Significance of intraparotid node metastasis in predicting local control in primary parotid cancer

Prognostic Implications of Occult Nodal Metastases in Patients with Clinically N0 Primary Parotid Gland Cancer

Background and Objectives: The role of occult nodal metastases in patients with parotid gland cancers remains unclear; such metastases are histologically diverse and exhibit unpredictable clinical courses. Here, we evaluated the prognostic utilities of such metastases, including metastases in the intraparenchymal lymph nodes (PARs). Materials and Methods: We retrospectively reviewed the medical charts of patients who underwent surgery to treat clinically N0 primary parotid gland cancers from 2000 to 2022. The primary outcome variables were 5-year overall survival (OS) and 5-year disease-free survival (DFS). We explored the effects of occult nodal metastases, including metastases in the PARs, especially in terms of the pathological T (pT) classification. Results: Among 74 patients, 48 (64.8%) were pT1/2 cases, and 26 (35.2%) were pT3/4 cases. Both perineural and lymphatic invasion were negatively associated with the 5-year DFS (hazard ratio [HR] = 3.533, 95% confidence interval [CI] = 1.325-9.421, p = 0.012; HR = 4.028, 95% CI = 1.497-10.839, p = 0.006, respectively). During pathological review, PAR metastases were observed in 12 patients (16.2%), and other occult metastases were present in 8 patients (10.8%). PAR metastases reduced the 5-year DFS in pT1/2 cases (87.2% vs. 22.2%, p = 0.001) but not in pT3/4 cases. Conclusions: PAR metastases significantly reduced the 5-year DFS in patients with clinically N0 primary parotid gland cancer. On subgroup analysis according to pT classification, this effect was significant among patients with early pT1/2 status but not patients with advanced pT3/4 status.

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 affects oncologic outcomes in cN0 mucoepidermoid carcinoma of the major salivary gland

The survival significance of the number of positive lymph nodes in salivary gland carcinoma remains unclear. Thus, the current study aimed to determine the effect of the number of positive lymph nodes on disease-specific survival (DSS) and overall survival (OS) in cN0 mucoepidermoid carcinoma (MEC) of the major salivary gland. Patients surgically treated for MEC of the major salivary gland between 1975 and 2019 were retrospectively enrolled from the surveillance, epidemiology, and end results database. The total population was randomly divided into training and test groups (1:1). Primary outcome variables were DSS and OS. Prognostic models were constructed based on the independent prognostic factors determined using univariate and multivariate Cox analyses in the training group and were validated in the test group using C-index. A total of 3317 patients (1624 men and 1693 women) with a mean age of 55 ± 20 years were included. The number of positive lymph nodes was an independent prognostic factor for both DSS and OS, but the effect began when at least two positive lymph nodes for DSS and three positive lymph nodes for OS were found. Predictive models for DSS and OS in the training group had C-indexes of 0.873 (95% confidence interval [CI] 0.853-0.893) and 0.835 (95% CI 0.817-0.853), respectively. The validation of the test group showed C-indexes of 0.877 (95% CI 0.851-0.902) for DSS and 0.820 (95% CI 0.798-0.842) for OS. The number of positive lymph nodes was statistically associated with survival in cN0 major salivary gland MEC. The current prognostic model could provide individualized follow-up strategies for patients with high reliability.

Neck management in metastatic cutaneous squamous cell carcinoma of the head and neck

Objective

Optimal neck management remains unclear in head and neck cutaneous squamous cell carcinoma (HNcSCC) with parotid metastasis. Our goal was to compare the impact of different cervical treatments on HNcSCC with parotid metastasis.

Methods

Patients were retrospectively included. The primary outcome variables were regional control (RC) and disease-specific survival (DSS). The impacts of observation, elective neck irradiation (ENI), and elective neck dissection (END) were analyzed using the Cox model and presented as hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

In total, 268 patients were enrolled. In the Cox model for RC, compared with ENI, observation was associated with a significantly higher risk of regional recurrence (p = 0.001, HR = 2.50, 95%CI = 1.45-4.30). However, END showed a comparable influence on regional recurrence (p = 0.246, HR = 0.70, 95%CI = 0.38-1.28). In the Cox model for DSS, END demonstrated a similar HR of 0.62 (95%CI = 0.30-1.26) compared to ENI (p = 0.184). However, patients who underwent observation were associated with an additional nearly twofold risk of cancer-related mortality (HR = 2.85, 95%CI = 1.55-5.23). Subgroup analysis showed that ENI predicted comparable RC (p = 0.389) and DSS (p = 0.346) in patients with one or two metastatic parotid lymph nodes, but worse RC (p = 0.007) and DSS (p = 0.024) in patients with more than three positive lymph nodes.

Conclusion

In HNcSCC with parotid metastasis, elective treatment of neck lymph nodes with END or ENI should always be performed.

Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer

In parotid gland cancer (PGC), cervical lymph node metastasis (LNM) and intra-parotid LNM are known as significant indicators of poor prognosis. However, the topography of LNM in the affected parotid gland and the lymphatic progression of PGC has never been explored in detail. This was a retrospective analysis of data from 423 patients with previously untreated primary PGC (2005 to 2020), excluding patients with squamous cell carcinoma, lymphoma or metastatic disease in the parotid gland. The pattern of LNM was analyzed by neck sub-level and parotid sub-site. Using the conditional probability of neck level involvement, a probability diagram was plotted on several thresholds to visualize the sequential progression of LNM in PGC. The pattern of LNM progression was found to be similar between low- and high-grade pathology, but the incidence differed significantly (8.0% vs. 45.4%). Intra-parotid LNs and level IIa LNs were the most common sites (57.3% and 61.0%) of LNM in PGC, followed by level III (31.7%), Ib (25.6%), IV (22.0%), IIb (20.7%) and Va (20.7%) LNM. In intra-parotid LNs, the incidence of LNM in the deep parotid LNs was relatively low (9.4%); most intra-parotid LNMs were observed in the superficial parotid (90.6%) and peri-tumoral (in contact with the tumor) (31.3%) LNs. LNM to levels Ia, Vb and contra-lateral LNM occurred only in the very late stage. Our results provide detailed information about LNM progression in PGC at the sub-level and can help clinicians decide the treatment extent, including surgery or radiation.

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.

Association between factor of parotid lymph node and prognosis in parotid cancer

INTRODUCTION

Survival significance of parotid lymph node (LN) factors in parotid cancer remains unclear, our goal was to assess the impact of number, size, and extranodal extension (ENE) of metastatic parotid LNs on prognosis in parotid cancer.

MATERIALS AND METHODS

Patients with surgically treated parotid cancer were retrospectively enrolled. Primary outcome variable was recurrence-free survival (RFS) and overall survival (OS). The hazard ratios (HRs) of main predictive variables including the number, size, and ENE of positive parotid LNs on RFS and OS were analyzed using Cox model. The secondary outcome variable was ENE of metastatic parotid LN, its association with clinicopathologic variables were evaluated using Chi-square test.

RESULTS

In total, 453 patients (186 male and 267 female) were included. The 10-year RFS and OS rates were 73% (95%CI: 69%-77%) and 61% (95%CI: 55%-67%), respectively. In Cox model, compared none parotid LN metastasis, one metastatic parotid LN did not offer additional compromise of RFS (p = 0.224) or OS (p = 0.135), but two or more positive LNs decreased the control of RFS (HR: 2.017; 95%CI: 1.378-4.632) and OS (HR: 2.173; 95%CI: 1.367-4.275). When accounting for the number of metastatic LNs, LN size or ENE was no longer related to RFS or OS. ENE of parotid LN tended to develop if there was presence of T3/4 stage, lymphovascular invasion, high histologic grade, N2/3 stage, and three or more positive parotid LNs.

CONCLUSION

Quantitative parotid LN burden but not ENE or LN size is an important determinant of survival in patients with parotid cancer.

Intraparotid lymph node metastasis affects distant metastasis in parotid adenoid cystic carcinoma

To evaluate the relationship between factors of metastatic intraparotid lymph node (IPLN) and distant metastasis in parotid adenoid cystic carcinoma (ACC). Patients with surgically treated parotid ACC were retrospectively enrolled, and primary outcome variable was distant metastasis free survival (DMFS). The effect of factors of metastatic IPLN on DMFS was evaluated using Cox model. In total, 232 patients were included. Extranodal extension of IPLN and cervical lymph nodes did not impact the DMFS, and the 7th but not 8th AJCC N stage was associated with DMFS. Groups of 0 and 1 metastatic IPLN had comparable DMFS, but presence of 2+ positive IPLN was related to increased worse DMFS (p = 0.034, HR 2.09). A new N stage (0 vs 1-2 vs 3+) based on total positive lymph node number exhibited better C-index than traditional N stage. IPLN metastasis increased the risk of distant metastasis, and the impact was mainly determined by the number of metastatic IPLN. Our proposed N stage provided better DMFS prediction than the 8th AJCC N classification.

Number of positive lymph nodes affects outcomes in parotid adenoid cystic carcinoma

Objectives

Survival significance of the number of positive lymph nodes (LNs) in parotid adenoid cystic carcinoma (ACC) remains unknown; thus, this study aimed to determine the impact of the number of positive LNs on the prognosis of parotid ACC.

Methods

Patients with surgically treated parotid ACC were enrolled from the SEER database. The number of positive LNs was analyzed using three models (0 vs 1+, 0 vs 1 vs 2 vs 3 vs 4 vs 4 vs 5 vs 6+, 0/1 vs 2-4 vs 5+), its hazard ratios on disease specific survival (DSS) and overall survival (OS) were assessed using univariate and multivariate Cox analyses.

Results

A total of 1,689 patients were included. In all models, the number of positive LNs was independently related to DSS and OS, model 3 had the highest C-index for DSS [0.83 (95% CI: 0.81-0.85)] and OS [0.82 (95% CI: 0.80-0.84)]. Compared with the 0/1 positive LN group, the 2-4 positive LN group had an HR of 2.81 (95% CI: 1.73-4.56) for DSS and 2.36 (95% CI: 1.58-3.54) for OS. The 5+ LN group had an HR of 20.15 (95% CI: 7.50-54.18) for DSS and 14.20 (95% CI: 5.45-36.97) for OS. No overlap existed in the 95% CI of the HR.

Conclusions

The three prognostic categories based on the number of positive LNs (0/1 vs 2-4 vs 5+) could stratify the DSS and OS in parotid ACC without overlap.

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.

[Surgery for parotid gland cancer-controversial and proven aspects]

BACKGROUND

Due to the rarity of primary parotid malignancies, there are currently only limited clinical study data on the optimal surgical therapy. Parotid malignancies encompass a broad spectrum of more than 20 different histological subtypes with varying biology, which thus represents a challenge for even experienced pathologists and head and neck surgeons with proven expertise in salivary gland surgery.

OBJECTIVE

The aim of this review article is to provide an overview of the current literature on surgical therapy of the primary tumor and the cN0 neck as well as treatment of the facial nerve, and to shed light on the various controversial aspects of this topic.

RESULTS

In salivary gland oncology there is a trend towards safe (R0) but more conservative surgery. Currently, less-invasive surgical approaches could potentially be applied in a small subgroup with carefully selected caudally located and R0-resected "low-grade tumors" in stages T1-T2 and cN0 in relatively young patients with high compliance and more in the context of structured clinical studies. Elective neck dissection in the case of cN0 status should be carried out if risk factors for occult cervical lymph node metastasis (T3-T4a, "high-grade subtypes," advanced age, lymphangitic carcinomatosis) are present. In cases of small "low-grade parotid carcinomas," narrow resection margins or even microscopic tumor residues on the facial nerve can potentially be adequately compensated with adjuvant radiation therapy. However, due to the lack of solid data, the significance of the actual effect of the radiation in this situation should be viewed with great caution.

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.

Significance of Pretreatment Neutrophil-to-Lymphocyte Ratio in Mucoepidermoid Carcinoma of Pediatrics: A Multicenter Study

Background: Our goal was to analyze the value of the pretreatment neutrophil-to-lymphocyte ratio (NLR) in the prognosis of pediatrics with parotid mucoepidermoid carcinoma (MEC). Methods: Patients (≤ 18 years old) undergoing surgical treatment for primary parotid MEC were enrolled from multiple clinical centers retrospectively. The χ²-test was used to analyze the associations between clinicopathological variables and the NLR. The main study endpoints were recurrence-free survival (RFS) and disease-specific survival (DSS). The prognostic value of NLR was assessed by Kaplan-Meier method and Cox model analysis. Results: There were 88 patients included in total, with mean NLR of 2.32 (range, 1.8-6.0). Histologic tumor grade and tumor stage were associated with the NLR significantly. The 10-year RFS rates were 98 and 81% for patients with an NLR < 2.32 and patients with an NLR ≥ 2.32, respectively, the difference was significant (p = 0.010). The 10-year DSS rate was 97 and 81% for patients with an NLR < 2.32 and patients with an NLR ≥ 2.32, respectively; the difference was not significant (p = 0.072). The independence of NLR in predicting the RFS was further confirmed in Cox model analysis. Conclusion: The NLR significantly affects the prognosis in pediatrics with primary parotid MEC.

Oncologic outcome and potential prognostic factors in primary squamous cell carcinoma of the parotid gland

BACKGROUND

Primary parotid squamous cell carcinoma (SCC) is an uncommon tumour, and there is limited data on its prognosis and treatment. The goal of the current study was to analyse the potential prognostic factors and clinical outcomes for this tumour type.

METHODS

Consecutive patients with surgically treated primary parotid SCC were retrospectively enrolled in this study. The primary end point was locoregional control (LRC) and disease-specific survival (DSS), which were calculated by the Kaplan-Meier method. Independent prognostic factors were evaluated by the Cox proportional hazards method.

RESULTS

In total, 53 patients were included for analysis. Perineural and lymphovascular invasion were observed in 21 and 16 patients, respectively. Intraparotid node (IPN) metastasis was reported in 23 patients with an incidence rate of 43.3%. Twenty-six patients with cN0 disease underwent neck dissection, and pathologic node metastasis was observed in 10 cases. The 5-year LRC and DS S rates were 35 and 49%, respectively. The Cox model was used to report the independence of disease stage and IPN metastasis in predicting LRC and the independence of disease stage and perineural invasion in predicting DSS.

CONCLUSIONS

The prognosis of primary parotid SCC is relatively unfavourable. IPN metastasis significantly decreases disease control, disease stage is the most important prognostic factor, and neck dissection is suggested for patients at any stage.

Prognostic Value of the Pretreatment Neutrophil-to-Lymphocyte Ratio in Pediatric Parotid Cancer

Objective: Our goal was to evaluate the prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) in pediatric patients with parotid cancer. Materials and Methods: Pediatric patients with primary parotid cancer were retrospectively enrolled from several clinical centers. The associations between the clinical-pathologic variables and NLR and the prognostic significance of NLR for recurrence-free survival (RFS) and disease-specific survival (DSS) were analyzed. Results: A total of 123 patients were included. The mean NLR was 2.51 and ranged from 1.7 to 6.1. The tumor stage and disease grade were significantly related to NLR. In patients with NLR < 2.51, the 10-year RFS rate was 97%, and in patients with NLR ≥ 2.51, the 10-year RFS rate was 84%; the difference was significant (p = 0.016). In patients with NLR < 2.51, the 10-year DSS rate was 98%, and in patients with NLR ≥ 2.51, the 10-year DSS rate was 83%; this difference was also significant (p = 0.035). Further Cox model analysis confirmed the independence of NLR in predicting the RFS and DSS rates. Conclusions: NLR is significantly associated with prognosis in pediatric patients with parotid cancer.

Predictors of distant metastasis in parotid acinic cell carcinoma

BACKGROUND

Distant metastasis (DM) is a common treatment failure pattern in acinic cell carcinoma (AciCC) of the major salivary glands; therefore, the main goal of this study was to analyse the predictors of DM in parotid AciCC.

METHODS

Consecutive patients with surgically treated parotid AciCC who were followed for at least 5 years were retrospectively reviewed. Data regarding age, sex, TNM stage, pathologic characteristics, surgical treatment, and follow-up examinations were collected and analysed. The primary end-point was DM control (DMC); the DMC survival was calculated from the date of surgery to the date of event or the latest follow-up examination and analysed by the Kaplan-Meier method. Independent prognostic factors were evaluated by the Cox proportional hazards method.

RESULTS

A total of 144 patients were included. Positive intraparotid nodes (IPNs) were noted in 34 (31.8%) patients. High-grade transformation was noted in 12 (8.3%) patients. A total of 83 (57.6%) patients underwent neck dissection, and neck node metastasis was proven in 37 (44.6%, 37/83) patients. The 10-year DMC rate was 86%. The Cox model analysis confirmed IPN metastasis (1.854 [1.061-4.144], p = 0.011) and high-grade transformation (4.219 [1.948-15.553], p < 0.001) as independent predictive factors of the DMC survival.

CONCLUSION

IPN metastasis and high-grade transformation are independent prognostic factors of the DMC survival.

Role of intraparotid node metastasis in mucoepidermoid carcinoma of the parotid gland

BACKGROUND

Prognostic factors for parotid mucoepidermoid carcinoma (MEC) usually include disease grade, tumor stage, node stage, perineural invasion, and lymphovascular invasion. But the role of intraparotid nodes (IPNs) remains unclear, therefore, the study aimed to analyze the significance of IPNs in predicting recurrence in parotid MEC.

METHODS

One hundred and ninety patients were included for analysis finally. Data regarding demography, pathological characteristics, IPN metastasis, TNM stage, follow up was collected and evaluated. The recurrence-free survival (RFS) was the main study endpoint.

RESULTS

A total of 47 (24.7%) patients had IPN metastasis, and the IPN metastasis was significantly related to tumor stage, pathologic N stage, lymph-vascular invasion, perineural invasion, and disease grade. Recurrence occurred in 34 (17.9%) patients. For patients without IPN metastasis, the 10-year RFS rate was 88%, for patients with IPN metastasis, the 10-year RFS rate was 54%, the difference was significant (p < 0.001). Further Cox model analysis confirmed the independence of IPN metastasis in predicting the prognosis.

CONCLUSION

The IPN metastasis is relatively common in parotid MEC, it is significantly related to tumor stage and disease grade, IPN metastasis means worse recurrence-free survival.

Role of the pretreatment neutrophil-to-lymphocyte ratio in the survival of primary parotid cancer patients

BACKGROUND

To analyze the value of the pretreatment neutrophil-to-lymphocyte ratio (NLR) in the survival of patients with parotid cancer.

METHODS

In total, 249 patients were enrolled. Information including age, sex, pretreatment NLR, and pathologic variables such as, tumor stage, intraparotid node (IPN) metastasis, and follow-up findings was extracted and analyzed.

RESULTS

IPN metastasis was noted in 45 (18.1%) patients, and the mean NLR was 2.48, with a range from 1.5 to 6.1. The NLR was significantly associated with tumor stage, disease stage, and disease grade. A total of 73 patients died of the disease, and the 10 -year disease-specific survival (DSS) rate was 62%. In patients with an NLR<2.48, the 10 -year DSS rate was 68%; in patients with an NLR≥2.48, the 10 -year DSS rate was 58%, and the difference was significant (P=0.006). Cox model analysis showed that the NLR was an independent prognostic factor for DSS.

CONCLUSION

The long-term survival of primary parotid cancer patients is relatively favorable, and the pretreatment NLR is significantly associated with prognosis.