Wolf in sheep's clothing - Oral proliferative verrucous leukoplakia: Progression with longitudinal molecular insights

BACKGROUND

Oral proliferative verrucous leukoplakia (OPVL) is a chronic form of oral leukoplakia that progresses to a multifocal disease with confluent, exophytic and proliferative features. The clinical differential diagnosis for OPVL includes frictional keratosis, leukoplakia, chronic hyperplastic candidiasis, squamous papilloma, verrucous hyperplasia, verrucous carcinoma and squamous cell carcinoma. In this study, we aimed to delineate the dynamic changes in molecular signature during OPVL progression. We compare to a cohort of oral cavity keratinizing squamous cell carcinoma (OSCC) patients covering the spectrum of verrucous carcinoma to invasive squamous cell carcinoma including cytologically bland cuniculatum variant.

METHODS

Samples from a large OPVL lesion that exhibited a histopathologic continuum of OPVL progression.

RESULTS

Canonical hotspot TERT promoter mutations were identified in all patients. TERT C228T was dominant and mutually exclusive with TERT C250T. In patients with TERT C250T, there was concurrent PI3 point mutation. TP53 mutations were also consistently found (8/10). At the protein level, p53 was abnormal, with loss of function and gain of function.

CONCLUSIONS

OPVL is a pathology that shows proximity to the gene expression profile of OSCC, highlighting signatures in common that can be important targets for drug treatment, as well as in the development of diagnostic and prognostic strategies for this disease.

Postoperative radiation performed at the same surgical facility associated with improved overall survival in oral cavity squamous cell carcinoma

BACKGROUND

The purpose of this analysis is to evaluate whether postoperative radiotherapy (PORT) at the same facility as surgery portends to better survival outcomes compared to PORT given at a different facility.

METHODS

Patients underwent upfront surgery at the National Cancer Database reporting facility followed by PORT. PORT was coded as performed at either the same facility or at a different facility as surgery.

RESULTS

A total of 10 832 patients were selected. Five-year overall survival (OS) was higher in patients undergoing PORT at the same facility: 52.5% vs 48.4% (P < 0.001). PORT performed at the same facility was associated with improved OS under multivariate (HR, 0.92; P = 0.01) and propensity score matched (hazard ratio, 0.90; P = 0.004) analyses.

CONCLUSIONS

OS was better among patients with head and neck cancer who received PORT at the same facility as surgery.

Impact of perineural invasion in the pathologically N0 neck in oral cavity squamous cell carcinoma

OBJECTIVE

Patients with oral cavity squamous cell carcinoma (OCSCC) undergo adjuvant radiation for pathologically high-risk features including positive nodal disease and extracapsular spread (ECS). In the absence of these high-risk features, our objective was to determine if perineural invasion (PNI) is an independent risk factor and if adjuvant radiation (XRT) improves disease control rates.

STUDY DESIGN

Historical cohort analysis.

SETTING

Tertiary university hospital.

METHODS

Eighty-eight OCSCC patients (46 males, 42 females; mean age = 56.7 years; median follow-up = 4.6 years) treated surgically with pathologically N0 (pN0) necks were studied. Overall, 23% (20/88) were pN0/PNI+ and of those with PNI, 70% (14/20) underwent XRT. Survival analysis using Kaplan-Meier followed by multivariable Cox models was performed.

RESULTS

Multivariate analysis verified PNI to be associated with worse disease-free interval (DFI) (P = .012) and local-regional control (LRC) (P = .005) and perivascular invasion (PVI) associated with worse DFI (P = .05). Among pN0/PNI+ patients, those who received XRT demonstrated significantly improved DFI (mean = 6.5 years vs 1.7 years; P = .014) and LRC (mean 6.7 years vs 1.9 years; P = .047). There was no improvement in overall survival (P = .68) or disease-specific survival (P = .8) in those receiving XRT.

CONCLUSIONS

PNI is an independent adverse risk factor in the absence of nodal metastasis and extracapsular spread. We observed a statistically significantly longer DFI and LRC when patients were treated with adjuvant radiation.

Sentinel Lymph Node Biopsy for Cutaneous Squamous Cell Carcinoma of the Head and Neck

Objectives:

Determine the safety and reliability of sentinel lymph node biopsy for head and neck cutaneous squamous cell carcinoma, the second most common skin cancer in the United States.

Methods:

One hundred four patients with cutaneous squamous cell carcinoma of the head and neck underwent sentinel lymph node biopsy at the University of Arizona Medical Center and the Southern Arizona Veterans Affairs Health Care System from 2001-2012. Detailed histological and clinical data was extracted from a retrospectively collected, institutional review board–approved data set.

Results:

This is the largest series to date of patients with cutaneous squamous cell carcinoma of the head and neck who have undergone sentinel lymph node biopsy. In this series, a sentinel lymph node was positive for metastatic disease in 6.7% of patients. The negative predictive value, the false negative rate, and the false omission rate will be reported. Correlations between sentinel lymph node status and various clinicopathologic properties including size, patient age, comorbidities, rate of growth, differentiation at biopsy, outcome, patterns of failure, and nodal burden will be described.

Conclusions:

Sentinel lymph node biopsy in patients with cutaneous squamous cell carcinoma of the head and neck is a safe and reliable strategy to identify those patients who may benefit from therapeutic lymph node dissection and adjuvant therapies.

A role for endogenous and radiation-induced DNA double-strand breaks in p53-dependent apoptosis during cortical neurogenesis

Prenatal exposure to low-dose radiation increases the risk of microcephaly and/or mental retardation. Microcephaly is also associated with genetic mutations that affect the non-homologous end-joining pathway of DNA double-strand break repair. To examine the link between these two causal factors, we characterized the neural developmental effects of acute radiation exposure in mouse littermate embryos harboring mutations in the Ku70 and p53 genes. Both low-dose radiation exposure and Ku70 deficiency induced morphologically indistinguishable cortical neuronal apoptosis. Irradiated Ku70-deficient embryos displayed anatomical damage indicative of increased radiosensitivity in the developing cerebral cortex. Deleting the p53 gene not only rescued cortical neuronal apoptosis at all levels but also restored the in vitro growth of Ku70-deficient embryonic fibroblasts despite the presence of unrepaired DNA/chromosomal breaks. The results confirm the role of DNA double-strand breaks as a common causative agent of apoptosis in the developing cerebral cortex. Furthermore, the findings suggest a disease mechanism by which the presence of endogenous DNA double-strand breaks in the newly generated cortical neurons becomes radiomimetic when DNA end joining is defective. This in turn activates p53-dependent neuronal apoptosis and leads to microcephaly and mental retardation.