Choice of Adjuvant Radiotherapy Facility in Major Salivary Gland Cancer

OBJECTIVE

Undergoing surgery and adjuvant radiotherapy (aRT) at the same facility has been associated with higher overall survival (OS) in head and neck squamous cell carcinoma. Our study investigates whether undergoing surgery and aRT at the same academic facility is associated with higher OS in major salivary gland cancer (MSGC).

METHODS

The 2006-2018 National Cancer Database was queried for patients with MSGC undergoing surgery at an academic facility and then aRT. Multivariable binary logistic and Cox proportional hazards regression models were implemented.

RESULTS

Of 2801 patients satisfying inclusion criteria, 2130 (76.0%) underwent surgery and aRT at the same academic facility. Residence in a less populated area (adjusted odds ratio [aOR] 1.69, 95% confidence interval [CI] 1.16-2.45), treatment without adjuvant chemotherapy (aOR 1.97, 95% CI 1.41-2.76), and aRT duration (aOR 1.02, 95% CI 1.01-1.04) were associated with undergoing surgery and aRT at different facilities on multivariable logistic regression adjusting for patient demographics, clinicopathologic features, and adjuvant therapy (p < 0.01). Five-year OS was higher in patients undergoing surgery and aRT at the same academic facility (68.8% vs. 61.9%, p < 0.001). Undergoing surgery and aRT at different facilities remained associated with worse OS on multivariable Cox regression (aHR 1.41, 95% CI 1.10-1.81, p = 0.007).

CONCLUSION

Undergoing surgery and aRT at the same academic facility is associated with higher OS in MSGC. Although undergoing surgery and aRT at the same academic facility is impractical for all patients, academic physicians should consider same-facility treatment for complex patients who would most benefit from clear multidisciplinary communication.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3620-3632, 2024.

Oncologic outcomes of the most prevalent major salivary gland cancers: retrospective cohort study from single center

BACKGROUND

The preoperative diagnosis of salivary gland cancer (SGC) is crucial for the application of appropriate treatment, particularly involving the extension of the resection.

METHODS

Retrospective search of medical database identified 116 patients treated surgically with malignant tumors of salivary gland between 2010 and 2020. Analysis included the demographical data, clinical course, type of surgical and adjuvant treatment, histology type and margin status, perivascular invasion (LVI), perineural invasion (PNI), metastatic lymph nodes (LN). Facial nerve function, recurrence-free and overall survival were evaluated. Adequate statistics were used for data analysis.

RESULTS

The final cohort included 63 SGC patients, with adenoid cystic carcinoma the most common pathological type (27%, n = 17), followed by adenocarcinoma (17.4% n = 11). T1 and T2 patients accounted for majority cases (n = 46). The lymph node metastases were confirmed with the histopathology in 31.7% (n = 20). Distant metastases were observed in 4.8% of cases (n = 3). 38% (n = 24) of SGC were treated selectively with surgery, 49.2% (n = 31) had postoperative radiotherapy and 15.9% (n = 10)-radio-chemotherapy. The final facial nerve function was impaired in 38% of patients. Mean overall survival (OS) for all patients was 108.7 (± 132.1) months, and was the most favorable for acinar cell carcinoma (118.9 ± 45.4) and the poorest for squamous cell carcinoma (44 ± 32). Cox regression analysis of disease-free survival and OS identified significant association only with patients' age over 65 years, the hazard ratio of 7.955 and 6.486, respectively.

CONCLUSIONS

The efficacy of treatment modalities for SGC should be verified with regard to the histopathological type, but also the patients' age should be taken into account.

Chemoradiotherapy versus radiotherapy in high risk salivary gland cancer

OBJECTIVE

The aim of this study was to investigate the potential survival benefits associated with chemoradiotherapy (CRT) as opposed to radiotherapy (RT) in patients with resected high-risk salivary gland cancer (SGC), with a specific focus on determining whether these benefits are influenced by the number of high-risk variables.

METHODS

Patients who underwent surgical treatment for high-risk SGC were retrospectively enrolled and categorized into either CRT or RT groups. The impact of adjuvant therapy on locoregional control (LRC) and overall survival (OS) was assessed using a multivariable Cox model.

RESULTS

A total of 152 patients were included following propensity score-matching. In comparison to RT, CRT did not demonstrate a significant survival advantage in terms of LRC (p = 0.485, HR: 1.14, 95%CI: 0.36-4.22) and OS (p = 0.367, HR: 0.99, 95%CI: 0.17-3.87) in entire population. But among patients with T3/4 stage, high-grade tumors, and 5 or more positive lymph nodes, the addition of chemotherapy to RT significantly (p = 0.042) correlated with a 15% reduction in the risk of cancer recurrence (95%CI: 4-54%). Conversely, in other subgroups with varying combinations of high-risk variables, CRT did not provide additional survival benefits for LRC and OS compared to RT.

CONCLUSION

Adjuvant chemotherapy may be considered in conjunction with RT specifically in cases where there is a presence of T3/4 stage, high-grade tumors, and 5 or more metastatic lymph nodes in high-risk SGC.

Patterns and Trends in Adjuvant Therapy for Major Salivary Gland Cancer

OBJECTIVE

To investigate adjuvant therapy indications, utilization, and associated survival disparities in major salivary gland cancer (MSGC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 National Cancer Database.

METHODS

Patients with surgically resected MSGC were included (N = 11,398). pT3-4 classification, pN2-3 classification, lymphovascular invasion, pathologic extranodal extension (pENE), and positive surgical margin (PSM) were considered indications for adjuvant radiotherapy (aRT). pENE and PSM were considered possible indications for adjuvant chemotherapy. Multivariable logistic and Cox regression models were implemented.

RESULTS

Among 6694 patients with≥ $\ge $ 1 indication for aRT, 1906 (28.5%) received no further treatment and missed aRT. Age, race, comorbidity status, facility type, and distance to reporting facility were associated with missed aRT (P < .025). Among 4003 patients with ≥1 possible indication for adjuvant chemoradiotherapy (aCRT), 914 (22.8%) received aCRT. Patients with pENE only (38.5%) and both pENE and PSM (44.0%) received aCRT more frequently than those with PSM only (17.0%) (P < .001). Academic facility was associated with aCRT utilization (P < .05). aCRT utilization increased between 2006 and 2017 in both academic (14.8% vs 23.9%) and nonacademic (8.8% vs 13.5%) facilities (P < .05). Among 2691 patients with ≥1 indication for aRT alone, missed aRT portended poorer OS (hazard ratio [HR]: 1.61, 95% confidence interval [CI]: 1.28-2.03, P < .001). Among 4003 patients with ≥1 possible indication for aCRT, aRT alone (HR: 1.02, 95% CI: 0.89-1.18, P = .780) and aCRT were associated with similar OS.

CONCLUSION

Missed aRT in MSGC occurs frequently and portends poorer OS. Further studies clarifying indications for aCRT are required.

The Number of Positive Lymph Nodes Instead of Extranodal Extension and Nodal Diameter is an Independent Predictor of Survival and Treatment Outcome of High-Grade Parotid Gland Carcinoma

BACKGROUND

There is emerging evidence that current 8th edition of the American Joint Committee staging system is not sensitive enough to predict parotid gland carcinoma (PGC) survival outcomes.

PURPOSE

The present study aimed to analyze pathological nodal factors related to survival and treatment outcomes in a cohort of patients surgically treated with PGC.

STUDY DESIGN, SETTING, SAMPLE

We performed a retrospective cohort study of consecutive patients surgically treated with PGC at the authors' institution from January 1993 to December 2018. The inclusion criteria were as follows: confirmed high-grade parotid gland malignancy on histopathology first surgical treatment of the parotid cancer with neck dissection with curative intent at the study clinic; and sufficient data for review. The exclusion criteria were previous treatment in another institution, low-grade carcinomas, cases where neck dissection was not performed, incurable local disease and distant metastases at the time of first diagnosis, and patients lost to follow-up.

PREDICTOR VARIABLE

Predictor variable comprised pathological nodal factors grouped as the number of cervical node metastases, extranodal extension (ENE), largest diameter of nodal metastasis, and involvement of parotid lymph nodes.

MAIN OUTCOME VARIABLES

Outcomes evaluated were overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS), locoregional recurrence-free survival, and distant metastasis-free survival (DMFS). OS was calculated from the day of biopsy or definitive surgery to the last known hospital follow-up date or the date of death found in the hospital records or social security data. DSS was calculated from the day of biopsy or definitive surgery until the last known follow-up or death from PGC reported in the patient record. Patients who died from causes other than the disease being studied are not counted in this measurement. Treatment outcome was evaluated through the occurrence of locoregional relapse of the disease or development of distant metastases. RFS was defined as the time from the date of biopsy or definitive surgery to the date of locoregional recurrence free survivalor DMFS reported in the patient record.

COVARIATES

Covariates were composed of a set of heterogeneous variables grouped into the following categories: demographic, pathologic, and clinical.

ANALYSES

Unadjusted and adjusted hazard ratios for each variable were calculated with univariate and multivariable Cox regression. The tatistical significance was defined at a P value of < .05.

RESULTS

The cohort of 112 patients included 62 males (55%) and 50 (45%) females. The mean age of the patients was 60.52 ± 15.22 years. The median follow-up time was 59 months (3-221 months). Adenoid cystic carcinoma was the most common tumor type with the incidence of 45%. Cumulative OS for the 5-and 10-year follow-up period was 75 and 61%, respectively. Locoregional recurrences occurred with 27 patients (24%), distant metastases occurred with 25 patients (22%), and both were diagnosed with 5 patients (6%). The number of metastatic nodes was the most important nodal prognostic factor related to OS (P = .02; HR = 2.67; CI = 0.03-6.35), DSS (P = .011; HR = 2.55; CI = .61-6.83), and DMFS (P = .005; HR = 2.85; CI = 0.12-4.76). The presence of pathological parotid nodes was associated with poorer RFS (P = .015; HR = 3.45; CI = 0.25-6.02).

CONCLUSION AND RELEVANCE

The number of metastatic lymph nodes, instead of ENE and largest nodal diameter, was the contributing factor associated with survival and treatment outcomes of surgically treated patients with high-grade PGC. Since the main function of staging system is to predict outcomes, the significance of ENE and nodal dimension in salivary gland cancer staging system requires further clarification. An important finding in the present study was that the presence of positive parotid lymph nodes was associated to locoregional treatment failure.

The Current Position of Postoperative Radiotherapy for Salivary Gland Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Because of the rarity, heterogeneous histology, and diverse anatomical sites of salivary gland cancer (SGC), there are a limited number of clinical studies on its management. This study reports the cumulative evidence of postoperative radiotherapy (PORT) for SGC of the head and neck.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Embase, Cochrane Library, and Web of Science databases between 7th and 10th November 2023.

RESULTS

A total of 2962 patients from 26 studies between 2007 and 2023 were included in this meta-analysis. The median RT dose was 64 Gy (range: 56-66 Gy). The median proportions of high-grade, pathological tumor stage 3 or 4 and pathological lymph node involvement were 42% (0-100%), 40% (0-77%), and 31% (0-75%). The pooled locoregional control rates at 3, 5, and 10 years were 92% (95% confidence interval [CI], 89-94%), 89% (95% CI, 86-93%), and 84% (95% CI, 73-92%), respectively. The pooled disease-free survival (DFS) rates at 3, 5, and 10 years were 77% (95% CI, 70-83%), 67% (95% CI, 60-74%), and 61% (95% CI, 55-67%), respectively. The pooled overall survival rates at 3, 5, and 10 years were 84% (95% CI, 79-88%), 75% (95% CI, 72-79%), and 68% (95% CI, 62-74%), respectively. Severe late toxicity ≥ grade 3 occurred in 7% (95% CI, 3-14%).

CONCLUSION

PORT showed favorable long-term efficacy and safety in SGC, especially for patients with high-grade histology. Considering that DFS continued to decrease, further clinical trials exploring treatment intensification are warranted.

Facility Volume and Changing Facilities for Postoperative Radiotherapy in Salivary Gland Cancer

OBJECTIVES

Changing location of postoperative radiotherapy (PORT) after treatment at a high-volume facility (HVF) is associated with worse survival in various head and neck cancers. Our study investigates this relationship in salivary gland cancer (SGC).

METHODS

The 2004-2016 National Cancer Database was queried for all cases of adult SGC treated with surgery and PORT with or without adjuvant chemotherapy. Patients with multiple cancer diagnoses, metastatic disease, or unknown PORT facility were excluded. Reporting facilities with >95th percentile annual case volume were classified as HVFs, the remainder were classified low-volume facilities (LVFs).

RESULTS

A total of 7885 patients met inclusion criteria, of which 418 (5.3%) were treated at an HVF. Patients treated at an HVF had higher rates clinical nodal positivity (18.2% vs. 14.0%, p < 0.001) and clinical T3/T4 (27.3% vs. 20.7%, p = 0.001) disease. Patients at HVFs changed facility for PORT at lower rates (18.9% vs. 24.5%, p = 0.009). Patients treated at an HVF had higher 5-year overall survival (5-OS) than those treated at an LVF (79.0% vs. 72.0%, p = 0.042). Patients treated at an HVF that changed PORT facility had worse 5-OS (60.8% vs. 83.2%, p < 0.001). Radiation facility change was an independent predictor of worse survival in patients treated at an HVF (HR: 8.99 [3.15-25.67], p < 0.001) but not for patients treated at a LVF (HR: 1.11 [0.98-1.25], p = 0.109).

CONCLUSIONS

Patients treated at an HVF changing facility for PORT for SGC experience worse survival. Our data suggest patients treated surgically at an HVF should be counseled to continue their PORT at the same institution.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Surgical Resection Improves Overall Survival in cT4b Major Salivary Gland Cancer

OBJECTIVE

To compare surgical and nonsurgical definitive treatment in cT4b major salivary gland cancer (MSGC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2004 to 2019 National Cancer Database.

METHODS

The NCDB was queried for patients with cT4b MSGC (N = 976). Patients undergoing definitive treatment with (1) surgical resection + adjuvant therapy, (2) radiotherapy (RT) alone, or (3) chemoradiotherapy (CRT) were included in Kaplan-Meier and Cox survival analyses.

RESULTS

Of 219 patients undergoing definitive treatment, 148 (67.6%) underwent surgical resection + adjuvant therapy and 71 (32.4%) underwent RT or CRT. There were no documented mortalities within 90 days of surgical resection. Tumor diameter and nodal metastasis were associated with decreased odds of undergoing definitive treatment (P < 0.025). Patients with positive surgical margins (PSM) had higher 5-year overall survival (OS) than those undergoing definitive RT or CRT (48.5% vs 30.1%, P = 0.018) and similar 5-year OS as those with negative margins (48.5% vs 54.0%, P = 0.205). Surgical resection + adjuvant therapy (adjusted hazard ratio: 0.55, 95% confidence interval [CI]: 0.37-0.84) was associated with higher OS than definitive RT or CRT (P < 0.025). A separate cohort of 961 patients with cT4a tumors undergoing surgical resection + adjuvant therapy was created; cT4a and cT4b (hazard ratio: 1.02, 95% CI: 0.80-1.29, P = 0.896) tumors had similar OS.

CONCLUSION

A minority of patients with cT4b MSGC undergo definitive treatment. Surgical resection + adjuvant therapy was safe and associated with higher OS than definitive RT or CRT, despite high rate of PSM. In the absence of clinical trial data, appropriately selected patients with cT4b MSGC may benefit from surgical resection.

Translational Insights in the Landscape of Salivary Gland Cancers: Ready for a New Era?

Salivary gland carcinomas (SGCs) are rare neoplasms, representing less than 10% of all head and neck tumors, but they are extremely heterogeneous from the histological point of view, their clinical behavior, and their genetics. The guidelines regarding their treatment include surgery in most cases, which can also play an important role in oligometastatic disease. Where surgery cannot be used, systemic therapy comes into play. Systemic therapy for many years has been represented by polychemotherapy, but recently, with the affirmation of translational research, it can also count on targeted therapy, at least in some subtypes of SGCs. Interestingly, in some SGC histotypes, predominant mutations have been identified, which in some cases behave as "driver mutations", namely mutations capable of governing the carcinogenesis process. Targeting these driver mutations may be an effective therapeutic strategy. Nonetheless, it is not always possible to have drugs suitable for targeting driver mutations-and targeting driver mutations is not always accompanied by a clinical benefit. In this review, we will analyze the main mutations predominant in the various histotypes of SGCs.

Pathological nodal status as a main predictive factor of survival and treatment outcomes of submandibular salivary gland cancers: A 25-year single center experience

INTRODUCTION

Aim of this study was to explore the survival predictive factors and treatment outcomes in a cohort of SGC patients treated at a single center over a period of 25 years.

MATERIALS AND METHODS

Patients who had received primary treatment for SGC were enroled. Outcomes evaluated were: overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS).

RESULTS

A total of 40 patients with SGC were enroled in the study. The most common tumor was the adenoid cystic carcinoma (60% of cases). Cumulative OS for 5-and 10-year follow up period was 81% and 60%, respectively. Thirteen patients (32.5%) developed distant metastases during follow-up. Nodal status, high-grade histology, tumor stage and adjuvant radiation-therapy (RT) were significant variables on multivariate analysis for survival and treatment outcomes.

CONCLUSIONS

Submandibular gland carcinomas represent rare and heterogenous tumor group regarding histological appearance and locoregional and distant metastatic potential. Tumor histological grade, AJCC tumor stage and nodal status were the strongest predictive factors for survival and treatment outcomes. RT improved OS and locoregional treatment outcome, but not DFS. Elective neck dissection (END) could be beneficial for selected cases of SGC. Superselective neck dissection of levels I-IIa may be the level of dissection for END. Distant metastases were the main cause of death and treatment failure. Prognostic factors for poor DMFS were AJCC stage III and IV, high tumor grade and nodal status.

A multicenter retrospective analysis of patients with salivary gland carcinoma treated with postoperative radiotherapy alone or chemoradiotherapy

BACKGROUND

The aim of this study was to interrogate if the use of postoperative chemoradiotherapy (POCRT) correlated with superior oncological outcomes for certain subgroups of patients with high-risk salivary gland carcinoma (SGC), compared with postoperative radiotherapy (PORT) alone.

METHODS

This multicenter retrospective study included 411 patients with surgically resected SGC who underwent PORT (n = 263) or POCRT (n = 148) between 2000 and 2015. Possible correlations of clinical parameters with outcomes were examined using the Kaplan-Meier analysis and Cox proportional-hazards regression model.

RESULTS

The median follow-up of survivors is 10.9 years. For the entire cohort, adding concurrent chemotherapy to PORT was not associated with OS, PFS, or LRC improvement. However, patients with nodal metastasis who underwent POCRT had significantly higher 10-year OS (46.2% vs. 18.2%, P = 0.009) and PFS (38.7% vs. 10.0%, P = 0.009) rates than those treated with PORT alone. The presence of postoperative macroscopic residual tumor (R2 resection) was identified as an independent prognosticator for inferior OS (P = 0.032), PFS (P = 0.001), and LRC (P = 0.007). Importantly, POCRT significantly correlated with higher 10-year LRC rates in patients with R2 resection (74.2% vs. 40.7%, P = 0.034) or adenoid cystic carcinoma (AdCC, 97.6% vs. 83.6%, P = 0.039). On multivariate analyses, the use of POCRT significantly predicted superior OS (P = 0.037) and PFS (P = 0.013) for node-positive patients and LRC for patients with R2 resection (P = 0.041) or AdCC (P = 0.005).

CONCLUSIONS

For surgically resected SGC, POCRT was associated with improved long-term OS and PFS for patients with nodal metastasis and superior LRC for patients with R2 resection or AdCC.

The evolving landscape of salivary gland tumors

Salivary gland cancers are a rare, histologically diverse group of tumors. They range from indolent to aggressive and can cause significant morbidity and mortality. Surgical resection remains the mainstay of treatment, but radiation and systemic therapy are also critical parts of the care paradigm. Given the rarity and heterogeneity of these cancers, they are best managed in a multidisciplinary program. In this review, the authors highlight standards of care as well as exciting new research for salivary gland cancers that will strive for better patient outcomes.

The protective role of postoperative radiation therapy in low and intermediate grade major salivary gland malignancies: A study of the Canadian Head and Neck Collaborative Research Initiative

BACKGROUND

The objective of this study was to examine the utility of postoperative radiation for low and intermediate grade cancers of the parotid and submandibular glands.

METHODS

The authors conducted a retrospective, Canadian-led, international, multi-institutional analysis of a patient cohort with low or intermediate grade salivary gland cancer of the parotid or submandibular gland who were treated from 2010 until 2020 with or without postoperative radiation therapy. A multivariable, marginal Cox proportional hazards regression analysis was performed to quantify the association between locoregional recurrence (LRR) and receipt of postoperative radiation therapy while accounting for patient-level factors and the clustering of patients by institution.

RESULTS

In total, 621 patients across 14 tertiary care centers were included in the study; of these, 309 patients (49.8%) received postoperative radiation therapy. Tumor histologies included 182 (29.3%) acinic cell carcinomas, 312 (50.2%) mucoepidermoid carcinomas, and 137 (20.5%) other low or intermediate grade primary salivary gland carcinomas. Kaplan-Meier LRR-free survival at 10 years was 89.0% (95% confidence interval [CI], 84.9%-93.3%). In multivariable Cox regression analysis, postoperative radiation therapy was independently associated with a lower hazard of LRR (adjusted hazard ratio, 0.53; 95% CI, 0.29-0.97). The multivariable model estimated that the marginal probability of LRR within 10 years was 15.4% without radiation and 8.8% with radiation. The number needed to treat was 16 patients (95% CI, 14-18 patients). Radiation therapy had no benefit in patients who had early stage, low-grade salivary gland cancer without evidence of nodal disease and negative margins.

CONCLUSIONS

Postoperative radiation therapy may reduce LLR in some low and intermediate grade salivary gland cancers with adverse features, but it had no benefit in patients who had early stage, low-grade salivary gland cancer with negative margins.

Postoperative Radiation Therapy Refusal in Major Salivary Gland Cancers

OBJECTIVE

Major salivary gland cancers (MSGCs) are often treated with primary surgery followed by adjuvant therapy for high-risk pathology. Patients with these cancers may opt out of recommended postoperative radiation therapy (PORT) for many reasons and consequently may suffer worse outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Database.

METHODS

Patients diagnosed with MSGC from 2004 to 2016 were identified, and overall survival and risk factors for refusal of recommended PORT were analyzed based on demographic, socioeconomic, and clinical factors. Multivariable logistic regression and a Cox model were used to conduct the analysis.

RESULTS

211 out of 4704 qualifying patients (4.5%) refused recommended PORT. Multivariable analysis demonstrated increased PORT refusal for age >74 years (odds ratio OR 4.34, confidence interval [CI] [2.43-7.85]), Asian race (OR 2.25, CI [1.10-4.23]), and certain facility types (comprehensive cancer center, OR 2.39, CI [1.08-6.34]; academic research program, OR 3.29, CI [1.49-8.74]; and integrated network cancer program, OR 2.75, CI [1.14-7.7]). N2 stage was associated with decreased PORT refusal (OR 0.67, CI [0.45-0.98]). The 5-year overall survival for patients who received and refused PORT were significantly different at 65.8% and 53.8%, respectively (p < .001). When controlling for several factors, PORT refusal was independently associated with significantly lower overall survival (HR 1.54, CI [1.21-1.98]).

CONCLUSION

Patient refusal of recommended PORT in MSGC is rare, associated with various disease and socioeconomic factors, and may decrease overall survival. Our findings can assist clinicians in counseling patients and identifying those who may be more likely to opt out of recommended PORT.

Clinical outcome after pencil beam scanning proton therapy and dysphagia/xerostomia NTCP calculations of proton and photon radiotherapy delivered to patients with cancer of the major salivary glands

OBJECTIVES

The purpose of this study is to report the oncological outcome, observed toxicities and normal tissue complication probability (NTCP) calculation for pencil beam scanning (PBS) PT delivered to salivary gland tumour (SGT) patients.

METHODS

We retrospectively reviewed 26 SGT patients treated with PBSPT (median dose, 67.5 Gy(RBE)) between 2005 and 2020 at our institute. Toxicities were recorded according to CTCAEv.4.1. Overall survival (OS), local control (LC), locoregional control (LRC) and distant control (DC) were estimated. For all patients, a photon plan was re-calculated in order to assess the photon/proton NTCP.

RESULTS

With a median follow-up time of 46 months (range, 3-118), 5 (19%), 2 (8%), 3 (12%) and 2 (8%) patients presented after PT with distant, local, locoregional failures and death, respectively. The estimated 4 year OS, LC, LCR and DC were 90%, 90%, 87 and 77%, respectively. Grade 3 late toxicity was observed in 2 (8%) patients. The estimated 4 year late high-grade (≥3) toxicity-free survival was 78.4%. The calculated mean difference of NTCP-values after PBSPT and VMAT plans for developing Grade 2 or 3 xerostomia were 3.8 and 2.9%, respectively. For Grade 2-3 dysphagia, the grade corresponding percentages were 8.6 and 1.9%. Not using an up-front model-based approach to select patients for PT, only 40% of our patients met the Dutch eligibility criteria.

CONCLUSION

Our data suggest excellent oncological outcome and low late toxicity rates for patients with SGT treated with PBSPT. NTCP calculation showed a substantial risk reduction for Grade 2 or 3 xerostomia and dysphagia in some SGT patients, while for others, no clear benefit was seen with protons, suggesting that comparative planning should be performed routinely for these patients.

ADVANCES IN KNOWLEDGE

We have reported that the clinical outcome of SGT patients treated with PT and compared IMPT to VMAT for the treatment of salivary gland tumour and have observed that protons delivered significantly less dose to organs at risks and were associated with less NTCP for xerostomia and dysphagia. Noteworthy, not using an up-front model-based approach, only 40% of our patients met the Dutch eligibility criteria.

Targeting human EGFR 2 (HER2) in salivary gland carcinoma

INTRODUCTION

Human epidermal growth factor receptor 2 (HER2) protein overexpression, gene amplification, and activating mutations have been identified in a subset of salivary gland carcinoma (SGC) histologies (HER2-positive), especially in salivary duct carcinoma, and represent an important therapeutic target.

AREAS COVERED

The evidence for targeting HER2 in the adjuvant setting is limited to small retrospective series. Conversely, there are prospective trials supporting the use of anti-HER2 therapy in patients with unresectable, recurrent, or metastatic HER2-positive SGC, including trastuzumab plus docetaxel, trastuzumab plus pertuzumab, trastuzumab-pkrb plus nanoxel, trastuzumab emtansine (T-DM1), and trastuzumab deruxtecan (T-Dxd).

EXPERT OPINION

HER2-targeting should be considered for patients with advanced HER2-positive SGC. There are no data to guide the selection of one anti-HER2 agent over another in the palliative setting. Trastuzumab plus docetaxel can be considered for patients with a high disease burden, while trastuzumab plus pertuzumab is a good option for patients with low disease burden or borderline performance status. T-DM1 or T-Dxd can be considered upon disease progression on trastuzumab-combination therapies, although these antibody-drug conjugates can also be used upfront. Future research should investigate predictive biomarkers, the combination of HER2 and androgen blockade, and the application of novel therapies from breast cancer.

Differences in sentinel lymph node biopsy utilization in eligible melanoma patients treated with Mohs micrographic surgery or wide local excision: A population-based logistic regression model and survival analysis

BACKGROUND

Primary melanoma management relies on tumor extirpation and staging sentinel lymph node biopsy (SLNB) in eligible patients. This study compares SLNB utilization in patients undergoing wide local excision (WLE) or Mohs micrographic surgery (MMS).

METHODS

American Joint Committee on Cancer seventh edition ≥ patients with T1b melanoma undergoing WLE or MMS in the Surveillance, Epidemiology, and End Results program were included. Propensity score matching was performed to compare patients who underwent MMS or WLE. Kaplan-Meier analysis and Fine-Gray cumulative incidence functions were used for overall and melanoma-specific survival.

RESULTS

Eight hundred twenty-five MMS cases and 38,760 WLE cases were identified. SLNB was performed in 32.61% of MMS patients and 61.77% of WLE patients with positive rates of 12.5% and 14.82%, respectively. Multiple logistic regression of factors associated with SLNB utilization revealed that WLE, male gender, younger age, extremity location, and nodular and rare melanoma subtypes were significantly associated with increased odds of receiving SLNB whereas head and neck location and lentigo maligna melanoma subtype were significantly less likely to receive SLNB.

LIMITATIONS

Potential selection bias from a retrospective data set.

CONCLUSION

Patients receiving WLE for ≥ T1b melanoma are more likely to receive a SLNB than patients undergoing MMS.

Adoption of adjuvant chemotherapy in high-risk salivary gland malignancies

BACKGROUND

The present study characterizes national trends in the utilization of adjuvant chemotherapy to treat salivary gland malignancies.

METHODS

The National Cancer Database was queried for salivary gland malignancies treated by surgery with radiation in 2004-2019. Proportions of patients receiving adjuvant chemotherapy over the study period were analyzed by linear regression. The impact of chemotherapy on overall survival was assessed using Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

Among 15 965 patients meeting inclusion criteria, 2355 (14.8%) received adjuvant chemotherapy. Chemotherapy utilization significantly increased from 4.9% to 16.5% over the study period (p < 0.001). No survival benefit was observed with adjuvant chemotherapy on propensity score-matched Kaplan-Meier analysis (HR: 0.98; 95% CI: 0.86-1.11; p = 0.72) or multivariable Cox regression (HR: 0.92; 95% CI: 0.78-1.09; p = 0.34).

CONCLUSIONS

Adjuvant chemotherapy has been increasingly utilized to treat salivary gland malignancies in recent years. Our findings highlight the importance of obtaining high-quality prospective data regarding the benefit of chemotherapy.

Salivary gland cancer: ESMO-European Reference Network on Rare Adult Solid Cancers (EURACAN) Clinical Practice Guideline for diagnosis, treatment and follow-up

•This ESMO–EURACAN Clinical Practice Guideline provides key recommendations for managing salivary gland cancer. •The guideline covers clinical and pathological diagnosis, staging and risk assessment, treatment and follow-up. •Treatment algorithms for parotid, submandibular, sublingual and minor salivary gland cancer are provided. •The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion.

Postoperative Chemoradiotherapy versus Radiotherapy Alone in Major Salivary Gland Cancers: A Stratified Study Based on the External Validation of the Distant Metastasis Risk Score Model

BACKGROUND

The role of additional chemoradiotherapy (CRT) for distant metastasis (DM) on the resected malignancy of the major salivary gland (SGM) remained unknown. We conducted this study to externally validate a recently reported DM risk score model and compare the survival outcome between adjuvant CRT and RT alone.

MATERIALS

We retrospectively reviewed the patients with SGM following postoperative radiotherapy (PORT). The cumulative incidence of DM was assessed using a competing risk method. Multivariate analysis was performed with Cox proportional-hazards regression to identify significant predictors for DM. Patients were classified as high- and low-risk subgroups with the cutoff value of the DM risk score model. The inverse probability of treatment weighting (IPTW) was conducted to minimize the bias of the groups.

RESULTS

A total of 586 eligible patients were analyzed and 67 cases underwent adjuvant CRT. The 5-year incidence of DM was 19.5% (95% CI 16.0-23.0%). The model reasonably discriminated the DM risk between the high- and low-risk subgroup in our cohort, and the c-index was 0.75. No survival benefit was observed for the CRT group compared with RT alone in the entire cohort after IPTW (p = 0.095). After subgroup analysis, increased mortality was identified with the administration of CRT in the low-risk subset (p = 0.002) while no significant difference in OS was illustrated in the high-risk subgroup (p = 0.98).

CONCLUSIONS

This external validation provides further exploration of the DM risk score model in major SGM. Our results demonstrated no support for the utility of additional chemotherapy to PORT in the major SGM, especially in the low-risk subgroup of patients with DM.

The effect of adjuvant radiotherapy on clinical outcomes in early major salivary gland cancer

BACKGROUND

This study investigated the effects of adjuvant radiotherapy on outcomes in early-stage major salivary gland cancers.

METHODS

A total of 655 patients were identified, including 355 (54.2%) received adjuvant radiotherapy and 300 (45.8%) had surgery alone. The effect of adjuvant radiotherapy on 5-year locoregional recurrence and disease-specific survival (DSS) was calculated using the Kaplan-Meier method, Wilcoxon rank sum test, and Cox proportional hazards model.

RESULTS

There were no significant differences in locoregional recurrence and DSS between patients receiving adjuvant radiotherapy and those not in both univariate and multivariable analysis. Although patients with positive margin status had a higher locoregional recurrence and those with moderate/poor differentiation had a worse DSS, stratified analysis still indicated there were no protective effects from the use of adjuvant radiotherapy.

CONCLUSIONS

The use of adjuvant radiation therapy was not associated with improved locoregional recurrence and DSS, even for those with high-risk histopathological factors.

The impact of interval between surgery and postoperative radiotherapy in major salivary gland carcinoma

Background

Radiotherapy following primary operation is strongly recommended for salivary gland carcinomas (SGCs) with adverse features. The interval between surgery and the initiation of radiotherapy (SRT) varied and a prolonged SRT may cause failure of cancer treatment. However, the association of SRT with survival is unclear in major SGCs.

Methods

This retrospective study included a total of 346 patients who underwent radiotherapy after the primary operation from Fudan University Shanghai Cancer Center from 2005 to 2020. The best cutoff value of the SRT was determined by the maximum log-rank statistic method. The primary endpoint of the study was overall survival (OS). Correlations between variables and OS were conducted by the univariable analysis using the Log-rank method, and a multivariate Cox proportional hazards regression was performed to identify the independent prognostic factors associated with OS. The estimated survival rates were captured using the Kaplan-Meier method.

Results

With a median follow-up time of 70.31 months, the estimated 5-year OS, LRFS, and DMFS were 83.3%, 80.1%, and 75.9%, respectively. The cutoff value for SRT was 8.5 weeks, while age, T stage, N stage, perineural invasion (PNI), pathological aggression, chemotherapy, and SRT were associated with OS in the univariable analysis. The Cox regression analysis demonstrated that older age (P < 0.001), T3-4 tumors (P = 0.007), positive N stage (P < 0.001), pathological aggression (P = 0.014), and longer SRT (P = 0.009) were independent prognostic factors for major SGCs. Using the stratification model, we observed that delay in the SRT was associated with worse OS (P = 0.006) in the high-risk group, whereas no significant difference was observed in the low-risk subgroup (P = 0.61).

Conclusions

The delay in the initiation of postoperative radiotherapy may be a prognostic factor for patients with major SGCs. It was suggested that radiotherapy should be delivered within 8.5 weeks following the operation, especially for patients with ≥2 risk factors, including older age, high pathological aggression, T3-4 tumors, and positive N stage.

A nomogram involving immune-inflammation index for predicting distant metastasis-free survival of major salivary gland carcinoma following postoperative radiotherapy

BACKGROUND

Postoperative radiotherapy (PORT) is beneficial in the improvement of local-regional control and overall survival (OS) for major salivary gland carcinomas (SGCs), and distant metastasis remained the main failure pattern. This study was designed to develop a nomogram model involving immune-inflammation index to predict distant metastasis-free survival (DMFS) of major SGCs.

PATIENTS AND METHODS

A total of 418 patients with major SGCs following PORT were randomly divided into a training (n = 334) and validation set (n = 84). The pre-radiotherapy neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were calculated and transformed as continuous variables for every patient. Associations between DMFS and variables were performed by univariate and multivariable analysis using Log-rank and Cox regression methods. A nomogram was constructed based on the prognostic factors identified by the Cox hazards model. The decision curve analysis (DCA) was conducted with the training and validation set.

RESULTS

The estimated 3-, 5-, and 10-year DMFS were 79.4%, 71.8%, and 59.1%, respectively. The multivariate analysis revealed that age (p = 0.033), advanced T stage (p = 0.003), positive N stage (p < 0.001), high-risk pathology (p = 0.011), and high PLR (p = 0.001) were significantly associated with worse DMFS. The nomogram showed good calibration and discrimination in the training (AUC = 80.9) and validation set (AUC = 87.9). Furthermore, the DCA demonstrated favorable applicability, and a significant difference (p < 0.001) was observed for the DMFS between the subgroups based on the nomogram points.

CONCLUSION

The nomogram incorporating clinicopathological features and PLR presented accurate individual prediction for DMFS of the patients with major SGCs following PORT. Further external validation of the model is warranted for clinical utility.

Systemic therapy for salivary gland malignancy: current status and future perspectives

Salivary gland malignancies are rare neoplasms that have a broad histological spectrum and a variety of biologic behaviors. Salivary gland malignancies are known as chemo-resistant tumors, which render optimal treatment challenging. This review summarizes the role of systemic therapy for salivary gland malignancies. To date, the advantage of adding concurrent chemotherapy has remained undefined for both postoperative and inoperable locally advanced salivary gland malignancy patients undergoing radiotherapy. For recurrent/metastatic disease, local and/or systemic treatment options should be discussed in a multidisciplinary setting with consideration to both patient needs and tumor factors. For symptomatic patients or those who may compromise organ function, palliative systemic therapy can be a reasonable option based on the results of phase II studies. Platinum combination regimens as first-line therapy have been widely accepted. Personalized therapies have become established options, particularly for androgen receptor-positive, HER2-positive and NTRK fusion-positive salivary gland malignancies (i.e. androgen receptor and HER2 in salivary duct carcinoma and NTRK3 in secretory carcinoma). For patients with adenoid cystic carcinoma, multi-targeted tyrosine kinase inhibitors have also been developed. Anti-PD1 checkpoint inhibitors have shown limited activity to date. Investigation of active systemic treatments for salivary gland malignancy remains a significant unmet need. Future directions might include a more comprehensive genomic screening approach (usually next-generation sequencing-based) and combination strategies using immune checkpoint inhibitors. These are rare malignancies that require ongoing effort in the conduct of high-quality clinical trials.

Differential diagnosis and treatment of salivary secretory carcinoma and acinic cell carcinoma

Secretory carcinoma (SC) and acinic cell carcinoma (AciCC) are two rare tumors originating in the salivary gland of the head and neck. Before the World Health Organization (WHO) classified SC as a new entity in 2017, the majority of SC cases were incorrectly diagnosed as AciCC. Indeed, they are similar in biological behaviors, clinical manifestations and histomorphological features. Especially, SC and zymogen granule-poor AciCC are difficult to differentiate, which brings a tough challenge in clinical diagnosis. This article provides an updated understanding of the differential diagnosis in SC and AciCC from two main perspectives: histopathology and molecular genetics. The targeted therapies for both tumors are also mentioned. It aims to give some hints in clinical diagnosis and treatment, in hopes that patients with adequate diagnosis could obtain the opportunityformore effective treatment.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Postoperative Management of Salivary Gland Tumors

OPINION STATEMENT

Salivary gland tumors represent a heterogeneous group of neoplasms characterized by varied histologies and disease outcomes. Initial treatment for the primary and gross nodal disease is usually surgery. Management of the clinically node-negative neck depends upon the risk of lymph nodal involvement. This is usually determined by the AJCC "T" stage and histology. Both surgery and radiation may be utilized to address the lymph nodes at risk. This is especially important for minor salivary gland tumors. Radiation plays an important role in the adjuvant management of salivary gland tumors by reducing the risk of locoregional recurrence. Certain histologies like adenoid cystic carcinoma have a predilection for neurotropic spread to the skull base. Radiation is particularly important in controlling disease at the skull base. The role of concurrent chemotherapy in the adjuvant treatment of salivary gland tumors is not established and remains an area of active research. Certain histologies like salivary duct carcinoma exhibit readily identifiable molecular targets amenable to targeted therapy. Finally, advanced testing of these tumors using next-generation sequencing can also potentially identify molecular targets amenable to therapy. While useful in the management of metastatic disease, the role of these therapies in the adjuvant setting remains unknown.

The Benefits of Adjuvant Trastuzumab for HER-2-Positive Salivary Gland Cancers

BACKGROUND

Although high-grade salivary gland cancers (SGCs) often express androgen receptor (AR) and/or HER-2/neu, therapeutically targeting these receptors in SGC remains investigational. We investigated the prevalence of receptor expression and the benefit of adjuvant HER-2 directed therapy in the high-risk postoperative setting and explored the clinical utility of sequentially targeting these receptors in the setting of advanced disease.

MATERIALS AND METHODS

We clinically annotated 95 patients with SGC (excluding adenoid cystic carcinoma) treated at our institution from 2002 to 2019 and recorded AR, HER-2/neu status, and tumor genomic profiling results when available. Clinicopathologic information was then integrated with outcomes.

RESULTS

Of 95 patients, most had high-risk histologies, with salivary duct carcinoma (SDC) as the most frequent diagnosis (43, 45%). Thirty-five (37%) experienced recurrence (51% SDC). HER-2/neu was positive (1-3+) by immunostaining in 34 of 52 (65%) evaluable cases. There was no difference in survival based on HER-2/neu or AR expression. Nine of 17 (53%) patients with HER-2+ SDC received adjuvant chemoradiation with trastuzumab. Median disease-free survival (DFS) and overall survival (OS) were longer among patients with HER-2/neu 3+ staining tumors who received adjuvant trastuzumab versus those who did not (DFS, 117 vs. 9 months; p = .02; OS, 74 vs. 43 months; p = .02), with no difference among other HER-2/neu subgroups (0-2+). Two of nine (22%) patients treated with adjuvant trastuzumab demonstrated recurrence, both with low HER-2/neu staining intensity (1+). Longer time to recurrence (hazard ratio, 0.94; p = .01) predicted improved outcomes. Both androgen deprivation and HER-2-directed therapies had clinical benefit beyond the first-line metastatic setting, with partial response observed beyond second-line use.

CONCLUSION

Although prospective data are lacking, the use of adjuvant trastuzumab in high-risk patients with SGC appears beneficial, particularly among patients with tumors exhibiting HER-2/neu 3+ immunostaining.

IMPLICATIONS FOR PRACTICE

Results of this study showed an improved disease-free and overall survival in patients treated with adjuvant trastuzumab for high-risk salivary gland cancers with strong HER-2/neu staining intensity. Following recurrence or metastatic spread, sequential HER-2, and androgen-directed therapies may benefit certain patients with salivary gland cancer.

Advances and challenges in precision medicine in salivary gland cancer

Salivary gland cancer (SGC) is a rare malignancy consisting of 22 subtypes with different genetic, histological and clinical characteristics. This rarity and heterogeneity makes systemic treatment of recurrent or metastatic (R/M) disease challenging. Use of chemotherapy is scarcely studied and chemotherapy at best has moderate effects. New therapeutic strategies are therefore warranted, but advances made in SGC are lagging behind on advances made in more common cancers. By unraveling tumor characteristics of SGC, such as genetic alterations and protein expression profiles, therapeutic strategies tailored to the patient's tumor can be rationalized. This genomic profiling and mapping of immunohistochemical expression profiles is essential in the search for a suitable treatment approach. Thereby, it alleviates the paucity in systemic treatment options and can significantly alter the prognosis of patients with R/M SGC. This review aims to give a comprehensive overview of known genetic alterations and expression profiles amenable for targeted therapy in every histological subtype of SGC. We discuss the remaining knowledge gaps and the implications of these targets for future studies and personalized treatments, thereby aiding clinicians faced with this rare and heterogeneous type of cancer.

Immortal Time Bias in National Cancer Database Studies

PURPOSE

In studies evaluating the benefit of adjuvant therapies, immortal time bias (ITB) can affect the results by incorrectly reporting a survival advantage. It does so by including all deceased patients who may have been planned to receive adjuvant therapy within the observation cohort. Given the increase in National Cancer Database (NCDB) analyses evaluating postoperative radiation therapy (PORT) as an adjuvant therapy, we sought to examine how often such studies accounted and adjusted for ITB.

METHODS AND MATERIALS

A systematic review was undertaken to search MEDLINE and EMBASE from January 2014 until May 2019 for NCDB studies evaluating PORT. After appropriate exclusion criteria were applied, 60 peer-reviewed manuscripts in which PORT was compared with postoperative observation or maintenance therapy were reviewed. The manuscripts were reviewed to evaluate whether ITB was accounted for, the method with which it was adjusted for, impact factor, year of publication, and whether PORT was beneficial.

RESULTS

Of the 60 publications reviewed, 23 studies (38.3%) did not include an adjustment for ITB. Most studies that did adjust for ITB employed a single landmark (LM) time (n = 31), 4 used a sequential landmark analyses, and 2 used a time-dependent Cox model. In 23 of 31 studies (74.2%) that did adjust for ITB via a single LM time, the rationale behind why the specified LM time was chosen was not clearly explained. There was no relationship between adjusting for ITB and year of publication (P = .074) or whether the study was published in a high-impact journal (P = .55).

CONCLUSIONS

Studies assessing adjuvant radiation therapy by analyzing the NCDB are susceptible to ITB, which overestimates the effect size of adjuvant therapies and can provide misleading results. Adjusting for this bias is essential for accurate data representation and to better quantify the impact of adjuvant therapies such as PORT.

Evaluation of Lymph Node Ratio Association With Long-term Patient Survival After Surgery for Node-Positive Merkel Cell Carcinoma

Importance

Merkel cell carcinoma (MCC) carries the highest mortality rate among cutaneous cancers and is rapidly rising in incidence. Identification of prognostic indicators may help guide patient counseling and treatment planning. Lymph node ratio (LNR), the ratio of positive lymph nodes to the total number of examined lymph nodes, is an established prognostic indicator in other cancers.

Objectives

The primary objective was to evaluate the association between LNR and patient survival after surgery for node-positive MCC. The secondary objective was to evaluate whether the survival rates associated with adjuvant therapies vary by patient LNR status.

Design, Setting, and Participants

Retrospective cohort study of patients with node-positive MCC treated with surgery and lymphadenectomy. We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) registry for patient records. Data originated from 2004 through 2017 for the NCDB and from 1973 through 2016 for the SEER registry. The SEER registry comprises a population-based US cohort while cases from the NCDB include all reportable cases from Commission on Cancer-accredited facilities and represents approximately 70% of all newly diagnosed cancers in the United States. All data analysis took place between August 1, 2018, and February 11, 2019.

Exposures

The ratio of positive lymph nodes to the total number of examined lymph nodes, LNR, was stratified into quartiles.

Main Outcomes and Measures

Overall survival (NCDB) and disease-specific survival (SEER).

Results

We identified 736 eligible cases in the NCDB and 538 eligible cases in the SEER registry. Among these 1274 patients, the mean (SD) age was 71.1 (11.5) years, and 401 (31.5%) were women. After controlling for clinical and tumor factors including AJCC N staging, patient LNR of 0.07 to 0.31 (hazard ratio [HR], 1.37; 95% CI, 1.03-1.81) and greater than 0.31 (HR, 2.84; 95% CI, 2.10-3.86) was associated with significantly worse survival than an LNR less than 0.07. Univariate supplementary analysis performed in the SEER data set revealed a similar association of LNR with disease-specific survival. For patients with an LNR greater than 0.31, treatment with surgery and adjuvant chemoradiation therapy was associated with improved survival compared with surgery and adjuvant radiation therapy alone (HR, 0.61; 95% CI, 0.38-0.97), while this was not found for patients with an LNR of 0.31 or lower (HR, 0.93; 95% CI, 0.65-1.33).

Conclusions and Relevance

For lymph node-positive MCC, LNR offers a potentially prognostic metric alongside traditional TNM staging that may be useful for both patient counseling and treatment planning after surgery.

Gender disparities in head and neck cancer chemotherapy clinical trials participation and treatment

OBJECTIVES

To characterize the representation of women in clinical trials directing the National Comprehensive Cancer Network (NCCN) guidelines for chemotherapy use in head and neck squamous cell carcinoma (HNSCC), as well as the relationship between gender and chemotherapy administration in the definitive treatment of HNSCC in the United States.

METHODS

A review of all HNSCC chemotherapy clinical trials cited by the 2018 NCCN guidelines was performed. Sex-based proportions were compared with the corresponding proportions in the general U.S. population of patients with HNSCC between 1985 and 2015, derived from the Surveillance, Epidemiology, and End Results (SEER) program. A second analysis using the National Cancer Database (NCDB), identified 63,544 adult patients diagnosed with stages III-IVB HNSCC between 2004 and 2014 and treated with definitive radiotherapy or chemoradiotherapy. Univariable and multivariable logistic regression analyses were used to identify predictors of chemotherapy administration.

RESULTS

While women comprised 26.2% of U.S. patients with HNSCC between 1985 and 2015, they comprised only 17.0% of patients analyzed in U.S. NCCN-cited chemotherapy clinical trials between 1985 and 2017. On multivariable analysis, women had decreased odds of receiving chemotherapy (Odds Ratio [OR]: 0.875; 95% Confidence Interval [CI]: 0.821-0.931; p < 0.001).

CONCLUSION

Women are underrepresented in HNSCC chemotherapy clinical trials cited by the national guidelines. Additionally, women are less likely than men to receive definitive chemoradiotherapy as oppose to definitive radiotherapy. Reasons for these disparities warrant further investigation as well as re-evaluation of eligibility criteria and enrollment strategies, in order to improve relevance of clinical trials to women with HNSCC.

Patterns of Care and Outcome of Clear Cell Carcinoma of the Head and Neck

OBJECTIVE

Clear cell carcinoma (CCC) is a rare salivary gland malignancy, believed to be generally low grade. We investigated CCC epidemiology and clinical behavior, using the National Cancer Database (NCDB).

STUDY DESIGN

Retrospective cohort study.

SETTING

NCDB.

SUBJECTS AND METHODS

All CCCs of the salivary glands were selected between 2004 and 2015. Patient demographics, tumor characteristics, treatments, and survival were analyzed. Cox regression analyses were performed in treated patients.

RESULTS

We identified 268 patients with CCC. Median age was 61 (21-90) years. Most were female (145, 54%). The most common site was oral cavity (119, 44%), followed by major salivary glands (68, 25%) and oropharynx (41, 15%). Most tumors were low grade (81, 68%) and stages I to II (117, 60.6%). Nodal (36, 17.5%) and distant metastases (6, 2.4%) were rare. Most were treated by surgery alone (134, 50.0%), followed by surgery and radiotherapy (69, 25.7%). Five-year overall survival (OS) was 77.6% (95% CI, 71.4%-84.2%). In univariate analysis, older age, major salivary gland and sinonasal site, stages III to IV, high grade, and positive margins were associated with worse OS. In multivariate analysis, only high tumor grade (hazard ratio [HR], 5.76; 95% CI, 1.39-23.85; P = .02), positive margins (HR, 4.01; 95% CI, 1.20-13.43; P = .02), and age ≥60 years (HR, 3.45; 95% CI, 1.39-8.55; P = .01) were significantly associated with OS.

CONCLUSION

We report the largest series of clear cell carcinomas of the head and neck. Outcomes are generally favorable following surgical-based treatments. In this series, pathologic tumor grade is associated with worse survival. Routine evaluation and reporting of tumor grade might better guide physicians in recommending appropriate treatments in this rare malignancy.

Survival Impact of Adjuvant Therapy in Salivary Gland Cancers following Resection and Neck Dissection

Objective

To evaluate the impact of postoperative radiotherapy (PORT) and chemotherapy on survival in salivary gland cancer (SGC) treated with curative-intent local resection and neck dissection.

Study Design

Retrospective population-based cohort study.

Setting

National Cancer Database.

Subjects and Methods

Patients with SGC who were undergoing surgery were identified from the National Cancer Database between 2004 and 2013. Neck dissection removing a minimum of 10 lymph nodes was required. Because PORT violated the proportional hazards assumption, this variable was treated as a time-dependent covariate.

Results

Overall, 4145 cases met inclusion criteria (median follow-up, 54 months). PORT was associated with improved overall survival in multivariable analysis, both ≤9 months from diagnosis (hazard ratio [HR], 0.26; 95% CI, 0.20-0.34; P < .001) and >9 months (HR, 0.75; 95% CI, 0.66-0.86; P < .001). In propensity score–matched cohorts, 5-year overall survival was 67.1% and 60.6% with PORT and observation, respectively ( P < .001). Similar results were observed in landmark analysis of patients surviving at least 6 months following diagnosis. Adjuvant chemotherapy was not associated with improved survival (HR, 1.15; 95% CI, 0.99-1.34; P = .06).

Conclusion

PORT, but not chemotherapy, is associated with improved survival among patients with SGC for whom neck dissection was deemed necessary. These results are not applicable to low-risk SGCs not requiring neck dissection.

Treatment of primary nonmetastatic melanoma at high-volume academic facilities is associated with improved long-term patient survival

BACKGROUND

Previous studies of cancer care have demonstrated improved long-term patient outcomes for those treated at high-volume centers. The influence of treatment center characteristics on outcomes for primary nonmetastatic melanoma is not currently established.

OBJECTIVE

We aimed to investigate the association of cancer treatment center case volume and academic affiliation with long-term patient survival for cases of primary nonmetastatic melanoma.

METHODS

Cases of melanoma diagnosed in US adults from 2004 to 2014 and included in the National Cancer Database were identified. Hospitals were grouped by yearly case-volume quartile: bottom quartile, 2 middle quartiles, and top quartile.

RESULTS

Facility case volume was significantly associated with long-term patient survival (P < .0001). The 5-year survival rates were 76.8%, 81.9%, and 86.4% for patients treated at institutions in the bottom, middle, and top quartiles of case volume, respectively. On multivariate analysis, treatment at centers in both middle quartiles (hazard ratio, 0.834; 95% confidence interval, 0.778-0.895) and in the top quartile (hazard ratio, 0.691; 95% confidence interval, 0.644-0.741) of case volume was associated with improved survival relative to that of patients treated at hospitals in the bottom quartile of case volume. Academic affiliation was associated with improved outcomes for top-quartile- but not middle-quartile-volume facilities.

LIMITATIONS

Disease-specific survival was not available.

CONCLUSIONS

Treatment at a high-volume facility is associated with improved long-term patient survival for melanoma. High-volume academic centers have improved patient outcomes compared with other high-volume centers.

Adjuvant Chemotherapy Is Associated With Improved Survival for Late-Stage Salivary Squamous Cell Carcinoma

OBJECTIVE

Salivary squamous cell carcinomas (SCCs) represent a unique disease entity because many are thought to represent metastases from primary cutaneous malignancies. Nevertheless, they represent a significant proportion of parotid gland cancers and have a notably poor prognosis. Recently, there has been controversy regarding the utility of adjuvant chemotherapy in the treatment of these malignancies, with most studies concluding that there is no survival benefit. We aim to determine the outcomes associated with the use of adjuvant radiotherapy and chemoradiotherapy in the treatment of early- and late-stage salivary SCC.

METHODS

A retrospective study of 2,285 of surgically resected adult salivary SCC diagnosed from 2004 to 2014 in the National Cancer Database was conducted. Patients were divided into early- (I/II) and late-stage (III/IV) groups. Demographic, facility, tumor, and survival variables were included in the analyses. Multivariate Cox survival regressions, propensity-score matched analyses, and univariate Kaplan-Meier analyses were conducted.

RESULTS

The use of adjuvant chemoradiotherapy for late-stage patients was associated with improved survival compared to the use of adjuvant radiotherapy alone (hazard ratio [HR] 0.774, P = 0.026). Five-year survival for late-stage patients treated with surgery alone, surgery with adjuvant radiotherapy, and surgery with adjuvant chemoradiotherapy was 31.1% (standard error [SE]: 2.5), 45.6% (SE: 2.2), and 58.9% (SE: 3.4). Use of adjuvant therapy (either chemoradiotherapy or radiotherapy alone) was associated with improved survival for early-stage patients (HR 0.746, P = 0.037).

CONCLUSION

The addition of chemotherapy to the adjuvant therapy of late-stage patients with salivary SCC may result in improved long-term survival. Expanded use of adjuvant therapy for early-stage disease may also improve patient outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:883-889, 2019.

Extracapsular extension is not a significant prognostic indicator in non-squamous cancers of the major salivary glands

Background

Extracapsular extension (ECE) is a well-established prognostic feature in squamous cell cancers of the head and neck. Although some extrapolate data from mucosal head and neck cancer to include ECE as a high-risk feature in salivary gland cancers, data is lacking about ECE’s prognostic value for these malignancies. We investigate whether ECE is a significant prognostic indicator in pathologic node-positive cancers of the major salivary glands.

Methods

A retrospective study of adult salivary gland cancer cases diagnosed from 2004 to 2013 in the NCDB was conducted. Demographic, tumor, treatment, and survival variables were included in the study. Univariate Kaplan-Meier analyses, as well as multivariate Cox survival regressions were performed.

Results

Positive ECE status was associated with significantly worse survival in salivary SCC (HR 1.687; p = 0.002) but not non-squamous salivary cancers (HR 1.000; p = 0.998) on multivariate analysis. While post-operative radiotherapy was not associated with improved survival for patients without high-risk adverse features (high grade or positive surgical margins), its use was associated with better survival for ECE-positive salivary SCC patients without one of these additional adverse features (HR 0.064; p = 0.010).

Conclusions

Although ECE is a significant prognostic indicator in salivary SCC, its prognostic significance for non-squamous salivary cancers may be limited. Radiotherapy may improve survival in cases with at least one high-risk adverse feature: high grade; positive surgical margins; and for salivary SCC specifically, positive ECE status.