Criteria for screening • A good screening test must be available • COE shows satisfactory sensitivity and specificity • Dentists and other trained health care workers are able to detect lesions BUT criteria for a positive test (lesion) need to be established
Is screening for oral cancer feasible? Yes OPMD exist Dentists and health care workers are able to detect them
Do oral cancer screening programmes work?
Japan Only two significant studies of screening programmes India
Oral cancer screening studies in Japan Toru Nagao
Tokoname study Tokoname city Nagoya Aichi prefecture Los Angeles County Museum of Art Population: 52,058 Over 40 yrs : 26,856 (52%) Beckoning cat
Study design Period: 1995 to 1998 Objectives: to elucidate efficacy of mouth examination Method: by invitation Strategy: Annual screening as part of general health screening Subjects: 40 yrs and older 9,536 (36%) (male:32%, female:68%)(age:61 ± 11 yrs) Total number of examinations: 3,275 ( in 1995) 19,056 (in 1996-1998) (including repeat examinations) Examiners: Dentists (n=42) Calibration of screeners 1 week before
Programme processes in oral cancer screening in Tokoname study in Japan Community Primary Secondary Tertiary Level Level Level Level Hospital General health Pathology lab screening units - Sc + posi Free shuttle bus available OMS units 250 examinations per day Detection Diagnosis Treatment (1 st screening) (2 nd Exam)
Specialist vs. Screening diagnosis Screening diagnosis Specialist Lichen Cancer Leuko Erythro Total (M/F) Others Diagnosis planus Cancer 2 2 (2/0) Leukoplakia 1 27 6 3 37 (28/9) Erythroplakia 0 * Lichen planus 3 2 32 3 40 (9/31) Other 5 8 4 36 53 (27/26) Normal 2 2 1 5 (1/4) Total 8 40 2 44 43 137 (67/70) Sensitivity :0.92 (95% CI 0.86-0.98) Detected lesions confirmed by specialists: • 2 of 8 cancers (25%) PPV: 0.78 (95% CI 0.70-0.86) • 27 of 40 leukoplakias (68%) • 32 of 44 lichen planus (80%) • 36 of 43 benign lesions (84%) Nagao et al. Oral Oncol. 2000;36(4):340-6.
Compliance for secondary testing and detection rate in organized cancer screening Colorectal cancer Screening ( Fecal occult blood test) Referral for Colorectal 2 nd testing Examinees as Examinees 620 cancer Colon polyp 10,000 for (6%) 17 (0.17%) 2 nd testing 157 (1.6%) 419(68%) Breast cancer Screening (Mammography) Referral for 2 nd testing Breast Examinees as Examinees 750 cancer 10,000 for (8%) 2 nd testing 23 (0.23%) 662(88%) Oral cancer In 2013, Japan Cancer Society screening Referral for Examinees 2 nd testing Oral Examinees 105 10,000 OPMDs cancer for (1%) 2 nd testing 41 (0.4%) 1 (0.01%) 72(69%) Nagao T et al. J Med Screen, 2000;7(4):203-8.
Summary of the outcomes • Satisfactory participation can be obtained for annual oral cancer screening when this is coupled to a general health screening: this allows detection of new lesions including oral cancer and precancer • Those with risk habits (smoking and drinking) are likely not to show-up in subsequent years. • An attendance of 69% for re-examination by specialists compares well with other reported studies measuring patient compliance • The performance of the Japanese dentists employed in screening was satisfactory
Kannan Ranganathan
Gold standard: Randomised controlled trial with mortality as the end point India
KERALA STUDY Vakkom Anjuthengu Arabian Sea Kadakavoor Chirayinkil INDIA Kizhuvilam Azhoor Bay of Bengal Kerala Intervention Clusters T RIVANDRUM C ITY Mangalapura Kadinamkula Indian Ocean Pothencod m Control Clusters e m Andoorkonam Kannan Ranganathan Kazhakutta m Sreekariyam Attipra T RIVANDRUM C ITY
The Kerala screening studies 1. Sankaranarayanan R, Ramadas K, Thara S, Muwonge R, Thomas G, Anju G, Mathew B. Long term effect of visual screening on oral cancer incidence and mortality in a randomized trial in Kerala, India. Oral Oncol. 2013 Apr;49(4):314- 21. 2. Sankaranarayanan R, Ramadas K, Thomas G, Muwonge R, Thara S, Mathew B, RajanB. Trivandrum Oral Cancer Screening Study Group. Effect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial. Lancet. 2005 Jun 4-10;365(9475):1927-33. 3. Ramadas K, Sankaranarayanan R, Jacob BJ, Thomas G, Somanathan T, Mahe C, Pandey M, Abraham E, Najeeb S, Mathew B, Parkin DM, Nair MK. Interim results from a cluster randomized controlled oral cancer screening trial in Kerala, India. Oral Oncol. 2003 Sep;39(6):580-8. 4. Sankaranarayanan R, Mathew B, Jacob BJ, Thomas G, Somanathan T, Pisani P, Pandey M, Ramadas K, Najeeb K, Abraham E. Early findings from a community-based, cluster-randomized, controlled oral cancer screening trial in Kerala, India. The Trivandrum Oral Cancer Screening Study Group. Cancer. 2000 Feb 1;88(3):664-73. 5. Subramanian S, Sankaranarayanan R, Bapat B, Somanathan T, Thomas G, Mathew B, Vinoda J, Ramadas K. Cost- effectiveness of oral cancer screening: results from a cluster randomized controlled trial in India. Bull World Health Organ. 2009 Mar;87(3):200-6. 6. Pandey M, Thomas G, Somanathan T, Sankaranarayanan R, Abraham EK, Jacob BJ, Mathew B; Trivandrum Oral Cancer Screening Study Group. Evaluation of surgical excision of non-homogeneous oral leukoplakia in a screening intervention trial, Kerala, India. Oral Oncol. 2001 Jan;37(1):103-9. 7. Mathew B, Sankaranarayanan R, Sunilkumar KB, Kuruvila B, Pisani P, Nair MK. Reproducibility and validity of oral visual inspection by trained health workers in the detection of oral precancer and cancer. Br J Cancer. 1997;76(3):390- 4.
Kerala study • 13 districts randomised • 7 intervention • 6 control • Subjects over 35 years • Subjects screened by non-medical HWs • Oral examination • Positives referred to hospital • Health, habits and socioeconomic data recorded
13 clusters 13 districts Results at 114 601 population 114 601 population 9 years >35 years >35 years Intervention arm Control arm 96,517 95,356 87,655 (91.0%) screened 5,145 positives 6.55% 3,218 attended for referral 131 cancers 2,252 precancers Total cancers in population Total cancers in population 205 (43.7 per 100,000) 158 (37.6 per 100,000) 77/205 died 87/158 died 37.6% 55%
Kerala study – after 9 years Intervention Control Deaths 37.6 55.0 NS Survival (5yr) 50.0 34.0 P<0.01 Stage I & II 42.0 23.0 P<0.005 Mortality rate 16.4 20.7 NS
Kerala study – after 9 years Intervention Control Males Tobacco & Alchol: Mortality rate 24.6 42.9 P<0.01 Females Tobacco & Alchol: Mortality rate 39.9 50.7 NS
Conclusions at nine years • Oral visual screening can reduce mortality in high-risk individuals • This has the potential of preventing at least 37 000 oral cancer deaths worldwide ‘ Our findings support the routine use of oral visual screening in the reduction of oral cancer mortality in the high-risk group …... ’ Sankaranarayanan et al (2005) Effect of screening on oral cancer mortality in Kerala, India: a cluster- randomised controlled trial. Lancet, 365, 1927–33
13 clusters Results at All subjects 191,872 population 15 years >35 years 1996 - 2010 Intervention arm Control arm 96,517 95,356 88,822 screened 92% 5,586 (6.3%) positive 188 cancers 2,336 precancers Total cancers in population Total cancers in population 279 (37.1 per 100,000) 244 (30.8 per 100,000) 138/279 died 154/244 died 50% 63%
13 clusters Results at High Risk 84,942 population 15 years >35 years Group 1996 - 2010 Intervention arm Control arm 45,791 39,151 5,246 screened positive Total cancers in population Total cancers in population 254 (57.3 per 100,000) 232 (58.5 per 100,000) 129/254 died 147/232 died 51% 63%
Kerala study – after 15 years (1996 - 2010) Intervention Control Deaths 50% 63% NS Survival (5yr) 55.5 43.4 P=0.003 Survival (10yr) 48.3 30.6 P=0.003 Stage I & II 47.4 34.8 P=0.002 Mortality rate 15.4 17.1 NS Sankaranarayanan et al, Oral Oncology, 2013. 49:314-321
Kerala study – after 15 years Intervention Control Tobacco & Alchol: Deaths 51% 63% Mortality rate 30.0 39.0 P<0.05 Advanced cancers 54% 66% P<0.05 No Habits: Mortality rate 1.9 1.3 NS
Effect of compliance with screening Mortality (% reduction) n n Tob & All (%) (%) Alc 22,008 10,373 3 Rounds 38% 47% P<0.05 (23%) (23%) 19,228 8,163 4 Rounds 79% 81% P<0.05 (20%) (18%) Sankaranarayanan et al, Oral Oncology, 2013. 49:314-321
Kerala study – after 15 years (1996 - 2010) Summary: • “..a sustained reduction in oral cancer mortality …….. In high-risk individuals….after 15 years” • Overall 12.5% were screened positive • 59% of those attended follow up • Significant reduction in mortality in high-risk group (39% vs 30%) • BUT significant reduction in mortality & incidence ONLY in high-risk individuals attending 4 rounds • NO significant reduction in the total population Sankaranarayanan et al, Oral Oncology, 2013. 49:314-321
Kerala study – after 15 years (1996 - 2010) Summary: “….our findings support the routine use of oral visual screening to reduce oral cancer mortality among the high-risk group ……….. …..We recommend that dentists and general practitioners perform a careful visual oral examination in tobacco or alcohol users during routine clinical interactions …” Sankaranarayanan et al, Oral Oncology, 2013. 49:314-321
Kerala study – after 15 years (1996 - 2010) Summary: “….our findings support the routine use of oral visual screening to reduce oral cancer mortality among the high-risk group ……….. …..We recommend that dentists and general practitioners perform a careful visual oral examination in tobacco or alcohol users during routine clinical interactions …” Opportunistic screening in high-risk groups may work Sankaranarayanan et al, Oral Oncology, 2013. 49:314-321
Paul Speight
Oral Cancer Screening to screen or not to screen? Is oral cancer a screenable disease? Is screening for oral cancer feasible? Is screening for oral cancer cost-effective?
Cost-effectiveness • The Kerala study also calculated costs of screening. • Compared to no screening
Cost-effectiveness Costs * Incremental costs at 9 years From: Brocklehurst et al. Cochrane Systematic Review 2013.
Cost-effectiveness Costs * Incremental costs at 9 years From: Brocklehurst et al. Cochrane Systematic Review 2013.
Cost-effectiveness • The screening cost less than US$ 6 per case • The incremental cost per life-year saved was $835 • Fell to $156 if only high risk individuals were to be targeted.
“ This is the first clinical prospective study to show that opportunistic screening for oral cancer may be cost-effective.” Subramanian, S. , Sankaranarayanan, R., Bapat, B. et al (2009) Cost-effectiveness of oral cancer screening: results from a cluster randomized controlled trial in India. Bull World Health Organ, 87, 200–206
Is screening for oral cancer cost-effective in a developed, low prevalence, country? The cost-effectiveness of screening for oral cancer in primary care. Speight PM, Palmer S, Moles DR, Downer MC, Smith DH, Henriksson M, etal. Health Technology Assessment 2006;10(14):1–144.
A hypothetical model of oral cancer screening • Baysian simulation model • The outcome was determined for 100,000 individuals entered into a 1 year screening cycle • And for 100,000 individuals not screened (control) • Costs calculated from record review and published cost data • Outcome measured in QALYs • Prevalence data and sensitivity and specificity taken from previous pilot screening programmes
Computer simulation model of cost-effectiveness of screening for oral cancer & precancer Complex model, including estimates of probabilities of transition between disease states
Result of screening high-risk group: QALYs in unscreened population = 1992982 QALYs in screened population = 1993294 QALYs gained = 312 Equivalent to 15 lives saved
Results Incremental cost-effectiveness ratios • No screen £0 • Opportunistic high risk screen, GDP £18,919 • Opportunistic high risk screen, GMP £19,703 • Opportunistic population screen, GMP £21,623
What is a life worth? In USA: • $40,000 was the price agreed by legislation for mammography In UK • NIHCE has approved £20,000 - £30,000 These have become benchmarks for the worth of a health care intervention
Costs of screening programmes £ per QALY Breast cancer 80,000 Cervical cancer 300,000 Colon cancer 6,500 Oral cancer 18,500 Roberts et al, 1985; Lancet i, 89-91; Gray & Briggs, NSC 1998
Is screening for oral cancer cost- effective? Probably For opportunistic screening of high risk individuals but more research is needed
Omar Kujan
Evidence base for Oral cancer screening Systematic reviews Omar Kujan
2003 2006 2010 2013
• Review of RCTs of screening programmes for oral cancer or OPMD • Mortality as primary outcome • Secondary outcomes: – incidence – stage – Adverse effects – costs • No RCTs in any developed or low-prevalence countries • Only one study met the inclusion criteria
Kerala study: Ramadas K, Sankaranarayanan R, Jacob BJ, Thomas G,Somanathan T, Mahe C, et al. Interim results from a cluster randomized controlled oral cancer screening trial in Kerala, India. Oral Oncolgy 2003; 39(6):580–8. Sankaranarayanan R, Mathew B, Jacob BJ, Thomas G, Somanathan T, Pisani P, et al. Early findings from a community-based, cluster randomized, controlled oral cancer screening trial in Kerala, India. Cancer 2000; 88(3): 664–73. Sankaranarayanan R, Ramadas K, Thara S, Muwonge R, Thomas G, Anju G, et al. Long term effect of visual screening on oral cancer incidence and mortality in a randomized trial in Kerala, India. Oral Oncology 2013; 49 (4):314–21 Sankaranarayanan R, Ramadas K, Thomas G, Muwonge R, Thara S, Mathew B, et al. Effect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial. Lancet 2005; 365(9475):1927–33.
Conclusions: The evidence from the Kerala trial is that visual screening can reduce the mortality rate in users of tobacco, alcohol or both and can produce a stage shift. ………visual examination could be effective at reducing mortality rates for oral cancer when used within a targeted screening programme. …..but the risk of bias in the included study means that further well- designed randomised controlled trials are necessary to establish the validity of this relationship.
Conclusions: The results suggest that there is insufficient evidence to recommend a whole population screening programme for oral cancer. In the meantime, opportunistic visual screening by appropriately trained dentists and oral health practitioners is recommended for all patients and particularly for those who use tobacco, alcohol or both.
Summary and Conclusions Paul Speight
JADA: 2010;141: 509-520
“…….. defines “screening” as the process by which a practitioner evaluates an asymptomatic patient to determine if he or she is “likely” or “unlikely” to have a potentially malignant or malignant lesion.”
“…….. defines “screening” as the process by which a practitioner evaluates an asymptomatic patient to determine if he or she is “likely” or “unlikely” to have a potentially malignant or malignant lesion.” Conclusions: “……screening by means of visual and tactile examination in the general adult population intended to detect early and advanced oral cancers may not alter disease specific mortality .” “……. insufficient evidence to determine whether screening by means of visual and tactile examination to detect potentially malignant and malignant lesions alters disease-specific mortality .” “…..screening by means of visual and tactile examination may decrease oral cancer–specific mortality among people who use tobacco, alcohol or both.”
National Cancer Institute, USA:
National Cancer Institute, USA: Benefits There is inadequate evidence to establish whether screening would result in a decrease in mortality from oral cancer. Magnitude of Effect: No evidence of benefit or harm. Study Design: Evidence obtained from one randomized controlled trial. Internal Validity: Poor. Consistency: Not applicable (N/A). External Validity: Poor.
US Preventive Services Task Force The USPSTF….. …....found inadequate evidence that the oral screening examination accurately detects oral cancer. …….found inadequate evidence that screening for oral cancer and treatment of screen-detected oral cancer improves morbidity or mortality. …….concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for oral cancer in asymptomatic adults. http://www.uspreventiveservicestaskforce.org/Page/Document/ UpdateSummaryFinal/oral-cancer-screening1
UK National Screening Committee UK National Screening Committee. Criteria for appraising the viability, effectiveness and appropriateness of a screening programme. London, UK: National Screening Committee, 2003. Updated 2015: http://legacy.screening.nhs.uk/oralcancer
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