High-risk factors of parotid lymph node metastasis in nasopharyngeal carcinoma: a case-control study

Abstract

BackgroundAlthough parotid-sparing IMRT decreased the dose distribution of parotid, parotid region recurrence has been reported. Prophylactic irradiation in parotid area would be necessary in patients with high risk of parotid lymph node metastasis (PLNM). This study was to detect the high-risk factors of PLNM in nasopharyngeal carcinoma.MethodsThis was a 1:2 case-control study. All patients in this study were newly diagnosed NPC with N2-3 classification from January 2005 to December 2012. Cases were 22 sides with ipsilateral PLNM. Controls were 44 patients who were randomly selected from N2-3 disease in database.Results20/1096 (1.82 %) NPC patients were found PLNM. Sum of the longest diameter for multiple lymph nodes (SLD) in level II was larger in case group than that in control group (6.0 cm vs. 3.6 cm, p = 0.003). Level II lymph node necrosis, level Va/b involvement, and rare neck areas involvement were more common in case group (p = 0.016, p = 0.034, and p < 0.001, respectively). RPN, level III, and level IV metastases showed no significant difference between the two groups. Multivariate analysis in logistic regression showed that only SLD ≥5 cm in II area (OR = 4.11, p = 0.030) and rare neck areas involvement (OR = 3.95, p = 0.045) were associated with PLNM in NPC patients.ConclusionsPLNM was an uncommon event in NPC patients. SLD ≥5 cm in level II and involvement in rare-neck areas may be potentially high-risk factors for PLNM. Sparing parotid in IMRT was not recommended for NPC patients with high risks of PLNM.

Prognostic effect of parotid area lymph node metastases after preliminary diagnosis of nasopharyngeal carcinoma: a propensity score matching study

“…Our results showed that the incidence of PLN metastasis was only 2.8%, which was similar to rates in other studies .Due to the low frequency of initial PLN metastasis with NPC, little attention has been paid to this condition in clinical practice. To the best of our knowledge, PLN metastasis has not yet been classified in the 7th UICC/AJCC staging system or the Chinese 2008 staging system for NPC.…”

“…Nasopharyngeal carcinoma (NPC) is the most commonly diagnosed head and neck malignancy in Southeast Asia, with unique aggregation in Southern China. Although 85% of cases of preliminarily diagnosed NPC involve cervical lymph node metastasis , parotid area lymph node (PLN) metastasis is rare, with an incidence rate of only 1–3.4% . In addition, the PLN is generally regarded as an unconventional surgical neck dissection area .…”

“…However, subsequent studies have demonstrated that overprotection of the parotid gland resulted in a few cases of PLN recurrence after treatment of NPC with IMRT , which suggested that potential or definite PLN metastasis in preliminarily diagnosed patients might be neglected in clinical practice. Hence, the potential risk of initial PLN metastasis in patients with NPC receiving IMRT has garnered attention . According to the latest guidelines for neck node level delineation in head and neck cancers , the parotid node group has been classified as level VIII.…”

Implication of viral microRNAs in the genesis and diagnosis of Epstein‑Barr virus‑associated tumors (Review)

“…Clinically, NPC has a high incidence of lymph node metastasis and occurs in a majority of the patients prior to their first visit to the clinic (97,98). The demand to improve the efficacy of anti-NPC therapy has prompted the identification of genes that are implicated in lymph node involvement, which is an indicative of disease progression and therapeutic failure (99)(100)(101). Thus, the investigation of the role of miRs in NPC may provide a mechanistic explanation of lymph node metastasis, as well as more a sensitive indicator for the prognosis of NPC.…”

The role of long noncoding RNA-LET in cell proliferation and invasion of nasopharyngeal carcinoma and its mechanism

“…It has extremely skewed ethnic and geographic distributions, which is a rare malignant tumor in Western countries, but is one of the most prevalent cancers in the southern region of the People’s Republic of China and Southeast Asia 3–5. At present, radiotherapy and radiochemotherapy are the major means of treating NPC, but because of its high metastasis, a significant proportion of patients still develop neck and distant metastasis and the prognosis of these patients remains poor 6,7. Therefore, further explorations of the molecular mechanisms of NPC carcinogenesis and more effective therapeutic strategies are urgently required.…”