Scoring Methodology
OralCheck assigns a risk weight to each answer based on published odds ratios. This page documents how that scoring works, which sources it's built on, and where the model has known limitations.
Weight Derivation
Each risk factor is assigned a weight proportional to the natural log of its published odds ratio (OR), scaled by a constant k:
The scaling constant k = 4.47 was chosen so that daily tobacco use (the highest-weighted modifiable factor, OR 6.0× per Gandini et al. 2008) maps to a weight of 8. That anchors all other weights to a consistent ordinal scale from the same evidence base.
Where studies report a range of ORs, we use the midpoint or a conservative estimate. Symptoms like erythroplakia, leukoplakia, and non-healing ulcers work as clinical overrides rather than additive scores. They're better understood as possible in-situ pathology than as population-level risk exposures, so they're treated differently in the model.
Risk Factor Weights
| Factor | Published OR | Weight | Source |
|---|---|---|---|
| Tobacco (daily) Anchor for the scaling constant k = 4.47 | 2.5 – 6.0× | 8 | Gandini et al., Oral Oncology, 2008 |
| Betel quid / paan / gutka (current) IARC Group 1 carcinogen independent of tobacco | 7 – 10× | 9 | IARC Monograph 85, 2004 |
| Tobacco (occasional) | ~3.0× | 5 | Gandini et al., Oral Oncology, 2008 |
| Alcohol (daily) IARC Group 1 carcinogen | ~3.0× | 5 | Bagnardi et al., Annals of Oncology, 2015 |
| HPV-related history Conservative estimate; OR ~15× for oropharyngeal specifically | 3 – 5× (blended) | 5 | Gillison et al., JAMA, 2008 |
| Age 65+ Median age at diagnosis is 62 | ~4.0× (adjusted) | 6 | SEER, NCI; multivariable-adjusted |
| Age 55 – 64 | ~2.5× | 4 | SEER, NCI |
| Betel quid (past use) | ~2.5× | 4 | IARC Monograph 85, 2004 |
| Alcohol (weekly) | ~2.0× | 3 | Bagnardi et al., Annals of Oncology, 2015 |
| Family history (first-degree) | ~2.0× | 3 | General epidemiological consensus |
| Diet low in fruit/vegetables Antioxidant-protective effect | ~2.0× | 3 | Pavia et al., Oral Oncology, 2006 |
| Age 35 – 54 | ~1.5× | 2 | SEER, NCI |
| Tobacco (former) Risk declines ~50% within 5 years of cessation | ~1.5× | 2 | Gandini et al., Oral Oncology, 2008 |
| HPV (not vaccinated) | ~1.5× | 2 | Gillison et al., JAMA, 2008 |
Tobacco + Alcohol Interaction Term
When both tobacco and alcohol use are present at meaningful levels (daily or weekly), the model adds an interaction bonus of +3 points.
The reason is that tobacco and alcohol together produce a multiplicative rather than additive increase in oral cancer risk. Combined regular use raises risk roughly 15× above baseline, while simply summing the individual weights only gets you to about 9×. The +3 captures that gap.
Source: Bagnardi V, et al. Annals of Oncology, 2015.
Risk Tier Thresholds
The maximum possible score is approximately 53 (all highest-risk answers plus the interaction bonus). A few reference points: a daily smoker alone scores 8 (moderate); tobacco + alcohol + interaction lands at 16 (elevated); betel + tobacco + alcohol + interaction reaches 25 (high).
Regardless of score, any symptom lasting 2+ weeks (a persistent sore, red or white patch, unexplained lump, or difficulty swallowing) overrides the tier to High and triggers a prompt for immediate evaluation.
Known Limitations
- 1OralCheck hasn't been validated against a clinical outcome dataset. The weights are grounded in published literature, but they haven't been calibrated against a prospective cohort.
- 2The screener combines oral cavity and oropharyngeal cancer risk into a single score. These are epidemiologically distinct entities: HPV-16 is primarily a driver of oropharyngeal cancer, while tobacco and alcohol dominate in oral cavity cancer.
- 3Biological sex isn't captured. Men have roughly 2× the oral cavity cancer incidence of women, and that's a gap in the current model.
- 4Immunosuppression (HIV, organ transplant recipients, long-term corticosteroid use) is linked to significantly elevated oral cancer risk and isn't currently asked about.
- 5The screener relies on self-reported data. Tobacco and alcohol use are commonly under-reported.
- 6Dental visit frequency is included as a detection-delay proxy, not as a causal risk factor with a well-characterized OR. Its weight is based on clinical rationale rather than direct epidemiological derivation.
References
- 1.Gandini S, et al. Tobacco smoking and cancer: a meta-analysis. Oral Oncology. 2008;44(7):617–638.View on PubMed / publisher →
- 2.Bagnardi V, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose–response meta-analysis. Annals of Oncology. 2015;26(1):39–55.View on PubMed / publisher →
- 3.Gillison ML, et al. Distinct risk factor profiles for human papillomavirus type 16–positive and human papillomavirus type 16–negative head and neck cancers. JAMA. 2008;168(3):294–305.View on PubMed / publisher →
- 4.International Agency for Research on Cancer. Betel-quid and Areca-nut Chewing and Some Areca-nut Derived Nitrosamines. IARC Monograph 85. Lyon, France: IARC; 2004.View on PubMed / publisher →
- 5.Napier SS, Speight PM. Natural history of potentially malignant oral lesions and conditions: an overview of the literature. Journal of Oral Pathology & Medicine. 2008;37(1):1–10.Leukoplakia 5–17% and erythroplakia 14–50% malignant transformation ratesView on PubMed / publisher →
- 6.Pavia M, et al. Evidence-based medicine on the relationship between diet and cancers of the oral cavity and pharynx. Oral Oncology. 2006;42(1):15–25.View on PubMed / publisher →
- 7.National Cancer Institute. SEER Cancer Statistics Review 1975–2021. Surveillance, Epidemiology, and End Results Program.View on PubMed / publisher →