Implications of intraglandular lymph node metastases in primary carcinomas of the parotid gland

Intraparotid node metastasis affects the long-term survival of patients with resectable recurrent parotid gland carcinoma

PURPOSE

The recurrence rate of parotid gland cancer is high, but research on the prognosis of recurrent parotid gland cancer (RPC) is relatively limited. We aim to determine the potential prognosis factors of RPC.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary cancer center.

METHODS

We conducted a retrospective review from 2012 to 2021 on RPC patients treated at the China National Cancer Center (CNCC). To analyze the impact of various variables on overall survival (OS) after recurrence, a univariate and multivariate Cox proportional hazard model was employed.

RESULTS

A total of 50/218 (23.0%) patients diagnosed with RPC and underwent surgery. The 5-year OS of all RPC patients in this cohort was 61.9%. 5 of 50 patients (10%) exhibited intraparotid node (IPN) metastasis. By univariate and multivariate analyses, we found that IPN metastasis was one of the prognostic factors of OS (p = 0.039) in RPC patients. The presence of IPN metastasis was also related to poor survival in individuals with negative cervical lymph nodes (CN0) (p = 0.011). In terms of the influence of surgical margins on prognosis, our findings revealed that RPC patients with negative margins exhibited a higher survival result than those with positive margins (p = 0.002).

CONCLUSION

According to this study, IPN metastasis indicate a high incidence of mortality in recurrent parotid cancer patients. Particularly, in CN0 patients, the presence of IPN metastasis was associated with poor survival in CN0 patients.

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.

Competing-risks nomograms for predicting cause-specific mortality in parotid-gland carcinoma: A population-based analysis

INTRODUCTION

Parotid-gland carcinoma (PGC) is a relatively rare tumor that comprises a group of heterogeneous histologic subtypes. We used the Surveillance, Epidemiology, and End Results (SEER) program database to apply a competing-risks analysis to PGC patients, and then established and validated predictive nomograms for PGC.

METHODS

Specific screening criteria were applied to identify PGC patients and extract their clinical and other characteristics from the SEER database. We used the cumulative incidence function to estimate the cumulative incidence rates of PGC-specific death (GCD) and other cause-specific death (OCD), and tested for differences between groups using Gray's test. We then identified independent prognostic factors by applying the Fine-Gray proportional subdistribution hazard approach, and constructed predictive nomograms based on the results. Calibration curves and the concordance index (C-index) were employed to validate the nomograms.

RESULTS

We finally identified 4,075 eligible PGC patients who had been added to the SEER database from 2004 to 2015. Their 1-, 3-, and 5-year cumulative incidence rates of GCD were 10.1%, 21.6%, and 25.7%, respectively, while those of OCD were 2.9%, 6.6%, and 9.0%. Age, race, World Health Organization histologic risk classification, differentiation grade, American Joint Committee on Cancer (AJCC) T stage, AJCC N stage, AJCC M stage, and RS (radiotherapy and surgery status) were independent predictors of GCD, while those of OCD were age, sex, marital status, AJCC T stage, AJCC M stage, and RS. These factors were integrated for constructing predictive nomograms. The results for calibration curves and the C-index suggested that the nomograms were well calibrated and had good discrimination ability.

CONCLUSION

We have used the SEER database to establish-to the best of our knowledge-the first competing-risks nomograms for predicting the 1-, 3-, and 5-year cause-specific mortality in PGC. The nomograms showed relatively good performance and can be used in clinical practice to assist clinicians in individualized treatment decision-making.

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.

Is There A Role for Limited Parotid Resections for Primary Malignant Parotid Tumors?

(1) Background: Lateral or total parotidectomy are the standard surgical treatments for malignant parotid tumors. However, some authors have proposed a more limited procedure. (2) Methods: We performed a review of the literature on this topic. Studies were included that met the following criteria: malignant parotid tumors, information about the extent of surgical resection, treated with less than a complete lateral lobectomy, and information on local control and/or survival. Nine articles fulfilled the inclusion criteria. (3) Results: Eight of the nine series reported favorable results for the more limited approaches. Most used them for small, mobile, low-grade cancers in the lateral parotid lobe. Most authors have used a limited partial lateral lobectomy for a presumed benign lesion. The remaining study analyzed pediatric patients treated with enucleation with poor local control. (4) Conclusions: There is weak evidence for recommending less extensive procedures than a lateral parotid lobectomy. In the unique case of a partial lateral parotidectomy performed for a tumor initially thought to be benign but pathologically proved to be malignant, close follow-up can be recommended for low grade T1 that has been excised with free margins and does not have adverse prognostic factors.

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.

Nomograms predictive for oncological outcomes in malignant parotid tumours: recurrence and mortality rates of 228 patients from a single institution

PURPOSE

Malignant parotid tumours are rare and multiple prognostic factors exist.

METHODS

Through a retrospective study we aimed to identify nomograms predicting recurrence and mortality rates in 228 primary parotid cancers. Patients clinical, treatment and tumour characteristics were retrospectively collected between 1980 and 2005 at our Institution. Factors predictive of disease-free-specific-survival (DSS) and overall survival (OS) were calculated by univariate and multivariate analysis. Nomograms were then constructed.

RESULTS

The 5- and 10-year DSS rates were 73% and 71.4%, and nomogram was drawn based on five parameters where perineural invasion showed the most significant predicting influence (p < 0.001). The median follow-up was of 95 months and the 5- and 10-year OS rates were 68.7% and 53.1%; six predictive variables (age, histological grade, perineural invasion, pathological lymph node status, resection margins and distant metastasis) were used to create nomogram.

CONCLUSIONS

Our nomograms provide a tailored outcome to a patient affected by malignant parotid tumour and give him/her a risk assessment for recurrence and mortality based on individual factors by a concordance index > 0.8.

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.

[Delineation of the primary tumour clinical target volumes and neck node levels selection of parotid cancers]

Salivary glands tumours are uncommon tumours showing a large diversity of histological types. This article presents a synthesis of patterns and paths of invasion of parotid glands tumours in order to propose an approach of the delineation of primary tumour clinical target volumes and of the selection of lymph nodes target volumes. This article does not discuss treatment indications but defines clinical target volumes to treat if radiotherapy is indicated. Postoperative situation being the most frequent, the delineation of primary tumour clinical target volume is based on an anatomical approach.

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.

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.

Contemporary Management of Benign and Malignant Parotid Tumors

To report the standard of care, interesting new findings and controversies about the treatment of parotid tumors. Relevant and actual studies were searched in PubMed and reviewed for diagnostics, treatment and outcome of both benign and malignant tumors. Prospective trials are lacking due to rarity of the disease and high variety of tumor subtypes. The establishment of reliable non-invasive diagnostics tools for the differentiation between benign and malignant tumors is desirable. Prospective studies clarifying the association between different surgical techniques for benign parotid tumors and morbidity are needed. The role of adjuvant or definitive radiotherapy in securing loco-regional control and improving survival in malignant disease is established. Prospective clinical trials addressing the role of chemotherapy/molecular targeted therapy for parotid cancer are needed. An international consensus on the classification of parotid surgery techniques would facilitate the comparison of different trials. Such efforts should lead into a clinical guideline.

Recurrent parotid gland carcinoma: how effective is salvage surgery?

OBJECTIVE

Recurrent parotid gland carcinomas (PGCs) are poorly characterized and studies focusing on this topic are rare due to their low incidence. The goal of this study is to analyze the therapeutic strategies, prognostic factors, and oncological outcomes of a series of patients with recurrent PGCs.

PATIENTS AND METHODS

Retrospective chart review (1997-2012) of patients with recurrent PGCs was initially treated with curative intent.

RESULTS

We identified 20 patients with recurrent PGCs. Eleven patients presented isolated local, regional, or distant metastases, while the rest had recurrences in multiple sites. Recurrent tumors tended to present more advanced T-stage (p = 0.01) and overall stage (p < 0.001), but not N-stage (p = 0.74) when compared to the initial tumors. Half the patients (50%) had distant metastases at the moment of recurrence diagnosis, and another three developed them after attempted salvage surgery. Only 8/20 patients with isolated local or regional recurrences were surgically salvaged with extended revision parotidectomy and neck dissection, respectively. The remaining 12 patients were managed on palliative basis. Overall survival (31.70 months vs. 20.73 months) and progression-free survival (28.70 months vs. 13.61 months) were not significantly different in patients managed surgically vs. palliatively.

CONCLUSION

Recurrent PGCs are aggressive neoplasms with a high rate of distant metastases. Surgical salvage can be considered in patients with limited local and/or regional recurrences. The alternative to surgical salvage is palliative management with different chemotherapeutic regimens. Survival does not differ between the two strategies in the present series.