A Population-Based Analysis of Mucoepidermoid Carcinoma of the Oral Cavity

Association between radiotherapy for surgically treated oral cavity cancer and secondary lung cancer

Background

There is limited research on the incidence of secondary lung cancer (SLC) after radiotherapy (RT) for oral cavity cancer (OCC). Therefore, we investigated the association between RT for OCC and the risk of SLC and the overall survival of these patients.

Methods

Patients diagnosed with OCC between 1975 and 2015 were selected from the Surveillance, Epidemiology, and End Results database. The cumulative incidence of SLC, relative risk (RR) of RT vs. no RT (NRT), standardized incidence ratios (SIR), and survival outcomes were assessed.

Results

A total of 10,936 patients with OCC were included. Of these, 429 (3.92%) patients developed SLC, where 136 (5.02%) received RT and 293 (3.56%) did not. The cumulative incidence of SLC during follow-up was 6.89% and 4.84% in the RT and NRT patients, respectively. RT was associated with a higher risk of SLC. In the subset analysis, the results showed that a higher risk of developing SLC among patients with index OCC in most subgroups. Dynamic RR and SIR revealed a decreased risk of SLC with increasing latency time. No difference was observed in the 10-year survival rates for patients with SLC who received RT or not or compared with primary lung cancer.

Conclusion

RT was associated with a higher risk of SLC, and patients diagnosed with OCC could be followed for 5-10 years after diagnosis.

Role of Hydrogen Sulfide in Oral Disease

Oral diseases are among the most common human diseases yet less studied. These diseases affect both the physical, mental, and social health of the patients resulting in poor quality of life. They affect all ages, although severe stages are mostly observed in older individuals. Poor oral hygiene, genetics, and environmental factors contribute enormously to the development and progression of these diseases. Although there are available treatment options for these diseases, the recurrence of the diseases hinders their efficiency. Oral volatile sulfur compounds (VSCs) are highly produced in oral cavity as a result of bacteria activities. Together with bacteria components such as lipopolysaccharides, VSCs participate in the progression of oral diseases by regulating cellular activities and interfering with the immune response. Hydrogen sulfide (H2S) is a gaseous neurotransmitter primarily produced endogenously and is involved in the regulation of cellular activities. The gas is also among the VSCs produced by oral bacteria. In numerous diseases, H2S have been reported to have dual effects depending on the cell, concentration, and donor used. In oral diseases, high production and subsequent utilization of this gas have been reported. Also, this high production is associated with the progression of oral diseases. In this review, we will discuss the production of H2S in oral cavity, its interaction with cellular activities, and most importantly its role in oral diseases.

A population-based analysis of adenosquamous carcinoma of the salivary gland

Background

Adenosquamous carcinoma (ASC) of the salivary gland is a rare malignancy, and the characteristics and prognosis of this disease remain unclear. This study aimed to assess the clinicopathological characteristics of this rare disease and further determine the potential prognostic factors that affect its outcome.

Methods

Data of patients with ASC of the salivary gland were extracted retrospectively from the Surveillance, Epidemiology, and End Results (SEER) database between 1973 and 2016. The clinicopathological characteristics of these patients were assessed, and prognostic factors were further determined using Cox regression analysis.

Results

A total of 106 patients with ASC of the salivary gland were identified. The mean age at diagnosis was 66.1±14.9 years, with a male-to-female ratio of 1.47. The parotid gland was the most common primary site (N=91; 85.8%). The 1-, 2-, and 5-year overall survival (OS) rates were 71.5%, 55.0%, 41.5%, respectively. The 1-, 2-, and 5-year disease-specific survival (DSS) rates were 80.8%, 72.2%, and 59.2%, respectively. The OS and DSS shortened with increasing tumor stage, regardless of the American Joint Committee on Cancer tumor-node-metastasis stage or SEER historic stage. Surgery was the main treatment option to improve survival, and post-operative radiotherapy could also prolong OS and DSS (both P<0.01). A multivariate Cox regression analysis demonstrated that distant metastases and the use of surgery or radiation were independent prognostic factors for a favorable OS among patients with ASC of the salivary gland, and early stage (T1/T2) and the use of surgery were independent prognostic factors for favorable DSS among the patients with ASC of the salivary gland.

Conclusions

This is the largest case series on ASC of the salivary gland. Advanced T stage, distant metastases, and the use of surgery and radiation were associated with OS or DSS of this disease.