Intraparotid Lymph Node Metastasis Decreases Survival in Pediatric Patients With Parotid Cancer

Long-term follow-up and prognostic analysis of parotid tumors in children and adolescents

Objectives

The objective of this study is to summarize the clinical characteristics, treatment, and prognosis of parotid tumors in children and adolescents.

Methods

Fifty-three children and adolescents diagnosed with parotid gland tumors were included. Survival was evaluated using the Kaplan-Meier method. Log-rank test and multivariate analysis were used to analyze the association between clinical factors and recurrence.

Results

Of the 53 patients, 30 cases were benign and 23 cases were malignant. All patients underwent surgery. Patients with malignant tumors with high-risk factors received radiotherapy or chemotherapy. The median follow-up time was 61 months. Of these, 1 patient with benign tumor and 5 patients with malignant tumors recurred. Of the patients with malignant tumors, 2 developed distant metastases and 2 died. The 5-year overall survival (OS) and 5-year locoregional recurrence-free survival (LRFS) rates for benign tumors were 100.0% and 92.9%, respectively, whereas the 5-year OS and 5-year LRFS rates for malignant tumors were 94.4% and 72.5%, respectively. The log-rank univariate test showed that tumor size >3.5 cm (p = .056), distant metastasis (p = .056), and stage III and IV (p = .032) were associated with recurrence. However, multivariate analysis did not show the above factors to be independent prognostic factors for LRFS.

Conclusion

Surgery for benign tumors depends on the location and size. Surgery for malignant parotid tumors depends mainly on the stage, grade, pathological type, and recurrence. Prophylactic lymph node dissection is required for high-grade tumors. Radiotherapy or chemotherapy for children needs more research. Both benign and malignant tumors have high survival rates after active treatment.

Level of evidence

Level 2.

The 8th AJCC classification is inferior to a new neck stage based on intraparotid lymph node in parotid gland cancer

BACKGROUND

Lymph node (LN) status is an important prognostic factor for parotid gland cancer (PGC). This study aimed to analyze the impact of extranodal extension (ENE) of intraparotid LN and LN metastasis burden on survival in PGC.

METHODS

Patients with surgically treated PGC and at least one metastatic cervical LN were retrospectively enrolled. Primary outcome variables were distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS). The impact of ENE and LN metastasis burden was assessed using the Cox model.

RESULTS

A total of 292 patients were included. ENE in cervical or intraparotid LN was not associated with DMFS, DSS, or OS. Intraparotid LN metastasis had a significant impact on prognosis, and the presence of only one metastatic intraparotid LN offered an approximately 1.5-fold risk of distant metastasis. Prognostic models based on the number of positive LNs (1 vs. 2-3 vs. 4+) were superior to the AJCC N stage in terms of DMFS, DSS, and OS.

CONCLUSIONS

ENE of cervical or intraparotid LN has a limited effect on the prognosis of PGC, and the number of positive LNs is better than the AJCC N stage in LN status evaluation.

Number of positive lymph nodes is superior to neck stage of the 8th AJCC in predicting prognosis in parotid mucoepidermoid carcinoma

BACKGROUND

To clarify the impact of the number of positive lymph nodes (LNs) on the prognosis of parotid mucoepidermoid carcinoma (MEC).

METHODS

Patients who underwent neck dissection for parotid MEC were retrospectively enrolled. The primary outcome variable was overall survival (OS). Associations between OS and LN factors, including the AJCC N stage, intraparotid LN metastasis, number of positive LNs, LN size, and extranodal extension (ENE), were evaluated using Cox proportional hazard regression analyses.

RESULTS

A total of 720 patients were included with a mean age of 56 ± 16 years. There was no additional survival compromise until two positive LNs were presented. After adjusting for the number of positive LNs, intraparotid LN metastasis, ENE, and LN size were not related to prognosis. Our proposed N stage based on the number of metastatic LNs (0/1 vs. 2-4 vs. 5+) showed a superior C-index to the AJCC N stage in OS prediction.

CONCLUSION

Quantitative LN burden was an important determinant of prognosis, and the proposed N stage provided better OS stratification than the AJCC N stage.

Role of Intra-Parotid Lymph Node Metastasis in Primary Parotid Carcinoma

The parotid gland contains intra-glandular lymph nodes, the distribution of which is crucial for understanding the pathogenesis of intra-parotid lymph node metastases of parotid carcinoma and other head and neck carcinomas. Positive intra-parotid lymph node metastasis predicts the risk of positive cervical nodal metastasis. It is important to establish whether prophylactic neck dissection, including intra-parotid lymph nodes, contributes to treatment outcomes. The presence or absence of intra-parotid lymph nodes or metastasis-positive lymph nodes warrants further study. A preoperative diagnosis by imaging and fine-needle aspiration cytology of intra-parotid lymph nodes is difficult. Although intraoperative frozen section biopsy is performed during surgery, it is challenging to identify intra-parotid lymph nodes. The number of lymph nodes was the largest (47%) in the lower half of the superficial lobe, with 35% of nodes being concentrated in the inferior part of the cervicofacial branch, i.e., the lower pole of the parotid gland. Therefore, superficial parotidectomy and lower pole lobectomy need to be performed in cases in which a malignant tumor localizes to the superficial lobe or a lower pole. When intra-parotid lymph node metastases are detected during surgery, selective neck dissection (at least levels II and III) needs to be simultaneously performed.

Prognostic role of intraparotid lymph node metastasis in primary parotid cancer: Systematic review

BACKGROUND

The prognostic importance of intraparotid lymph node metastasis (P+) in patients with primary parotid gland carcinoma is unclear.

METHODS

Nineteen retrospective and noncomparative cohort studies, published between 1992 and 2020, met the inclusion criteria and included 2202 patients for this systematic review.

RESULTS

The pooled prevalence of the P in adult patients in the unselected studies was 24.10% (95% confidence interval = 17.95-30.25). The number of P+ lymph nodes per patient was counted in only three studies and ranged from 1 to 11. The 5-year recurrence-free survival rate based on Kaplan-Meier analysis varied from 83% to 88% in P- patients compared to 36% to 54% in P+ patients. The average hazard ratio for tumor recurrence in patients with P+ compared to P- was 2.67 ± 0.58.

CONCLUSIONS

P+ is an independent negative prognostic factor in primary parotid gland cancer and should be included into the treatment planning.