Postoperative radiation therapy for small, low-/intermediate-grade parotid tumors with close and/or positive surgical margins

Tumor budding - a potential biomarker in low grade salivary gland carcinomas?

Background

Low-grade salivary gland carcinoma is regularly treated with surgical therapy of the salivary gland without elective neck dissection in T1/2 carcinomas, either alone or with adjuvant radiation therapy. However, occult metastasis and locoregional recurrence influence therapy and outcome. Tumor budding is an emerging prognostic pathological factor in many carcinomas, but has not yet been adequately considered in salivary gland carcinomas.

Methods

We conducted a retrospective single-center study of 64 patients diagnosed with low-grade carcinoma of the major salivary glands treated between 2003 and 2017. Pathological risk factors and TNM classification were thoroughly assessed for each case. All hematoxylin and eosin (HE)-stained histological specimens underwent careful examination, and tumor budding was identified following the guidelines set forth by the International Tumor Budding Consensus Conference in 2016.

Results

Tumor budding was not statistically significant concerning 5-year survival rate (5-YSR) (p=0.969) and mean overall survival (log-rank p=0.315). Whereas 5-year disease-free survival rate (5-YDFSR) was 87% in the low tumor budding group and 61.1% in the intermediate and high tumor budding group (p=0.021). Mean disease-free survival accounted for 100.2 months (CI: 88.6;111.9) in the low budding score group and 58.7 months (CI: 42.8;74.6) in the other group (log-rank p=0.032). Notably, pT1/2 showed significantly lower tumor buds than pT3/4 stages (2.43 tumor buds/0.785 mm2 vs. 4.19 tumor buds/0.785 mm2, p=0.034). Similar findings were noted comparing nodal-positive and nodal-negative patients, as well as patients with and without lymphovascular invasion and perineural invasion (each p<0.05).

Conclusions

Tumor budding might be used as an additional prognostic factor for recurrence in low-grade salivary gland carcinoma, seemingly associated with a higher nodal metastasis rate and advanced tumor stages and a worse 5-YDFSR. Consequently, the evaluation of tumor budding in resection specimens of low-grade salivary gland tumor may prove valuable in decision-making for neck dissection and follow-up strategy.

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.

Adjuvant radiotherapy in node-negative salivary malignancies of the parotid gland: A multi-institutional analysis

BACKGROUND AND PURPOSE

To determine the role of adjuvant radiotherapy (ART) in parotid gland cancer without nodal metastasis, we evaluated the survival outcomes, prognostic factors, and dose-response relationships in patients with node-negative parotid gland cancer patients.

MATERIALS AND METHODS

Patients who underwent curative parotidectomy and were pathologically diagnosed with parotid gland cancer without regional or distant metastases between 2004 and 2019 were reviewed. The benefit of ART in terms of locoregional control (LRC) and progression-free survival (PFS) were evaluated.

RESULTS

In total, 261 patients were included in the analysis. Of them, 45.2 % received ART. The median follow-up period was 66.8 months. Multivariate analysis revealed that histological grade and ART were independent prognostic factors for LRC and PFS (all p <.05). For patients with high-grade histology, ART was associated with a significant improvement in 5-year LRC (p =.005) and PFS (p =.009). Among patients with high-grade histology who completed RT, higher biologic effective dose (≥77 Gy10) significantly increased PFS (adjusted hazard ratio [HR], 0.10 per 1-Gy increase; 95 % confidence interval [CI], 0.02-0.58; p =.010). ART significantly improved LRC (p =.039) in patients with low-to-intermediate histological grade as well per multivariate analysis, and subgroup analyses revealed patients with T3-4 stage and close/positive resection margins (<1 mm) would benefit from ART.

CONCLUSION

ART should be strongly recommended for patients with node-negative parotid gland cancer with high-grade histology in terms of disease control and survival. In patients with low-to-intermediate-grade disease, those with high T stage and incomplete resection margin benefit with ART.

Influence of Grading on Management and Outcome in Mucoepidermoid Carcinoma of the Parotid-A Multi-institutional Analysis

OBJECTIVE

To evaluate clinical outcome of low (G1), intermediate (G2), and high-(G3) grade mucoepidermoid carcinomas (MEC) of the parotid gland.

STUDY DESIGN

Retrospective chart review including 212 patients. Clinicopathological data was statistically analyzed regarding grading, overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS).

RESULTS

105 (49.5%) G1, 73 (34.5%) G2, and 34 (16%) G3 MEC were included and 56 (26.4%) patients presented with neck node metastases. The risk of occult nodal metastases was significantly associated with grading and increased from 9.2% in G1 to 26.7% and 27.8% in G2 and G3 tumors, respectively (p = 0.008). Elective periparotid and cervical lymph node dissection was performed in 170 (80.2%) and 70 (33%) patients, respectively. All patients with positive periparotid nodes when subjected to an additional neck dissection had associated cervical neck node involvement (p < 0.001). Grading was an independent significant prognostic factor for OS (HR 4.05; 95%CI: 1.15-14.35; p = 0.030) and DSS (HR 17.35; 95%CI: 1.10-273.53; p = 0.043). In a subgroup analysis, elective neck dissection (END) was also significantly associated with a better DFS (p = 0.041) in neck node-negative G1 MECs.

CONCLUSION

The risk of occult nodal metastasis in intermediate-grade MEC is as high as in high-grade MEC and that END in G1 tumors is associated with a prolonged DFS. Additionally, periparotid node involvement seems to be a predictor for positive neck node involvement. This study presents some preliminary data to consider END in clinically neck node negative patients with parotid MEC; however, larger series are needed.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:124-132, 2023.

Oncological outcomes of preoperatively unexpected malignant tumors of the parotid gland

PURPOSE

Unexpected parotid cancers are often encountered due to inaccuracies in the preoperative evaluation. This study aimed to examine the clinical characteristics and oncological outcomes of these cancers and to propose the appropriate management strategy.

METHODS

This is a multicenter case series study in which a total of 302 patients were diagnosed postoperatively with parotid cancers between 2003 and 2017. Of these, 85 cases without evidence of malignancy prior to surgery but identified as malignant on postoperative pathology were included.

RESULTS

Of 85 patients, 76 and 9 underwent superficial and total parotidectomy, respectively. A positive resection margin was present in 24.7% of the cases. Postoperative radiotherapy was administered to 43.6% of patients; 4.2% had a local recurrence, and no patients died of the disease. The 5-year overall and relapse-free survival rates were 100.0% and 95.2%, respectively. Patients who underwent piecemeal resection had significantly poorer oncologic outcomes. Age, sex, histologic grade, T stage, extracapsular extension, resection margin status, and postoperative radiotherapy did not affect recurrence and survival.

CONCLUSION

Preoperatively unexpected parotid cancers had excellent local control and overall survival despite positive or close resection margin, with or without postoperative radiotherapy. Therefore, patients with unexpected parotid malignancies may benefit from less aggressive postoperative management option.

Efficacy of surgery combined with postoperative 125 I interstitial brachytherapy for treatment of acinic cell carcinoma of the parotid gland in children and adolescents

BACKGROUND

Acinic cell carcinoma (AciCC) is rare in children; therefore, reaching a consensus on its management is challenging and radiotherapy is limited by concerns about long-term toxicity. The purpose of this study is to analyze the effectiveness and safety of surgery plus postoperative ¹²⁵ I interstitial brachytherapy (IBT) for children and adolescents with AciCC of the parotid gland (PG) treated at a single institution.

PROCEDURE

Sixteen patients ≤ 18 years old with AciCC of the PG treated with surgery plus ¹²⁵ I IBT from 2007 to 2018 were included. Surgery was the primary treatment; ten patients underwent total gross excision and six subtotal gross excision. The matched peripheral dose was 60-120 Gy. Overall survival, disease-free survival (DFS), local control rate, distant metastasis, and radiation-associated toxicities were analyzed, and factors influencing outcomes were evaluated.

RESULTS

During follow-up (1.8-12.6 years; mean, 6.3 years), lymph node metastasis was observed in one case, 2.6 years after ¹²⁵ I IBT treatment. The five-year overall and DFS rates were 100% and 91.7%, respectively. On univariate analysis, tumor size ≥ 3 cm (100% vs 50%; P = 0.025) and extraglandular extension (100% vs 50%; P = 0.025) were significant prognostic indicators for DFS. No severe radiation-associated complications occurred.

CONCLUSIONS

Children and adolescents with AciCC of the PG with high-risk features can be managed using surgery plus postoperative ¹²⁵ I IBT with excellent local control. Radiation-related complications were minor. Patients with facial nerve involvement can have their facial nerves preserved. Residual tumors can be safely managed using adjuvant ¹²⁵ I IBT.

Surgical extent and role of adjuvant radiotherapy of surgically resectable, low-grade parotid cancer

BACKGROUND

Due to the rarity of low-grade parotid gland cancer and the diversity of histologic subtype, its optimal treatment modalities and prognostic factors have not been established yet. In this study, we aimed to identify the prognostic factors and adequate treatment modalities for patients with low-grade parotid gland cancer.

METHODS

We retrospectively analyzed clinico-pathologic data from 287 patients with low-grade parotid gland cancer from 1999 to 2018.

RESULTS

Recurrence-free survival, disease-specific survival, and overall survival rates at 10 years were 80.6%, 93.9%, and 84.4%, respectively. Among all patients, 56.1% received surgery alone, and the remaining 43.9% received surgery with adjuvant radiotherapy. Resection margin status and TNM stage were significant unfavorable prognostic factors. In patients with T1-2 tumor, surgical extent (total vs. less-than-total) did not show any significant effect on disease recurrence and patients' survival, and the disease was controlled well if a negative surgical margin was obtained after surgery, even with microscopic clear margin of<1 mm. In patients with adverse pathologic features (positive margin, lymphovascular invasion, perineural invasion, extracapsular nodal spread, T3-4, and N1-3), adjuvant radiotherapy significantly decreased loco-regional recurrence.

CONCLUSIONS

Oncological outcomes were good in patients with low-grade parotid gland cancer with surgery and radiotherapy. In patients with T1-2 low-grade parotid gland cancer, surgery alone showed good local control rate regardless of the extent of surgery, if a negative surgical margin was obtained after surgery. Adjuvant radiotherapy played a significant role in controlling loco-regional recurrence in patients with adverse pathologic features.

Comprehensive Analysis of Clinicopathologic Factors Predictive of an Unfavorable Prognosis in Patients With Acinic Cell Carcinoma of the Parotid Gland

Objectives.

In subset of patients, acinic cell carcinoma (AcCC) exhibits aggressive features such as recurrence, distant metastasis, and mortality. This study aimed to investigate clinicopathologic factors influencing patients’ prognosis and to identify adverse features predictive of an unfavorable prognosis.

Methods.

Between January 2000 and December 2016, 59 patients with AcCC were enrolled in this study.

Results.

The patients’ 5-year overall survival rate was 93.3%, and their 5-year recurrence-free survival rate was 80.5%. During the study period, recurrence occurred in 10 patients. The mean time to recurrence after surgery was 26 months (range, 5–60 months). During the study period, three patients died from the disease. Univariate analysis showed that sex, surgical extent, extranodal extension, T classification, and TNM stage were significantly associated with disease recurrence. Multivariate analysis showed that, among the clinicopathologic factors included in the analysis, only TNM stage displayed a statistically significant correlation with disease recurrence.

Conclusion.

Surgical treatment alone yielded good results for AcCC, and additional treatment did not affect the recurrence-free survival rate or the overall survival rate, even when the resection margin was less than 1 mm. Other pathologic factors did not show prognostic significance for disease recurrence or death.

Challenges with preoperative diagnosis of low/intermediate-grade carcinoma of the parotid gland: single-center study of 112 patients

BACKGROUND

The malignancy of parotid carcinoma varies, and accurate preoperative assessment of malignancy is important for selecting the appropriate treatment. However, the preoperative diagnosis of low/intermediate-grade carcinoma is difficult, and surgery may sometimes be performed without any prior knowledge of malignancy.

METHODS

The results of fine-needle aspiration cytology (FNA), imaging studies (MRI and US), physical examination, and frozen section biopsy (FSB) were evaluated in 112 patients with low/intermediate-grade parotid carcinoma.

RESULTS

The result of FNA was benign/inadequate specimen in 44.6% of the patients. In addition, the tumor was diagnosed as benign by MRI/US in 21.4% of the patients and 37.5% had no symptoms/signs of malignancy on physical examination. The rate of misdiagnosis as benign decreased when FNA was combined with imaging and physical findings. However, malignancy could not be diagnosed by FNA and FSB in 12.5% of the patients who were only found to have malignant tumors by the final pathological examination.

CONCLUSION

FNA shows a high misdiagnosis rate of malignancy in patients with low/intermediate-grade cancer. Therefore, it is necessary to carefully evaluate the findings of imaging studies and physical examination, and FSB should be conducted if such findings suggest the possibility of malignancy.

Close Margins and Adjuvant Radiotherapy in Acinic Cell Carcinoma of the Parotid Gland

Importance

The precise indications and oncologic effects of adjuvant radiotherapy in acinic cell carcinoma of the parotid gland are not well known, particularly in patients with negative, but close (≤1 mm), margins without other high-risk histopathologic factors.

Objective

To evaluate the oncologic outcomes of patients with acinic cell carcinoma of the parotid gland and the results of adjuvant therapy for those with close (≤1-mm) margins.

Design, Setting, and Participants

In a retrospective case series with medical record review at a single academic tertiary referral center, patients treated surgically from January 2000 to December 2014 for acinic cell carcinoma of the parotid gland were identified from an institutional database. All data analysis was performed in September 2017.

Exposures

All patients underwent parotidectomy with or without adjuvant radiotherapy or chemoradiotherapy.

Main Outcomes and Measures

The primary end point was locoregional control. Secondary end points included recurrence patterns and survival.

Results

Forty-five patients were identified in this case series (23 [51%] female), with a mean (SD) age of 47.1 (19.5) years. The median follow-up in surviving patients was 56.7 months (range, 18.5-204 months). Four patients (9%) experienced recurrence (1 local and 3 distant) at a median of 67.3 months (range, 12.7-136 months) after surgery. Thirteen patients (29%) had at least one high-risk histopathologic factor (advanced T category, nodal disease, lymphovascular or perineural invasion, high-grade, or positive margins). The remaining 32 patients (71%) without these high-risk factors had significantly improved disease-free survival (hazard ratio, 0.08; 95% CI, 0.01-0.71). Of patients without high-risk factors, those with close (≤1-mm) margins were significantly more likely to receive adjuvant radiotherapy (10 [56%] vs 1 [7%]; difference, 49%; 95% CI, 16%-82%), although this was not associated with disease control. At a median follow-up of 64.3 months (range, 33-204 months) in the 18 patients with close (≤1-mm) margins without other high-risk factors (10 with adjuvant radiotherapy and 8 without adjuvant therapy), only 1 patient (who had received adjuvant radiotherapy) experienced a recurrence, at 136 months after surgery.

Conclusions and Relevance

Patients with acinic cell carcinoma of the parotid gland whose only histopathologic risk factor is a close (≤1 mm) but negative margin do not appear to benefit from adjuvant radiotherapy. Recurrent disease is rare but may occur many years after initial treatment, and patients with acinic cell carcinoma could benefit from lifelong clinical surveillance.

Is serum bilirubin level a predictor factor in parotid gland carcinoma?

Introduction

Bilirubin levels have been associated with risk of several malignancies. The association between pretreatment serum bilirubin levels and overall survival of patients with parotid gland carcinoma is unclear.

Objectives

In this study, we assessed the effect of serum bilirubin levels to overall survival in malignant parotid tumors.

Methods

This study included a total of 35 patients, 15 female and 20 male. The mean age of these patients was 60.7 ± 14.5 years. All patients who were diagnosed with parotid gland carcinoma and underwent total parotidectomy between 2008 and 2018, were retrospectively assessed. The relationship between the overall survival of patients and total bilirubin, direct bilirubin, and indirect bilirubin levels was estimated. The receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off points.

Results

Patients with low direct bilirubin, total bilirubin and indirect bilirubin had significantly longer overall survival than those with high levels. Cut-off values for total bilirubin, direct bilirubin and indirect bilirubin were detected as 0.545 mg/dL, 0.175 mg/dL and 0.435 mg/dL, respectively.

Conclusion

In our study, we observed that increased preoperative bilirubin levels are associated with reduced survival time in the postoperative period of patients with parotid gland carcinoma.

Mucoepidermoid Carcinoma of the Parotid: Very Close Margins and Adjuvant Radiotherapy

BACKGROUND/AIMS

The importance of adjuvant radiotherapy in patients with close margin resections for mucoepidermoid carcinoma of the parotid gland remains unclear.

METHODS

Patients who underwent parotidectomy for mucoepidermoid carcinoma with or without adjuvant radiotherapy at a single academic tertiary care center from 2000 to 2014 were identified. Included patients had negative but close (≤2 mm) surgical margins without other high-risk histopathological factors including advanced T-stage, positive nodal disease, lymphovascular or perineural invasion, or high-grade histology.

RESULTS

Nineteen patients were identified, of whom 15 (79%) were observed postoperatively, while 4 (21%) underwent adjuvant radiotherapy. There were no significant differences in extent of parotidectomy, elective neck dissection, T staging, or tumor size between patients who were observed and those undergoing adjuvant radiation. There were no locoregional or distant recurrences in any patients at a mean follow up 74.3 months. Patients undergoing adjuvant radiation, however, had significantly more intermediate-grade as compared to low-grade histology (75% vs. 13%, difference 62%, 95% CI 4% to 100%).

CONCLUSIONS

Patients with negative but close (≤2 mm) surgical margins without other high-risk histopathological factors have excellent long-term locoregional control with surgery alone. The effects of adjuvant radiotherapy for those who have intermediate-grade disease remain uncertain.

Salivary Gland Malignancies

Salivary gland tumors are rare pathologic entities that are derived from major and minor salivary gland tissue located throughout the head and neck region. These tumors are distinctly heterogenous, comprising numerous cell types, especially those deemed malignant. The incidence of malignant salivary gland tumors is widely distributed in both adult and pediatric patient populations. Accurate diagnosis and optimal treatment of these tumors pose challenges to both interpreting pathologists and ablative surgeons. This article examines the epidemiology and pathology of malignant tumors of the major and minor salivary glands and provides recommendations for the most successful treatment approaches.

Treatment outcomes in metastatic and localized high-grade salivary gland cancer: high chance of cure with surgery and post-operative radiation in T1-2 N0 high-grade salivary gland cancer

BACKGROUND

High-grade salivary gland cancer is a distinct clinical entity that has aggressive disease progression and early systemic spread. However, because of the rarity of the disease, the clinical outcomes, prognostic factors and clinical decision on the optimal treatments have not been fully understood.

METHODS

In this study, we retrospectively analyzed the clinical data of 124 patients with high-grade salivary gland cancers and performed multivariate survival analyses to evaluate the clinico-pathological factors affecting the treatment outcomes.

RESULTS

The 5-year disease-specific survival was 63.4% in patients with high-grade salivary gland cancers. Among the clinico-pathological factors, presence of lymph node metastasis (hazard ratio 5.63, 95% confidence interval 2.64-12.03, P < 0.001) and distant metastasis (hazard ratio 4.59, 95% confidence interval 2.10-10.04, P < 0.001) at diagnosis were the most potent unfavorable prognostic factors. Importantly, patients with early-stage disease (T1-2N0M0) showed apparently a relatively excellent prognosis (93.2% 5-year disease-specific survival); meanwhile N (+) and M1 status at diagnosis resulted in dismal outcomes (44.6 and 21.1% 5-year disease-specific survival, respectively). On comparing surgery alone as a treatment modality, surgery plus postoperative radiation significantly benefited the patients, but the difference between adjuvant radiation and chemoradiation was not found to be significant. Pathological subtypes of high-grade salivary gland cancers were not significantly associated with prognosis.

CONCLUSIONS

Despite of an overall unfavorable prognosis in high-grade salivary gland cancer, patients with early-stage disease are expected to have excellent prognosis (over 90% survival rates) with surgery plus adjuvant radiation, which may implicate the patients' consultation, therapeutic decision making, and the need for early detection of the disease.

Pediatric Salivary Cancer: Epidemiology, Treatment Trends, and Association of Treatment Modality with Survival

Objective To characterize the epidemiology of pediatric salivary cancer and associate patient, tumor, and treatment factors with treatment modality and survival. Study Design Cross-sectional analysis. Setting US national database. Subjects and Methods We identified 588 patients 19 years or younger diagnosed with salivary cancer in the National Cancer Database 2004-2013. We characterized patient, tumor, and treatment factors as proportions and associated these factors with treatment modality and overall survival via multivariable logistic regression and multivariable Cox proportional hazards regression, respectively. Results In total, 588 patients were included. Mucoepidermoid carcinoma was identified in 234 of 588 patients (40%) and acinar cell carcinoma in 215 of 588 (37%). Parotid tumors were seen in 504 (86%) of patients. Surgery alone was used to treat 351 (60%) of patients; surgery plus adjuvant radiation was used to treat 145 (25%). Overall 5-year survival was 93%. Controlling for patient and tumor characteristics, treatment with surgery and radiation vs surgery alone was associated with improved overall survival (hazard ratio [HR] = 0.15; 95% confidence interval [CI], 0.02-0.92; P = .041). High tumor grade was associated with decreased overall survival (HR = 33.17; 95% CI, 5.89-186.8; P < .001). Treatment with surgery plus radiation remained associated with improved overall survival in the subset of patients with high tumor grade (HR = 0.12; 95% CI, 0.02-0.64; P = .014). Conclusion Tumor grade is an important predictor of survival in pediatric patients with salivary gland cancer. Surgery plus adjuvant radiation vs surgery alone is associated with improved overall survival and may be considered for high-risk patients, particularly those with high-grade tumors.

A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution

BACKGROUND

This study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival.

METHODS

The subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated.

RESULTS

Preoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis.

CONCLUSIONS

Although a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

Margin Analysis: Malignant Salivary Gland Neoplasms of the Head and Neck

There are no established protocols for the optimum surgical margin required for salivary gland malignancies. Factors including histologic diagnosis and TNM stage have been shown to be important in prognosis and survival outcome and mandate special consideration of margin size. Salivary cancers are treated differently at different anatomic sites, and different histologic types show a propensity for major or minor glands. Low-grade malignancies are treated with soft tissue margins of 1 cm or less. The facial nerve is preserved unless infiltrated and encased. Adenoid cystic carcinoma and carcinoma ex pleomorphic adenoma require more complex planning to obtain negative margins.

Postoperative radiation therapy for parotid mucoepidermoid carcinoma

Salivary gland cancers are rare and represent approximately 5% of all head and neck cancers and only 0.3% of all malignancies. The majority (75%) of salivary gland tumors occur in the parotid gland, and while benign lesions are more common, mucoepidermoid carcinoma (MEC) makes up 40–50% of malignant parotid gland tumors. No randomized controlled trials exist regarding the role of adjuvant radiation for patients who undergo surgical resection of low-grade MECs. Herein, we report two cases of successful postoperative radiation therapy in low-grade, pT2N0 MEC of the parotid gland. The role of adjuvant radiation therapy for patients with MEC of the parotid gland is based on data from institution reviews and lacks data from randomized controlled trials. Per our review of the literature, the pathological findings of positive surgical margins and/or perineural invasion in two patients with low-grade MEC of the parotid gland warranted adjuvant radiation for improved local control after partial parotidectomy. Both patients tolerated postoperative radiation therapy with only mild side effects and, at last follow-up, five years after completion of therapy, had no clinical or radiographic evidence of either local recurrence or distant metastasis.

Factors influencing survival in acinic cell carcinoma: a retrospective survival analysis of 2061 patients

BACKGROUND

Acinic cell carcinoma is an uncommon salivary neoplasm with clinical and histologic features known to influence prognosis. The purpose of this study was to further describe variables influencing survival in a large cohort of patients with acinic cell carcinoma.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) registry, we obtained demographic, clinicopathologic, and treatment data pertaining to patients diagnosed with acinic cell carcinoma. Kaplan-Meier and Cox regression analyses were performed to compare survival with various clinical and pathological parameters.

RESULTS

We identified 2061 patients with acinic cell carcinoma from 1973 to 2009. Sex, staging, grade, subsite, and treatment were significant predictors of disease-specific survival (DSS). Patients who received surgery alone had the highest 20-year DSS (92.4%), followed by those treated with surgery and radiation (71.9%) or radiation alone (62.3%).

CONCLUSION

Our results suggest that histologic grade is a stronger predictor of survival than TNM classification, survival after surgical resection alone is excellent, and adjuvant radiation may be of limited benefit