Predictive value of CCND1/cyclin D1 alterations in the malignant transformation of potentially malignant head and neck disorders: Systematic review and meta‐analysis.

Background: To evaluate published evidence on the predictive value of CCND1 amplification/cyclin D1 overexpression as malignant transformation risk markers in potentially malignant disorders (PMDs) of the head and neck. Material and Methods: We searched PubMed, Embase, Web of Science, and Scopus for studies published before June 2018. We conducted a meta‐analysis to quantify the impact of CCND1/cyclin D1 amplification/overexpression on malignant transformation of head and neck PMDs. Results: Nine studies met inclusion criteria. Quantitative evaluation indicated strong statistically significant association between CCND1/cyclin D1 amplification/overexpression and the progression of head and neck PMD to head and neck squamous cell carcinoma (risk ratio [RR] = 2.04, 95% confidence interval [CI] = 1.37‐3.03, P < .001, and RR = 2.27, 95% CI = 1.32‐3.91, P = .003, respectively). We observed moderate heterogeneity among studies (I2 = 40.7%), and we cannot rule out small‐study effects such as publication bias. The oral cavity subgroup showed the strongest association between CCND1/cyclin D1 amplification/overexpression and progression to cancer. Conclusion: CCND1/cyclin D1 amplification/overexpression is important to predict the malignant transformation risk of head and neck PMDs, especially oral PMDs. [ABSTRACT FROM AUTHOR]