CANCER SCREENING Er Chaozer Department of General Medicine, Tan Tock Seng Hospital
Introduction Screening average risk patients Benefits and harms from screening Early cancer detection early treatment better prognosis Screening and confirmation test: pain (e.g. painful cervical smear), discomfort, complication (e.g. perforation of bowel from colonoscopy), time and cost False positive: anxiety, worry False negative: false reassurance Over-diagnosis A cancer that patient would have never even known/had symptom/died from Over treatment Informed and individualized decision Extreme age group (e.g. 80 years old), Significant comorbid (e.g. ESRD on HD, end stage COPD, CCF)
Introduction Colorectal cancer Lung cancer Prostate cancer Cervical cancer Breast cancer Ovarian cancer Endometrial cancer Various guidelines Singapore MOH Cancer Screening American Cancer Society (ACS) U.S. Preventive Services Task Force (USPSTF) American College of Physician (ACP) U.K. NHS Cancer Screening Program
Colorectal Cancer Screening 55-year-old Chinese gentleman visited you at the clinic. He saw on TV about colorectal cancer screening and asked if he should have it done. What would you do? A) Examine the abdomen + per rectum B) Faecal occult blood test C) Refer to the colorectal surgeon D) CT abdomen
Colorectal Cancer Screening method Faecal occult blood test (FOBT) : guaiac FOBT (gfobt) faecal immunochemical test (FIT): more sensitive, no dietary restriction, minimal stool handling Colonoscopy: gold standard, polypectomy at the same setting Risk of perforation and bleeding (<1%) Missed rate of large adenoma (>1cm): 6-12% Bowel preparation Flexible sigmoidoscopy Lower risk of perforation and bleeding Simpler bowel preparation Unable to examine proximal half of colon Better to combine with FOBT
Colorectal Cancer CT colonography (virtual colonoscopy) Minimally invasive Risk of cumulative radiation if used repetitively for surveillance Effective in detecting neoplasm >1cm Double contrast barium enema (DCBE) Instillation of barium and then distend colon with air via a catheter inserted into rectum Bowel preparation Stool DNA test May be more sensitive than FOBT Costly, lacks of standardized laboratory protocol, lack of data on appropriate screening intervals
Colorectal Cancer MOH Guideline 2010 Start screening from age of 50 FOBT annually Colonoscopy every 10 year CT colonography every 5 years DCBS: not preferred, can be done every 5 years Flexible sigmoidoscopy is better combined with FOBT, interval not advised American College of Gastroenterology (ACG) 2009 Start at age 50 Colonoscopy every 10 years as the preferred cancer prevention test If colonoscopy unavailable or patient prefers alternative: flexible sigmoidoscopy every 5-10 years, CT colonography every 5 years
Colorectal Cancer ACS and USMSTF (US Multi-society Task Force on Colorectal Cancer) 2008 Starts screening at age of 50 Flexible sigmoidoscopy every 5 years Colonoscopy every 10 years DCBE every 5 years CT colonography every 5 years FOBT annually Stool DNA test at unspecified interval USPSTF 2008 Screen age 50-75 Against screening age 76-85 Insufficient evidence to recommend CT colonography and stool DNA testing
Colorectal Cancer ACP (American College of Physician) 2012 Start screening at age 50 Stop screening when age >75 or life expectancy of <10 years Colonoscopy every 10 years Flexible sigmoidoscopy, DCBE or CT colonography every 5 years FOBT annually Stool DNA testing: uncertain NHS Bowel Cancer Screening Biennial FOBT from age 60-74/ age 50-74 in Scotland Colonoscopy at age of 55
Lung Cancer 60-year-old Chinese gentleman with COPD, DM and HTN, visited your clinic for routine follow up. He smokes 1 pack/day for the past 35 years. He asked if he needs lung cancer screening What would you do? A) Reassure him, no screening required B) CXR C) CT chest D) refer to respiratory physician
Lung Cancer Screening method: low dose CT chest MOH Guideline 2010 Does not recommend CXR or sputum cytology as lung cancer screening Does not recommend low dose CT chest outside clinical trial setting (National Lung Screening Trial was published in 2011) ACS 2013 Screen those 55 to 74 years old, in good health, have at least a 30 pack-year smoking history AND are either still smoking or have quit within the last 15 years with annual low dose CT chest (LDCT) Does not recommend screening people who are at average risk
Lung Cancer USPSTF 2014 Annual screening for lung cancer with LDCT in adults aged 55 to 80 years who have a 30 packyear smoking history and currently smoke or have quit smoking within the last 15 years Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery. American Association of Thoracic Surgery Annual LDCT in current and former smokers aged 55 to 79 years who have a 30 pack-year smoking history Annual LDCT at age 50-79 in patients who have a 20 pack-year smoking history and additional comorbid condition that produce a cumulative risk for cancer of at least 5% over the next 5 years Not included in the UK cancer screening program
Prostate Cancer A 45-year-old Chinese gentleman visited your clinic for a routine health check. He asked if PSA should be done for prostate cancer screening. What would you do? A) Check PSA B) Digital examination C) Digital examination + PSA D) Refer urology E) Reassure
Prostate Cancer Screening method: PSA with or without digital examination PSA is elevated in BPH, prostatitis, recent ejaculation and urinary retention PSA is lowered by 5 alpha reductase inhibitor Digital examination does not cause a clinically significant rise in PSA Over-diagnosis Over treatment Prostate surgery->incontinence, UTI, sexual dysfunction No change in mortality 1000 symptom-free men need to be screened for prostate cancer in order to save one additional life
Prostate Cancer MOH Guideline 2010 Lack of evidence to support population-based screening for early detection of prostate cancer. Men who are between 50-75 years of age, with an estimated life expectancy of more than 10 years, may be offered prostate cancer screening after a discussion of both the potential benefits and harms associated with cancer screening PSA annually but may be performed every 2 years in low risk men with baseline PSA <1 ng/ml
Prostate Cancer American Urological Association 2013, revised 2015 Shared decision making for men age 55 to 69 years that are considering PSA screening and proceeding based on a man s values and preferences. No routine PSA screening in men age 70+ years or any man with less than a 10-15 year life expectancy Routine screening interval of two years or more may be preferred over annual screening (reduce over-diagnosis and false positivity) American College of Physicians 2013 Inform men between age of 50 to 69 years about the limited potential benefits and substantial harms of prostate cancer screening Should not perform screening in patients who do not express a clear preference for screening Should not screen men <50 years old, >69 years old or men with life expectancy of <10-15 years
Prostate Cancer American College of Preventive Medicine 2015 Do not routinely perform PSA-based screening for prostate cancer. In rare circumstances, such as a strong family history of prostate cancer, screening may be appropriate USPSTF 2012 and American Academy of Family Physicians 2015 Against PSA based screening for prostate cancer in all age groups American Cancer Society 2010 Asymptomatic men with age >50 who have at least 10-year life expectancy should have an opportunity to make an informed decision with their physician Not included in the UK NHS cancer screening program
Cervical Cancer A 28-year-old Chinese lady came to your practice to ask for advice for cervical cancer screening. She is leading active sexual life. She has no history of cervical CA, cervical intraepithelial neoplasia (CIN) or immunocompromised disorder (e.g. HIV). She enquired about cervical cancer screening. What would you do? A) Pap smear yearly B) Per vagina yearly C) US pelvis D) Refer to the gynaecologist E) Reassure
Cervical Cancer Screening method: Cervical smear, co-testing (cervical smear + HPV DNA testing) MOH Guideline 2010 Screening starts from 25 years old Local data: 1.7% of CIN 3 from 1998-2002 aged <25 Cervical precursor lesions not likely to be detected until a few years after exposure Interval: every 3 years HPV DNA testing not recommended as trials were ongoing Stop at age of 69 if smear taken at 69 years old is negative and has had 2 consecutive negative smears within the last 10 year
Cervical Cancer
Cervical Cancer ACS/American Society for Colposcopy and Cervical Pathology/ American Society for Clinical Pathology Annual testing should not be performed Co-testing is preferred to cytology alone in women aged 30-65 (weak recommendation) American Congress of Obstetricians and Gynecologists (ACOG) Preferred co-testing as it improves detection of adenocarcinoma (20% of all cervical cancer) USPSTF Both strategies are acceptable Co-testing is not preferred and should be applied only to women who would like to extend intervals to every 5 years UK NHS Cervical Cancer Screening Program Pap smear every 3 years from age 25-49 Pap smear every 5 years from age 50-64
Woman s Cancer A 60-year-old Chinese lady visited your clinic for her BP review. She asked if she should go for woman s cancer (e.g. breast, ovarian and endometrial) screening? What would you do? A) Reassure her, no need screening B) Mammogram, US pelvis C) refer to gynaecologist D) Breast examination, pelvic examination
Breast Cancer Screening method: mammogram Clinical examination does not change mortality MOH Guideline 2010 Age 50-69: mammogram every 2 years Age 40-49: Women should be informed of the benefits, limitations and potential harms associated with screening mammography so that they can make an informed choice. If screening is to be performed, it should be done annually. Age 70-75: Singaporean women have lower incidence of breast cancer in this age group, screening mammography may be less beneficial and should be individualized by considering the potential benefits and risks of mammography in the context of current health status and estimated life expectancy. If individual screening is performed, it should be at two-yearly intervals. Age <40: do not screen
Breast Cancer USPSTF 2016 Age 50-74: biennial mammography Age 40-49: Women who place higher value on the potential benefit than the potential harms may choose to begin biennial screening Age>75: current evidence is insufficient to assess the benefits and harms of screening mammography in women aged 75 years or older ACS 2015 Women aged 45 to 54 years should be screened annually. Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually. Women should have the opportunity to begin annual screening between the ages of 40 and 44 years. Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer.
Breast Cancer UK NHS Breast Screening Program Mammogram every 3 years from age 50-70 Extends to age 47-73 in England Age>73: can do it voluntarily
Ovarian Cancer Screening method: tumour marker CA 125 or US pelvis MOH Guideline 2010 Screening women at average risk for epithelial ovarian cancer with serum markers and/or ultrasound is not recommended. No effective methods for routine screening of asymptomatic women at average risk for ovarian cancer. Screening is strongly discouraged as it may invariably lead to unnecessary interventions that ultimately risk the health and well-being of asymptomatic members of the general population USPSTF 2012 Do not screen for ovarian cancer in asymptomatic women without known genetic mutations that increase risk for ovarian cancer Not included in the UK NHS cancer screening program
Endometrial Cancer Screening method: transvaginal US, Pap smear is insensitive MOH 2010 Do not screen women with average or increased risk for endometrial cancer High risk patients like those with HNPCC (Hereditary non-polyposis colorectal cancer) should be offered annual screening with transvaginal US and endometrial biopsy by age 30-35 Insufficient evidence to establish whether a decrease in mortality from endometrial cancer occurs with screening by endometrial sampling or transvaginal ultrasound ACS 2001 HNPCC is the only association with sufficient risk to warrant routine screening. Women with or at risk for HNPCC should be offered screening annually by age 35 All menopausal women should be informed about the risks and symptoms of endometrial cancer No evidence to support the screening of asymptomatic women
Breast CA Biennial mammogram Lung CA >30 pack years Annual low dose CT Ovarian & Endometrial CA Not recommended Age =25 Age=50 Age=55 Age=100 Age Cervical CA PAP smear every 3 years Colorectal CA FOBT yearly Colonoscopy every 10 years CT colonography every 5 years Prostate CA Discuss with patient about risk/benefits
Conclusion Understand the limitations, benefits and harm of cancer screening Understand patient s wishes, belief and value Perform cost-effective, patient centered and individualized cancer screening UK NHS Cancer Screening http://www.nhs.uk/livewell/preventing-cancer/pages/cancer-screening.aspx American Cancer Society (ACS) https://www.cancer.org/health-care-professionals/american-cancer-society-prevention-early-detection-guidelines.html United States Preventive Service Task Force (USPSTF) https://www.uspreventiveservicestaskforce.org/browserec/index Ministry of Health (MOH), Singapore https://www.moh.gov.sg/content/moh_web/home/publications/guidelines/cpg/2010/cancer_screening.html American College of Physicians (ACP) https://www.acponline.org/clinical-information/guidelines