Cancer screening final final


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Cancer screening final final

  1. 1. Cancer Screening In Women Evidence Base Medicine Khalid Sait (FRCSC) Prof. - Consultant Obstetrics and Gynecological Oncology KAUH, Jeddah, Saudi Arabia 0505693160
  2. 2. Outline Rational for screening Evaluation of screening tests Levels of evidence Screening for selected cancers
  3. 3. Screening a means of detecting disease early, in a symptomatic individuals
  4. 4. Characteristics of Diseases Well- suited for Screening Important public health problem Long, recognizable pre-symptomatic phase Available treatment, which is favorably affects its natural history Treatment is more effective in the pre- symptomatic phase A suitable screening test exists
  5. 5. Why Screen for Cancer? Outcome of cancer treatment is very dependent on the stage of the disease when diagnosis is made Goal Is to shift the extent of disease at diagnosis from advanced to early through the systematic examination of a symptomatic and symptomatic women
  6. 6. Scientific Basis Requirements that must be met for screening to be useful:  There must be a test or procedure that will detect cancers earlier  There must be evidence that treatment at an earlier stage of disease will result in an improved outcome Proof of benefit  Demonstration of a decrease in cause-specific mortality
  7. 7. Screening Tests Examinations, tests, or procedures are not diagnostic of cancer They indicate that a cancer may be present The diagnosis is then made following further tests that may include a biopsy and pathologic confirmation
  8. 8. Characteristics of a Good Screening Test Acceptable Inexpensive Widely available Safe Accurate
  9. 9. Accuracy of the Test? Reliability: Do you get the same results each time? Validity: Does the test measure what it says it's measuring? Sensitivity: If the disease is present, how often does the test detect it? Specificity: If the disease is absent, how often does the test give negative results?
  10. 10. Sensitivity Proportion of people with the disease who test positive in the screen  i.e., The ability of the test to detect disease when it is present Relatively independent of prevalence
  11. 11. Specificity Proportion of people who do not have the disease and test negative in the screen  (i.e., The ability of a test to tell that The disease is not present) Relatively independent of prevalence
  12. 12. Predictive Values Positive predictive value  Proportion of persons who test positive and have the disease Negative predictive value  Proportion of persons who test negative and do not have the disease Depends on prevalence of disease (Pretest probability)
  13. 13. Assessment of Screening Tests Best evidence to support the usefulness of screening: Randomized, controlled screening trial with cause-specific morality as the end-point - The group receiving the screening test has a better cause- specific morality rate than the control group Case control and cohort studies (Weaker Evidence) Reduction in the incidence of advanced-stage disease Improved survival Stage shift (to earlier stage)
  14. 14. Levels of Evidence Level 1: evidence obtained from at least one randomized controlled trial Level 2: evidence obtained from controlled trials without randomization Level 3: evidence obtained from cohort or case-control analytic studies, preferably from more than one center or research group Level 4: evidence obtained from multiple-time series with or without intervention Level 5: opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees
  15. 15. Breast Cancer Leading cause of cancer death in women Leading cause of death in women aged 40 to 45 Goal of screening is detection of early stage and in-situ disease that has better prognosis
  16. 16. Tools of Breast Cancer Screening 1. Mammogram 2. Breast self-examination 3. Clinical examination
  17. 17. Tools of Breast Cancer Screening 1. Mammogram Mammogram: major screening tool Mammogram is less sensitive in younger women It has lower positive predictive value in younger women Best supporting evidence
  18. 18. Tools of Breast Cancer Screening 2. Clinical examination Optimal technique? Sensitivity 55 to 60% Specificity 95% Abnormal exam. and a normal mammogram was associated with a cancer detection rate of 7.4 per 1000 records (555983 records) Supplement mammogram
  19. 19. Tools of Breast Cancer Screening 3. Breast self-examination No controlled data available Safe and free!
  20. 20. Recommendations of ACS(2004) 1. Monthly breast self-examination:  No longer recommended beginning at age of 20 years  Recommends that women should be informed about the potential benefits and limitations associated with BSE and that women may choose to do BSE regularly, occasionally , or not at all.  Education of symptoms 2. Clinical breast examination:  20 –39 years: every 3 years  40+ years: annual 3. Mammogram:  40+ years: annual
  21. 21. Recommendations of ACS(2004) High risk patients When to stop screening?
  22. 22. Cervical Cancer Squamous cell carcinoma of cervix strongly associated with persistent infection with certain subtypes of human papilloma virus (HPV) Development of invasive cancer is preceded by well-defined precancerous lesions Pap smear very effective in detecting precancerous lesions Pap smear relatively inexpensive and accepted by medical profession and (?) the public
  23. 23. Evidence of Benefit There has been a fall in the incidence and mortality from cervical cancer that followed the introduction of screening program Iceland: 80% reduction in mortality over 20 years Finland: 50% reduction Sweden: 34% reduction level of evidence 3, 4, 5
  24. 24. HPV DNA Testing with Cytology for the Screening of cervical Cancer and its precursor Lesions Not yet approved by FDA for screening Based on the available data, both published and unpublished , the ACS guideline review panel found this technology to be promising Should the FDA approve HPV DNA testing for this purpose , it would be reasonable to consider that for women aged 30 and over , as alternative to cervical cytology testing alone .
  25. 25. Recommendations of ACS(2004) Start three years after onset of vaginal intercourse, no later than age 21 years old then do it annually for convention pap and every two year for thin prep. after age of 30 pap can be done every three years in no risk women HIV patient: Twice a year after initial diagnosis then yearly if negative Once patient reach 70 years old and had no abnormal pap in previous 10 years pap test become unnecessary Not indicated for women who had total hysterectomy for benign disease
  26. 26. Colorectal Cancer 2nd leading cause of cancer death in US Most cases diagnosed after age 50 Goal of screening:  Detection and removal of polyps to prevent development of cancer  Detection of early stage disease
  27. 27. Tools of Colorectal Screening 1. Fecal occult blood detection 2. Endoscopy  Flexible sigmoidoscopy  Colonoscopy 3. Radiographic studies  Single contrast barium enema  Double contrast barium enema
  28. 28. Fecal Occult Blood (FOB) Usual source of blood  Cancer  Large polyp (> 2 cm)  Decreased the 13 years cumulative mortality by 33 %  Sensitivity 26 %  Specificity 95% Cost effective as the only test Level of evidence 1
  29. 29. Fecal Occult Blood (FOB) Recommendations for proper testing: Preparatory diet 3 serial specimens Avoidance of NSAID (except for low dose ASA for vascular disease) Single test during rectal exam not recommended
  30. 30. Flexible Sigmoidoscopy Less than half of colon examined Poorer performance than FOB or colonoscopy over 10 years Case control studies 60-80 % reduction in mortality with high sensitivity and specificity Yearly FOB and sigmoidoscopy every 5 years equivalent to colonoscopy every 10 years Level of evidence 3, 4, 5
  31. 31. Recommendation of ACS(2004) Age 50+ 1. Fecal occult blood every year OR 2. Flexible sigmoidoscopy every 5 years OR 3. Fecal occult blood every year and flexible sigmoidoscopy every 5 years OR 4. Double contrast barium enema every 5 years OR 5. Colonoscopy every 10 years starting at age 50
  32. 32. Recommendation of ACS(2004) Intensive surveillance for: 1- Person at increase risk due to history of adenomatous polyps 2- History of curative intent resection of colorectal cancer 3- History of colorectal cancer or adenoma diagnosed in first degree relative before age 60 years 4- History of long duration IBD 5- Patient at risk of hereditary syndrome
  33. 33. Epithelial Ovarian Cancer 26,000 new cases diagnosed each year, 14,000 die Incidence: 1.4:100000(age <40) 45:100000(age >60) Life time risk is 1:70 5 % are familial One 1st degree relative – 3 to 4% Two first degree relatives > 15%
  34. 34. Epithelial Ovarian Cancer No pre-malignant lesion and symptoms cannot be relied on to identify women with early disease but pt. With early stage are ass. With good prognosis) Little is know about natural history and rate of progression
  35. 35. Screening methods USS or CA 125 alone has too low PPV CA125 and USS regimens being studied Doppler Imaging
  36. 36. CA 125 Correlates with stage of disease Increase 90 % - Stage II,III,IV Increase 50 % - Stage I
  37. 37. CA 125 and Ovarian cancer Pre menopausal Post menopausal Sensitivity 84 % 50 % Specificity 69% 92 %
  38. 38. Color Doppler and Ovarian Cancer The new vasculature that arise in malignant contains less smooth muscle than its offer less resistant to blood flow (>0.4) this can measure as pulstil index of the vessels Vascular pattern Scoring system Sensitivity of 96 % and specifity of 98 %
  39. 39. Screening for ovarian cancer No adequate test Screening Not yet cost effective Difficult to no how often to screen Trials are under taken for general population as well as high risk group Data too limited to recommend, However BME and education of women should be done about symptom and signs
  40. 40. Endometrial Cancer 36,000 new cases diagnosed in USA each year , 6500 dies It is primarily a disease of the postmenopausal female( 25 % occurring in patients younger than 40 years of age )
  41. 41. Recommendation of ACS(2004) Women with average or mod. risk should be inform about risks and symptoms of endometrial cancer at the onset of menopause and strongly encourage to report any unexpected bleeding or spotting to physicians Very high risk patients: Annual screening begin at age 35 recommendation base on expert opinion in the absent of defentive scientific evidence , should also be informed about the benefit and risk and limitation of testing in endometrial cancer screening
  42. 42. Lung Cancer Leading cause of cancer death in women in US High case fatality Early randomized studies using chest X-ray, and sputum cytology in smokers were negative Recent data using low dose CT suggests a benefit. Data too limited to recommend
  43. 43. Other ACS Recommendations Cancer related check-up for 20+  20-39 every 3 years  40+ annually Examination of thyroid, lymph nodes, oral cavity and skin Health counseling about tobacco, sun exposure, diet, nutrition, risk factors, sexual practices and environmental and occupational exposures
  44. 44. Conclusions Guideline for cancer screening represent evidence – based strategies for reducing the morbidity and mortality rate associated with late – stage diagnosis of specific cancer.
  45. 45. Conclusions Three sectors in the society: 1- Health care system , which make cancer screening available to eligible populations 2- Health care providers, who should counsel patients about recommended cancer screening and assure that screening is performed in a timely manner 3- Individual, who should heed the recommendations made by public health agencies and their physician on screening and obtain recommended screening test and pursue follow up tests
  46. 46. Cancer Screening In Women Evidence Base Medicine Dr Khalid Sait (FRCSC) Ass. Prof. - Consultant Obstetrics and Gynecological oncology KAUH, Jeddah, Saudi Arabia 0505693160 Q & A Thank You