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

Abstract

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.

Role of Intraparotid and Neck Lymph Node Metastasis in Primary Parotid Cancer Surgery: A Population-Based Analysis

“…A recent systematic review including studies until 2020 revealed a mean pooled prevalence of the PAR+ rate of 24% [ 12 ]. The number of PAR+ lymph nodes varied from 1 to 11 in these hospital-based studies, which fits to the present study.…”

“…The 5-year recurrence-free survival rate based on Kaplan–Meier analysis varied from 83% to 88% in PAR− patients, compared to 36% to 54% in PAR+. Only for studies allowed an OS analysis, the average calculated HR for a risk of death in patients with PAR+ compared to PAR− was increased by 2.14 [ 12 ]. In a newer analysis on major salivary gland cancer, the PAR+ rate was 21% and PAR+ 5-year OS rate was 57.6%, compared to 79.4% in PAR− patients [ 5 ].…”

“…Intraparotid lymph nodes can be the only involved lymph node station in a high proportion of patients with parotid cancer, i.e., these patients are classified as N0 [ 10 , 11 ]. Intraparotid metastasis (PAR+) seems to be an independent prognosticator for worse overall survival in parotid cancer [ 5 , 12 ].…”

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part B: treatment and prognosis

“…However, a recent review on this topic raised the objection that intraparotid lymph node metastasis may not be first echelon lymph nodes for regional spreading in all cases. “It is imaginable that if the tumour is located in the far inferior part of parotid gland, level IIa or IIb lymph node metastasis might regularly occur without intraparotid lymph node metastasis” 46 . The study by Erovic et al 9 overcame this objection.…”

Frozen Section of Parotid Gland Tumours: The Head and Neck Pathologist as a Key Member of the Surgical Team

“…For malignant tumours, FS enables stratification between lymphomas and primary parotid gland carcinomas as well as “low-” and “high-grade” subtypes. Reliable FS information on the dignity of the parotid lesion should sustain further surgical measures, such as termination of surgery (for benign tumours) or continuation with removal of the whole parenchyma of the parotid gland (e.g., complete parotidectomy in cases with primary parotid malignant tumours) with elective neck dissection [ 11 , 12 , 13 ] and resection (as well as reconstruction) of the facial nerve in cases of nerve infiltration through a malignant lesion (other than lymphoma) [ 14 ]. Intraoperative evaluation of intraparotid lymph nodes could enable rationalised performance of complete parotidectomy and elective neck dissection [ 15 ].…”