Effect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial

doi:10.1016/S0140-6736(05)66658-5

The Lancet

Volume 365, Issue 9475, 4–10 June 2005, Pages 1927-1933

https://doi.org/10.1016/S0140-6736(05)66658-5 Get rights and content

Summary

Background

Oral cancer is common in men from developing countries, and is increased by tobacco and alcohol use. We aimed to assess the effect of visual screening on oral cancer mortality in a cluster-randomised controlled trial in India.

Methods

Of the 13 clusters chosen for the study, seven were randomised to three rounds of oral visual inspection by trained health workers at 3-year intervals and six to a control group during 1996–2004, in Trivandrum district, Kerala, India. Healthy participants aged 35 years and older were eligible for the study. Screen-positive people were referred for clinical examination by doctors, biopsy, and treatment. Outcome measures were survival, case fatality, and oral cancer mortality. Oral cancer mortality in the study groups was analysed and compared by use of cluster analysis. Analysis was by intention to treat.

Findings

Of the 96 517 eligible participants in the intervention group, 87 655 (91%) were screened at least once, 53 312 (55%) twice, and 29 102 (30%) three times. Of the 5145 individuals who screened positive, 3218 (63%) complied with referral. 95 356 eligible participants in the control group received standard care. 205 oral cancer cases and 77 oral cancer deaths were recorded in the intervention group compared with 158 cases and 87 deaths in the control group (mortality rate ratio 0·79 [95% CI 0·51–1·22]). 70 oral cancer deaths took place in users of tobacco or alcohol, or both, in the intervention group, compared with 85 in controls (0·66 [0·45–0·95]). The mortality rate ratio was 0·57 (0·35–0·93) in male tobacco or alcohol users and 0·78 (0·43–1·42) in female users.

Interpretation:

Oral visual screening can reduce mortality in high-risk individuals and has the potential of preventing at least 37 000 oral cancer deaths worldwide.

Introduction

Oral cancer is common in men in developing countries.¹ There were 274 300 new cases and 145 500 deaths worldwide in 2002, of which two-thirds took place in developing countries.¹ Although the disease is largely preventable by individuals avoiding risk factors such as tobacco or alcohol use, a high rate of oral cancer has been recorded in the Indian subcontinent, central and eastern Europe, parts of France, southern Europe, South America, and Oceania.² Oral cancer is the most common form of cancer and of cancer-related death in men in India.1, 2 Its high risk in the Indian subcontinent is related to the popularity of pan-tobacco (a combination of betel leaf, lime, arecanut, and sun-cured tobacco) chewing in the region.³ A rising trend in oral cancer mortality has been recorded, especially in central and eastern Europe.⁴

Screening for oral cancer might be useful, because of the easily detectable precancerous lesions, early invasive cancers, and improved survival after treatment of early stage cancers. Visual inspection of the oral cavity is a simple, acceptable, and accurate screening test for oral neoplasia.5, 6, 7, 8, 9, 10 But will a visual, inspection-based screening programme lead to a substantial reduction in oral cancer mortality? We undertook a trial in 1996 to assess the efficacy of visual screening to reduce oral cancer mortality in a high-risk population in Kerala, India. This collaborative project was undertaken by the International Agency for Research on Cancer (IARC) of WHO and the Regional Cancer Centre (RCC).

Section snippets

Participants and procedures

Methods of this cluster-randomised trial have been described elsewhere.11, 12 Of the 13 clusters (panchayaths or municipal administrative units) in the Trivandrum district (Kerala, India) chosen for the study, seven were randomised to receive three rounds of oral visual screening by trained health workers at 3 year intervals, and six to a control group to receive standard care. The study protocol was reviewed and approved by the scientific and ethics review committees of the RCC and the IARC,

Results

Figure 1 shows the study profile with respect to eligible individuals, person-years, oral cancer incidence, and mortality rates, and figure 2 shows the same profile in people at high risk (ie, users of tobacco or alcohol, or both). Of all the eligible individuals, 87 829 (91%) in the intervention group and 80 086 (84%) in the control group were interviewed. The study groups were well balanced as indicated by the similar distribution of age, sex, religion, and socioeconomic status (table 1). The

Discussion

Our results showed that overall, the rate of oral cancer deaths in the intervention group (that was screening for cancer) was non-significantly lower than those in the control group, 9 years after initiation of screening. However, in users of tobacco or alcohol, or both, this value was significantly lower in the intervention group than in controls. Mortality rates were also reduced in users of tobacco or alcohol, or both, in the intervention group compared with controls, although this

References (26)

K Ramadas et al.
Interim results from a cluster randomized controlled oral cancer screening trial in Kerala, India
Oral Oncol
(2003)
J Ferlay et al.
GLOBOCAN 2002: cancer incidence, mortality and prevalence worldwide
(2004)
Betel-quid and areca-nut chewing and some areca-nut-derived nitrosamines
(2004)
C La Vecchia et al.
Trends in oral cancer mortality in Europe
Oral Oncol
(2004)
KAAS Warnakulasuriya et al.
Utilisation of primary care workers for early detection of oral cancer and precancer cases in Sri Lanka
Bull World Health Organ
(1984)
KAAS Warnakulasuriya et al.
Reproducibility of an oral cancer and precancer detection program using a primary health care model in Sri Lanka
Cancer Detect Prev
(1991)
FS Mehta et al.
Detection of oral cancer using basic health workers in an area of high oral cancer incidence in India
Cancer Detect Prev
(1986)
B Mathew et al.
Reproducibility and validity of oral visual inspection by trained health workers in the detection of oral precancer and cancer
Br J Cancer
(1997)
B Mathew et al.
Cancer screening by local volunteers
World Health Forum
(1996)

R Sankaranarayanan

Healthcare auxiliaries in the detection and prevention of oral cancer

Oral Oncol

(1997)

R Sankaranarayanan et al.

Early findings from a community based cluster randomised controlled oral cancer screening trial in Kerala, India

Cancer

(2000)

B Mathew

A guide for health workers on early detection of oral cancer

(1988)

Cited by (568)

A systematic review of artificial intelligence techniques for oral cancer detection
2024, Healthcare Analytics
Oral cancer is a form of cancer that develops in the tissue of an oral cavity. Detection at an early stage is necessary to prevent the mortality rate in cancer patients. Artificial intelligence (AI) techniques play a significant role in assisting with diagnosing oral cancer. The AI techniques provide better detection accuracy and help automate oral cancer detection. The study shows that AI has a wide range of algorithms and provides outcomes in the most precise manner possible. We provide an overview of different input types and apply an appropriate algorithm to detect oral cancer. We aim to provide an overview of various AI techniques that can be used to automate oral cancer detection and to analyze these techniques to improve the efficiency and accuracy of oral cancer screening. We provide a summary of various methods available for oral cancer detection. We cover different input image formats, their processing, and the need for segmentation and feature extraction. We further include a list of other conventional strategies. We focus on various AI techniques for detecting oral cancer, including deep learning, machine learning, fuzzy computing, data mining, and genetic algorithms, and evaluates their benefits and drawbacks. The larger part of the articles focused on deep learning (37%) methods, followed by machine learning (32%), genetic algorithms (12%), data mining techniques (10%), and fuzzy computing (9%) for oral cancer detection.
Screening of head neck cancer
2024, Oral Oncology Reports
The frequency of head and neck cancer (HNC) has surged on a global scale in recent times, leading to an escalation in both morbidity and mortality. Early detection and diagnostic technologies can prove highly beneficial. Cancer screening and awareness campaigns are also popular methods to promote cancer education and community outreach. Despite this, HNC does not garner as much attention in the general public's consciousness or the lay press as other tumors. Research indicates that systematic visual oral examinations can be used to screen asymptomatic individuals and detect the disease, since HNC is frequently preceded by a clinical premalignant phase that can be seen with the naked eye. A positive screening result will cover both oral cancer and potentially malignant diseases of the mouth.
Reported physical examination methods for screening of oral cancer and oral potentially malignant disorders: a systematic review
2024, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
This systematic review aimed to describe the method followed during physical examination and the anatomical structures of the head and neck assessed in screening for oral cancer and oral potentially malignant disorders (OPMDs).
An extensive literature search was carried out using MEDLINE/PubMed, EMBASE, Scopus, LILACS, Web of Science, Cochrane databases, and gray literature. The risk of bias was available in all papers included.
Of 9,688 records identified, 27 were included in this review, reporting data from 356,250 individuals screened and distributed across 11 countries. Most of these (n = 19) were based on 1 round of screening conducted by a dental professional or other health care workers. Most screening programs included visual inspection and palpation of the lips, oral cavity, and the most visible oropharyngeal sites, but the descriptions reported were imprecise. Additional inspection and palpation of the neck (submental, submandibular, cervical, and supraclavicular regions) to assess for the presence of swellings and any palpable neck nodes were also performed in 15 programs.
In conclusion, there was considerable heterogeneity in the method of physical examination in screening programs for oral cancer and OPMDs among the included studies.
The accuracy of asynchronous tele-screening for detecting dental caries in patient-captured mobile photos: A pilot study
2024, Saudi Dental Journal
Unaided visual inspection is a primary dental screening technique. Given the uneven distribution of dental services and prolonged waiting periods, an alternative screening approach is required to increase access to dental care. The purpose of this study was to evaluate the accuracy and reliability of tele-screening for detecting dental caries using mobile intra-oral photos taken by participants.
Dental care seekers attending Umm Al-Qura University Teaching Dental Hospital in 2022 were invited to participate in this study. The participants were initially examined by dental interns at the hospital under the supervision of faculty dentists (reference standard) before intra-oral photos were acquired by a trained sixth-year dental student using a Samsung S10 camera. Following an introduction to the photography guide, the same participants then took intra-oral photos of their teeth at home using their mobile devices, which were all uploaded to WhatsApp for later review. Two trained dental reviewers (sixth-year dental students) independently reviewed the intra-oral photos. Sensitivity, specificity, and Kappa scores were estimated to assess the performance of the tele-screening approach relative to the reference unaided dental examination.
Twenty-three participants, with a mean age of 30 ± 12 years, were enrolled. The mean decayed, missing, and filled teeth (DMFT) was 13.43 ± 5.48. Patient-delivered tele-screening demonstrated a sensitivity, specificity, and inter-rater reliability kappa of 94 %, 90 %, and 0.81, respectively, when compared to unaided dental examination. Dentist-delivered tele-screening approach demonstrated a sensitivity of 88–89 %, specificity of 88–91 %, and kappa score of 0.75–0.79 relative to unaided dental examination.
This study demonstrated that the tele-screening approach based on reviewing intra-oral photos taken by participants can be a valid and reliable alternative to unaided dental examination. This is important for ensuring sustainable access to dental care.
Task shifting to nonphysician health workers for improving access to care and treatment for cancer in low- and middle-income countries– a systematic review
2023, Research in Social and Administrative Pharmacy
Cancer is a complex global health issue overburdening health systems especially in low- and middle-income countries (LMICs). This burden is becoming more severe and complex as the global shortage of cancer care workforce persists. Since task shifting offers an alternative to address workforce shortages, a systematic review with the following research question was carried out: What is the scope of roles and tasks shifted to nonphysician health workers in improving access to cancer control services? The aim of this review is to critically identify, appraise and present evidence on how task shifting could be integrated and scaled to expand access to quality cancer control services in LMICs.
The aim of this review is to critically identify, appraise and present evidence on how task shifting could be integrated and scaled to expand access to quality cancer control services in LMICs.
Four databases were searched – CINAHL, EMBASE, MEDLINE and SCOPUS from inception to October 15, 2022, and included all studies that reported task shifting of cancer control services to nonphysician health workers. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines was followed to report the review process. Risk of bias was assessed using the National Heart, Lung, and Blood Institute quality assessment scale. The studies were summarized using narrative synthesis. A meta-analysis could not be carried out because the review only assessed the scope of roles that were shifted to nonphysician health workers and because of the heterogeneity in the characteristics of the studies included in the review.
The search identified 170 articles out of which 16 were included in the review. Three studies were randomized controlled trials, four were cluster randomized trials, while 9 were cross-sectional. Tasks were shifted to primary healthcare workers, nurses, and community health workers. Tasks shifted included screening, patient education, and diagnostic procedures. Evidence from the studies showed that the quality and effectiveness of tasks performed were comparable, and in some cases, better than usual care.
Findings showed that tasks in certain areas of cancer control services such as screening, education, and diagnosis can be shifted to nonphysician health workers and that it could be effective in improving access to certain cancer control services. Therefore, this review has shown that task shifting could be an effective strategy in addressing current workforce shortages in cancer care and that there is a need to examine the care required along the cancer continuum to better understand which interventions can most effectively be shifted to more advanced health professionals such as pharmacists to improve access to cancer control services in LMICs.
Cost-effectiveness of population-based screening for oral cancer in India: an economic modelling study
2023, The Lancet Regional Health - Southeast Asia
Oral cancer screening reduces mortality associated with oral cancer. The current study evaluated the cost-effectiveness of commonly used screening techniques, namely conventional oral examination (COE), toluidine blue staining (TBS), oral cytology (OC), and light-based detection (LBD) in the Indian scenario.
The study used a Markov modelling approach to estimate the cost and health outcomes of four different approaches (COE, TBS, OC, and LBD) for screening oral cancer over time from a societal perspective. The discount rate was assumed as 3%. The outcomes estimated were oral cancer incident cases, deaths averted, and quality-adjusted life years (QALYs). To address the high burden of risk factors (tobacco and/or alcohol) in India, two Markov models were developed: Model A adopted a mass-screening strategy, whereas Model B adopted a high-risk screening strategy versus no screening. Probabilistic sensitivity analysis (PSA) was undertaken to address any parameter uncertainty.
Mass-screening using LBD at three years had the least incident cases (3271.68) and averted the maximum number of oral cancer deaths (459.76). High-risk screening using COE at ten years interval incurred the least lifetime cost of 2,292,816.21 US$ (182,794,468.26 INR). The high-risk strategies (US$/QALY), namely COE 5 years (−29.21), COE 10 years (−90.68), TBS 10 years (−60.54), and LBD 10 years (−13.51), were dominant over no-screening.
The most cost-saving approach was the conventional oral examination at an interval of 10 years for oral screening in high-risk populations above 30 years of age.
Department of Health Research, Ministry of Health & Family Welfare, Government of India.

View all citing articles on Scopus

View full text

Fast track — ArticlesEffect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial

Summary

Background

Methods

Findings

Interpretation:

Introduction

Section snippets

Participants and procedures

Results

Discussion

Oral Oncol

GLOBOCAN 2002: cancer incidence, mortality and prevalence worldwide

Betel-quid and areca-nut chewing and some areca-nut-derived nitrosamines

Trends in oral cancer mortality in Europe

Oral Oncol

Utilisation of primary care workers for early detection of oral cancer and precancer cases in Sri Lanka

Bull World Health Organ

Reproducibility of an oral cancer and precancer detection program using a primary health care model in Sri Lanka

Cancer Detect Prev

Detection of oral cancer using basic health workers in an area of high oral cancer incidence in India

Cancer Detect Prev

Reproducibility and validity of oral visual inspection by trained health workers in the detection of oral precancer and cancer

Br J Cancer

Cancer screening by local volunteers

World Health Forum

Healthcare auxiliaries in the detection and prevention of oral cancer

Oral Oncol

Early findings from a community based cluster randomised controlled oral cancer screening trial in Kerala, India

Cancer

A guide for health workers on early detection of oral cancer

Fast track — Articles
Effect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial