Oral cancer in young adults: report of three cases and review of the literature

High incidence of HPV infection in minors with oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma in minors is considered to be a distinct entity from OSCC in older patients, with an uncertain etiology. Human papillomavirus (HPV) infection may trigger the initiation and promote the progression of OSCC, but these roles have not been firmly established.We aimed to explore the correlation between HPV infection and the development of oral squamous cell carcinoma in minors and know the characteristics of OSCC in young patients more thoroughly.

METHOD

From January 2013 to December 2022,6 cases of OSCC aged < 15 years were selected from the Department of Oral Pathology, Peking University School of Stomatology, Beijing, China. All cases underwent testing for high-risk HPV mRNA infection using the RNA scope technique, and immunohistochemical staining was performed to investigate the expression of p16, pan-cytokeratin (CK), CK5/6, CK7, CK8/18, epidermal growth factor receptor (EGFR), p53, and Ki-67. Furthermore, we reviewed the literature on OSCC in patients aged < 21 years.

CONCLUSIONS

Minors OSCC is associated with HPV infection, and that p16 can serve as an immunohistochemical marker of HPV positivity.

Alterations of Rb Pathway Components Are Frequent Events in Patients with Oral Epithelial Dysplasia and Predict Clinical Outcome in Patients with Squamous Cell Carcinoma

OBJECTIVE

This study was designed to test the hypothesis that alterations in expression of G1/S modulators cyclin D1, p16 and pRb occur in patients with oral epithelial dysplasia, considered to be at increased risk for malignant transformation. In addition, the analysis of expression of all three markers in the same set of oral cancer patients would provide a unique opportunity to determine whether these alterations have cooperative or synergistic effects on oral cancer development and prognosis.

PATIENTS AND METHODS

A prospective study was undertaken to carry out immunohistochemical analysis of cyclin D1, p16 and pRb proteins in serial paraffin-embedded tissue sections of 220 oral squamous cell carcinomas (OSCCs), 90 potentially malignant lesions (52 oral hyperplastic lesions, 38 dysplasias) and 81 matched histologically normal oral tissues and correlated them with clinicopathological parameters. Ninety-eight OSCC patients were followed up for a maximum period of 94 months with overall median survival of 21 months.

RESULTS

Seventy-five of 90 (83%) potentially malignant lesions and 198 of 220 (90%) OSCCs showed altered expression of at least one of the proteins in the pRb pathway, while 10 of 90 (11%) patients with potentially malignant lesions and 40 (18%) of 220 OSCC patients showed all three alterations. Loss of p16 was the earliest event in oral tumorigenesis. In a multivariate model, loss of pRb was associated with transition from hyperplasia to dysplasia (OR = 3.727, p = 0.005). The transition of potentially malignant lesions to malignant stage was associated with pRb-/cyclin D1+ phenotype (OR = 2.294, p = 0.001) and p53+ phenotype (OR = 2.230, p = 0.002). Loss of pRb and accumulation of p53 (pRb-/p53+) phenotype was associated with histologic progression of the tumors and acquisition of invasive potential. Multivariate analysis using Cox's proportional hazards model revealed that pRb-/p53+ phenotype was the most significant adverse prognosticator for disease-free survival (hazards ratio, (HR) = 2.642, p = 0.004).

CONCLUSIONS

Deregulation of the p16/pRb/cyclin D1 pathway is an early event in acquisition of dysplasia, but deregulation of both pRb and p53 pathways is associated with malignant transformation and adverse prognosis in oral tumorigenesis.