cancer Screening in Primary Care
USPSTF Grade D Recommendations for Cervical Cancer Screening
- Against screening in women < age 21 years - Against screening with HPV testing in women age <30 years - Against screening in women > 65 years who have had adequate prior screening and are not otherwise at high risk for cervical cancer. - Against screening in women w/ TAH, w/removal of the cervix and who do not have a history of a high-grade precancerous lesion (i.e., cervical intraepithelial neoplasia [CIN] grade 2 or 3) or cervical cancer.
Cervical Cancer- USPSTF:
- Begin 3 years after onset of sexual activity but no later than age 21 - Pap smear for women ages 21 to 65 years every 3 years Or - Women ages 30 to 65 years, a combination of cytology and human papillomavirus (HPV) testing every 5 years - Grade A High Risk Groups - History of cervical cancer - In utero exposure to diethylstilbestrol (DES) *Same recommendations as average risk - HIV, immunocompromised Test twice during first year after diagnosis and then annually The American Cancer Society cervical cancer screening guidelines state that women should begin screening approximately three years after she begins having vaginal intercourse, but no later than 21 years of age. Screening should be done every year with regular Pap tests or every two years using liquid-based tests. At or after age 30, women who have had three normal tests in a row may get screened every 2-3 years. Women 70 and older who have had three or more consecutive normal Pap tests in the last 10 years may choose to stop cervical cancer screening.
Causes of Death in U.S.: 2016
- Heart disease: 614,348 - Cancer: 591,699 - Chronic lower respiratory diseases: 147,101 - Accidents (unintentional injuries): 136,053 - Stroke (cerebrovascular diseases): 133,103 - Alzheimer's disease: 93,541 - Diabetes: 76,488 - Influenza and Pneumonia: 55,227 - Nephritis, nephrotic syndrome: 48,146 - Suicide: 42,773
Who decides?
- Multiple groups make recommendations for cancer screening - US Preventative Services Task Force - American Cancer Society - Multiple other Disease-Specific Groups Insurance plan coverage of preventive services is variable
HPV Vaccines
- Two vaccines—Cervarix and Gardasil—are available to prevent the HPV types that cause most cervical cancers and anal cancers. - One of the HPV vaccines, Gardasil, prevents cervical, vulvar and vaginal cancers in women and genital warts in both women and men. - Only Gardasil has been tested and licensed for use in males - Both vaccines are given in a series of 3 shots over 6 months - 2009 44% of US adolescents had been vaccinated - Side effects- mostly pain at injection site, fever, malaise, no reports of mental retardation
Chemoprevention
- Use of natural or synthetic agents to decrease the chances of cancer (like statins to decrease the risk of stroke) - Anti-inflammatory agents - Antioxidants - Hormone antagonists*
Breast Cancer - USPSTF:
1) The USPSTF recommends against routine screening mammography in women aged 40 to 49 years. The decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient's values regarding specific benefits and harms. This is a "C" level recommendation. 2) The USPSTF recommends biennial screening mammography for women aged 50 to 74 years. This is a "B" recommendation. 3) The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of screening mammography in women 75 years or older. This is an "I" statement. 4) The USPSTF recommends against teaching breast self-examination This is a "D" recommendation.
Statistics and Epidemiology
A total of 100 patients are screened for cancer using a newly developed test with the following results: 8 results are truly positive 1 result is falsely positive 1 result is falsely negative 90 results are truly negative What is the positive predictive value of this new test? Which bias affects studies of cancer screening and makes randomized clinical trials for mortality crucial to assess cancer screening tests? Recall bias Length Bias Lead Time Bias Volunteer Bias Lead Time Bias makes it appear that patients live longer with their diagnosis though this may have nothing to do with the test
PSA Guidelines:
ACS Screening Guidelines: (w/ or without the DRE) If PSA <2.5ng/mL, screen every 2 years If PSA >2.5ng/mL, yearly screening If PSA >4.0ng/mL, refer If PSA 2.5-4.0ng/mL, risk assessment before referral
Risk Factors for Cancer (in order of priority)
Advancing age **** Smoking & other forms of tobacco Alcohol consumption Sun exposure Obesity Infectious diseases: (Hep B, HPV, HIV, H. pylori) Family history of cancer Cancer is a disease of advancing age. The incidence of cancer shown here increases sharply after age 35-40increased with age.
Colorectal Cancer- USPSTF
Age 50 to 75, average risk men and women should follow one of the following examination schedules: - 3 fecal occult blood tests or 1 fecal IHC test every year - Flexible sigmoidoscopy (FSIG) every five years - Annual fecal occult blood test and flexible sigmoidoscopy every 5 years: Combined testing is preferred over either annual FOBT or FSIG every 5 years alone - A double-contrast barium enema every 5 years - A colonoscopy every 10 years (Grade A) CT colonography: Insufficient Evidence (ACS says every 5 years) - Fecal DNA testing: Insufficient Evidence Recommends against screening between the ages of 76-85 (Grade C) or over age 85 (Grade D) ------------ The American Cancer Society recommends that beginning at age 50, men and women should receive a fecal occult blood test (FOBT) every year, or a flexible sigmoidoscopy (FSIG) every five years, or an annual FOBT and FSIG every five years (preferred to either method alone), or a double-contrast barium enema every five years, or a colonoscopy every ten years. The five year tests are less sensitive as screening tools.
The Cancer-Related Check-Up: Is there Such a Entity?
All periodic encounters with clinicians offer potential for health counseling, cancer screening, and case finding. These encounters should include the performance or referral for conventional cancer screening tests as appropriate by age and gender, but such visits also are an opportunity for case-finding examinations of the thyroid, testicles, ovaries, lymph nodes, oral region, and skin. Self-examination techniques or an increased awareness of the signs and symptoms of skin cancer, breast cancer, or testicular cancer can be discussed (though not officially recommended). Include guidance on smoking cessation, diet, physical activity, and shared decision making about cancer screening, or testing for early cancer detection for cancer sites at which population-based screening is not yet recommended. In the past the ACS recommended a "cancer-related checkup" as a stand-alone examination, they now stress that the occasion of a general periodic health examination provides a good opportunity to address examinations and counseling that could lead to the prevention and early detection of cancer. ACS, 2010
Case 1 A 50 year old man is evaluated during a routine examination that includes a discussion of health maintenance issues. He has no family history of colorectal cancer and refuses colonoscopy due to insurance issues. He is willing to consider alternatives and will undergo colonoscopy if something is found on other testing. What other options can you discuss with him?
Annual fecal occult blood testing Sigmoidoscopy every 5 years (especially when combined with occult blood testing) ACS would also support double contrast barium enema every 5 years
Lung Cancer- USPSTF:
Annual screening for lung cancer with low-dose computed tomography (LDCT) in persons at high risk for lung cancer based on age and smoking history 55 to 80 years old 30 pack year history Smoke currently or in the last 15 years Grade B Recommendation
FYI
Breast cancer incidence rates in women have been relatively stable since 2004, after decreasing 7% from 2002 to 2003, primarily due to a reduction in use of hormone replacement therapy. Lung cancer rates have recently begun to decline after increasing for several decades. Differences in the lung cancer pattern between men and women reflect later smoking uptake and slower cessation among women. Colorectal cancer incidence rates have been declining since the mid-1980s. In contrast, incidence rates are increasing for liver and thyroid cancers and for melanoma.
Screening Recommendations
Colorectal Cervical Breast Prostate Lung Others Skin, Pancreas, Oral, Testicular, Thyroid
Case 3 A 68 year old man is examined during a routine evaluation. He has a 5 pack year smoking history but quit 12 years ago. His only medical problem is hyperlipidemia which is well-controlled. He has not noted any changes in his bowel habits and his last colonoscopy was at age 60 and had no abnormalities. Is there any cancer screening that should be discussed with the patient at this visit?
Colorectal cancer- he is up to date with his colonoscopy for another 2 years Lung Cancer- his low usage does not qualify him for low dose CT scan Prostate- you can discuss PSA testing with him if not done previously
Prostate Cancer- ACS:
Counseling regarding the prostate-specific antigen (PSA) test and the digital rectal examination (DRE) should be offered annually, beginning at age 50, to men who have a life expectancy of at least 10 years. Men at high risk (African-American men (45) and men with a strong family history of one or more first-degree relatives diagnosed with prostate cancer at an early age (40)) should begin this discussion at age 40 - 45. PSA is more sensitive than DRE (4.0 mcg/l cut-off) Men ages 50 - 70 most likely to benefit from screening and early diagnosis. Benefits are smaller for Asian and Hispanic-American men Overdiagnosis and aggressive Rx of subclinical disease has lead to "watchful waiting" approach to results
Changing the Pattern of Disease
Decrease Incidence --> Prevention strategies!! Decrease Deaths --> Screening --> Increase treatment options
Case 2 A 57 year old man is evaluated on routine examination. His only medical issue with hypertension managed with HCTZ. He has no family history of cancer but has a friend with prostate cancer and asks you about screening him. Do you order a PSA?
Discuss the risks and benefits of PSA testing with the patient His life expectancy is at least 10 years and therefore he may derive some benefit
Why the Controversy?
Experts disagree on whether women of average risk benefit from screening between the ages of 40 and 49 - Meta-analysis showed no benefit in this groups after 5-7 years, but a benefit in 10-14 years - Multiple false positives and unnecessary biopsies - 18% reduction in mortality when ages 40-49 are included in the screening, but the number needed to screen to obtain this benefit is similar to the number of false positives
Screening
Goals of Screening: - Some types of cancer can be found before they cause symptoms - Checking for cancer (or for conditions that may lead to cancer) in people who have no symptoms is called screening - Screening can help find and treat some types of cancer early For a screening test to be effective it must: - Detect cancer earlier than it normally would be found - Have evidence that early diagnosis results in improved outcomes. just because there are tests to screen for cancer doesnt mean we should use it if there is no evidence that it will help a patient ...Lead Time Bias: survival from the time of diagnosis to death looks increased, not because the treatment prolonged life, but because it was found earlier
HPV Testing
HPV DNA testing: - Inform patient that HPV infection is not usually detectable or harmful. There > 40 HPVs that can infect the cervix. Types 16 & 18 account for 70 % of cervical cancers - HPV infection is very common, almost everyone who has had sexual intercourse has been exposed to HPV - Not considered a sexually transmitted disease - A positive HPV test, does not indicate cancer, the majority of woman with an HPV infection will not develop advanced cervical neoplasia. Most HPV infections clear over time If it was abnormal, but then goes back to normal, you will return to the screening
Breast Cancer Screening
High Risk Groups - With known BRCA mutation - Unknown mutation and first-degree relative with a BRCA mutation or woman with 20-25% or greater lifetime risk of breast cancer based on the Gail Risk Prediction Model - Other Risk Models available to estimate risk by analyzing the family history of patients with first or second-degree relatives with breast cancer but did not have genetic testing (Claus, Tyrer-Cuzick, BRCAPRO, Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm models) - Prior chest radiation for Hodgkins disease Annual screening mammography and MRI starting at age 30
Colorectal Cancer
Higher-risk Individuals: - History of adenomatous polyps - History of CR (colorectal) surgery - Family history of CRC or adenomas dx in first-degree relative, based on age at dx (start screening 10 years younger than the age at diagnosis for the relative). So if your father was dx at 50yrs you need to start at 40 yrs - Inflammatory Bowel Disease - Hereditary Syndromes: nonpolyposis or adenomatous polyposis People at moderate or high risk for colorectal cancer may benefit from colonoscopy and/or genetic counseling. These patients should do screening more frequently or genetic counseling more frequently, but it is case by case basis.
Epidemiology
Incidence: newly diagnosed cases per year Prevalence: how many people are alive total that year with that diagnosis (reflects how long one lives with the diagnosis and the effectiveness of a therapy) Sensitivity: the probability of testing positive, if the disease is truly present. Specificity: the probability of testing negative, if the disease is truly absent. Ideal population-based screening test will have high sensitivity AND high specificity (i.e. true positives and true negatives)
Prevention Strategies
Obesity Both BMI and dietary choices may contribute to cancer risk For example: fruit and vegetable consumption may protect against cancers of the mouth and pharynx, esophagus, lung, stomach, and colon and rectum Obesity has increased dramatically in the last twenty years. Mississippi has the highest percentage of obese adults, 34.9 %, followed by other twelve states with percentages higher than 30%. The American Cancer Society recommends that individuals eat five or more servings of vegetables and fruits a day for cancer prevention. Fruit and vegetable consumption may protect against cancers of the mouth and pharynx, esophagus, lung, stomach, and colon and rectum. However, there has been little improvement in consumption since the mid-1990s. Less than one in four adults was eating the recommended servings in 2005.
Other Cancers
Ovarian PLCO trial of 78,000 women showed no difference in mortality using Ca-125 and transvaginal US screening September 7th, 2016 the FDA released a statement specifically stating that clinicians should not recommend the use of ovarian cancer screening tests "Despite extensive research and published studies, there are currently no screening tests for ovarian cancer that are sensitive enough to reliably screen for (the cancer) without a high number of inaccurate results." Endometrial Cancer Insufficient evidence for screening average risk women Oral Cavity Insufficient evidence, though annual dental exams are a form of screening Bladder Cancer Recommend against screening with cytology Skin Cancer Self examination may be helpful, insufficient evidence for other methods Pancreatic Cancer Inconclusive; evidence using K-ras mutation in stool and endoscopic ultrasounds is unclear as of yet Testicular Cancer No evidence that self examination or physical exam improves outcome
Predictive Value of Screening Tests ...goes one step beyond the sensitivity and specificity
Positive Predictive Value: - The likelihood that you have condition if the test results are positive - Calculated as: true positives / all positives - What proportion of patients who test positive will actually have the disease? Negative Predictive Value The likelihood of you not having disease if test is negative Calculated as: true negatives / all negatives What proportion of the patients who test negative will actually not have the disease?
Why the controversy?
Prostate Cancer is often slow-growing Some prostate cancer is not life threatening- 40% of cancers found with screening would never have caused harm Treatment is associated with significant adverse effects Randomized controlled trials have not resolved uncertainties regarding the value of early screening Informed Decision is inconsistently implemented in practice
Prostate Cancer- USPSTF:
Recommends against Routine PSA testing Prostate cancer is a serious health problem that affects thousands of men and their families. But before getting a PSA test, all men deserve to know what the science tells us about PSA screening: there is a very small potential benefit and significant potential harms. We encourage clinicians to consider this evidence and not screen their patients with a PSA test unless the individual being screened understands what is known about PSA screening and makes the personal decision that even a small possibility of benefit outweighs the known risk of harms." —USPSTF Co-Chair Michael LeFevre, M.D., M.S.P.H., May 22, 2012 Grade: D Recommendation
Mandelblatt, J. et al. Ann Intern Med. 2009;151:738-747. www.annals.org
Screening biennially from ages 50 to 69 years achieved a median 16.5% reduction in breast cancer deaths versus no screening. An "Every-other-year mammogram" schedule starting at age 40 (instead of age 50) reduced mortality only by an additional 3% , but consumed more resources, and yielded more false-positive results. Biennial screening after age 69 years yielded some additional mortality reduction in all models, but overdiagnosis of BC increased most substantially at older ages. Limitation: Results do not include morbidity from false-positive results, patient knowledge of earlier diagnosis, or unnecessary treatment. Conclusion: Biennial screening achieves most of the benefit of annual screening with less harm. Decisions about the best strategy depend on program and individual objectives and the weight placed on benefits, harms, and resource considerations
Incidence and Prevalence Data
Sources of Cancer Statistics - Pathology Reports - Medicare Billing - Cancer Registries (Hospital, State, Federal) - SEER: Surveillance, Epidemiology and End Results, part of NCI - Cancer Facts and Figures: published annually by CDC and NCI* this is all collected state-wide and nationally
Evidence for Lung Cancer Screening
The National Lung Screening Trial (10 year study), the largest RCT to date with over 50,000 patients, enrolled participants ages 55 to 74 years, who at the time of randomization had a tobacco use history of at least 30 pack-years and, if former smokers, had quit within the past 15 years. Benefit to CT screening in high risk based on age and those with pack yr history of at least 30 years. Smaller RCTs from Europe had different eligibility criteria and have not yet duplicated the findings of NLST; therefore, only moderate certainty exists about the magnitude of benefit from screening. Modeling evidence suggests that an annual screening program starting at age 55 years and ending at age 80 years (among current or former smokers with a 30 pack-year smoking history and <15 years since quitting) resulted in approximately 50% of lung cancer cases detected at an early stage. This screening protocol would result in a 14% reduction in lung cancer mortality, (est. 521/100,000 lung cancer deaths prevented) population. The associated harms are 4% overdiagnosis rate and radiation-induced lung cancer deaths of less than 1%.
USPSTF US (Preventative Services Task Force)
The USPSTF is an independent panel of non-Federal experts in prevention and evidence-based medicine and is composed of primary care providers (such as internists, pediatricians, family physicians, gynecologists/obstetricians, nurses, and health behavior specialists). The USPSTF conducts scientific evidence reviews of a broad range of clinical preventive health care services (such as screening, counseling, and preventive medications). USPSTF develops recommendations for primary care clinicians and health systems as "Recommendation Statements." Supported by AHRQ's Prevention and Care Management Portfolio (administrative, research, technical, and dissemination support). http://www.ahrq.gov/professionals/clinicians-providers/guidelines-recommendations/guide
FYI
This slide shows trends in cancer incidence rates for all sites combined from 1975 to 2011. The current cancer incidence rate (averaged during 2007-2011) is 22% lower in women than in men. The reasons for this are not well understood, but likely reflect differences in environmental and hormonal exposures. During the most recent 5 years of data, rates declined slightly in men and were stable in women. The decrease among men is attributed mainly to declines in prostate, lung, and colorectal cancers. SEER 9 represents approximately 9% of the US population and is the only source for long-term (since 1975) population-based incidence data.
Prevention Strategies
Tobacco: Smoking Cessation Programs Alcohol: AA, reduction in daily consumption Sun Exposure: SPF 15, Hats, Avoidance Obesity: weight loss, increased activity, diet Infectious Diseases: Hep B Vaccine, HPV Vaccine, H. pylori treatment, HIV prevention Tobacco: Approximately 18% of the world's population, 1 billion men and 250 million women smoke. Use of tobacco is expected to increase in low income countries and to decrease in high income countries Between 2002 and 2030, tobacco attributable deaths are projected to decline by 9% in high-income countries but are expected to double from 3.4 to 6.8 million in low and middle income countries
Rating Scale of Evidence
U.S. Preventive Services Task Force reviews studies and publishes recommendations and ratings based on the strength of the evidence and magnitude of the benefit minus harm. 5 CATEGORIES OF RECOMMENDATIONS: A = Strongly recommends providing screening to eligible patients B = Recommends providing the screening C = Makes no recommendations regarding screening (risk: benefit ratio equivocal) D = Recommends against routine screening (not effective or perhaps harmful) I = Evidence is insufficient to make a recommendation. don't have evidence one way or another
usually the insurance companies use the guidelines from...
US Preventative Services Taskforce
FYI The PSA bump
When prostate cancer screenings started to be performed! We SAW new cancers and documented them. Its not that there was more cancer, just that there was more KNOWN cancer.
Trends in Recent* Flexible Sigmoidoscopy or Colonoscopy Prevalence (%), by Educational Attainment and Health Insurance Status, Adults 50 Years and Older, US, 1997-2004
While there has been a downward trend during recent years in the use of FOBT, the prevalence of flexible sigmoidoscopy (FSIG) or colonoscopy increased from 1999 to 2004. Adults with less than a high school education were less likely to report FSIG or colonoscopy than all adults. Even more striking is that the prevalence for adults with no health insurance is approximately 26 percentage points lower than the prevalence for all adults. Continuing efforts are needed to address health system barriers to colon cancer screening, to encourage health care practitioners to promote screening to their patients, and to raise awareness among eligible adults about the importance of getting screened for CRC.
Breast Cancer- ACS
Women ages 40 to 44 should have the choice to start annual breast cancer screening with mammograms if they wish to do so. Women ages 45 to 54 should get mammograms yearly. Women age 55 and older should switch to mammograms every 2 years, or have the choice to continued annually. Screening should continue as long as a woman is in good health with a 10 year life expectancy. Screening MRI is recommended for women with an approximately 20% - 25% or greater lifetime risk of breast cancer (based on Risk Models), including women with a strong family history of breast or ovarian cancer and women who were treated for Hodgkin's Disease. Women at increased risk (e.g., family history, genetic tendency, past breast cancer) may start mammography screening earlier, or breast ultrasound and MRI. ---------------- The American Cancer Society states that women aged 40 and older should have an annual mammogram and clinical breast exam (CBE) as part of a periodic health exam. Women should know how their breasts normally feel and report any changes to their health care provider. A breast self-examination (BSE) is an option for women starting in their 20s.
What to tell patients:
Women also should be informed of the scientific evidence demonstrating the value of detecting breast cancer before symptoms develop, and that the balance of benefits to possible harms strongly supports the value of screening and the importance of adhering to a schedule of regular mammograms. The benefits of mammography include a reduction in the risk of dying from breast cancer and, if breast cancer is detected early, less aggressive surgery (ie, lumpectomy vs mastectomy), less aggressive adjuvant 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 that some breast cancers detected with mammography may still have poor prognosis. Furthermore, women should be informed about the potential harms associated with mammographic screening, including false-positive results, and the possibility of undergoing a biopsy for abnormalities that prove to be benign.
the goal of screening is to
reduce the number of deaths from cancer, not necessarily to reduce the number of cases.
Cigarette smoking disproportionately affects the health of people with low SES and education
smoke free.gov is a good tool for smoking cessation
...Lead Time Bias:
survival from the time of diagnosis to death looks increased, not because the treatment prolonged life, but because it was found earlier
