CANCER SCREENING John Brill M D MPH Malignancy
CANCER SCREENING John Brill, M D, MPH
Malignancy, A Brief History • Osteosarcomas found in dinosaur bones • Egyptian scroll written between 3000 -1500 BC referred to tumors of the breast • Hippocrates is credited with being the first to recognize the difference between benign and malignant tumors. The swollen blood vessels around the malignant tumors so reminded him of crab claws, he called the disease karkinos http: //www. rare-cancer. org/history-of-cancer. html
Malignancy, A Brief History • 1761, Giovanni Morgagni of Padua: first autopsies to relate the patient's illness to their pathologic findings. • 19 th century: Rudolf Virchow, often called the “founder of cellular pathology”, scientific basis for the modern pathologic study of cancer. • 19 th century English surgeon, Stephen Paget, theory on cancer growth referred to as the "seed and soil theory". • 1896 a German Physics Professor Wilhelm Conrad Roentgen used the term ‘X-ray’ http: //www. rare-cancer. org/history-of-cancer. html
What Makes a Cancer ‘Screenable’? • Pre-Malignant State • Effective Interventions • Screening Methods • Burden of Suffering • • Colon/Pancreas Testicular/Lung Cervix/Prostate Lung/Langerhan’s Cell Histiocytosis
Ideal Screening Test • Cheap • Sensitive • Specific • Accessible • Safe • Acceptable • • • Stool Cards/Colonoscopy PSA/Mammogram Colonoscopy/Breast SE Pap smear/Colonoscopy Stool Cards/Colonoscopy Skin exam/Barium enema
US Preventive Services Task Force Ratings • A. — The USPSTF strongly recommends that clinicians provide [the service] to eligible patients. Good evidence that [the service] improves important health outcomes; benefits substantially outweigh harms. • B. — The USPSTF recommends that clinicians provide [this service] to eligible patients. At least fair evidence that [the service] improves important health outcomes; benefits outweigh harms. • C. — The USPSTF makes no recommendation for or against routine • • provision of [the service]. At least fair evidence that [the service] can improve health outcomes but the balance of benefits and harms is too close to justify a general Recommendation. D. — The USPSTF recommends against routinely providing [the service] to asymptomatic patients. At least fair evidence that [the service] is ineffective or that harms outweigh benefits. I. — The USPSTF concludes that the evidence is insufficient to recommend for or against routinely providing [the service]. Evidence that the [service] is effective is lacking, of poor quality, or conflicting; balance of benefits and harms cannot be determined.
Primum non nocere • Examples of a ‘perfectly safe’ test (for $20!):
Brain Oral Cavity Lung Breast Liver Pancreas Uterus Blood Skin Stomach Colon Ovary Cervix
Brain Oral Cavity Lung Liver Pancreas Prostate Penis Blood Skin Stomach Colon Testes
Oral Cancer • USPSTF: evidence is insufficient to recommend for or against routine screening. Rating: I Recommendation. • Rationale: no good-quality evidence that screening leads to improved health outcomes for either high-risk adults (i. e. , those over the age of 50 who use tobacco) or for average-risk adults in the general population
Clinical Considerations • Direct inspection and palpation is the most commonly recommended method of screening • Little data on the sensitivity and specificity of this method. • Tobacco use in all forms is the biggest risk factor for oral cancer. Alcohol abuse combined with tobacco use increases risk. • Clinicians should be alert to the possibility of oral cancer when treating patients who use tobacco or alcohol.
Humphrey Bogart • Throat Cancer • He played in a number of films from the 30's to shortly before his death in 1957. He is fondly remembered for many rôles that he made his own: Rick in Casablanca, Sam Spade in The Maltese Falcon, Lt. Commander Queeg in The Caine Mutiny.
Skin Cancer • USPSTF: evidence is insufficient to recommend for or against routine screening for skin cancer using a total-body skin examination. Rating: I Recommendation. • Rationale: Evidence is lacking that skin examination by clinicians is effective in reducing mortality or morbidity from skin cancer.
Clinical Considerations • Benefits from screening are unproven, even in highrisk patients. • Fair-skinned aged >65, atypical moles, and >50 moles high risk • ‘Clinicians should remain alert for skin lesions with malignant features noted in the context of physical examinations performed for other purposes. ’ • Asymmetry, border irregularity, color variability, diameter >6 mm ("A, " "B, " "C, " "D"), or rapidly changing lesions Suspicious lesions should be biopsied.
Cybil Shephard • Born February 18, 1950 • Dated Elvis Presley • Played Maddie Hayes on Moonlighting (1985) and Martha Stewart (2005)
Lung Cancer • Evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer. Rating: I Recommendation • Rationale: Screening can detect lung cancer at an earlier stage but poor evidence that any screening decreases mortality. • Because of the invasive nature of diagnostic testing and the possibility of a high number of false-positive tests in certain populations, there is potential for significant harms from screening.
Gary Cooper Born: 7 May 1901 Birthplace: Helena, Montana Died: 13 May 1961 (lung cancer) Best Known As: Tall, laconic star of High Noon Started as an extra in westerns in the 1920 s and went on to become one of Hollywood's greatest stars, known for his Oscar-winning roles in Sergeant York (1941) and High Noon (1952).
Breast Cancer: 3 methods • Mammography • USPSTF recommends screening mammography, with or without clinical breast examination (CBE), every 1 -2 years for women aged 40 and older. Rating: B Recommendation
Mammography, cont • Evidence is strongest for women aged 50 -69 • 40 -49, the evidence is weaker and the absolute benefit is smaller, than it is for older women. • Most, but not all, studies: mortality benefit for women undergoing mammography at ages 40 -49
Mammography, cont • Absolute benefit is smaller among women in 40 s than it is among older women because the incidence is lower. • Evidence of benefit is also generalizable to women aged 70 and older if their life expectancy is not compromised by comorbid disease. • The balance of benefits and potential harms, therefore, grows more favorable as women age. • Not sufficient evidence to specify the optimal screening interval for women aged 40 -49
Clinical Breast Exam • Evidence is insufficient to recommend for or against routine CBE alone to screen for breast cancer. Rating: I Recommendation. • Rationale: No screening trial has examined CBE alone (without mammography) • USPSTF could not determine the benefits of CBE alone or the incremental benefit of adding CBE to mammography.
Breast Self-Exam • USPSTF: evidence is insufficient to recommend for or against teaching or performing routine breast selfexamination (BSE). Rating: I Recommendation. • Rationale: • Poor evidence that BSE reduces mortality. • Fair evidence that BSE is associated with an increased risk for biopsies.
Clinical Considerations • Women at increased risk for breast cancer (family history of breast cancer in a mother or sister, previous breast biopsy revealing atypical hyperplasia, or first childbirth after age 30) are more likely to benefit from regular mammography
Clinical Considerations cont • In the trials that demonstrated effectiveness, mammography was done every 12 -33 months. • For women aged 50 and older, little evidence that annual mammography is more effective than every other year. • For women aged 40 -49, also no clear advantage of annual mammography over biennial mammography. • Nevertheless, some experts recommend annual mammography based on the lower sensitivity of the test and on evidence that tumors grow more rapidly in this 40 -49 age group.
Clinical Considerations cont • Age at which to discontinue screening mammography is uncertain. • Older women face a higher probability of developing and dying from • breast cancer but also have a greater chance of dying from other causes. Women with comorbid conditions that limit their life expectancy are unlikely to benefit from screening. • Clinical Considerations cont • USPSTF did not examine whether women should be screened for genetic mutations (e. g. , BRCA 1 and BRCA 2) • Clinicians who advise women to perform BSE or who perform routine CBE should understand that there is currently insufficient evidence that these practices affect breast cancer mortality, and that they are likely to increase the incidence of clinical assessments and biopsies.
Rachel Carson • One of the most influential women in the history of science. With the publication of her best-selling book, Silent Spring, she singlehandedly launched the American and global environmental movements. The bitterest irony of all is that she may herself have been a victim of environmental toxins. Two years after the publication of Silent Spring on April 14, 1964 , she died of breast cancer. While writing the book, she had undergone a radical mastectomy and radiation treatment.
Sandra Day O’Connor • First female Supreme Court Justice. She went public about her ordeal with breast cancer six years after her diagnosis in 1988 when she spoke at a meeting of the National Coalition for Cancer Survivorship. Not slowed by her illness, she returned to the bench just five days after her mastectomy.
Colorectal Cancer • The USPSTF strongly recommends that clinicians screen men and women 50 years of age or older for colorectal cancer. Rating: A Recommendation • Rationale: fair to good evidence that several screening methods reduce mortality from colorectal cancer
Methods • Good evidence that periodic fecal occult blood testing (FOBT) • • reduces mortality Fair evidence that sigmoidoscopy alone or in combination with FOBT reduces mortality. No direct evidence that screening colonoscopy reduces CRC mortality; efficacy of colonoscopy is supported by its integral role in trials of FOBT, extrapolation from sigmoidoscopy studies, limited case-control evidence, and the ability of colonoscopy to inspect the proximal colon. Double-contrast barium enema less sensitive than colonoscopy; no direct evidence that it is effective in reducing mortality. Insufficient evidence that newer screening technologies (eg, computed tomographic colography) are effective
Methods • There are insufficient data to determine which strategy is best. • Colorectal cancer screening is likely to be costeffective (less than $30, 000 per additional year of life gained) regardless of the strategy chosen. • Unclear whether increased accuracy of colonoscopy offsets the procedure's additional complications, inconvenience, and costs.
Ovarian Cancer • USPSTF recommends against routine screening for ovarian cancer. Rating: D Recommendation • Rationale: Fair evidence that screening with serum CA-125 level or transvaginal ultrasound can detect ovarian cancer at an earlier stage but fair evidence that earlier detection would likely have a small effect, at best, on mortality • Because of low prevalence of ovarian cancer and the invasive nature of diagnostic testing after a positive screen, there is fair evidence that screening could likely lead to important harms.
Prostate • Evidence is insufficient to recommend for or against routine screening for prostate cancer using prostate specific antigen (PSA) testing or digital rectal examination (DRE). Rating: I Recommendation. • Rationale: good evidence that PSA screening can detect early-stage prostate cancer but mixed and inconclusive evidence that early detection improves health outcomes. • Screening is associated with important harms, including frequent false-positive results and unnecessary anxiety, biopsies, and potential complications of treatment of some cancers that may never have affected a patient's health.
Bill Bixby Actor, 1934 - 1993 • Died of Prostate Cancer • Best known as TV’s Incredible Hulk
Colin Powell • Secretary of State under George W. Bush
Testicular Cancer • USPSTF recommends against routine screening for testicular cancer in asymptomatic adolescent and adult males. Rating: D Recommendation. • Rationale: no evidence that screening with clinical examination or testicular selfexamination reduces mortality • Even in the absence of screening, the current treatment interventions provide very favorable health outcomes.
How good did you learn?
Which of the following cancers receives an “A” screening recommendation from the UWPSTF? A. B. C. D. Colorectal Lung Breast Prostate
The USPSTF concludes that there is insufficient evidence to recommend for or against screening for all of the following cancers EXCEPT: A. Lung B. Prostate C. Testicular D. Oral
The only method for breast cancer screening for which there is evidence of benefit is: A. Self-Breast Exam B. Clinical Breast Exam C. Breast Exam by overly-excited teenage boy D. Mammogram
You are seeing a 50 -year old actress with a 40 pack-year smoking history. She demands to be checked for ‘every cancer known to man. ’ Based on USPSFT data, you could make a rational argument for screening her for all of the following except: A. Lung Cancer B. Oral Cancer C. Ovarian Cancer D. Breast Cancer
References http: //www. ahrq. gov/clinic/uspstfix. htm
- Slides: 41