Global burden of oral cancer in 2022 attributable to smokeless tobacco and areca nut consumption: a population attributable fraction analysis.

BACKGROUND: Consuming products that contain smokeless tobacco or areca nut increases the risk of oral cancer. We aimed to estimate the burden of oral cancer attributable to smokeless tobacco or areca nut consumption globally and by type of smokeless tobacco or areca nut product in four major consuming countries. METHODS: We calculated population attributable fractions (PAFs) using prevalence of current use of smokeless tobacco or areca nut products from national surveys and corresponding risks of oral cancer from the literature. We applied PAFs to national estimates of oral cancer incidence in 2022 from the Global Cancer Observatory's Cancer Today database to obtain cases attributable to smokeless tobacco or areca nut consumption. We modelled 95% uncertainty intervals (UIs) using Monte Carlo simulations. FINDINGS: Globally, an estimated 120 200 (95% UI 115 300-124 300) cases of oral cancer diagnosed in 2022 were attributable to smokeless tobacco or areca nut consumption, accounting for 30·8% (95% UI 29·6-31·9) of all oral cancer cases (120 200 of 389 800). An estimated 77% of attributable cases were among male patients (92 600 cases, 95% UI 88 000-96 500) and 23% were among female patients (27 600 cases, 26 000-29 000). Regions with the highest PAFs were Melanesia, Micronesia, and Polynesia (78·6%, 95% UI 74·4-80·5), southcentral Asia (57·5%, 54·8-59·5), and southeastern Asia (19·8%, 19·0-20·6). Lower-middle-income countries represented 90·2% of the world total attributable cases (108 400 cases, 95% UI 103 400-112 200). INTERPRETATION: Our findings suggest that one in three cases of oral cancer globally are attributable to smokeless tobacco or areca nut consumption, and could be prevented through smokeless tobacco and areca nut control. Global cancer control efforts must incorporate further measures to reduce smokeless tobacco and areca nut consumption in populations with the largest attributable burden. FUNDING: French National Cancer Institute.

An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles.

OBJECTIVE: New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers. DESIGN: A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles. RESULTS: Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence. CONCLUSION: New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact.

Perspective on oral cancer screening: Time for implementation research and beyond.

Screening aims to detect cancer in asymptomatic populations. In oral cancer, clinical oral examination is the current standard method for screening. Oral cancer screening may be performed by a physician or a healthcare workers and is an affordable and feasible method. There is some evidence that this low-cost method is effective in decreasing mortality from oral cancer in high risk population. The cluster-randomised trial in India that had 15 years of follow-up reported an 81 % mortality reduction in high-risk populations of tobacco and/or alcohol users who adhered to four screening rounds. The observational studies similarly reported 21-22 % reduction in advanced oral cancer and 24-26 % reduction in oral cancer mortality among high risk population. Implementation and evaluation of oral cancer screening programmes in high risk population will support the goals of the World Health Organisation on global oral health.

Global estimates of incidence and mortality of cervical cancer in 2020: a baseline analysis of the WHO Global Cervical Cancer Elimination Initiative.

BACKGROUND: Tracking progress and providing timely evidence is a fundamental step forward for countries to remain aligned with the targets set by WHO to eliminate cervical cancer as a public health problem (ie, to reduce the incidence of the disease below a threshold of 4 cases per 100 000 women-years). We aimed to assess the extent of global inequalities in cervical cancer incidence and mortality, based on The Global Cancer Observatory (GLOBOCAN) 2020 estimates, including geographical and socioeconomic development, and temporal aspects. METHODS: For this analysis, we used the GLOBOCAN 2020 database to estimate the age-specific and age-standardised incidence and mortality rates of cervical cancer per 100 000 women-years for 185 countries or territories aggregated across the 20 UN-defined world regions, and by four-tier levels of the Human Development Index (HDI). Time trends (1988-2017) in incidence were extracted from the Cancer Incidence in Five Continents (CI5) plus database. Mortality estimates were obtained using the most recent national vital registration data from WHO. FINDINGS: Globally in 2020, there were an estimated 604 127 cervical cancer cases and 341 831 deaths, with a corresponding age-standardised incidence of 13·3 cases per 100 000 women-years (95% CI 13·3-13·3) and mortality rate of 7·2 deaths per 100 000 women-years (95% CI 7·2-7·3). Cervical cancer incidence ranged from 2·2 (1·9-2·4) in Iraq to 84·6 (74·8-94·3) in Eswatini. Mortality rates ranged from 1·0 (0·8-1·2) in Switzerland to 55·7 (47·7-63·7) in Eswatini. Age-standardised incidence was highest in Malawi (67·9 [95% CI 65·7 -70·1]) and Zambia (65·5 [63·0-67·9]) in Africa, Bolivia (36·6 [35·0-38·2]) and Paraguay (34·1 [32·1-36·1]) in Latin America, Maldives (24·5 [17·0-32·0]) and Indonesia (24·4 [24·2-24·7]) in Asia, and Fiji (29·8 [24·7-35·0]) and Papua New Guinea (29·2 [27·3-31·0]) in Melanesia. A clear socioeconomic gradient exists in cervical cancer, with decreasing rates as HDI increased. Incidence was three times higher in countries with low HDI than countries with very high HDI, whereas mortality rates were six times higher in low HDI countries versus very high HDI countries. In 2020 estimates, a general decline in incidence was observed in most countries of the world with representative trend data, with incidence becoming stable at relatively low levels around 2005 in several high-income countries. By contrast, in the same period incidence increased in some countries in eastern Africa and eastern Europe. We observed different patterns of age-specific incidence between countries with well developed population-based screening and treatment services (eg, Sweden, Australia, and the UK) and countries with insufficient and opportunistic services (eg, Colombia, India, and Uganda). INTERPRETATION: The burden of cervical cancer remains high in many parts of the world, and in most countries, the incidence and mortality of the disease remain much higher than the threshold set by the WHO initiative on cervical cancer elimination. We identified substantial geographical and socioeconomic inequalities in cervical cancer globally, with a clear gradient of increasing rates for countries with lower levels of human development. Our study provides timely evidence and impetus for future strategies that prioritise and accelerate progress towards the WHO elimination targets and, in so doing, address the marked variations in the global cervical cancer landscape today. FUNDING: French Institut National du Cancer, Horizon 2020 Framework Programme for Research and Innovation of the European Commission; and EU4Health Programme.

Pan-American prevalence of smokeless tobacco use and association with oral potentially malignant disorders and head and neck cancer: a systematic review and meta-analysis.

OBJECTIVES: To determine the prevalence of smokeless tobacco (SLT) use and its association with oral potentially malignant disorders (OPMDs) and head and neck cancer (HNC) in the Pan-American Health Organization (PAHO) region. STUDY DESIGN: A literature search was conducted across 9 databases and other sources. The eligibility criteria were pediatric (0-18 years old) and adult (19 years and older) populations consuming any type of SLT. Meta-analysis was performed to determine the prevalence of SLT and the association between its use and OPMDs/HNC in the PAHO region; the Grading of Recommendations Assessment, Development, and Evaluation tool was used to verify the certainty of evidence. RESULTS: Fifty-nine studies from 6 PAHO countries were included, of which 51 were also subjected to quantitative analysis. The pooled SLT prevalence of use was 15% (95%CI: 11.93-18.69) overall, 17% (95%CI: 13.25-22.65) in adults, and 11% (95%CI: 8.54-14.78) in the pediatric population. The highest reported SLT prevalence of use was 33.4% (95%CI: 27.17-39.93) in Venezuela. HNC was positively associated with SLT use (OR = 1.98, 95%CI: 1.54-2.55), with a moderate certainty of evidence. Among OPMDs, only leukoplakia reported a positive association with SLT use (OR = 8.38; 95%CI: 1.05-67.25). However, the quality of the evidence was very low. CONCLUSION: A high consumption of SLT use, chewing tobacco and snuff, is reported among the adult population residing in the PAHO region with a positive association with the development of oral leukoplakia and HNC.

Benefits, harms and cost-effectiveness of cervical screening, triage and treatment strategies for women in the general population.

In 2020, the World Health Organization (WHO) launched a strategy to eliminate cervical cancer as a public health problem. To support the strategy, the WHO published updated cervical screening guidelines in 2021. To inform this update, we used an established modeling platform, Policy1-Cervix, to evaluate the impact of seven primary screening scenarios across 78 low- and lower-middle-income countries (LMICs) for the general population of women. Assuming 70% coverage, we found that primary human papillomavirus (HPV) screening approaches were the most effective and cost-effective, reducing cervical cancer age-standardized mortality rates by 63-67% when offered every 5 years. Strategies involving triaging women before treatment (with 16/18 genotyping, cytology, visual inspection with acetic acid (VIA) or colposcopy) had close-to-similar effectiveness to HPV screening without triage and fewer pre-cancer treatments. Screening with VIA or cytology every 3 years was less effective and less cost-effective than HPV screening every 5 years. Furthermore, VIA generated more than double the number of pre-cancer treatments compared to HPV. In conclusion, primary HPV screening is the most effective, cost-effective and efficient cervical screening option in LMICs. These findings have directly informed WHO's updated cervical screening guidelines for the general population of women, which recommend primary HPV screening in a screen-and-treat or screen-triage-and-treat approach, starting from age 30 years with screening every 5 years or 10 years.

Clinical predictors of malignant transformation and recurrence in oral potentially malignant disorders: A systematic review and meta-analysis.

OBJECTIVE: We performed a systematic review dedicated to pooling evidence for the associations of clinical features with malignant transformation (MT) and recurrence of 3 oral potentially malignant disorders (OPMDs) (actinic cheilitis [AC], oral leukoplakia [OL], and proliferative verrucous leukoplakia [PVL]). STUDY DESIGN: We selected studies that included clinical features and risk factors (age, sex, site, size, appearance, alcohol intake, tobacco use, and sun exposure) of OL, PVL, and AC associated with recurrence and/or MT. RESULTS: Based on the meta-analysis results, non-homogeneous OL appears to have a 4.53 times higher chance of recurrence after treatment. We also found 6.52 higher chances of MT of non-homogeneous OL. Another clinical feature related to higher MT chances is the location (floor of the mouth and tongue has 4.48 higher chances) and the size (OL with >200 mm2 in size has 4.10 higher chances of MT). Regarding habits, nonsmoking patients with OL have a 3.20 higher chance of MT. The only clinical feature related to higher chances of MT in patients with PVL was sex (females have a 2.50 higher chance of MT). CONCLUSIONS: Our study showed that some clinical features may indicate greater chances of recurrence after treatment and MT of OPMD.