Role of Postoperative Radiotherapy in Nonmetastatic Head and Neck Adenoid Cystic Carcinoma

Radiotherapy for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for radiotherapy in salivary gland cancer and to specify the modalities and target radiation volumes.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Postoperatively, radiotherapy to the primary tumor site±to the lymph nodes is indicated if one or more of the following adverse histoprognostic factors are present (risk>10% of locoregional recurrence): T3-T4 category, lymph node invasion, extraglandular invasion, close or positive surgical margins, high tumor grade, perineural invasion, vascular emboli, and/or bone invasion. Intensity-modulated radiation therapy (IMRT) is the gold standard. For unresectable cancers or inoperable patients, carbon ion hadrontherapy may be considered.

CONCLUSION

Radiotherapy in salivary gland cancer is indicated in postoperative situations in case of adverse histoprognostic factors and for inoperable tumors.

Pediatric Salivary Gland Pathology

Benign and malignant salivary gland disorders are uncommon in the pediatric population; however, these can be frequently seen in pediatric otolaryngology or oral and maxillofacial surgery practices. The astute clinician should be aware of the clinical presentation, diagnosis, and management options for common inflammatory, infectious, benign, and malignant disorders of salivary glands.

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.

Platinum-based adjuvant chemoradiotherapy versus adjuvant radiotherapy in patients with head and neck adenoid cystic carcinoma

PURPOSE

The objective of the study was to assess the effectiveness and toxicity of platinum-based adjuvant chemoradiotherapy (POCRT) in comparison to postoperative radiotherapy (PORT) in patients with head and neck adenoid cystic carcinoma (HNACC).

MATERIALS AND METHODS

This retrospective study analyzed patients diagnosed with HNACC at our center between January 2010 and April 2020. A 1:1 propensity score matching method was used to create a matched cohort.

RESULTS

In this study, 206 patients were analyzed, with 147 patients (71.4%) receiving postoperative radiotherapy (PORT) and 59 patients (28.6%) receiving POCRT. Twenty-one patients experienced local-regional failure. The 3-, 5-, and 10-yr local-regional control (LRC) rate for the cohort were 92.0%, 90.6%, and 86.9%, respectively. In both the entire cohort and the matched cohort, the POCRT group exhibited superior LRC compared to the PORT group (Gray's test, all P < 0.05*). Multivariate analysis identified adjuvant concurrent chemotherapy as an independent prognostic factor for LRC (Competing risks regression, HR = 0.144, 95% CI 0.026-0.802, P = 0.027*). In addition, the POCRT group had higher incidences of upper gastrointestinal toxicity and hematologic toxicities, including leukopenia, neutropenia, and anemia (all P < 0.05*).

CONCLUSION

In terms of reducing locoregional failures in HNACC patients, POCRT may potentially offer a more effective therapeutic approach than using PORT alone, although it also entails an augmented burden of treatment-related toxicity.

Role of combined surgical and radiotherapy treatment in nonmetastatic WHO I nasopharyngeal carcinoma patients

BACKGROUND

Keratinizing squamous cell carcinoma (KSCC) is recognized as WHO I nasopharyngeal carcinoma (NPC). Current guidelines for treating nasopharyngeal cancer do not delineate specific strategies for individual pathologic subtypes.

OBJECTIVES

To explore the optimal treatment for KSCC of the nasopharynx.

MATERIAL AND METHODS

Data on patients were extracted from the SEER database. Survival differences between patients treated with radiotherapy alone and combined surgery were assessed using Kaplan-Meier and Cox regression models and compared using propensity score matching (PSM). In addition, we explored the survival differences between the two groups of patients in different risk stratifications.

RESULTS

In our study, 165 patients underwent surgical intervention, while 1238 patients did not. In both univariate (CSS: p = .001, HR = 0.612; OS: p < .001, HR = 0.623) and multivariate (CSS: p = .004, HR = 0.655; OS: p < .001, HR = 0.655) analyses, combined surgery was identified as a significant prognostic factor. These findings were consistent after PSM. Using RPA, patients were categorized into two groups. CSS improved in the high-risk group, whereas the difference in low-risk patients was not significant.

CONCLUSIONS AND SIGNIFICANCE

For patients diagnosed with WHO I nasopharyngeal carcinoma, the combination of radiotherapy and surgery has significant clinical advantages, especially for patients at high risk.

Machine learning-based survival prediction nomogram for postoperative parotid mucoepidermoid carcinoma

Parotid mucoepidermoid carcinoma (P-MEC) is a significant histopathological subtype of salivary gland cancer with inherent heterogeneity and complexity. Existing clinical models inadequately offer personalized treatment options for patients. In response, we assessed the efficacy of four machine learning algorithms vis-à-vis traditional analysis in forecasting the overall survival (OS) of P-MEC patients. Using the SEER database, we analyzed data from 882 postoperative P-MEC patients (stages I-IVA). Single-factor Cox regression and four machine learning techniques (random forest, LASSO, XGBoost, best subset regression) were employed for variable selection. The optimal model was derived via stepwise backward regression, Akaike Information Criterion (AIC), and Area Under the Curve (AUC). Bootstrap resampling facilitated internal validation, while prediction accuracy was gauged through C-index, time-dependent ROC curve, and calibration curve. The model's clinical relevance was ascertained using decision curve analysis (DCA). The study found 3-, 5-, and 10-year OS rates of 0.887, 0.841, and 0.753, respectively. XGBoost, BSR, and LASSO stood out in predictive efficacy, identifying seven key prognostic factors including age, pathological grade, T stage, N stage, radiation therapy, chemotherapy, and marital status. A subsequent nomogram revealed a C-index of 0.8499 (3-year), 0.8557 (5-year), and 0.8375 (10-year) and AUC values of 0.8670, 0.8879, and 0.8767, respectively. The model also highlighted the clinical significance of postoperative radiotherapy across varying risk levels. Our prognostic model, grounded in machine learning, surpasses traditional models in prediction and offer superior visualization of variable importance.

Primary and Recurrent Intraosseous Adenoid Cystic Carcinoma-Analysis of Two Cases and Literature Review

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that mostly occurs in minor glands, especially in the palate. Intraosseous adenoid cystic carcinoma (IACC) is rarer. There is no clear conclusion on the clinical, radiologic and pathological characteristics of IACC because of few reported IACC cases, leading to insufficient understanding of IACC. We reviewed 52 previous reports of primary IACC (PIACC) and analyzed the clinical features of those patients involved, attempting to provide a better understanding of PIACC. Moreover, we present a case of primary PIACC and a case of recurrent IACC (RIACC). The two patients showed similarities in clinical and pathological results, along with slight differences in radiological and immunohistochemical results. The patient of case 1 seemed to display a worse prognosis, which can only be proved after long term follow-up.

Risk Factors for Locoregional Recurrence and Distant Metastasis in 143 Patients with Adenoid Cystic Carcinoma of the External Auditory Canal

AIMS

Adenoid cystic carcinoma (ACC) grows slowly and is characterised by potential recurrence and metastasis to distant organs. This study aimed to evaluate the risk factors for locoregional recurrence (LRR) and distant metastasis in patients with ACC of the external auditory canal (EAC).

MATERIALS AND METHODS

Demographic, pathological, therapeutic and survival data of 143 patients with EAC ACC were reviewed in this study. Univariate and multivariate Cox proportional hazard regression analyses were carried out to determine the risk factors for LRR and distant metastasis. Factors associated with overall survival after LRR and distant metastasis were also analysed.

RESULTS

During a median follow-up of 49 months, 31 of 143 patients were observed with LRR and 34 developed distant metastasis. Bone invasion and histological subtype were independent risk factors for locoregional recurrence-free survival. T stage and LRR were independent risk factors for distant metastasis-free survival. Salvage surgery and adjuvant radiotherapy or chemoradiotherapy for LRR resulted in better survival, whereas extrapulmonary metastasis and LRR were associated with a higher risk of poor survival after distant metastasis.

CONCLUSION

Patients with distant metastases, especially those with LRR, are at significant risk of poor prognosis. Our findings emphasise the importance of long-term regular follow-up and recommend surgical intervention with radiotherapy for recurrent EAC ACC.

Assessing the Impact of Charged Particle Radiation Therapy for Head and Neck Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Purpose: Head and neck adenoid cystic carcinoma (HNACC) is a radioresistant tumor. Particle therapy, primarily proton beam therapy and carbon-ion radiation, is a potential radiotherapy treatment for radioresistant malignancies. This study aims to conduct a meta-analysis to evaluate the impact of charged particle radiation therapy on HNACC. Methods: A comprehensive search was conducted in Pubmed, Cochrane Library, Web of Science, Embase, and Medline until December 31, 2022. The primary endpoints were overall survival (OS), local control (LC), and progression-free survival (PFS), while secondary outcomes included treatment-related toxicity. Version 17.0 of STATA was used for all analyses. Results: A total of 14 studies, involving 1297 patients, were included in the analysis. The pooled 5-year OS and PFS rates for primary HNACC were 78% (95% confidence interval [CI] = 66-91%) and 62% (95% CI = 47-77%), respectively. For all patients included, the pooled 2-year and 5-year OS, LC, and PFS rates were as follows: 86.1% (95% CI = 95-100%) and 77% (95% CI = 73-82%), 92% (95% CI = 84-100%) and 73% (95% CI = 61-85%), and 76% (95% CI = 68-84%) and 55% (95% CI = 48-62%), respectively. The rates of grade 3 and above acute toxicity were 22% (95% CI = 13-32%), while late toxicity rates were 8% (95% CI = 3-13%). Conclusions: Particle therapy has the potential to improve treatment outcomes and raise the quality of life for HNACC patients. However, further research and optimization are needed due to the limited availability and cost considerations associated with this treatment modality.

Adenoid Cystic Carcinoma (AdCC): A Clinical Survey of a Large Patient Cohort

Adenoid cystic carcinoma (AdCC), a rare heterogenous disease, presents diagnostic, prognostic, and therapeutic challenges. To obtain more knowledge, we conducted a retrospective study on a cohort of 155 patients diagnosed in 2000-2022 with AdCC of the head and neck in Stockholm and investigated several clinical parameters in correlation to treatment and prognosis in the 142/155 patients treated with curative intent. The strongest favourable prognostic factors were early disease stage (stage I and II) as compared to late disease (stage III and IV) and major salivary gland subsite as compared to other subsites, with the best prognosis in the parotid gland, irrespective of the stage of the disease. Notably, in contrast to some studies, a significant correlation to survival was not found for perineural invasion or radical surgery. However, similar to others, we confirmed that other common prognostic factors, e.g., smoking, age, and gender, did not correlate to survival and should not be used for prognostication of AdCC of the head and neck. To conclude, in AdCC early disease stage, major salivary gland subsite and multimodal treatment were the strongest favourable prognostic factors, while this was not the case for age, gender and smoking nor perineural invasion and radical surgery.

Adenoid cystic carcinoma of the head and neck: Patterns of recurrence and implications for intensity-modulated radiotherapy

BACKGROUND

We seek to inform radiotherapy (RT) delivery for adenoid cystic carcinoma of the head and neck (ACC) by evaluating RT techniques and recurrence patterns.

METHODS

We identified patients with ACC treated with curative-intent RT from 2005 to 2021. Imaging was reviewed to determine local recurrence (LR).

RESULTS

Ninety-one patients were included. The 5-year LR risk was 12.2% (6.6-22.7). One patient each experienced a marginal and out-of-field recurrence. Patients receiving >60 Gy postoperatively had a 5-year LR risk of 0% compared to 10.7% (4.2-27.2) with ≤60 Gy. Those receiving 70 and <70 Gy definitively had a 5-year LR risk of 15.2% (2.5-91.6) and 33.3% (6.7-100.0), respectively. No patients had regional nodal failure.

CONCLUSIONS

Modern, conformal RT for ACC results in low rates of LR. Doses >60 and 70 Gy may improve control in the postoperative and definitive settings, respectively. Elective nodal treatment can be omitted in well-selected patients.

Role of postoperative radiotherapy in resected adenoid cystic carcinoma of the head and neck

PURPOSE

Although postoperative radiotherapy (PORT) is demonstrably effective in local control of head and neck adenoid cystic carcinoma (HNACC), its application is controversial and the subset of patients who would benefit most from PORT is unknown. Herein, we analyzed the data of HNACC patients to clarify the role of PORT.

METHODS

We retrospectively reviewed 187 patients with nonmetastatic HNACC who underwent surgical resection between 2005 and 2019. The study endpoints were locoregional failure-free survival (LRFFS), progression-free survival (PFS), and overall survival (OS). Subgroup analysis and recursive partitioning analysis (RPA) were performed to identify patients most likely to benefit from PORT.

RESULTS

With a median follow-up of 84.7 months, the 5-year LRFFS, PFS, and OS were 70.0%, 52.6%, and 86.4%, respectively. Survival was significantly shorter in patients who experienced local failure than in those who did not (5-year OS: 88.1% vs. 80.5%, P = 0.001). The local failure rate was significantly lower in patients who underwent PORT (16.9% vs. 31.0%, P = 0.021), despite the high frequency of adverse factors. Especially, significant decreases in local failure and similar OS rates could be obtained after PORT among patients with positive margins, T2-4 stage disease, and minor salivary gland tumors. The RPA model for PFS categorized patients into four groups according to three prognostic factors (T-stage, location, and sex). The RPA model for LRFFS and OS suggested three groups based on two factors (T-stage, margin for LRFFS; T-stage, grade 3 for OS).

CONCLUSION

PORT could prevent dismal survival, while significantly reducing local failures in high-risk HNACC patients.

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.

Clinical Prediction Nomograms to Assess Overall Survival and Disease-Specific Survival of Patients with Salivary Gland Adenoid Cystic Carcinoma

Aim

Salivary gland adenoid cystic carcinoma (SACC) is the second highest incidence of malignant salivary gland tumor. The purpose of this study was to establish nomograms combined with SACC patients based on the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

Patients with SACC were included in the SEER∗Stat Database from 2004 to 2016. The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was applied to filter potential prognostic clinical variables. Multivariate analysis from the Cox proportional hazards model was performed to determine the independent prognostic factors on overall survival (OS) and disease-specific survival (DSS), applied to develop nomograms. The Schönfeld residual test verified the proportional hazard assumption. The discrimination and consistency of nomograms was assessed and validated according to concordance index (C-index), receiver operating characteristic (ROC) curves, and calibration curves using an internal 1,000 times bootstrap resampling. The nomogram's net clinical benefit was assessed through decision curve analysis (DCA).

Results

A total of 658 patients with SACC were included. Age, T stage, N stage, M stage, histologic grade, and surgery were independent prognostic factors for OS and DSS. Based on these independent prognostic factors, nomograms were developed to predict 3-, 5-, and 10-year OS and DSS. In the validation of 1,000 times bootstrap resampling, the C-index and ROC curves had good discriminatory ability. The calibration curves indicated excellent consistency between the predicted and actual survival results in the nomograms. The DCA curves demonstrated that the nomograms had good clinical benefit and were superior to the TNM stage and other variables.

Conclusions

Two nomograms developed in this study precisely predicted the 3-, 5-, and 10-year OS and DSS rates of patients with SACC in accordance with independent prognostic factors, and their clinical value is better than TNM staging, providing a prognostic reference for other SACC patients.

Prognosis of adenoid cystic carcinoma in head and neck region treated with different regimens-A single-centre study

BACKGROUND

No study has evaluated the impact of regimen on recurrence, metastasis and survival in patients with adenoid cystic carcinoma (ACC). The present study aimed to compare the efficacy of radioactive seed implantation and other regimens in treating ACC, so as to investigate the clinical applicability of radioactive seed implantation and determine the indications for this regimen.

METHODS

A total of 188 patients with ACC in oromaxillofacial region were allocated to four groups according to the treatment regimen: group 1 was treated with a combination of surgery and ¹²⁵ I seed therapy, group 2 with a combination of surgery and external radiotherapy, group 3 with surgery, whereas group 4 was untreated. The Kaplan-Meier method was used to assess the survival rates, and the Cox regression analyses were used to identify the associated prognostic factors.

RESULTS

The overall survival rates of 188 patients and groups 1, 2, 3 and 4 were 85.7%, 75%, 68.2% and 37.5%, respectively. Cox regression analysis revealed that age, T stage, N stage and regimen were independent prognostic factors of survival. Amongst patients with primary ACC, the efficacy of radioactive seed implantation was higher in those with perineural invasion than in those without.

CONCLUSION

Patient age, T stage, N stage and regimen are independent prognostic factors of survival in patients with ACC. Patients treated with surgery combined with postoperative ¹²⁵ I seed radiotherapy have a higher overall survival rate, and those with perineural invasion are more suitable for radioactive seed implantation therapy.

Survival and prognosis of metastatic head and neck adenoid cystic carcinoma

BACKGROUND

To investigate the clinical characteristics, treatment, and prognosis of patients with metastatic head and neck adenoid cystic carcinoma (HNACC).

METHOD

The clinical data of metastatic HNACC from 1999 to 2020 at the National Cancer Center of China were retrospectively collected.

RESULTS

One hundred seventy-four patients with metastatic HNACC were enrolled and median overall survival (OS) was 45.6 months. Univariate analysis indicated that smoking history, disease-free interval (DFI), number and sites of metastases, and systemic therapy were associated with OS. In the multivariate analysis, non-smokers, DFI ≥3 years, and lung metastasis were prognostic factors. Local therapy for localized disease could prolong survival in patients with both recurrent and metastatic disease.

CONCLUSION

No smoking history, DFI ≥3 years, and lung metastasis were favorable prognostic factors. Local therapy for metastases could not provide survival benefits, but local therapy for localized disease may prolong survival. Whether initial systemic therapy could improve prognosis needs further exploration.

Current opinions on diagnosis and treatment of adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare malignant tumor derived mainly from the salivary glands, representing approximately 1% of all headandneck carcinomasand 10% of all salivary gland neoplasms. ACC displays a paradoxical behavioral combination of an indolent growth pattern but an aggressive progression, with local recurrence and distant metastasis. The propensity of ACC of the head and neck (ACCHN) for perineural invasion and its anatomical location, especially if it extends to the nasal cavity and paranasal sinuses, facilitates tumor involvement in the surrounding structures, such as the orbit, pterygopalatine fossa, Meckel'scave, and cavernous sinus, which can lead to skull base involvement and intracranial extension. Despite advances in molecular mechanisms and diagnostic imaging, ACC treatment remainschallenging due to the lack ofconsensuson treatment patterns. In this review, we aimed toprovideanupdatedinsight intothe understanding of ACCHN by focusing on clinical behavior, imaging diagnosis, pathological features, and therapeutic strategies. We reviewed the molecular mechanisms, especially in ACCHN with perineural invasion, and elaborated on treatment options, including chemotherapy, targeted therapies, and immunotherapy, to establish a comprehensive understanding of ACC to arrive at a policy for proper diagnosis, preoperative evaluation, and therapeutic strategies.

Is postoperative radiotherapy an essential treatment for nonmetastatic lymphoepithelial carcinoma of the salivary gland?

BACKGROUND

Lymphoepithelial carcinoma of salivary gland (LECSG) is a rare malignant tumor. Whether postoperative radiotherapy (PORT) can improve locoregional control and which patients can benefit from PORT are unknown. This study aimed to evaluate the role of PORT and provide individualized suggestions for postoperative therapy in patients with LECSG.

PATIENTS AND METHODS

We retrospectively reviewed patients with nonmetastatic LECSG who underwent surgery with or without PORT. Recursive partitioning analysis (RPA) was performed to categorize the patients and predict progression-free survival (PFS).

RESULTS

A total of 223 patients were included, 34 (15.2%) received surgery alone, whereas the remaining 189 (84.8%) underwent PORT in the initial treatment. Although patients in the PORT group were with advanced T stage and N stage, the PORT group had an advantage over the non-PORT group on 1-year, 5-year and 10-year PFS and locoregional control (LRC). PORT was an independent prognostic factor for PFS and LRC. Furthermore, compared with T stage and N stage, the size of the primary tumor and the number of positive lymph nodes were better prognostic predictors. The RPA model was generated according to the endpoint of PFS and categorized patients into 3 prognostic groups: low-risk (maximum diameter of primary lesion (≤3cm) and number of positive lymph nodes (≤2)), intermediate-risk (maximum diameter of primary lesion (>3cm) and number of positive lymph nodes (≤2)), and high-risk (number of positive lymph nodes (>2)), with corresponding 5-year PFS rates of 90.0%, 75.0%, and 51.0%, respectively. Significant improvement in PFS was observed in the PORT group among intermediate-risk (P=0.000) and high-risk patients (P=0.000).

CONCLUSIONS

PORT was shown to be a positive prognostic factor for PFS and LRC of LECSG. PORT was an essential treatment especially for patients with >3cm maximum diameter of primary lesion and/or >2 positive lymph nodes.

The Role of Pretreatment 18F-FDG PET/CT for Early Prediction of Neoadjuvant Chemotherapy Response in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma

Introduction

To evaluate the role of maximal standardized uptake values (SUVmax) and total lesion glycolysis (TLG) from serial ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for early prediction of neoadjuvant chemotherapy (NAC) response in locoregionally advanced nasopharyngeal carcinoma (LANPC).

Methods

A total of 121 LANPC patients who completed pretreatment ¹⁸F-FDG PET/CT between June 2017 and July 2020 were retrospectively included. The median age of all the participants was 50 years old (range: 19–74 years), with 94 (77.7%) males and 27 (22.3%) females. The SUVmax from the primary tumor site (SUVmax-PT) and the total lesion glycolysis from the primary tumor site (TLG-PT) were recorded. Tumor response was calculated according to the Response Evaluation Criteria in Solid Tumor (RECIST) 1.1 Criteria at two-week post-secondary NAC cycle. Patients who achieved an objectively partial or full reaction after two cycles of NAC were defined as ‘responders’, and patients who obtained stability or progression were classified as ‘non-responders’.

Results

After two cycles of NAC, 96 patients were categorized as “responders” and 25 patients as “non-responders”. The optimal thresholds of the SUVmax-PT were 11.8 and 38.5 for the TLG-PT. Non-responders were significantly associated with high SUVmax-PT (HR, 3.49; 95% CI, 1.17–10.36; p = 0.024) and TLG-PT (HR, 4.45; 95% CI, 1.44–13.78; p = 0.010) in multivariate analysis. Recursive partitioning analysis (RPA) categorized patients into three prognostic groups based on SUVmax-PT and TLG-PT: high-response group, intermediate-response group, and low-response group, with corresponding favorable response rates of 94%, 80%, and 55%, respectively. Moreover, a nomogram was created based on metabolic parameters that precisely projected an individual’s response of NAC (C-index, 0.787; 95% CI, 0.533–1.000).

Conclusion

Pretreatment ¹⁸F-FDG PET/CT to measure SUVmax-PT and TLG-PT could be a useful non-invasive method for early indication of NAC efficacy. The nomogram based on PET/CT parameters may potentially provide direction for treatment decisions based on NAC levels.

The Immune Landscape of Chinese Head and Neck Adenoid Cystic Carcinoma and Clinical Implication

Novel systemic agents and effective treatment strategies for recurrence adenoid cystic carcinoma (ACC) of the head and neck are still worthy of further exploration. Here, we analyzed the mutations and expression profiles of 75 Chinese ACC patients, characterized the prognostic value of the immune signature for recurrence or distant metastasis, and explored the potential of immunotherapeutic biomarkers in ACC. In general, MYB fusion and somatic mutations accounted for a high proportion, which was 46.7% (35/75). ACCs displayed an overall low mutation burden and lack of programmed cell death ligand-1 (PD-L1) expression. The antigen-presenting machinery (APM) expression score and immune infiltration score (IIS) were the lowest among ACC patients, compared with other cancer types. For 61 primary cases, the locoregional recurrence-free survival (LRRFS) was statistically significantly correlated with the IIS [univariate analysis; hazard ratio (HR) = 0.32; 95% CI, 0.11–0.92; p = 0.035] and T-cell infiltration score (TIS) (univariate analysis; HR = 0.33; 95% CI, 0.12–0.94; p = 0.037]. Patients with lower IIS (log-rank p = 0.0079) or TIS (log-rank p = 0.0079) had shorter LRRFS. Additionally, solid pattern was also a prognostic factor related to locoregional recurrence, whereas postoperative radiotherapy (PORT) exerted its beneficial effects. We further evaluated the pretreatment immune profile of five ACC patients treated with PD-1 inhibitors. Patients who responded to camrelizumab or pembrolizumab observed elevated APM and TIS, compared with patients with progressive disease. Our study highlights the immune infiltration pattern and messenger RNA (mRNA) signatures of Chinese ACC patients, which has the potential value for prognosis and immunotherapy.

Salivary Gland Cancers

Salivary gland carcinomas are a rare and heterogenous group of cancers with varying underlying biology and clinical behavior. A quickly evolving body of data has advanced the understanding of these tumors, leading to effective therapeutics for several histologic subtypes. Biologically rational clinical trials have developed from an understanding of MYB and NOTCH signaling in adenoid cystic carcinoma. The recognition of androgen receptor signaling and HER2-targeted therapy has offered therapeutic options in non-ACC salivary cancers. The use of TRK inhibitors in salivary secretory carcinoma has led to exceptional responses. Immunotherapy is an exciting new therapeutic avenue that requires further exploration.

Sublingual gland neoplasms: clinicopathological study of 8 cases

Background

Sublingual gland neoplasms are very rare and the majority of them are malignant. The aim of this study was to evaluate the clinical course, treatment, and outcomes of these uncommon neoplasms based on the authors’ experience and the recent literature.

Material and Methods

The medical charts of 8 patients with primary epithelial sublingual gland tumors treated between 1994 and 2020 were reviewed.

Results

Malignant tumors comprised 75% (6/8) of cases. Adenoid cystic carcinoma was the most common (50%, 3/6) and characterized by high risk of local recurrence and lung metastasis. Pleomorphic adenoma was the only representative of benign tumors with no evidence of local recurrence in follow up.

Conclusions

Treatment of choice of sublingual gland tumors is surgery. However, due to the fact that adenoid cystic carcinoma is the most common malignancy with poor prognosis, surgical treatment should be combined with postoperative radiotherapy. Benign sublingual tumors are less common and treatment of choice in these cases is tumor resection together with sublingual gland.

Key words:Salivary gland neoplasms, sublingual gland, pleomorphic adenoma, adenoid cystic carcinoma, mucoepidermoid carcinoma.

An Overview on the Histogenesis and Morphogenesis of Salivary Gland Neoplasms and Evolving Diagnostic Approaches

Simple Summary

Diagnosing salivary gland neoplasms (SGN) remain a challenge, given their underlying biological nature and overlapping features. Evolving techniques in molecular pathology have uncovered genetic mutations resulting in these tumors. This review delves into the molecular etiopatho-genesis of SGN, highlighting advanced diagnostic protocols that may facilitate the identification and therapy of a variety of SGN.

Abstract

Salivary gland neoplasms (SGN) remain a diagnostic dilemma due to their heterogenic complex behavior. Their diverse histomorphological appearance is attributed to the underlying cellular mechanisms and differentiation into various histopathological subtypes with overlapping fea-tures. Diagnostic tools such as fine needle aspiration biopsy, computerized tomography, magnetic resonance imaging, and positron emission tomography help evaluate the structure and assess the staging of SGN. Advances in molecular pathology have uncovered genetic patterns and oncogenes by immunohistochemistry, fluorescent in situ hybridization, and next–generation sequencing, that may potentially contribute to innovating diagnostic approaches in identifying various SGN. Surgical resection is the principal treatment for most SGN. Other modalities such as radiotherapy, chemotherapy, targeted therapy (agents like tyrosine kinase inhibitors, monoclonal antibodies, and proteasome inhibitors), and potential hormone therapy may be applied, depending on the clinical behaviors, histopathologic grading, tumor stage and location, and the extent of tissue invasion. This review delves into the molecular pathways of salivary gland tumorigenesis, highlighting recent diagnostic protocols that may facilitate the identification and management of SGN.