Salivary gland adenoid cystic carcinoma in the U.S population: Importance of grade, site of metastases, and adjuvant radiation for survival.

BACKGROUND: Adenoid cystic carcinoma (AdCC) is a rare and relatively heterogenous salivary gland malignancy, for which there is debate regarding grading, and clinical prognostic factors, including the role of adjuvant radiotherapy. METHODS: Surveillance, Epidemiology, and End Results (SEER) data were reviewed for AdCC cases from 2000 to 2018. RESULTS: A total of 1978 patients with AdCC were identified. Most patients were between 50 and 59 years of age (21.4 %), female (59.9 %), and Caucasian (76.8 %). Most tumors were localized at presentation (44.3 %), and moderately differentiated (or grade II) (43.7 %). Overall and DSS 5-year survival rates were 70.7 % (95 % CI, 69.9-78.8), and 78.6 % (95 % CI, 77.6-79.6). The best overall 5-year survival rate was observed for those treated with surgery plus radiation, 76.8 % (95 % CI, 75.5-78.1). Multivariate analysis revealed male sex, age > 65 (H.R. 2.659 (95 % CI,2.291-3.098), p < .001), grade III/IV (H.R.5.172 (95 % CI, 3.418-7.824), p < .001), nodal metastasis, distant metastasis (H.R. 2.400 (95 % CI, 2.178-2.645), p < .001), chemotherapy only, and combination therapy as negative prognostic factors, and receiving surgery plus radiation therapy (H.R.0.586 (95 % CI, 0.505-0.679), p < .001) as a positive prognostic factor. When limited just to the lungs, had much better survival than those patients with distant metastases to other sites such as the bones and liver (p < .001). CONCLUSION: This SEER study identifies grade, particularly III and IV, to be the strongest single predictor of worse survival. Patients did best when treated with surgery and postoperative radiotherapy. These results can inform future management of patients with this challenging cancer type.

Omission of radiotherapy to lymph node level III in patients with cN0 adenoid cystic carcinoma of the major salivary gland: a single center experience.

PURPOSE: Due to the rarity of adenoid cystic carcinoma (ACC) of the major salivary gland, there is no consensus on the extent of prophylactic neck irradiation (PNI) for patients with clinically negative lymph nodes (cN0) disease. MATERIALS AND METHODS: We conducted a retrospective analysis of all patients with ACC of the major salivary gland who received treatment at our center between January 2010 and April 2020. The primary endpoint was regional failure-free survival (RRFS). Secondary endpoints included overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and acute toxicity. RESULTS: A total of 139 patients were included in the analysis. For cN0 patients, the 5-year RRFS, OS, DMFS, and LRFS were 93.2%, 90.2%, 75.7%, and 91.4%, respectively. Multivariate analysis revealed that PORT was an independent prognostic factor for RRFS and LRFS. No statistically significant differences were observed between the Level III sparing PNI group and the Standard PNI group in terms of RRFS, OS, DMFS, and LRFS. The doses delivered to the larynx and thyroid in the Level III sparing PNI group were significantly lower than those in the Standard PNI group. CONCLUSION: In patients with cN0 ACC of the major salivary gland, PNI improves regional control, and the level III nodal region sparing radiotherapy does not increase the risk of level III recurrence, while potentially reducing toxicity.

Effectiveness and risk of second primary malignancies after radiotherapy in major salivary gland carcinomas: A retrospective study using SEER database.

OBJECTIVE: To investigate the effectiveness of radiotherapy and its association with second primary malignancies (SPMs) risk in major salivary gland carcinomas (MSGCs) patients. METHODS: Cohort 1 included 7274 surgically treated MSGC patients from the Surveillance, Epidemiology, and End Results database, assessing the effectiveness of radiotherapy. Cohort 2 (n = 4213) comprised patients with ≥5-year survival in Cohort 1 to study SPMs. RESULTS: Radiotherapy decreased overall survival in MSGCs patients, but improved it in high-grade MSGCs. Cumulative SPMs incidences at 25 years were 16.5% in the radiotherapy (RT) group compared to 14.5% in the non-radiotherapy (NRT) group. For second head and neck carcinomas (SHNCs), incidences were 3.4% in RT versus 1.6% in NRT. Radiotherapy increased the relative risks of tumors, particularly SHNCs (RR = 1.78). The 10-year OS rates of SHNCs after radiotherapy were significantly lower. CONCLUSION: Radiotherapy improves survival in advanced-stage MSGCs but increases the risk of developing SPMs, particularly SHNCs.

Oncologic Safety of Close Margins in Patients With Low- to Intermediate-Grade Major Salivary Gland Carcinoma.

Importance: Postoperative radiation therapy for close surgical margins in low- to intermediate-grade salivary carcinomas lacks multi-institutional supportive evidence. Objective: To evaluate the oncologic outcomes for low- and intermediate-grade salivary carcinomas with close and positive margins. Design, Setting, and Participants: The American Head and Neck Society Salivary Gland Section conducted a retrospective cohort study from 2010 to 2019 at 41 centers. Margins were classified as R0 (negative), R1 (microscopically positive), or R2 (macroscopically positive). R0 margins were subclassified into clear (>1 mm) or close (≤1 mm). Data analysis was performed from June to October 2023. Main Outcomes and Measures: Main outcomes were risk factors for local recurrence. Results: A total of 865 patients (median [IQR] age at surgery, 56 [43-66] years; 553 female individuals [64%] and 312 male individuals [36%]) were included. Of these, 801 (93%) had parotid carcinoma and 64 (7%) had submandibular gland carcinoma, and 748 (86%) had low-grade tumors and 117 (14%) had intermediate-grade tumors, with the following surgical margins: R0 in 673 (78%), R1 in 168 (19%), and R2 in 24 (3%). Close margins were found in 395 of 499 patients with R0 margins (79%), for whom margin distances were measured. A total of 305 patients (35%) underwent postoperative radiation therapy. Of all 865 patients, 35 (4%) had local recurrence with a median (IQR) follow-up of 35.3 (13.9-59.1) months. In patients with close margins as the sole risk factor for recurrence, the local recurrence rates were similar between those who underwent postoperative radiation therapy (0 of 46) or observation (4 of 165 [2%]). Patients with clear margins (n = 104) had no recurrences. The local recurrence rate in patients with R1 or R2 margins was better in those irradiated (2 of 128 [2%]) compared to observed (13 of 64 [20%]) (hazard ratio [HR], 0.05; 95% CI, 0.01-0.24). Multivariable analysis for local recurrence found the following independent factors: age at diagnosis (HR for a 10-year increase in age, 1.33; 95% CI, 1.06-1.67), R1 vs R0 (HR, 5.21; 95% CI, 2.58-10.54), lymphovascular invasion (HR, 4.47; 95% CI, 1.43-13.99), and postoperative radiation therapy (HR, 0.10; 95% CI, 0.04-0.29). The 3-year local recurrence-free survivals for the study population were 96% vs 97% in the close margin group. Conclusions and Relevance: In this cohort study of patients with low- and intermediate-grade major salivary gland carcinoma, postoperative radiation therapy for positive margins was associated with decreased risk of local recurrence. In isolation from other risk factors for local recurrence, select patients with close surgical margins (≤1 mm) may safely be considered for observation.

Sole brachytherapy for inoperable, recurrent, and irradiated salivary gland cancer.

BACKGROUND AND PURPOSE: Salivary gland cancers (SGCs) are hard to treat when inoperable, and sole brachytherapy appears to be a promising therapeutic strategy. This study aimed to evaluate the effectiveness, safety, and capability of pain palliation using sole brachytherapy for inoperable, recurrent, and irradiated SGCs. MATERIALS AND METHODS: Patients with inoperable SGCs treated using sole brachytherapy at Peking University School and Hospital of Stomatology were retrospectively included. Patients were divided into primary and recurrent groups and irradiated and non-irradiated groups. Local control (LC), overall survival (OS), radiation-relevant toxicities, and Visual Analogue Scale (VAS) score for pain, were recorded and evaluated. RESULTS: A total of 176 patients from 2006 to 2020 were included. The 5-year LC rate was 48.6 %; for the primary, recurrent, non-irradiated and irradiated groups, the rates were 72.6 %, 39.5 %, 56.8 %, and 34.5 %, respectively. The 5-year OS rates was 52.6 %; for the primary, recurrent, non-irradiated, and irradiated groups, the rates were 62.9 %, 48.6 %, 58.9 %, and 42.3 %, respectively. The mean ± standard deviation of posttreatment VAS score of pain was 2.154 ± 2.989, which was significantly decreased from the score of 6.923 ± 2.280 prior to brachytherapy. Skin hyperpigmentation, mucositis, and dysphagia were the most frequently reported adverse events. CONCLUSIONS: Brachytherapy as a sole modality, was retrospectively proven effective and safe in the management of inoperable SGCs and was beneficial in multiple irradiation and pain control.

Post-operative radiotherapy in adenoid cystic carcinoma of salivary glands versus surgery alone: what is the evidence about survival and local control? A systematic review and meta-analysis.

BACKGROUND: Adenoid cystic carcinoma of the salivary glands is a relatively rare malignancy characterized by slow growth and a poor prognosis, and effective treatments remain challenging to identify. This systematic review, following the PRISMA guidelines, aimed to analyze the potential benefits of post-operative radiotherapy in terms of local control of recurrences and survival advantages when compared with surgery alone in patients with adenoid cystic carcinoma. METHODS: A comprehensive systematic review was conducted by searching the MEDLINE, Cochrane, EMBASE, and OVID databases from January 1999 to July 2022. The goal was to identify articles comparing surgery alone with surgery plus postoperative radiotherapy for adenoid cystic carcinoma of the salivary glands. Downs and Black Checklist was used to assess the methodological quality and risk of bias of each included study. The data analysis was performed using Review Manager version 5.4.1. RESULTS: This review included 8 studies comprising a total of 3103 patients, divided based on the analyzed outcomes. The pooled odds ratio for overall survival at 5 years was 0.87 (95% confidence interval 0.43-1.76, p = 0.70), and at 10 years was 1.23 (95% confidence interval 0.69-2.16, p = 0.48). In both cases, no statistically significant differences were observed. However, the pooled odds ratio for local control at 5 years was 3.37 (95% confidence interval 1.35-8.42, p = 0.009), providing strong support for the use of post-operative radiation. CONCLUSIONS: The findings from the meta-analysis suggest that post-operative radiotherapy significantly improves local control in patients with adenoid cystic carcinoma. However, there was no statistically significant increase in survival at 5 and 10 years. It is essential to note that the quality of the studies included in this meta-analysis ranged from fair to poor. To better clarify the indications for post-operative radiotherapy, future high-quality research is needed, particularly with improved stratification of patient groups. Additionally, it is important to recognize that achieving local control in adenoid cystic carcinoma is crucial for enhancing the overall quality of life for patients. We acknowledge that this review was not registered in the PROSPERO database, and the data pooling was conducted using a random effects model.

Adjuvant Radiotherapy for Major Salivary Gland Malignancies: Impact on Locoregional Control and Survival Outcomes.

BACKGROUND/AIM: This study aimed to assess the effect of adjuvant radiotherapy on locoregional control, disease-free survival, and overall survival rates in patients with major salivary gland malignancies. The study also aimed to provide findings to guide clinicians in selecting appropriate candidates for adjuvant radiotherapy and optimizing treatment strategies for this challenging disease. PATIENTS AND METHODS: A retrospective single-center analysis was conducted, reviewing the medical records of patients diagnosed with major salivary gland malignancies between November 2008 and May 2023. Inclusion criteria were histologically confirmed malignancy, surgical resection of the primary tumor, adjuvant radiotherapy, and availability of clinical and follow-up data. Survival analyses were performed using the Kaplan-Meier method, and Cox proportional hazards regression models were used to assess survival outcomes. RESULTS: The study included 37 patients with major salivary gland malignancies. The most common site was the parotid gland, and the predominant histopathological diagnosis was salivary duct carcinoma. Adjuvant radiotherapy was generally well-tolerated, with the most common acute toxicities being grade 1-2 mucositis and dermatitis. The 5-year overall survival and progression-free survival rates were 93.8% and 62.9%, respectively. Locoregional control rate at five years was 89.1%. Recurrence occurred in 12 patients, with most cases observed within two years from the start of adjuvant radiotherapy. Distant metastasis was observed in nine patients. CONCLUSION: This retrospective analysis highlights the positive impact of adjuvant radiotherapy on locoregional control and survival outcomes in major salivary gland malignancies. The findings contribute to the existing body of evidence, aiding clinicians in treatment decision-making and potentially informing future prospective studies and treatment guidelines for this challenging disease.

Is radical radiotherapy with/without surgery an effective treatment in the lymphoepithelial carcinoma of the salivary gland？.

BACKGROUND: There is limited information of radical radiotherapy (RT) on lymphoepithelial carcinoma of salivary gland (LECSG) regarding to the rarity of the disease. We conducted this retrospective study that evaluated the feasibility and efficacy of radical RT with/without surgery in LECSG. METHODS: We retrospectively reviewed patients that were pathologically diagnosed of LECSG and had definite or suspicious residual disease. The prescribed dose given to P-GTV and/or P-GTV-LN was 66 to 70.4 Gy. The clinical target volume (CTV) involved ipsilateral salivary gland and corresponding lymph node drainage area. RESULTS: A total of 56 patients were included. With a median follow-up of 60 months (range: 8 to 151 months), the 1-, 5-, and 10-year progression-free survival (PFS) rates were 94.6%, 84.7% and 84.7%; locoregional progression-free survival (LRPFS) rates were 98.2%, 87.4% and 87.4%; distance metastasis-free survival (DMFS) rates were 94.6%, 86.7% and 86.7%; and overall survival (OS) rates were 98.2%, 92.4% and 89.0%, respectively. A total of 7 patients without surgery were included. All patients were alive and only one patient experienced failure of distant metastasis four months after RT. The results of univariate analysis showed that compared with N stage, the number of positive lymph nodes (2 positive lymph nodes) was better prognostic predictor especially in PFS. There were no treatment-related deaths and most toxicities of RT were mild. CONCLUSIONS: Radical RT with/without surgery in LECSG for definite or suspicious residual disease is feasibility and efficacy. Most toxicities of RT were mild due to the target volume involved ipsilateral area.

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.

Could definitive radiotherapy be a treatment option for lymphoepithelial carcinoma of major salivary gland: Comparison of clinical outcomes of upfront surgery and upfront chemoradiotherapy.

OBJECTIVES: The optimal treatment and associated clinical outcomes for lymphoepithelial carcinoma of the major salivary gland (LECSG) are currently unclear. As such, the purpose of this study was to assess the survival rates of LECSG patients who received either upfront surgery or upfront chemoradiotherapy (CRT). MATERIALS AND METHODS: In this retrospective study, we analyzed cases of LECSG patients treated at our center from January 2010 to April 2021. The cumulative incidences of overall survival rate (OS) and locoregional failure-free survival rate (LRFFS) were evaluated using the Kaplan-Meier method. In order to balance potential risk factors between the treatment groups, we conducted propensity score matching (PSM) at a 1:1 ratio. RESULTS: The study enrolled a total of 107 patients, among whom 24 received surgery alone, 56 underwent surgery combined with postoperative radiotherapy, and 27 underwent definitive radiotherapy. The 5-year LRFFS rate and 5-year OS rate for the entire cohort were 86.6% and 84.4%, respectively. Following PSM, the 5-year LRFFS and OS rates for the upfront CRT cases were comparable to those of upfront surgery, both before and after matching. However, the upfront surgery group showed a tendency toward more de novo facial nerve injury and post-treatment facial nerve injury. CONCLUSION: The results of this study suggest that upfront CRT is as effective as upfront surgery in terms of locoregional control and overall survival for LECSG patients. Therefore, upfront CRT could be considered a viable treatment option, potentially avoiding the risks associated with surgical intervention.

Role of Adjuvant Radiotherapy in Acinic Cell Carcinoma of the Salivary Glands: A Systematic Review.

A systematic review was carried out to evaluate if adjuvant radiotherapy for acinic cell carcinomas (ACCs) of salivary glands improves survival. Twelve retrospective studies published between 2000 and 2020 that analysed the effect of radiotherapy on salivary gland neoplasms and ACCs of salivary glands and met the inclusion criteria were included in the review. The overall quality of the studies was moderate to low. There was no high-quality evidence for improved survival with radiotherapy for ACCs of the salivary gland. Some evidence suggests that there may be an advantage for patients with high-grade tumours, but these data should be interpreted with caution due to the small number of patients and low-quality evidence. Good quality of evidence is lacking. Recommendation for adjuvant radiotherapy for tumours with poor prognostic factors will require discussion and shared decision-making with the patients.

Survival outcomes, prognostic factors, and effect of adjuvant radiotherapy and prophylactic neck dissection in salivary acinic cell carcinoma: A prospective multicenter REFCOR study of 187 patients.

BACKGROUND: Acinic cell carcinomas (AciCCs) are malignant tumours of the salivary glands. The aim of this work was to analyse data from the national REFCOR multicenter cohort (i) to investigate the prognostic factors influencing survival outcomes in AciCC, (ii) to assess the impact on survival of postoperative radiotherapy (RT) in patients treated for AciCC without high-grade transformation and (iii) to explore the prognostic impact of prophylactic neck dissection (ND) in patients treated for AciCC of the major salivary glands. PATIENTS AND METHODS: Data from all the patients treated for salivary AciCC between 2009 and 2020 were extracted from the REFCOR database. Survival outcomes and prognostic factors influencing Disease-Free Survival (DFS) and Overall Survival (OS) were investigated using univariate and multivariate analyses. Propensity score matching was used to assess the impact of postoperative RT and prophylactic ND on DFS. RESULTS: A total of 187 patients were included. After a median follow-up of 53 months, their 5-year OS and DFS rates were 92.8% and 76.2%, respectively. In multivariate analysis, male sex, older age, higher T and N status, and high grade were independently associated with a worse DFS. In the subpopulation analysed after propensity score matching, patients with cN0 AciCC without high-grade transformation who were treated by surgery and RT did not have an improved DFS compared to patients who were treated by surgery alone (hazard ratio (HR) = 0.87, p = 0.8). Factors associated with nodal invasion were T3-T4 status and intermediate/high histological grade. After propensity score matching, prophylactic ND was associated with a trend toward a better DFS (HR = 0.46, p = 0.16). CONCLUSIONS: These results suggest that (i) long-term follow-up (>5 years) should be considered in patients with AciCC, (ii) treatment by surgery alone could be an option in selected cN0 patients with AciCC without high-grade transformation and (iii) prophylactic ND may be considered preferentially in patients with T3-T4 status and/or intermediate/high histological grade.

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.

[Radiation therapy of malignant salivary gland tumors]. / Strahlentherapie von malignen Speicheldrüsentumoren.

Due to their rarity, histologic heterogeneity, and localization, treatment of malignant salivary gland tumors requires an interdisciplinary approach. First-line treatment includes complete tumor resection. Postoperative radiation therapy is advised in patients with risk factors, i.e., incomplete tumor resection, high-grade tumors, or perineural invasion. Definitive radiation therapy is only advised for inoperable tumors because of significantly lower local control and survival rates when compared to combined surgery and radiation therapy. In radiation oncology, modern techniques such as intensity-modulated radiation therapy (IMRT) or particle therapy with heavy ions (i.e., C12) have led to improved outcomes in the treatment of head and neck tumors, especially of adenoid cystic carcinomas. Given the biological and physical benefits of particles, particle therapy, particularly carbon ion radiation, is a promising therapeutic approach for salivary gland tumors that will be further investigated in prospective clinical studies.

PSMA-Directed Imaging and Therapy of Salivary Gland Tumors: A Single-Center Retrospective Study.

We analyzed the diagnostic performance of prostate-specific membrane antigen (PSMA) PET/CT and the dosimetry, efficacy, and safety of 177Lu-PSMA-617 radioligand therapy (RLT) in salivary gland malignancies (SGMs). Methods: We identified 28 SGM patients with PSMA PET/CT from our database. CT and PSMA PET/CT images were evaluated separately by 3 masked readers in joint reading sessions. Pathologic findings were grouped into 6 TNM regions, and lesion-based disease extent was classified as no disease (n = 1, 4%), unifocal (n = 2, 7%), oligometastatic (n = 9, 32%), multifocal (n = 3, 11%), or disseminated (n = 13, 47%). For each region, the SUVmax of the lesion with the highest uptake was measured and the visual PSMA expression score was evaluated on a per-patient basis using PROMISE criteria. The association between PSMA expression and clinical and histopathologic markers was tested using the Student t test. Five patients underwent PSMA RLT with intratherapeutic dosimetry. Response was assessed using RECIST 1.1, and adverse events were graded according to version 5.0 of the Common Terminology Criteria for Adverse Events. Results: Compared with CT, PSMA PET/CT demonstrated additional metastatic lesions in 11 of 28 (39%) patients, leading to upstaging of TNM and lesion-based disease extent in 3 (11%) and 6 (21%) patients, respectively. PSMA PET/CT detected CT-occult local tumor, regional lymph nodes, nonregional lymph nodes, and bone metastases in 1 (4%), 4 (14%), 2 (7%), and 4 (14%) patients, respectively; no additional lesions were detected in the other predefined regions. PSMA expression level was higher than liver in 6 patients (25%). A significantly higher SUVmax was observed in male than female patients (15.8 vs. 8.5, P = 0.007) and in bone than lung lesions (14.2 vs. 6.4, P = 0.006). PSMA RLT was discontinued after 1 cycle in 3 of 5 patients because of insufficient tumor doses. No adverse events of grade 4 or higher occurred. Conclusion: In SGMs, PSMA PET/CT demonstrated a superior detection rate and led to upstaging in about one third of patients when compared with CT. The male sex and the presence of bone metastases were associated with significantly higher PSMA expression. PSMA RLT was well tolerated, but most patients did not have more than 1 cycle because of insufficient tumor doses.

No survival benefit from adding chemotherapy to adjuvant radiation in advanced major salivary gland cancer.

This study aimed to compare survival of patients with advanced major salivary gland cancers treated with adjuvant chemoradiation therapy (CRT) versus radiotherapy (RT) alone, after surgical resection. The Taiwan Cancer Registry database was used to identify patients (2009-2017) with advanced (T3-4 or nodal positivity) major salivary gland cancers, treated post-surgically with adjuvant CRT or RT alone. Overall survival (OS) and disease-specific survival (DSS) evaluated using Kaplan-Meier. Stratified analyses conducted on clinicopathological features. A total of 395 patients were analyzed: 178 (45.1%) received adjuvant CRT; 217 (54.9%) received adjuvant RT alone. Median radiation dose was 66 Gy in 33 fractions. Cisplatin was most common chemotherapy regimen. After a median follow-up of 3.37 years, there was no significant difference in OS or DSS (p = 0.1354 and 0.3361, respectively) between groups. Adding chemotherapy to adjuvant RT was not significantly associated with improved OS (adjusted hazard ratio [aHR] 0.94; 95% CI 0.72-1.23) and DSS (aHR 0.96; 95% CI 0.72-1.28). Stratified analysis of clinicopathological features found no significant advantages for improved OS or DSS from adding chemotherapy to adjuvant RT. Thus, in this population database, the use of chemotherapy provided limited survival benefits in advanced major salivary gland cancers after surgical resection.

Elevated preradiotherapy serum lactate dehydrogenase predicts distant metastasis for lymphoepithelial carcinoma of major salivary gland following postoperative radiotherapy.

BACKGROUND: To evaluate the predicting factors associated with distant metastasis (DM) for lymphoepithelial carcinoma of salivary gland (LECSG) following postoperative radiotherapy (PORT). METHODS: We retrospectively collected 160 eligible patients from two cancer institutions. The DM rate was evaluated using competing risk method. RESULTS: The median follow-up time was 65.6 months. Elevated preradiotherapy serum LDH (ratio >0.5) (p = 0.006) and N classification (N2-3) (p = 0.001) were independently associated with DM for the LECSG. After the risk stratification, the high-risk subgroup was defined as the patients presented higher risk score (score >0), whereas 5-year cumulative incidence of DM in the high- and low-risk group was 30.9% and 6.0%, respectively (p < 0.001). Moreover, a significantly worse overall survival (OS) was observed in the high-risk patients compared with the low-risk subgroup (5-year OS: 83.9% vs. 97.8%, p = 0.006). CONCLUSION: Elevated preradiotherapy serum LDH could serve as a predictive factor for DM in the LECSG following PORT.

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.

Management of Adenoid Cystic Carcinoma of the Head and Neck: Experience of the National Cancer Institute, Egypt.

PURPOSE: This study presents the experience of the National Cancer Institute, Cairo University, in diagnosis and management of ACC of the head and neck. METHODS: This is a retrospective review of 57 patients with ACC managed during the period from January 2011 to January 2016. Data about the characteristics and management of the disease were recorded. All patients were followed up to detect the development of local recurrence and distant metastasis and their management. RESULTS: The mean age was 45.5 ± 15.1, with a femaleto-male ratio of 1.5:1. The minor salivary glands were affected in 61.4% of cases. Four patients (7%) were metastatic at presentation. The main presenting symptom was swelling, followed by pain. Surgical resection was performed in 48 patients (84.2%) followed by adjuvant radiotherapy in 36 of them. Four patients received radical radiotherapy. Treatment failed in 3 patients. Recurrences were recorded in 21 out of the 50 cured patients; 9 had locoregional recurrence, 9 had distant metastases, and 3 had both. The overall survival (OS) and disease-free survival (DFS) at three years were 79% and 57.1%, respectively. Surgical resection improved OS (p<0.001). Advanced T-stage, lymph node invasion, solid tumors, close or positive margins worsened OS. Adjuvant radiotherapy was associated with better DFS (p = 0.003), while solid tumors were associated with worse DFS. CONCLUSION: Despite aggressive management with radical surgery and adjuvant radiotherapy, recurrence affects 42% of the patients within three years. Patients with unresectable tumors have a poor prognosis. Adjuvant radiotherapy improves DFS but not OS.

Prediction model to estimate overall survival benefit of postoperative radiotherapy for resected major salivary gland cancers.

OBJECTIVES: To develop and validate a prediction model to estimate overall survival (OS) with and without postoperative radiotherapy (PORT) for resected major salivary gland (SG) cancers. MATERIALS AND METHODS: Adults in the National Cancer Database diagnosed with invasive non-metastatic major SG cancer between 2004 and 2015 were identified. Exclusion criteria included prior malignancy, pT1N0 or unknown stage, no or unknown surgery, and neoadjuvant therapy. Cox proportional hazards models evaluated the effect of covariates on OS. A multivariate regression model was utilized to predict 2-, 5-, and 10-year OS. Internal cross-validation was performed using 50-50 hold-out and Harrell's concordance index. RESULTS: 18,400 subjects met inclusion criteria, including 9,721 (53%) who received PORT. Distribution of SG involvement was 86% parotid, 13% submandibular, and 1% sublingual. Median follow-up for living subjects was 4.9 years. PORT was significantly associated with improved OS for the following subgroups by log-rank test: pT3 (p < 0.001), pT4 (p < 0.001), high grade (p < 0.001), node-positive (p < 0.001), and positive margin (p < 0.001). The following variables were incorporated into a multivariate model: age, sex, Charlson-Deyo comorbidity score, involved SG, pathologic T-stage, grade, margin status, ratio of nodal positivity, and PORT. The resulting model based on data from 6,138 subjects demonstrated good accuracy in predicting OS, with Harrell's concordance index of 0.73 (log-rank p < 0.001). CONCLUSION: This cross-validated prediction model estimates 2-, 5-, and 10-year differences in OS based on receipt of PORT for resected major SG cancers using readily available clinicopathologic features. Clinicians can utilize this tool to aid personalized adjuvant therapy decisions.