Utility of Elective Neck Dissection in Clinically Node-Negative Parotid Malignancy

Elective Neck Dissection in cT1-4 N0M0 Head and Neck Basaloid Carcinoma

OBJECTIVE

To investigate the survival benefit of elective neck dissection (END) over neck observation in surgically resected cT1-4 N0M0 head and neck basaloid carcinoma (HNBC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 hospital-based National Cancer Database.

METHODS

Patients with surgically resected cT1-4 N0M0 HNBC were selected. Linear, binary logistic, Kaplan-Meier, and Cox proportional hazards regression models were implemented.

RESULTS

Of 857 patients satisfying inclusion criteria, the majority were male (77.0%) and white (88.1%) with disease of the oral cavity (21.5%) or oropharynx (42.9%) classified as high grade (76.9%) and cT1-2 (72.9%). 389 (45.4%) patients underwent END. END utilization between 2006 and 2017 increased for cT1-2 disease (33.3% vs 56.9%, R2 = .699) but remained relatively constant for cT3-4 disease (66.7% vs 57.9%, R2 = .062). One-hundred and fifteen (29.6%) ENDs detected occult nodal metastases (ONMs). The 5-year overall survival (OS) of patients undergoing neck observation and END was 65.6% and 66.8%, respectively (P = .652). END was not associated with improved OS in survival analyses stratified by patient demographics, clinicopathologic features, and adjuvant therapy. Compared with surgery alone, adjuvant radiotherapy (adjusted hazard ratio: 0.74, 95% confidence interval [CI]: 0.57-0.97, P = .031) was associated with improved OS. END (hazard ratio [HR]: 0.96, 95% CI: 0.71-1.28, P = .770) and ONM (HR: 1.12, 95% CI: 0.78-1.61, P = .551) were not associated with OS.

CONCLUSION

END is performed in nearly half of patients with HNBC but is not associated with improved OS, even after stratifying survival analyses by patient demographics, clinicopathologic features, and adjuvant therapy. The rate of ONM approaching 30%, however, justifies inclusion of END in the surgical management of HNBC.

Patterns and Trends in Adjuvant Therapy for Major Salivary Gland Cancer

OBJECTIVE

To investigate adjuvant therapy indications, utilization, and associated survival disparities in major salivary gland cancer (MSGC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 National Cancer Database.

METHODS

Patients with surgically resected MSGC were included (N = 11,398). pT3-4 classification, pN2-3 classification, lymphovascular invasion, pathologic extranodal extension (pENE), and positive surgical margin (PSM) were considered indications for adjuvant radiotherapy (aRT). pENE and PSM were considered possible indications for adjuvant chemotherapy. Multivariable logistic and Cox regression models were implemented.

RESULTS

Among 6694 patients with≥ $\ge $ 1 indication for aRT, 1906 (28.5%) received no further treatment and missed aRT. Age, race, comorbidity status, facility type, and distance to reporting facility were associated with missed aRT (P < .025). Among 4003 patients with ≥1 possible indication for adjuvant chemoradiotherapy (aCRT), 914 (22.8%) received aCRT. Patients with pENE only (38.5%) and both pENE and PSM (44.0%) received aCRT more frequently than those with PSM only (17.0%) (P < .001). Academic facility was associated with aCRT utilization (P < .05). aCRT utilization increased between 2006 and 2017 in both academic (14.8% vs 23.9%) and nonacademic (8.8% vs 13.5%) facilities (P < .05). Among 2691 patients with ≥1 indication for aRT alone, missed aRT portended poorer OS (hazard ratio [HR]: 1.61, 95% confidence interval [CI]: 1.28-2.03, P < .001). Among 4003 patients with ≥1 possible indication for aCRT, aRT alone (HR: 1.02, 95% CI: 0.89-1.18, P = .780) and aCRT were associated with similar OS.

CONCLUSION

Missed aRT in MSGC occurs frequently and portends poorer OS. Further studies clarifying indications for aCRT are required.

The prognostic value of selective neck dissection in early-stage major salivary gland carcinoma: a population-based analysis

Objective

This population-based study aims to assess the survival benefits of selective neck dissection (SND) compared to neck observation in patients with T1/T2N0M0 major salivary gland malignancy (MSGC).

Methods

We conducted a retrospective review of T1/T2N0M0 MSGC patients who underwent primary tumor surgical extirpation with or without elective neck dissection in the Surveillance, Epidemiology, and End Results database (SEER) from 2004-2015. The impact of SND and clinical variables on overall survival (OS) and disease-specific survival (DSS) was evaluated using Univariate and Multivariate Cox proportional hazards regression models. Kaplan-Meier survival curves were generated, and survival rates were assessed via the log-rank test.

Results

Of 3778 post-operative T1-T2N0M0 MSGC patients, 2305 underwent elective neck dissection, while 1473 did not. Median follow-up was 106 months. Univariate and Multivariate analysis identified SND as a prognostic factor for OS in all the study population. After stratified analysis, we found that in the poorly high-grade (differentiated and undifferentiated) patients, the survival showed a significant OS and DSS benefit after receiving SND compared with the neck observations [HR for OS (95%CI): 0.571(0.446-0.731), P<0.001] and [HR for DSS (95%CI): 0.564(0.385-0.826), P=0.003], other than in the well differentiated or moderately differentiated subgroup. Especially, when the pathological is squamous cell carcinoma, the results show that the people underwent SND had better prognosis, not only in OS [HR (95%CI): 0.532(0.322-0.876), P=0.013], but also in DSS [HR (95%CI): 0.330(0.136-0.797), P=0.014]. The multivariate analysis also yielded encouraging results, compared with neck observation, receiving SND bought about a significant independent OS (adjusted HR, 0.555; 95% CI, 0.328-0.941; P=0.029) and DSS (adjusted HR, 0.349; 95% CI, 0.142-0.858; P=0.022) advantage in high grade squamous cell carcinoma MSGC patients. The Kaplan-Meier survival curves also demonstrated that adjusted SND still had significantly better OS(P=0.029) and DSS(P=0.022) than the observation group in patients with high-grade squamous cell carcinoma of MSGC.

Conclusion

Poorly differentiated and undifferentiated T1/T2N0M0 major salivary gland malignancy treated with selective neck dissection demonstrated superior survival compared to neck observation, especially in the pathological subtype of squamous cell carcinoma. These findings suggest the potential benefits of multimodal therapy for appropriately selected patients, emphasizing significant clinical implications.