Survival in patients with parotid gland carcinoma - Results of a multi-center study

Disease and toxicity outcomes for a modern cohort of patients with squamous cell carcinoma of cutaneous origin involving the parotid gland: Comparison of volumetric modulated arc therapy and pencil beam scanning proton therapy

OBJECTIVES

We sought to describe outcomes for locally advanced cutaneous squamous cell carcinoma (SCC) involving the parotid treated with volumetric modulated arc therapy (VMAT) versus pencil beam scanning proton beam therapy (PBT).

MATERIALS AND METHODS

Patients were gathered from 2016 to 2022 from 5 sites of a large academic RT department; included patients were treated with RT and had parotid involvement by: direct extension of a cutaneous primary, parotid regional spread from a previously or contemporaneously resected but geographically separate cutaneous primary, or else primary parotid SCC (with a cutaneous primary ostensibly occult). Acute toxicities were provider-reported (CTCAE v5.0) and graded at each on treatment visit. Statistical analyses were conducted.

RESULTS

Median follow-up was 12.9 months (1.3 - 72.8); 67 patients were included. Positive margins/extranodal extension were present in 34 cases; gross disease in 17. RT types: 39 (58.2 %) VMAT and 28 (41.8 %) PBT. Concurrent systemic therapy was delivered in 10 (14.9 %) patients. There were 17 treatment failures (25.4 %), median time of 168 days. Pathologically positive neck nodes were associated with locoregional recurrence (p = 0.015). Oral cavity, pharyngeal constrictor, and contralateral parotid doses were all significantly lower for PBT. Median weight change was -3.8 kg (-14.1 - 5.1) for VMAT and -3 kg (-16.8 - 3) for PBT (p = 0.013). Lower rates of ≥ grade 1 xerostomia (p = 0.002) and ≥ grade 1 dysguesia (p < 0.001) were demonstrated with PBT.

CONCLUSIONS

Cutaneous SCC involving the parotid can be an aggressive clinical entity despite modern multimodal therapy. PBT offers significantly lower dose to organs at risk compared to VMAT, which seemingly yields diminished acute toxicities.

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.

Number of positive lymph nodes combined with the logarithmic ratio of positive lymph nodes predicts long-term survival for patients with node-positive parotid gland carcinoma after surgery: a SEER population-based study

PURPOSE

To evaluate the prognostic value of the number of positive lymph nodes (NPLN), the ratio of positive lymph nodes (pLNR), and the logarithmic ratio of positive lymph nodes (LODDS) in patients with parotid gland carcinoma. On this basis, establishing and validating an optimal nomogram.

METHODS

A total of 895 patients with T1-4N1-3M0 parotid gland carcinoma were included in our study from the Surveillance, Epidemiology, and End Results (SEER) database. Patients' data were randomly assigned to the training cohort and the validation cohort by a ratio of 7:3. Univariate and multivariate COX regression analysis were used to explore the relationship between the study factors and the prognosis of parotid gland carcinoma, including overall survival (OS) and cause-specific survival (CSS). The Akaike Information Criterion (AIC) was used to evaluate model fit. Harrell's concordance index (C-index), integrated discrimination improvement (IDI), and net reclassification index (NRI) were used to evaluate the predictive ability of these models. The decision curve analysis was used to evaluate the clinical benefit of the nomograms compared with the TNM stage.

RESULTS

NPLN, pLNR, and LODDS are independent risk factors for the prognostic of PGC. According to the AIC, C index, IDI, and NRI, the models combined with NPLN and LODDS were the best. The decision curves suggested that our nomograms had good predictive abilities for the prognosis of parotid gland carcinoma.

CONCLUSION

The two nomograms which contained NPLN and LODDS had the potential to predict OS and CSS in patients with parotid gland carcinoma.

Risk Factors for Poor Survival Outcomes in Parotid Metastatic Cutaneous Squamous Cell Carcinoma

OBJECTIVE

We aimed to analyze risk factors associated with poor survival outcomes for metastatic cutaneous head-and-neck SCC to the parotid.

METHODS

All patients undergoing surgery for metastatic cutaneous SCC to the parotid with curative intent between 2011 and 2018, were reviewed. Demographic and clinical characteristics were evaluated. Histopathological data including tumor size and histology, tumor grade, TNM stage, resection margins, lymphovascular invasion, and perineural invasion, were analyzed. Overall survival (OS), disease-specific survival (DSS), and freedom from locoregional recurrence (LRR) were assessed.

RESULTS

Ninety patients were included (mean age, 77 years; 75 men [83.3%]). A total parotidectomy was performed in 48 patients (53.3%), and 42 (46.7%) underwent a superficial parotidectomy. Seventy patients (77.8%) underwent adjuvant RT. The median follow-up was 31 months (20-39 months). Tumor volume ≥ 50 cm³ and a shorter RT duration (<20 days) were associated with reduced OS (p = 0.002 and p = 0.01, p = 0.02 and p = 0.009, respectively), and DSS (p = 0.004 and p = 0.02, p = 0.04 and p = 0.02, respectively) on univariable and multivariable analysis, respectively. Only a shorter RT duration was associated with worse freedom from LRR on univariable and multivariable analysis, (p = 0.04 and p < 0.001, respectively). However, with death as a competing risk, a shorter duration of RT was not significantly associated with freedom from LRR.

CONCLUSION

A shorter duration of adjuvant RT, and excised tumor volume ≥50 cm³ were predictive factors of reduced OS and DSS, and a shorter duration of RT was also associated with reduced freedom from LRR in patients with metastatic SCC to the parotid gland.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2022.

The role of perineural invasion in parotid malignancy outcomes: A systematic review and meta-analysis

PURPOSE

At present, perineural invasion is used as a histologic indicator of aggressive salivary gland disease. In other head and neck malignancies, perineural invasion impacts staging of cancer lesions and therefore affects treatment options.

OBJECTIVE

To compare survival outcomes in primary parotid malignancies with and without perineural invasion.A systematic review pooled data from the scientific literature in patients with any primary parotid malignancy to investigate the prognosis of those with perineural invasion.

DATA SOURCES

PubMed (Medline), Scopus and Cochrane databases were queried from inception to July 2020 without any initial search constraints. Additional publications were included from review of pertinent articles.

STUDY SELECTION

Our inclusion criteria included primary parotid cancers with reported perineural invasion on survival outcomes. Exclusion criteria were non-English language text, non-human studies, reviews, textbooks, abstracts, case reports and case series. Two authors independently reviewed articles for inclusion. Of the initial 465 records, 83 articles were reviewed in full to yield a final collection of 14 studies.

DATA EXTRACTION AND SYNTHESIS

PRISMA-p guidelines were used in the reporting of our studies. A MOOSE Checklist was also used. MINORS criteria were applied to assess risk of bias. Random-effects models were used to estimate pooled effect sizes. No institutional review board review was needed for our study.

MAIN OUTCOMES AND MEASURES

Primary study outcomes were set prior to data collection and included overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS) and distant-metastasis-free survival (DMFS) in patients with and without perineural invasion.

RESULTS

Fourteen studies contributed to this meta-analysis. Compared to patients without perineural invasion, the pooled rate of mortality (HR = 3.64), time to recurrence (HR = 3.56), disease-specific mortality (HR = 2.77) and distant metastasis (HR = 3.84) was significantly higher for patients with PNI (all p <.001). Controlling for perineural invasion status, no moderator was associated with these survival outcomes (all p >.05). Given the clinical severity of perineural invasion, few studies were null as shown in a panel of publication bias plots.

CONCLUSION

Perineural invasion portends a poor survival outcome in patients with parotid malignancies.

LEVEL OF EVIDENCE: 1

Nomogram-Based Prediction of Overall and Disease-Specific Survival in Patients With Postoperative Major Salivary Gland Squamous Cell Carcinoma

Background : The major salivary gland squamous cell carcinoma is a rare head and neck tumor, often accompanied by lymph node metastasis. Even if the patient undergoes surgery, the prognosis remains unsatisfactory. To explore the prognostic factors of postoperative major salivary gland squamous cell carcinoma to establish a prognostic risk stratification model to guide clinical practice. Methods: Patients’ information was retrieved from the Surveillance, Epidemiology, and End Results database from 2004 to 2018. Optimal cutoff points were determined using X-tile software, and overall survival and disease-specific survival were calculated by the Kaplan-Meier method. Independent prognostic factors affecting the overall survival and disease-specific survival were identified by multivariate analysis, and corresponding 2 nomogram models were constructed. The discriminative ability and calibration of nomograms were evaluated by the Concordance index, area under curves, and calibration plots. Results: A total of 815 patients with postoperative major salivary gland squamous cell carcinoma were enrolled. The cutoff values for the number of lymph nodes were 2, and the cutoff values for the lymph node ratio were 0.11 and 0.5, respectively. Age, T stage, tumor size, lymph nodes, lymph node ratio, and radiotherapy were prognostic factors for overall survival and disease-specific survival. Nomograms for disease-specific survival and overall survival were established and showed favorable performance with a higher Concordance index and area under curves than that of the tumor–node–metastasis stage and Surveillance, Epidemiology, and End Results stage. The calibration plots of 1-, 3-, and 5-year overall survival and disease-specific survival also exhibited good consistency. What's more, patients were divided into low-, moderate-, and high-risk groups according to the scores calculated by the models. The overall survival and disease-specific survival of patients in the high-risk group were significantly worse than those in the moderate- and low-risk group. Conclusions: Our nomogram integrated clinicopathological features and treatment modality to demonstrate excellent performance in risk stratification and prediction of survival outcomes in patients with major salivary gland squamous cell carcinoma after surgery, with important clinical value.

Partial parotid sialoadenectomy in a horse with parotid ductal carcinoma: Surgical description and case report

OBJECTIVES

To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma.

STUDY DESIGN

Case report ANIMALS: Twelve year old American Quarter Horse gelding.

METHODS

The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small intestinal submucosal (SIS) sheet. Cisplatin beads were implanted in the wound bed prior to closure. Firocoxib (0.1 mg/kg orally, daily, every 24 h) treatment was initiated.

RESULTS

Postoperative complications included right-sided facial nerve paralysis, difficulty with deglutition of fibrous feeds, and surgical site dehiscence. Wound healing was achieved by second intention. Partial improvement in nerve function was observed within the first 6 months. At 12 months postparotidectomy, no sign of tumor reoccurrence or metastatic disease was present, and the gelding returned to work.

CONCLUSION

Partial parotid sialoadenectomy was performed with a favorable long-term outcome. Regional anatomic knowledge is crucial.

Predicting cancer-specific mortality in patients with parotid gland carcinoma by competing risk nomogram

BACKGROUND

The aim of the present study was to establish a competing risk nomogram to predict parotid gland cancer-specific mortality (PGC-SM).

METHODS

Seven thousand nine hundred and sixty-two patients extracted from SEER database were randomly categorized into training and validation sets. The competing risk model was used to identify factors associated with PGC-SM. The nomogram was evaluated via concordance indexes (C-indexes), calibration plots, and decision curve analysis (DCA).

RESULTS

Male, elderly, white, widowed, larger tumor, no surgery, advanced tumor grade, lymph node (LN) metastasis, adenocarcinoma (ADC), and higher TNM stage were associated with higher incidence of PGC-SM. Calibration plots showed that the nomogram was well calibrated. C-indexes for nomogram were 0.84 (95% CI: 0.81-0.86) and 0.84 (95% CI: 0.82-0.86) in training and validation sets, respectively. DCA demonstrated the clinical usefulness of nomogram.

CONCLUSIONS

The competing risk nomogram shows high performance in predicting PGC-SM, which might enable clinicians formulate suitable treatment protocols for patients with parotid gland carcinoma (PGC).

The Role of Postoperative Radiotherapy and Prognostic Model in Primary Squamous Cell Carcinoma of Parotid Gland

Background

Primary squamous cell carcinoma of parotid gland (parotid SCC) is a high malignant histologic subtype of parotid cancers with aggressive clinical presentation. However, the clinical features and survival benefit of postoperative radiotherapy (PORT) for primary parotid SCC are not well known.

Methods

A retrospective population-based study was performed to identify the role of PORT in parotid SCC patients diagnosed between 1975 and 2016 from SEER database. A prognostic risk model was established based on patient clinical features, including age, tumor stage, and node involvement status. Patients were stratified into high, intermediate, and low risk according to this model. The survival benefit of radiotherapy was compared in the whole cohort and different risk groups.

Results

Nine hundred thirty-one parotid SCC patients were extracted from SEER database, 634 (68.1%) in the RT group and 286 (30.7%) in the non-RT group. Overall, 503 (54.0%) deaths occurred, with a median follow-up of 84 months, the 5-year OS was 43.6% in the whole cohort, 47.7 vs 35.9% in patients with/without PORT (P = 0.005), and 58.9 vs. 38.8 vs. 27.1% in low-, intermediate-, and high-risk group (P < 0.001). Compared with surgery alone, PORT significantly improved the OS of patients with medium risk (47.5 vs. 20.6, P < 0.001), whereas not in the low risk (61 vs. 54%, P = 0.710) and high (25.6 vs. 28.7%, P = 0.524).

Conclusion

This prognostic model can separate the patients with parotid squamous cell carcinoma into different risk. PORT significantly improved the OS of patients with intermediate risk, whereas high-risk group may need more intensive treatment strategies.

The impact of nodal status in major salivary gland carcinoma: A multicenter experience and proposal of a novel N-classification

OBJECTIVES

Despite differences in oncological behavior, the 8th edition of AJCC TNM staging currently proposes the same N-classification for major salivary glands (MSG) carcinoma and squamous cell carcinoma of the upper aerodigestive tract. The present study aims to investigate a more reliable definition of N-categories for MSG carcinoma.

MATERIALS AND METHODS

A retrospective multicenter study was performed, including 307 patients treated for primary MSG carcinoma from 1995 to 2019. Outcome measures included overall survival (OS), disease specific survival, and local, regional, and distant recurrence. Survival analysis was performed using log-rank test and Cox proportional-hazards model. Overall number (ON) and largest diameter (LD) of nodal metastases, including intra-parotid metastases, were considered to develop three novel proposals of N-classification; their performance were compared with the current TNM staging using Akaike information criterion (AIC), Bayesian information criterion (BIC), and Nagelkerke pseudo-R2.

RESULTS

Intra-parotid nodes, ON and LD of nodal metastases emerged as major prognosticators for OS, while extra-nodal extension did not impact on any survival. The current N-classification did not show a satisfactory OS stratification. Three novel N-classifications were developed according to number of metastatic nodes (0 vs 1-3 vs ≥ 4) and/or their maximum diameter (<20 mm vs ≥ 20 mm). They all showed better accuracy in OS stratification, and achieved better AIC, BIC and Nagelkerke pseudo-R2 indices when compared to current N-classification.

CONCLUSION

All the proposed N-classifications improved OS stratification and could help in defining a specific N-classification for MSG carcinoma. Their validation and assessment in an external cohort is needed.

The underappreciated role of auriculotemporal nerve involvement in local failure following parotidectomy for cancer

BACKGROUND

Locoregional recurrence rates following parotidectomy for cancer remain as high as 20-30%. The auriculotemporal nerve (ATN) may allow parotid cancers to spread from the facial nerve (FN) toward the skull base, causing local recurrence.

METHODS

Retrospective review of 173 parotidectomies for malignancy. Preoperative and post-recurrence imaging were reviewed by a neuroradiologist for signs of tumor adjacent to the ATN.

RESULTS

Clinical and imaging signs of possible ATN involvement correlated with FN weakness and sacrifice. Eight patients had pathologically confirmed tumor from the ATN or V3. Forty-four percent of local recurrences had post-recurrence imaging showing tumor along the course of the ATN. Locoregional failure along the ATN was also associated with preoperative FN weakness, intraoperative FN sacrifice, and failure to complete recommended adjuvant therapy.

CONCLUSIONS

Parotid cancers may invade the FN and spread to the skull base via the ATN. If not appropriately managed, this may lead to local recurrence.

Prognostic value of lymph node density for major salivary gland carcinoma without clinical lymph node metastasis

BACKGROUND AND OBJECTIVE

This study aimed to investigate whether lymph node density (LND) was correlated with overall survival (OS) in major salivary gland carcinoma without clinical lymph node metastasis.

METHODS

Sixty patients who were diagnosed with major salivary gland carcinoma without clinical lymph node metastasis were enrolled. Of these, 50 patients underwent neck dissection. LND was defined as the ratio of the number of positive lymph nodes to the total number of resected lymph nodes.

RESULTS

An LND of ≥0.1 was significantly associated with a short OS (p < 0.05). Multivariate analysis with adjustment for pathological N classification and positive surgical margin showed that an LND of ≥0.1 is a predictor of OS.

CONCLUSION

Results demonstrated that lymph node density functions as a predictor of outcomes for major salivary gland carcinoma without clinical lymph node metastasis.

Intermediate-grade carcinoma of the parotid and the impact of adjuvant radiation

PURPOSE

To determine the influence of adjuvant radiotherapy on survival in surgically-managed early stage intermediate-grade mucoepidermoid and acinic cell carcinoma of the parotid.

MATERIALS AND METHODS

The National Cancer Database was reviewed between 2004 and 2015 to identify patients with intermediate-grade, early T-stage, node-negative parotid carcinoma who underwent parotidectomy ± radiotherapy.

RESULTS

There were 744 patients identified of which 81% had mucoepidermoid carcinoma and 19% had acinic cell carcinoma. Positive surgical margins were identified in 21% and adjuvant radiotherapy was administered in 38% of cases. Of the 159 patients with positive margins, 113 (71%) received adjuvant radiotherapy. Of the 585 patients with negative margins, 173 (30%) underwent adjuvant radiotherapy. In multivariable analysis, age (over 52 years: HR 5.19, 95%CI 2.33-11.57), insurance status (private insurance: HR 0.24 95%CI 0.13-0.43), and extent of parotidectomy (total parotidectomy: HR 2.02 95%CI 1.23-3.31) were significantly associated with overall survival, while adjuvant radiotherapy was not a significant predictive factor (HR 0.81, 95%CI 0.49-1.36). In patients with positive margin resections, however, adjuvant radiation was an independent predictor of improved survival when adjusted for age, insurance status, and extent of parotidectomy (HR 0.34, 95%CI 0.13-0.88). Conversely, in patients with negative margin resections, adjuvant radiation did not influence survival outcomes when adjusted for these covariates (HR 1.02, 95%CI 0.53-1.93).

CONCLUSIONS AND RELEVANCE

In patients with early stage intermediate-grade parotid carcinoma, adjuvant radiotherapy significantly and independently improves survival in those with post-operative positive margins. Adjuvant therapy, however, does not appear to improve survival outcomes in those with negative margin resections.

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.

A nomogram to estimate the risk of developing distant metastases in parotid cancer

BACKGROUND

Parotid cancer (PC) is a heterogeneous group of malignant tumors whose management mainly focuses on locoregional control. However, distant metastases (DM) can represent the most common cause of treatment failure. We have defined the predictors and developed a model that can predict a single patient's risk to develop DM.

METHODS

We have analyzed our institutional database of 259 patients with PC and use it to develop a nomogram. C-index and calibration curves were used to assess performance of our model.

RESULTS

DM appeared in 18.9% of patients. Age, cT, pN, perineural invasion, and adenoid cystic carcinoma were significantly associated with distant failure.

CONCLUSIONS

We here present the first model to identify patients with PC at high risk of DM. Such tool can be of great value in managing these rare cancers in terms of a more precise prognosis and follow-up while waiting for better systemic therapies to come in the future.

A retrospective multicenter study of sublingual gland carcinoma in Japan

OBJECTIVE

Salivary gland carcinoma is rare among head and neck cancers. Sublingual gland carcinoma, a type of salivary gland carcinoma, is even rarer; therefore, the number of cases at a single institute is too small for sufficient evaluation of tumor characteristics. We conducted a multicenter, retrospective analysis of sublingual gland carcinomas in patients who visited 12 institutions associated with the Kyoto Hospital and Affiliated Facilities Head and Neck Clinical Oncology Group.

METHODS

Thirteen previously untreated patients who visited the institutions between 2006 and 2015 were enrolled. The overall survival (OS) and disease-free survival (DFS) rates for all patients and by disease stage were analyzed. Statistical analyses were performed for all patients with respect to disease stage.

RESULTS

Eight of thirteen patients were diagnosed with adenoid cystic carcinoma on pathological study. A significant difference in OS rate was observed between patients with Stage I-III and Stage IV disease; however, the difference in DFS rate by disease stage was not significant.

CONCLUSION

Stage IV disease was identified as a poor prognostic factor in patients with sublingual gland carcinoma. However, even patients with Stage I-III disease experienced relatively short DFS. Distant metastasis is a serious problem among patients with sublingual gland carcinoma.

Subgroups of parotid gland infiltrating ductal carcinoma benefit from postoperative radiotherapy: a population-based study

Aim: To analyze the prognostic factors and the impact of postoperative radiotherapy (PORT) in parotid gland infiltrating ductal carcinoma (IDC). Materials & methods: 252 patients diagnosed with parotid gland IDC were identified from the SEER database. Kaplan–Meier and Cox regression analysis was performed to evaluate the prognostic factors. Propensity score matching was applied then. Results: Multivariate analysis showed old age and chemotherapy were independent risk factors in parotid gland IDC. Subgroup analysis demonstrated that overall survival (OS) rate of the PORT group was significantly superior to that of the no radiotherapy group in the T3–4 subgroup (p = 0.049), N1 subgroup (p = 0.019) and Tumor, Node, Metastasis (TNM) III subgroup (p = 0.025). Conclusion: PORT improved survival of parotid gland IDC patients within T3–4, N1 and TNM III subgroups.

Contemporary treatment patterns and outcomes of salivary gland carcinoma: a National Cancer Database review

PURPOSE

Salivary gland carcinomas (SGC) are rare malignancies and data regarding treatment outcomes stratified by histologic subtype are currently limited. This study aims to examine current, national treatment patterns and overall survival (OS) of patients with the major histologic subtypes of salivary gland carcinoma.

SUBJECTS AND METHODS

A review was performed of the National Cancer Database (NCDB) of patients with confirmed diagnoses of mucoepidermoid carcinoma, acinic cell carcinoma, adenoid cystic carcinoma, adenocarcinoma, or carcinoma ex pleomorphic receiving curative treatment between 2004 and 2014. Univariate and multivariate regression modeling were performed to identify risk factors significantly associated with overall survival (OS). Adjusted survival analyses stratified by treatment and staging were performed with the primary outcome of overall survival (OS) and were further stratified based on histologic subtype.

RESULTS

The final analysis included 7342 patients [3547 men (48.3%) and 3795 women (51.7%); mean age 58.3 years (range 18-90 years)]. Mucoepidermoid carcinoma was the most common histology encountered [n = 2669 (36.4%)]. Unadjusted and adjusted analysis demonstrated improved survival with surgery and radiation therapy (RT) for adenoid cystic (HR = 0.69; p = 0.029), adenocarcinoma (HR = 0.61; p < 0.001), high-grade mucoepidermoid carcinoma (HR = 0.70; p = 0.026), and carcinoma ex pleomorphic (HR = 0.64; p = 0.028), while surgery with chemoradiation therapy (CRT) was associated with worse OS regardless of histologic subtype. The impact of advanced stage on survival varied amongst the histologic subtypes but portended the worst prognosis for patients with adenocarcinoma and carcinoma ex pleomorphic.

CONCLUSIONS

The results of this NCDB review demonstrate unique treatment patterns and survival outcomes for SGC based on major histologic subtype.

The limited role of elective neck dissection in patients with cN0 salivary gland carcinoma

PURPOSE

To evaluate whether elective neck dissection (END) was beneficial for cN0 patients with salivary gland carcinoma.

MATERIALS AND METHODS

The rates of regional failure-free survival and disease-free survival were calculated using Kaplan-Meier methods and Cox models. The risk factors for occult lymph node metastasis (OLNM) in cN0 patients undergoing END was analyzed using logistic regression. A nomogram was formulated to calculate the estimated probability of OLNM.

RESULTS

Neck dissection was performed in 84 patients (43.3%). OLNM was detected in eight of the patients who underwent END. During the follow-up period, regional recurrences involving cervical lymph nodes were found in 10 patients. Cox model analysis revealed that neck dissection was not related to regional failure-free survival and disease-free survival. Logistic regression analysis revealed that older age, neural symptoms, and positive adjacent lymph nodes were associated with OLNM. A nomogram comprising age, neural symptoms, and adjacent lymph nodes was developed to predict the risk of OLNM.

CONCLUSION

The incidence of OLNM was low in cN0 patients after detailed preoperative evaluations. There was no strong evidence supporting END as a conventional therapy in cN0 patients with salivary cancers. Our nomogram is a simple and practical instrument for strengthening the prediction of OLNM.

The number and ratio of positive lymph nodes are independent prognostic factors for patients with major salivary gland cancer: Results from the surveillance, epidemiology, and End Results dataset

INTRODUCTION

To investigate whether the positive lymph node number (PLNN) and positive lymph node ratio (PLNR) could predict the prognosis of patients with major salivary gland cancer (MSGC) and to identify the optimal cutoff points for these variables that stratify patients according to their risk of survival.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database to identify all patients with MSGC between 1988 and 2014. A logistic regression analysis was carried out to evaluate the risk factors for lymph node metastasis (LNM) in MSGC. The X-tile program was used to identify the cutoff values for the PLNN and PLNR in MSGC patients with LNM. Cox proportional hazards regression models were performed to identify the predictors of cancer-specific survival (CSS).

RESULTS

In the SEER database, 8668 eligible patients were identified and 3046 of them had LNM. The logistic regression analysis indicated that older age, male sex, larger tumor size, higher grade, tumor extension and high-risk pathology were associated with LNM. The X-tile program showed that a PLNN>4 and a PLNR>0.15 were prognostic indicators of CSS. A multivariable analysis indicated that, after the factors that might potentially affect the prognosis were adjusted for, the PLNN and PLNR were still associated with CSS.

CONCLUSIONS

Our Results demonstrated that the PLNN and PLNR were independent prognostic indicators for MSGC patients with lymph node metastasis.