| Item | Key details | Best supporting citations |
|---|---|---|
| Disease definition / terminology | Oral squamous cell carcinoma (OSCC), also called oral cavity squamous cell carcinoma (OCSCC), is the predominant malignancy of the oral cavity, arising from squamous epithelium and accounting for ~90% of oral cancers/head and neck oral cavity cancers. | (pqac-00000002, pqac-00000004, pqac-00000029) |
| Key risk factors | Major established risks: tobacco smoking/chewing, alcohol, betel quid/areca nut, poor oral hygiene, chronic irritation, and immunosuppression; HPV contributes less strongly in oral cavity than oropharynx, with pooled oral-cavity HPV prevalence around 10% in one recent review. | (pqac-00000003, pqac-00000006, pqac-00000015) |
| Driver genes / pathways | Recurrent drivers include TP53 (~60–73%+), CDKN2A (~9–25% by mutation; combined inactivation ~50–58%), PIK3CA / PI3K pathway (~20% hotspot mutations in some cohorts; pathway altered in ~30.5%), FAT1 (~22%), NOTCH1 (~11% and enriched in OSCC). Core pathways: TP53/cell cycle, PI3K-AKT-mTOR, MAPK, Notch. | (pqac-00000031, pqac-00000036, pqac-00000038) |
| Copy-number alterations | Frequent CNAs include EGFR amplification/gain (reported ~25% in one tobacco-exposed series), CCND1 amplification (~15%; broader 11q13 gains), and 3q26/28 gains including SOX2; MYC gains also recurrent. | (pqac-00000032, pqac-00000033, pqac-00000035) |
| Global burden (GBD 2021, 2021 counts) | Worldwide lip/oral cavity cancer burden in 2021: 421,577 incident cases, 208,379 deaths, and 5,874,070 DALYs. South Asia bears the highest burden; men are more affected overall. | (pqac-00000008, pqac-00000013) |
| Global burden (GBD 2021, age-standardized rates) | 2021 age-standardized rates: ASIR 4.88 per 100,000, ASDR 2.42 per 100,000, age-standardized DALYs 67.71 per 100,000. Longer-term GBD analyses also report rising incidence since 1990. | (pqac-00000013, pqac-00000009) |
| KEYNOTE-048: pembrolizumab monotherapy | Updated ~4-year analysis (median follow-up 45.0 months): vs cetuximab-chemotherapy, OS improved in PD-L1 CPS ≥20: median 14.9 vs 10.8 months, HR 0.61; CPS ≥1: 12.3 vs 10.4 months, HR 0.74; total population: 11.5 vs 10.7 months, HR 0.81 (noninferior overall). | (pqac-00000016, pqac-00000018, pqac-00000050) |
| KEYNOTE-048: pembrolizumab + chemotherapy | Updated analysis: OS improved vs cetuximab-chemotherapy in CPS ≥20 HR 0.62, CPS ≥1 HR 0.64, and total population HR 0.71; median OS in the total population ~13.0 vs 10.7 months in one extracted figure summary. | (pqac-00000018, pqac-00000019, pqac-00000050) |
| Liquid biopsy in OSCC | In HPV-negative OSCC, paired oral-rinse/plasma ctDNA showed detection rates of 94.3% in oral rinse and 80.5% in plasma; recurrent genes included TP53, TERT, MYC, PIK3CA, with a 7-gene predictive model (TP53, TERT, IKZF1, EP300, MYC, EGFR, PIK3CA). ctDNA signaled recurrence ~4 months before clinical manifestation. Earlier multiplex studies found tumor DNA in 100% of oral cavity saliva samples and >80% of matched plasma samples. | (pqac-00000039, pqac-00000041, pqac-00000042) |


*Table: This table condenses the most clinically actionable facts about oral cavity squamous cell carcinoma, including definition, etiologic factors, molecular drivers, burden, treatment evidence, and liquid-biopsy performance. It is useful as a compact reference for a disease knowledge base or report summary.*