Predictors of Nodal Metastasis in Mucoepidermoid Carcinoma of the Oral Cavity and Oropharynx

Elective Neck Dissection Improves Regional Control in cN0 Minor Salivary Gland Carcinoma in the Oral Cavity

PURPOSE

Consensus regarding whether elective neck dissection (END) provides better outcomes than observation in clinically node negative minor salivary gland (MSG) carcinoma is lacking. Therefore, this study aimed to compare the impact of END with that of observation on regional control (RC) and overall survival (OS) and to detect the predictors for lymph-node metastasis in oral MSG carcinoma.

PATIENTS AND METHODS

A single-institution, retrospective cohort study was designed; it included patients with clinically node negative oral MSG carcinoma treated at a tertiary teaching hospital between January 2002 and January 2022. The primary predictor variable was END and primary outcome variables were RC and OS. The secondary outcome variable was lymph-node metastasis. Other covariates included demographic and pathologic features, TNM stage, and adjuvant treatment. The Kaplan-Meier method and Cox proportional hazards model were used to determine the effect of END on RC and OS. The chi-squared test and logistic regression models were used to identify independent predictors for lymph-node metastasis.

RESULTS

A total of 268 patients (107 men and 161 women) with a mean age of 46.4 ± 15.5 years were included. The 5-year RC rate was statistically different between the observation and END groups (75%; 95% confidence interval [CI], 67%-83; 95% CI, 81%-93%, respectively; P = .014). Cox regression analysis confirmed that END (hazard ratio [HR] 2.395; 95% CI: 1.433-8.275; P = .034) was independently associated with a decreased risk of regional recurrence. The 5-year OS rates for the observation and END groups were 66% (95% CI, 56-76%) and 76% (95% CI, 66-86%), respectively, and the difference was not statistical (P = .057). Occult metastasis occurred in 24.6% of patients. Primary tumor location on the tongue/floor of the mouth (odds ratio [OR], 4.287; 95% CI, 1.773-9.125; P = .011), T3/4 stage (OR, 3.286; 95% CI, 1.228-8.253; P = .021), and high-grade disease (OR, 6.674; 95% CI, 2.199-14.326; P < .001) were independently associated with an increased risk of occult metastasis.

CONCLUSIONS

RC was better with END than with observation, but OS was comparable with the two approaches. Primary tumor location on tongue/floor of the mouth, T3/4 stage, and high-grade disease were associated with an increased risk of lymph-node metastasis.

PET-CT in Clinical Adult Oncology-V. Head and Neck and Neuro Oncology

Simple Summary

Positron emission tomography (PET), typically combined with computed tomography (CT) has become a critical advanced imaging technique in oncology. With PET-CT, a radioactive molecule (radiotracer) is injected in the bloodstream and localizes to sites of tumor because of specific cellular features of the tumor that accumulate the targeting radiotracer. The CT scan, performed at the same time, provides information to facilitate attenuation correction, so that radioactivity from deep or dense structures can be better visualized, but with head and neck malignancies it is critical to provide correlating detailed anatomic imaging. PET-CT has a variety of applications in oncology, including staging, therapeutic response assessment, restaging, and surveillance. This series of six review articles provides an overview of the value, applications, and imaging and interpretive strategies of PET-CT in the more common adult malignancies. The fifth report in this series provides a review of PET-CT imaging in head and neck and neuro oncology.

Abstract

PET-CT is an advanced imaging modality with many oncologic applications, including staging, assessment of response to therapy, restaging, and longitudinal surveillance for recurrence. The goal of this series of six review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for specific oncologic indications, and the potential pitfalls and nuances that characterize these applications. In addition, key tumor-specific clinical information and representative PET-CT images are provided to outline the role that PET-CT plays in the management of oncology patients. Hundreds of different types of tumors exist, both pediatric and adult. A discussion of the role of FDG PET for all of these is beyond the scope of this review. Rather, this series of articles focuses on the most common adult malignancies that may be encountered in clinical practice. It also focuses on FDA-approved and clinically available radiopharmaceuticals, rather than research tracers or those requiring a local cyclotron. The fifth review article in this series focuses on PET-CT imaging in head and neck tumors, as well as brain tumors. Common normal variants, key anatomic features, and benign mimics of these tumors are reviewed. The goal of this review article is to provide the imaging professional with guidance in the interpretation of PET-CT for the more common head and neck malignancies and neuro oncology, and to inform the referring providers so that they can have realistic expectations of the value and limitations of PET-CT for the specific type of tumor being addressed.