Salivary gland tumours

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 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.

Salivary gland-type cancers: cross-organ demographics of a rare cancer

BACKGROUND

Salivary gland-type cancers (SGTCs) are histologically heterogeneous and can affect organs other than the salivary glands. Some tumors outside the salivary glands are diagnosed on their unique histological characteristics. Comprehensive cross-organ studies on SGTCs are limited.

METHODS

We retrospectively analyzed the data of patients with salivary duct carcinoma (SDC), adenoid cystic carcinoma (AdCC), mucoepidermoid carcinoma (MEC), epithelial-myoepithelial carcinoma (EMC), acinic cell carcinoma (AcCC), and polymorphous adenocarcinoma (PAC) who visited our institution between 2009 and 2019. The primary tumor sites were classified into four categories; major salivary glands, head/neck (H/N) excluding (exc) major salivary glands (MSG) regions, broncho-pulmonary regions, and "others". H/N exc MSG was further divided into three subcategories, nasal/paranasal sinus, oral and pharynx/larynx.

RESULTS

We identified 173 patients with SGTCs, with SDC, AdCC, MEC, EMC, AcCC, and PAC accounting for 20%, 42%, 27%, 3%, 8%, and 1% of the cases, respectively. The most frequent primary site was the major salivary glands (64%), followed by H/N exc MSG regions (27%), broncho-pulmonary regions, and "others", thus non-salivary gland origins accounted for 9% of all cases. Patients with SDC, MEC, AcCC, or SGTC of the major salivary glands and broncho-pulmonary regions were more frequently treated by surgery. The overall survival time of the patients with MEC was significantly better than that of patients with SDC or EMC.

CONCLUSIONS

This cross-organ study highlights the clinical significance of SGTCs, underscoring the need for developing novel therapies for this rare disease entity.

Salivary Gland Tumors: A 20 Year Review From a Single Community Practice

Objective: Salivary gland tumors are a heterogenous group of lesions with variable pathology and clinical outcomes. Most published data are derived from studies conducted at tertiary care centers. Our study analyzed the experience from a community setting to determine significant differences, if any, in pathological distribution and clinical outcomes compared to the existing literature. Methods: We performed a retrospective analysis of all major salivary gland tumors that presented to a large community practice over a 20 year period. Retrospective chart analysis was performed for demographics, clinical presentation, imaging, cytology, histopathology, and clinical outcome data. Results: Of 806 patients, the parotid gland was the most common site in 683 patients (84.7%), followed by submandibular in 78 (9.7%) and sublingual in 45 (5.6%). A total of 203 patients were managed conservatively with observation without definitive diagnosis or lost to follow-up. A total of 495 patients underwent surgical intervention within the community practice. Twenty-six patients underwent surgical excision at an outside hospital. Eighty-two patients were determined to have a benign diagnosis based on ultrasound-guided fine needle aspiration or excisional biopsy alone. Final histopathology was benign in 505 cases (83.7%), while 98 tumors (16.3%) received a diagnosis of primary or secondary malignancy. For the parotid gland, pleomorphic adenoma (155) and Warthin's tumor (155) were the most common benign diagnoses, while mucoepidermoid carcinoma (13), adenocarcinoma (8), and acinic cell carcinoma (8) were the most common primary malignancies. Conclusions: We found a higher rate of benign tumor pathology compared to the existing literature. While the outcome data on surgical treatment of benign tumors are comparable to the existing literature, the same conclusion cannot be drawn for malignant tumors, given relatively small numbers in our series and likely disparity in the complexity of the surgical cases in tertiary care centers.

Perimesencephalic subarachnoid hemorrhage as a rare delayed complication of radiation therapy in a patient with parotid basaloid squamous cell carcinoma

In this case report, we address a rare entity of parotid cancer: basaloid squamous cell carcinoma, which was surgically unresectable and had thus far only been treated with radiation therapy. Following twenty years of continuous remission, our patient presented with an acute perimesencephalic subarachnoid hemorrhage. The cause of the acute perimesencephalic subarachnoid hemorrhage was a delayed complication of radiation therapy.

Primary Malignant Melanoma in the Parotid Gland: A Case Report and Literature Review

Primary melanoma of the parotid gland is an extremely rare and challenging tumor with a poor prognosis, and its ultrasonic characteristics have yet to be reported. This article presents a case of a 77-year-old man with a left parotid mass that was confirmed as a melanoma following surgery. The ultrasonic features of melanoma were examined in detail, with a particular focus on their diagnostic value. Furthermore, we summarized the clinical characteristics, treatment options, and outcomes associated with primary melanoma of the parotid gland based on a thorough analysis of the available literature.

Aggressive Primary Thyroid Mucoepidermoid Carcinoma with Extensive Pulmonary Involvement

Mucoepidermoid carcinomas (MECs) represent the most common malignant neoplasms of the salivary glands, but they have also been described in other unusual sites. Primary MECs originating in the thyroid gland are exceedingly rare, accounting for less than 0.5% of thyroid tumors. Owing to their low to medium grade, they are usually associated with an indolent evolution and a good long-term prognosis, generally being managed surgically based on the extent of the disease. However, this does not always apply, as primary thyroid MECs may present as metastatic or locally advanced diseases. While several treatment options have been explored in such cases, no consensus currently exists on their optimal treatment plan, and they should be managed in a multidisciplinary fashion. We report the case of a 67-year-old patient with primary MEC of the thyroid, which behaved aggressively, with extensive pulmonary metastasis, ultimately leading to the rapid clinical deterioration and death of the patient.

A Rare Case of Submandibular Gland Squamous Cell Carcinoma: Diagnostic Challenges and Surgical Management

Squamous cell carcinoma (SCC) in salivary glands is rare, often posing diagnostic challenges. This case report presents a 75-year-old male with progressively increasing swelling and pain in the right submandibular gland, eventually diagnosed as moderately differentiated SCC. The diagnostic journey involved fine needle aspiration cytology, imaging studies, and histopathological examination. The patient underwent surgical intervention, including submandibular gland excision and selective neck dissection, which successfully achieved local control. Subsequent postoperative follow-up indicated a favorable outcome, with no significant complaints. This report contributes insights into the multidisciplinary diagnostic approach and underscores the importance of imaging modalities in managing salivary gland SCC. This rare case emphasizes the need for ongoing research to refine management strategies for salivary gland SCC. By presenting a comprehensive diagnostic and therapeutic approach, this report contributes to the limited literature on this malignancy, emphasizing its rarity and the necessity for continued exploration of long-term outcomes. In conclusion, our case provides valuable insights into the medical knowledge surrounding SCC in salivary glands, warranting attention and further investigation.

Nivolumab plus ipilimumab in advanced salivary gland cancer: a phase 2 trial

Salivary gland cancers (SGCs) are rare, aggressive cancers without effective treatments when metastasized. We conducted a phase 2 trial evaluating nivolumab (nivo, anti-PD-1) and ipilimumab (ipi, anti-CTLA-4) in 64 patients with metastatic SGC enrolled in two histology-based cohorts (32 patients each): adenoid cystic carcinoma (ACC; cohort 1) and other SGCs (cohort 2). The primary efficacy endpoint (≥4 objective responses) was met in cohort 2 (5/32, 16%) but not in cohort 1 (2/32, 6%). Treatment safety/tolerability and progression-free survival (PFS) were secondary endpoints. Treatment-related adverse events grade ≥3 occurred in 24 of 64 (38%) patients across both cohorts, and median PFS was 4.4 months (95% confidence interval (CI): 2.4, 8.3) and 2.2 months (95% CI: 1.8, 5.3) for cohorts 1 and 2, respectively. We present whole-exome, RNA and T cell receptor (TCR) sequencing data from pre-treatment and on-treatment tumors and immune cell flow cytometry and TCR sequencing from peripheral blood at serial timepoints. Responding tumors universally demonstrated clonal expansion of pre-existing T cells and mutational contraction. Responding ACCs harbored neoantigens, including fusion-derived neoepitopes, that induced T cell responses ex vivo. This study shows that nivo+ipi has limited efficacy in ACC, albeit with infrequent, exceptional responses, and that it could be promising for non-ACC SGCs, particularly salivary duct carcinomas. ClinicalTrials.gov identifier: NCT03172624 .

Intraparotid node metastasis affects the long-term survival of patients with resectable recurrent parotid gland carcinoma

PURPOSE

The recurrence rate of parotid gland cancer is high, but research on the prognosis of recurrent parotid gland cancer (RPC) is relatively limited. We aim to determine the potential prognosis factors of RPC.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary cancer center.

METHODS

We conducted a retrospective review from 2012 to 2021 on RPC patients treated at the China National Cancer Center (CNCC). To analyze the impact of various variables on overall survival (OS) after recurrence, a univariate and multivariate Cox proportional hazard model was employed.

RESULTS

A total of 50/218 (23.0%) patients diagnosed with RPC and underwent surgery. The 5-year OS of all RPC patients in this cohort was 61.9%. 5 of 50 patients (10%) exhibited intraparotid node (IPN) metastasis. By univariate and multivariate analyses, we found that IPN metastasis was one of the prognostic factors of OS (p = 0.039) in RPC patients. The presence of IPN metastasis was also related to poor survival in individuals with negative cervical lymph nodes (CN0) (p = 0.011). In terms of the influence of surgical margins on prognosis, our findings revealed that RPC patients with negative margins exhibited a higher survival result than those with positive margins (p = 0.002).

CONCLUSION

According to this study, IPN metastasis indicate a high incidence of mortality in recurrent parotid cancer patients. Particularly, in CN0 patients, the presence of IPN metastasis was associated with poor survival in CN0 patients.

P16 expression and presence of lymphoid stroma are correlated with good prognosis in mucoepidermoid carcinoma of the head and neck

BACKGROUND

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. This study was designed to identify valuable prognosticator in MEC.

METHODS

Histopathologic analysis, immunohistochemistry, and in situ hybridization were performed on 128 carcinomas diagnosed as MEC of the head and neck.

RESULTS

Expression of p16 was found in 96 cases (76%) of MEC. Lymphoid stroma was identified in 63 cases (49%). There was a significant correlation between loss of p16 expression and absence of lymphoid stroma. Expression of p16 was significantly associated with better clinicopathologic features. Lymphoid stroma was significantly associated with lower histologic grade. Overall survival (OS) was significantly longer in cases expressing p16 (P = 0.00096) and lymphoid stroma cases (P = 0.0023). Multivariate analysis revealed loss of p16 expression as negative prognosticators for OS.

CONCLUSION

Our data showed p16 expression and the presence of lymphoid stroma were significantly associated with good clinical outcomes. Testing for these factors could lead to better prognostication and treatment of patients with MEC.

Utility of the Milan System for Reporting Salivary Gland Cytopathology in Parotid Gland Masses: The Experience of Two Tertiary Centers

Background The application of fine needle aspiration (FNA) in parotid masses via the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) enhances the diagnosis of these lesions alongside radiological investigations.  Objectives Our objective was to assess the risk of malignancy, sensitivity, specificity, and false positive and negative results for each category of the MSRSGC. Additionally, we assessed the level of agreement between the FNA results using MSRSGC and post-resection histopathological diagnosis. Methods We conducted a retrospective chart review of parotid gland masses that received FNA and postoperative pathological diagnosis at King Saud University Medical City and King Fahad Medical City between 2018 and 2022. We summarized the categorical variables using frequencies and percentages. Results A total of 172 cases met the inclusion criteria. Males encompassed 102 patients (59.3%) of the study sample, and 89 (51.7%) of parotid masses were on the left side. The risk of malignancy for the MSRSGC categories was 37.5% (Category I), 9.0% (II), 50.0% (III), 4.7% (IVa), 50.0% (IVb), 100.0% (V), and 71.0% (VI). FNA had an overall success rate of 81%. The sensitivity was 64% and specificity was 94% for non-neoplastic masses. For benign masses, the sensitivity was 91% and specificity was 66%; however, the sensitivity was 40% and specificity was 97% for malignant lesions. We found that the percentage of agreement between the FNA and final pathology was 80%. Conclusion FNA using MSRSGC is a valuable preoperative clinical tool. However, the low sensitivity rates based on the diagnosis of malignant lesions should alert clinicians not to be overly reliant on biopsy results and instead defer to definitive surgical management.

Research trends and perspectives on immediate facial reanimation in radical parotidectomy (Review)

For patients diagnosed with advanced malignant parotid tumour, radical parotidectomy with facial nerve sacrifice is part of the treatment. Multiple surgical techniques have been developed to cure facial paralysis in order to restore the function and aesthetics of the face. Despite the large number of publications over time on facial nerve reanimation, a consensus on the timing of the procedure or the donor graft selection has remained to be established. Therefore, the aim of the present study was to conduct a bibliometric analysis to identify and analyse scientific publications on the reconstruction of the facial nerve of patients who underwent radical parotidectomy with facial nerve sacrifice. The analysis on the topic was conducted using the built-in tool of the Scopus database and VOSviewer software. The first 100 most cited articles were separately reviewed to address the aim of the study. No consensus was found regarding the recommended surgical techniques for facial nerve reanimation. The most used donor cranial nerves for transfer included the following: Masseteric branch of the V nerve, contralateral VII nerve with cross-face graft, the XI nerve and the XII nerve. The best timing of surgery is also controversial depending on pre-exiting pathology and degree of nerve degeneration. However, most of the clinical experience suggests facial nerve restoration immediately after the ablative procedure to reduce complications and improve patients' quality of life.

Intraosseous clear cell mucoepidermoid carcinoma: A case report and evaluation

Salivary gland tumours are relatively uncommon, and there exists a considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants, in addition to overlapping histological patterns similar to those observed in different tumour entities. One such group of variations is clear cell tumours of oral cavity which constitute an assorted group of lesions that may be odontogenic or metastatic or of salivary gland origin. The clear cell variant of mucoepidermoid carcinoma is at times misleading to the clinician because of its atypical location and innocent appearance. The pathologist needs to be familiar with the molecular alterations so that there may be a strong potential to implement good treatment. Hereby, we report a rare case of intraosseous clear cell variant of mucoepidermoid carcinoma which histopathologically posed challenges due to its variable presentation, suggesting the need for histochemical stains and molecular work-up for a definitive diagnosis and a better therapeutic and prognostic insight.

Clinico-pathological profile of parotid gland tumors at a tertiary care center in North India

Aim of the Study

The objective of this study was to know the various types of parotid tumors and their clinical presentations, surgical management, and post-operative outcome.

Material and Methods

Data of 102 patients assessed from hospital records who underwent parotid surgery between the years 2013 and 2018 were obtained. Parameters included age, sex, socio-demographic profile, presenting complaints, examination findings, and cytopathology. Surgical techniques, post-operative complications such as a facial scar, retro-mandibular and pre-auricular depression, facial palsy, Frey's syndrome, and numbness over the ear lobule were analyzed.

Result

Out of a total of 102 patients, 54.0% of patients were male, and 45.1% were female. The mean age of patients was 33.30 ± 13.87 years ranging from 7 to 65 years. The most common clinical presentation was swelling in the parotid region (95.1%), and associated symptoms with swelling were pain (17.5%), facial palsy (4.9%), discharging sinus (4.9%), and ulcerative lesions (1%) at the time of presentation. Pleomorphic adenoma was the most common benign neoplasm (76.5%), followed by Warthin's tumors (2.9%). Mucoepidermoid carcinoma was the most common malignant neoplasm (3.9%). After parotid surgery, 35% of patients had a sensory impairment or hypoesthesia of the ear lobule, and 23.28% had temporary facial nerve weakness. 5.0% of patients had permanent facial weakness, and 2.06% of patients had weakness of the marginal mandibular nerve.

Conclusion

Pleomorphic adenoma and mucoepidermoid carcinoma are the most common benign and malignant tumors, respectively, and parotidectomy is the treatment of choice, depending on the tumor location. Successful treatment depends on early diagnosis and histopathological and radiological investigations. Sensory impairment and temporary facial nerve paralysis are the most common post-operative complications, which are minimized by proper knowledge of anatomy and meticulous dissection of the facial nerve during parotid surgery.

A systematic review on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer

BACKGROUND

Salivary gland cancer is a rare disease, and approximately 20% of tumors in the salivary glands are malignant. Reliable biomarkers may have a role in monitoring salivary gland cancer.

AIM

To review the current literature on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer.

MATERIALS AND METHOD

This study systematically reviewed the literature on studies detecting salivary gland cancer by biomarkers in liquid biopsies and saliva samples by systematically searching PubMed and Embase between 1 January 2013 and 7 March 2023.

RESULTS

Five studies covering 64 malignant cases of salivary gland cancer were included, which considered inflammatory biomarkers or markers of genetic material in either blood or saliva. In saliva, there were demonstrated elevations of CA-19-9 in malignant cases, and elevations of miRNA in malignant and benign cases. In blood, there were demonstrated elevations of IL-33 in malignant and benign cases, elevations of ctDNA in malignant cases, and elevations of CTC in malignant cases.

CONCLUSION AND SIGNIFICANCE

The studies indicate that there is potential in the detection method. The studies detecting genetic material by liquid biopsies showed the most promising results. At present, there is still progression to be made before the method can be implemented for diagnostic use.

[Why is the histomorphological diagnosis of small salivary gland tumours so much more difficult?]

There is a widespread impression among clinicians and pathologists that the histomorphological diagnosis of minor salivary gland tumours is more difficult and more frequently misdiagnosed than that of major glands. This is based on subjective clinical impression; scientific proof of and potential reasons for this difference are lacking. We identified 14 putative clinical, histopathological and combined clinical-histological reasons and four consequences, which together could explain the perceived greater difficulty of diagnosing minor gland tumours. We performed a thorough literature search and a statistical comparison of data from a personal large consultation series (biased for "difficult" cases) with cumulated data from a routine, unselected (non-consultation) series from the literature. Through this comparison, we could prove with statistical significance a series of reasons and consequences for this greater diagnostic difficulty in minor glands. Frequent incisional biopsies, almost obligatory low-grade bland cytology in malignant tumours and insufficient clinical-pathological communication emerged as the most important reasons. The special anatomic location of the hard palate contributes to further diagnostic difficulties, such as tumour necrosis, mucosal ulceration, pseudoinvasion and the "tumoural-mucosal fusion" phenomenon. Knowledge of these pitfalls in clinic and pathology can help overcome these difficulties and reduce the misdiagnosis rate in minor gland tumours. Our findings result in a series of recommendations both for the clinic and pathology.

Prognostic Impact of Tumor Immune Microenvironment and Its Predictive Role in Salivary Gland Cancer

BACKGROUND

Recently, many studies have investigated the role of tumor immune microenvironment (TIME) in carcinogenesis, highlighting its relation to both tumor regression and progression. In particular, the "inflammatory system", made of innate and adaptive immune cells, interacts with cancer cells and their surrounding stroma. In this setting, the aim of this review is to summarize the current literature regarding the TIME of major salivary gland carcinomas (MSGCs), with particular attention on the characteristics and prognostic role of tumor infiltrating lymphocytes (TILs), the mechanisms that lead to TILs exhaustion and the important additional immune infiltrating factors that help SGC progression or remission.

METHODS

A comprehensive literature search was performed concerning published articles on the role of TIME in MSGCs.

RESULTS

In this work we summarize the advancing knowledge on TIME in SGCs by demonstrating the key prognostic and/or predictive value of specific immune features.

CONCLUSION

From the analysis of the current 'status of the art' it clearly emerges a need for precise, unambiguous phenotyping of immune cell populations, as well as a more thorough understanding of the frequencies and interactions of multiple immune cell types inside the TIME and their spatial localization (intratumoral vs. stromal).

Epidemiology, outcomes, and prognostic factors in submandibular gland carcinomas: a national DAHANCA study

PURPOSE

The aim of this study is to present incidence, histological subtypes, survival rates, and prognostic factors based on a national cohort of patients with salivary gland carcinoma.

METHODS

All Danish patients with submandibular gland carcinoma diagnosed from 1990 to 2015 (n = 206) were included and analyzed following histological re-evaluation. Data were collected by the Danish Head and Neck Cancer Group (DAHANCA). Overall, disease-specific and recurrence-free survival were evaluated. Prognostic factors were analyzed with multivariate Cox Hazard Regression.

RESULTS

The study population consisted of 109 (53%) men and 97 (47%) women, median age 62 years (range 11-102). Adenoid cystic carcinoma was the most frequent subtype (50%). Tumour classification T1/T2 (75%) and N0 (78%) was most frequent. The mean crude incidence was 0.17/100,000/year. Most patients (n = 194, 94%) were treated with primary surgery, and 130 (67%) received postoperative radiotherapy. The 5- and 10-year survival rates were for overall survival 64% and 41%, disease-specific survival 74% and 61%, and recurrence-free survival 70% and 56%, respectively. Survival rates were higher for adenoid cystic carcinoma compared to other subtypes, but the difference was not significant in multivariate analysis. Recurrence occurred in 69 patients, and 37 (53.6%) of them had recurrence in a distant site. Advanced T-classification and regional lymph-node metastases had significant negative impact on survival rates.

CONCLUSION

The incidence of submandibular gland carcinoma in Denmark was 0.17/100,000/year and stable during the time period. The most frequent subtype was adenoid cystic carcinoma. Half of the recurrences presented in a distant site, and multivariate analysis confirmed that advanced stage was independent negative prognostic factor for recurrence and survival.

Discovery proteomics reveals potential protein signature associated with malignant phenotype acquisition in pleomorphic adenoma

OBJECTIVE

To analyze the proteomic profile of salivary pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (CXPA) samples and correlate them with the malignant transformation of the PA.

MATERIALS AND METHODS

Thirty samples (10 PA, 16 CXPA, and 4 residual PA) were microdissected and submitted to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The proteomic data and protein identification were analyzed through LC-MS/MS spectra using the MaxQuant software.

RESULTS

The proteomic analysis identified and quantified a total of 240 proteins in which 135 were found in PA, residual PA, and CXPA. The shared proteins were divided into six subgroups, and the proteins that showed statistically significant differences (p > 0.05) and fold-change > or <2.5 in one subgroup to another subgroup were included. Seven proteins (Apolipoprotein A-I-APOA1, haptoglobin-HP, protein of the synaptonemal complex 1-SYCP1, anion transport protein of band 3-SLC4A1, subunit μ1 of AP-1 complex-AP1M1, beta subunit of hemoglobin-HBB, and dermcidin-DCD) were classified as potential protein signatures, being HP, AP1M1, and HBB with higher abundance for PA to residual PA, APOA1 with higher abundance for PA to CXPA, SLC4A1 with lower abundance in the PA to CXPA, SYCP1with lower abundance for residual PA to CXPA, and DCD with higher abundance in the CXPA with epithelial differentiation to myoepithelial differentiation.

CONCLUSIONS

In this work, we demonstrated the comparative proteomic profiling of PA, residual PA, and CXPA, and seven were proposed as protein signatures, some of which may be associated with the malignant phenotype acquisition.

Prognostic risk factor of major salivary gland carcinomas and survival prediction model based on random survival forests

Salivary gland malignancies are rare and are often acompanied by poor prognoses. So, identifying the populations with risk factors and timely intervention to avoid disease progression is significant. This study provides an effective prediction model to screen the target patients and is helpful to construct a cost-effective follow-up strategy. We enrolled 249 patients diagnosed with salivary gland tumors and analyzed prognostic risk factors using Cox proportional hazard univariable and multivariable regression models. The patients' data were split into training and validation sets on a 7:3 ratio, and the random survival forest (RSF) model was established using the training sets and validated using the validation sets. The maximally selected rank statistics method was used to determine a cut point value corresponding to the most significant relation with survival. Univariable Cox regression suggested age, smoking, alcohol consumption, untreated, neural invasion, capsular invasion, skin invasion, tumors larger than 4 cm, advanced T and N stage, distant metastasis, and non-mucous cell carcinoma were risk factors for poor prognosis, and multivariable analysis suggested that female, aging, smoking, untreated, and non-mucous cell carcinoma were risk factors. The time-dependent ROC curve showed the AUC of the RSF prediction model on 1-, 2-, and 3-year survival were 0.696, 0.779, and 0.765 respectively in the validation sets. Log-rank tests suggested that the cut point 7.42 risk score calculated from the RSF was most effective in dividing patients with significantly different prognoses. The prediction model based on the RSF could effectively screen patients with poor prognoses.

Current trends in the treatment of recurrent adenocystic cancer of the salivary glands: case report

Salivary gland carcinomas is a rare family of neoplasms with different histological characteristics and biological behavior. Treatment regimens have remained virtually unchanged for decades, leaving the leading role for surgical treatment and radiation therapy. However, a special place in the salivary gland carcinomas group is occupied by adenoid cystic carcinoma, which is quite often characterized by a recurrent and / or metastatic course with the use of chemotherapy as the main option in treatment. It is worth noting the fact that the results of standard chemotherapy regimens show unsatisfactory results, respectively, with recurrent or metastatic adenoid cystic carcinoma, treatment options are minimal. Accordingly, there is a need to study new therapeutic methods for the treatment of this disease. In this situation, high hopes were placed on targeted therapy, in particular, the family of epidermal growth factor receptors, c-Kit are the most frequently studied molecular targets. Due to the rare occurrence of adenoid cystic carcinoma, the number of cases of using targeted therapy for analysis is relatively small, so each clinical observation is of particular value. The following is a clinical case of treatment of recurrent adenoid cystic carcinoma using a personalized treatment approach.

Aim. To describe the clinical observation of the use of targeted drugs in recurrent or metastatic adenocystic cancer of the salivary glands.

Malignant salivary gland tumours: treatment outcomes from a tertiary referral centre in the UK

Salivary gland malignant tumours are a complex and highly variable pathological group. Their diagnosis can be challenging, and management is guided by multidisciplinary teams. This project aimed to establish clinicopathological and sociodemographic features that significantly impacted overall disease-free or progression-free survival in patients diagnosed with malignant salivary gland disease between 2010 and 2019 in a tertiary referral centre. In total, 86 patients were included for analysis, with a female:male gender ratio of 1.3:1. Mean age at diagnosis was 57.7 years. Mucoepidermoid carcinomas constituted almost 25% (n = 20) of all cases, with adenoid cystic carcinomas (20%, n = 17) and acinic cell carcinomas (17.5%, n = 15) being the next most frequently diagnosed. The parotid gland was the most frequently affected site (80.2%, n = 69). Perineural and lymphovascular invasion, and a maximum tumour dimension of ≥4 cm were highly associated with the decision to provide a neck dissection as part of treatment. Involved margins, extracapsular spread, and lymphovascular and perineural invasion were associated with the need for adjuvant treatment. However, no factors remained statistically significant on multivariate analysis. This retrospective service evaluation demonstrates the difficulty of predicting treatment outcomes for patients diagnosed with malignant salivary gland disease.

Immunological and biological dissection of normal and tumoral salivary glands

Salivary glands naturally play central roles in oral immunity. The salivary glands microenvironment inevitable may be exposed to exogenous factors consequently triggering the initiation and formation of various malignant and benign tumors. Mesenchymal stem cells are recruited into salivary gland microenvironment, interact with tumor cells, and induce inhibitory cytokines as well as cells with immunosuppressive phenotypes such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). The immune components and tumor immune responses in malignant and benign SGTs are still under investigation. Immune responses may directly play a limiting role in tumor growth and expansion, or may participate in formation of a rich milieu for tumor growth in cooperation with other cellular and regulatory molecules. Immune checkpoint molecules (e.g. PDLs, HLA-G and LAG3) are frequently expressed on tumor cells and/or tumor-infiltrating lymphocytes (TILs) in salivary gland microenvironment, and an increase in their expression is associated with T cell exhaustion, immune tolerance and tumor immune escape. Chemokines and chemokine receptors have influential roles on aggressive behaviors of SGTs, and thereby they could be candidate targets for cancer immunotherapy. To present a broad knowledge on salivary glands, this review first provides a brief description on immunological functions of normal salivary glands, and then describe the SGT's tumor microenvironment, by focusing on mesenchymal stem cells, immune cell subsets, immune checkpoint molecules, chemokines and chemokine receptors, and finally introduces immune checkpoint inhibitors as well as potential targets for cancer therapy.

Bmi-1: A master regulator of head and neck cancer stemness

Head and neck cancers are composed of a diverse group of malignancies, many of which exhibit an unacceptably low patient survival, high morbidity and poor treatment outcomes. The cancer stem cell (CSC) hypothesis provides an explanation for the substantial patient morbidity associated with treatment resistance and the high frequency of tumor recurrence/metastasis. Stem cells are a unique population of cells capable of recapitulating a heterogenous organ from a single cell, due to their capacity to self-renew and differentiate into progenitor cells. CSCs share these attributes, in addition to playing a pivotal role in cancer initiation and progression by means of their high tumorigenic potential. CSCs constitute only a small fraction of tumor cells but play a major role in tumor initiation and therapeutic evasion. The shift towards stem-like phenotype fuels many malignant features of a cancer cell and mediates resistance to conventional chemotherapy. Bmi-1 is a master regulator of stem cell self-renewal as part of the polycomb repressive complex 1 (PRC1) and has emerged as a prominent player in cancer stem cell biology. Bmi-1 expression is upregulated in CSCs, which is augmented by tumor-promoting factors and various conventional chemotherapies. Bmi-1⁺ CSCs mediate chemoresistance and metastasis. On the other hand, inhibiting Bmi-1 rescinds CSC function and re-sensitizes cancer cells to chemotherapy. Therefore, elucidating the functional role of Bmi-1 in CSC-mediated cancer progression may unveil an attractive target for mechanism-based, developmental therapeutics. In this review, we discuss the parallels in the role of Bmi-1 in stem cell biology of health and disease and explore how this can be leveraged to advance clinical treatment strategies for head and neck cancer.

An organoid library of salivary gland tumors reveals subtype-specific characteristics and biomarkers

BACKGROUND

Salivary gland tumors (SGTs) include a large group of rare neoplasms in the head and neck region, and the heterogeneous and overlapping features among the subtypes frequently make diagnostic difficulties. There is an urgent need to understand the cellular mechanisms underlying the heterogeneity and overlap among the subtypes, and explore the subtype-specific diagnostic biomarkers.

METHODS

The tumor tissue and the adjacent normal tissue from the 6 most common types of SGTs were processed for organoid culture which only maintained tumor epithelial cells. Organoids were histologically evaluated based on phenotype markers, followed by transcriptional profiling using RNA-sequencing. The transcriptomic similarities and differences among the subtypes were analyzed by subtype consensus clustering and hierarchical clustering. Furthermore, by comparative transcriptional analysis for these 6 types of SGTs and the matched organoids, the potential diagnostic biomarkers from tumor epithelium were identified, in which two selected biomarkers were evaluated by qPCR and confirmed by immunohistochemistry staining using a tissue microarray.

RESULTS

We generated a biobank of patient-derived organoids (PDOs) with 6 subtypes of SGTs, including 21 benign and 24 malignant SGTs. The PDOs recapitulated the morphological and transcriptional characteristics of the parental tumors. The overlap in the cell types and the heterogenous growth patterns were observed in the different subtypes of organoids. Comparing the bulk tissues, the cluster analysis of the PDOs remarkably revealed the epithelial characteristics, and visualized the intrinsic relationship among these subtypes. Finally, the exclusive biomarkers for the 6 most common types of SGTs were uncovered by comparative analysis, and PTP4A1 was demonstrated as a useful diagnostic biomarker for mucoepidermoid carcinoma.

CONCLUSIONS

We established the first organoid biobank with multiple subtypes of SGTs. PDOs of SGTs recapitulate the morphological and transcriptional characteristics of the original tumors, which uncovers subtype-specific biomarkers and reveals the molecular distance among the subtype of SGTs.

Myoepithelioma of the Parotid Gland: A Case Report and Literature Review

Tumors of the salivary glands are rare and have various histo-pathological subtypes. The overall incidence is 2.5-3 per 100,000 patients per year. Myoepithelioma of the parotid gland is very rare with an incidence of only 1-1.5% among all salivary gland tumors. The diagnostic criteria for benign myoepithelioma were laid down on the basis of the work of Barnes and Sciubba. A 30-year-old lady presented to our university with a mass slowly increasing in size. There were no aggravating and/or relieving factors found. On examination a 3 × 3 cm diffuse swelling was found around the right pre auricular area. Fine Needle Aspiration Cytology (FNAC) was performed. The findings were suggestive of a pleomorphic adenoma. The patient underwent a right sided superficial parotidectomy to remove the tumor. The final histopathology report revealed the tumor to be a myoepithelioma. Myoepithelioma is a benign salivary gland neoplasm formed almost entirely of myoepithelial cells arranged in a sheet, island or cord-like fashion. On CT scans, it presents as a well-circumscribed homogenous lesion with lobulated or smooth margins. Myoepitheliomas may also have nodules that enhance under contrast and areas of linear bands that do not. The recommended treatment for a myoepithelioma is complete surgical excision with wide margins. It has a very low recurrence rate compared to the 15-18% recurrence rate for pleomorphic adenomas. Utilization of immunohistochemical staining is of utmost importance in suspected myoepithelioma cases to ensure proper treatment and follow-up. Myoepitheliomas are rare tumors which must be included in the differential if a patient presents with a tumor of characteristics similar to those described above. Immunohistochemistry and electron microscopy are useful tools for the diagnosis of myoepitheliomas.

Population Based Average Parotid Gland Volume and Prevalence of Incidental Tumors in T1-MRI

Representative epidemiologic data on the average volume of the parotid gland in a large population-based MRI survey is non-existent. Within the Study of Health in Pomerania (SHIP), we examined the parotid gland in 1725 non-contrast MRI-scans in T1 weighted sequence of axial layers. Thus, a reliable standard operating procedure (Intraclass Correlation Coefficient > 0.8) could be established. In this study, we found an average, single sided parotid gland volume of 27.82 cm3 (95% confidence interval (CI) 27.15 to 28.50) in male and 21.60 cm3 (95% CI 21.16 to 22.05) in female subjects. We observed positive associations for age, body mass index (BMI), as well as male sex with parotid gland size in a multivariate model. The prevalence of incidental tumors within the parotid gland regardless of dignity was 3.94% in the Northeast German population, slightly higher than assumed. Further epidemiologic investigations regarding primary salivary gland diseases are necessary.

Parotidectomy and neck dissection in locally advanced and relapsed cutaneous squamous cell carcinoma of the head and neck region

OBJECTIVE

To investigate the prognostic factors to developing parotid and neck metastasis in locally advanced and relapsed Cutaneous Squamous Cell Carcinoma (CSCC) of the head and neck region.

METHODS

Single-center retrospective cohort study enrolling consecutive patients with advanced CSCC from 2009 to 2019. Seventy-four cases were identified. Study variables demographic data, clinical skin tumor stage, neck stage, parotid stage (P stage), surgical treatment features, and parotid, regional, and distant metastases. Survival measures: Overall Survival (OS) and Disease-Specific Survival (DSS).

RESULTS

The study group included 72.9% men (median age, 67 years); 67.5% showed T2/T3 tumors, 90.5% comorbidities, 20.2% immunosuppressed, with median follow-up: 35.8 months. The most frequent skin primary were auricular and eyelid regions, 75% underwent primary resection with flap reconstruction. Parotid metastasis was present in 50%, 32.4% showing parotid extracapsular spread, multivariate analysis found OR = 37.6 of positive parotid metastasis evolving into positive neck metastasis, p = 0.001. Occult neck metastasis, neck metastasis, and neck extracapsular spread were observed in 13.5%, 51.3%, and 37.8%, respectively. Kaplan-Meier survival: Clinical T4 versus T1, p = 0.028, P1 stage: 30% and 5% survival at 5 and 10 years, P3 stage: 0%, p = 0.016; OS and DSS showed negative survival for the parotid metastasis group, p = 0.0283.

CONCLUSION

Our outcomes support a surgically aggressive approach for locally advanced and relapsed CSCC, with partial parotidectomy for P0, total parotidectomy for P1-3, selective I-III neck dissection for all patients and adjuvant radiochemotherapy to appropriately treat these patients with advanced CSCC of the head and neck region.

LEVEL OF EVIDENCE

II b - Retrospective Cohort Study - Oxford Centre for Evidence-Based Medicine (OCEBM).

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.

Bioinformatic Analysis for Mucoepidermoid and Adenoid Cystic Carcinoma of Therapeutic Targets

Salivary gland neoplasms are a heterogeneous neoplasm group, including mucoepidermoid carcinoma (MECa), adenoid cystic carcinoma (AdCC), and many others. Objective: We aimed to identify new critical genes of MECa and AdCC using bioinformatics analysis. Methods: Gene expression profile of GSE153283 was analyzed by the GEO2R online tool to use the DAVID software for their subsequent enrichment. Protein–protein interactions (PPI) were visualized using String. Cytoscape with MCODE plugin followed by Kaplan–Meier online for overall survival analysis were performed. Results: 97 upregulated genes were identified for MECa and 86 for AdCC. PPI analysis revealed 22 genes for MECa and 63 for AdCC that were validated by Kaplan–Meier that showed FN1 and SPP1 for MECa, and EGF and ERBB2 for AdCC as more significant candidate genes for each neoplasm. Conclusion: With bioinformatics methods, we identify upregulated genes in MECa and AdCC. The resulting candidate genes as possible therapeutic targets were FN1, SPP1, EGF, and ERBB2, and all those genes had been tested as a target in other neoplasm kinds but not salivary gland neoplasm. The bioinformatic evidence is a solid strategy to select them for more extensive research with clinical impact.

Extended cervicomastoid approach with sternocleidomastoid flap reconstruction for parotid surgery: A better esthetic technique

Aim of the Study

The aim of the study is to compare the esthetic outcome of extended cervicomastoid approach with reconstruction with conventional approach (modified Blair's incision) for parotid surgery.

Materials and Methods

48 patients were enrolled and grouped into A: surgery through extended cervicomastoid incision with sternocleidomastoid reconstruction and B: surgery through modified Blair's incision. After parotid surgery, patients were followed up to 6 months on the basis of flap ischemia, patient satisfaction, and cosmesis (visual analog scale [VAS]).

Results

In our study, preauricular depression over the face was present in 4.2% and 95.8% patients Group A and B at 6 months, respectively (P < 0.001) and retromandibular depression (70.8%) in Group B (P < 0.001). Subjective Frey's syndrome was present in 8.3% of patients of Group B (P > 0.05). The mean value of VAS between the two groups was 1.08 ± 0.28 and 3.29 ± 0.62 at 6 months (P = 0.001) while mean change was significantly (P = 0.03) higher in Group A (1.00 ± 0.00) as compared to Group B (0.20 ± 0.72) from postoperative to 6 months, respectively. Patient of Group A had good satisfaction level (62.5% and 91.7%) at 6 weeks and 6 months while Group B patients had fair satisfaction level (87.5%) at 6 weeks and poor satisfaction level 79.2% at 6 months.

Conclusion

Parotidectomy through extended cervicomastoid incision with sternocleidomastoid flap reconstruction experienced lower rates of postoperative complications, flap necrosis, and gustatory sweating in comparison to cervicomastoid facial approach, and thus, the previous incision is esthetically superior that allows cheek contour reconstruction with no increase in operative time or postoperative complications.

Advanced magnetic resonance imaging findings in salivary gland tumors

Salivary gland tumors (SGTs) make up a small portion (approximately 5%) of all head and neck tumors. Most of them are located in the parotid glands, while they are less frequently located in the submandibular glands, minor salivary glands or sublingual gland. The incidence of malignant or benign tumors (BTs) in the salivary glands varies according to the salivary gland from which they originate. While most of those detected in the parotid gland tend to be benign, the incidence of malignancy increases in other glands. The use of magnetic resonance imaging (MRI) in the diagnosis of SGTs is increasing every day. While conventional sequences provide sufficient data on the presence, localization, extent and number of the tumor, they are insufficient for tumor specification. With the widespread use of advanced techniques such as diffusion-weighted imaging, semi-quantitative and quantitative perfusion MRI, studies and data have been published on the differentiation of malignant or BTs and the specificity of their subtypes. With diffusion MRI, differentiation can be made by utilizing the cellularity and microstructural properties of tumors. For example, SGTs such as high cellular Warthin’s tumor (WT) or lymphoma on diffusion MRI have been reported to have significantly lower apparent diffusion values than other tumors. Contrast agent uptake and wash-out levels of tumors can be detected with semi-quantitative perfusion MRI. For example, it is reported that almost all of the pleomorphic adenomas show an increasing enhancement time intensity curve and do not wash-out. On quantitative perfusion MRI studies using perfusion parameters such as Ktrans, Kep, and Ve, it is reported that WTs can show higher Kep and lower Ve values than other tumors. In this study, the contribution of advanced MRI to the diagnosis and differential diagnosis of SGTs will be reviewed.

Diversity of the Origin of Cancer Stem Cells in Oral Squamous Cell Carcinoma and Its Clinical Implications

Simple Summary

Oral squamous cell carcinoma (OSCC) histopathologically accounts for ≥90% of oral cancer. In this review article, we focus on the diversity of the origin of OSCC and also discuss cancer stem cells (CSCs). CSCs are a subset of cancer cells that occupy a very small portion of the cancer mass and have characteristics of stem cells. When gene abnormalities accumulate in somatic stem cells, those cells transform into CSCs. CSCs as the origin of cancer then autonomously grow and develop into cancer. The histopathological phenotype of cancer cells is determined by the original characteristics of the somatic stem cells and/or surrounding environment. OSCC may be divided into the following three categories with different malignancy based on the origin of CSCs: cancer from oral epithelial stem cell-derived CSCs, cancer from stem cells in salivary gland-derived CSCs, and cancer from bone marrow-derived stem cell-derived CSCs.

Abstract

Oral squamous cell carcinoma (OSCC) histopathologically accounts for ≥90% of oral cancer. Many clinicopathological risk factors for OSCC have also been proposed, and postoperative therapy is recommended in guidelines based on cancer stage and other risk factors. However, even if the standard treatment is provided according to the guidelines, a few cases rapidly recur or show cervical and distant metastasis. In this review article, we focus on the diversity of the origin of OSCC. We also discuss cancer stem cells (CSCs) as a key player to explain the malignancy of OSCC. CSCs are a subset of cancer cells that occupy a very small portion of the cancer mass and have characteristics of stem cells. When gene abnormalities accumulate in somatic stem cells, those cells transform into CSCs. CSCs as the origin of cancer then autonomously grow and develop into cancer. The histopathological phenotype of cancer cells is determined by the original characteristics of the somatic stem cells and/or surrounding environment. OSCC may be divided into the following three categories with different malignancy based on the origin of CSCs: cancer from oral epithelial stem cell-derived CSCs, cancer from stem cells in salivary gland-derived CSCs, and cancer from bone marrow-derived stem cell-derived CSCs.

Cancers of the Oral Cavity and Pharynx: 20-Year Comparative Survival and Mortality Analysis by Age, Sex, Race, Stage, Grade, Cohort Entry Time-Period and Disease Duration: A Systematic Review of 218,066 Cases for Diagnosis Years 1973-2014: (SEER*Stat 8.3.5)

This article summarizes the results of a retrospective population-based cohort study using the statistical database of SEER*Stat 8.3.54 (produced 3/5/2018 for diagnosis years 1973-2014) to assess, determine, compare, and summarize the occurrence, long-term survival, and mortality indices of 218,066 patients with oral cavity and pharynx cancers by age, sex, race, stage, grade, and disease duration.

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.

Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study

BACKGROUND

Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only.

METHODS

This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019.

RESULTS

A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin's tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours.

CONCLUSIONS

This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Evaluation of HER2/neu expression in different types of salivary gland tumors: a systematic review and meta-analysis

This study is a systematic review and meta-analysis to assess the overexpression rate of HER2 in patients with salivary gland tumors. We included peer-reviewed publications from 1995 to 2020, indexed in medical databases, using search terms such as "human epidermal growth factor receptor 2 (HER2)" and "salivary gland tumors", and extracted relevant data. The extracted data were analyzed with RevMan 5.3 software. Intra-and intergroup post hoc analyses of outcome variables were performed using t-tests, and the rates of HER2 positivity among studies were evaluated. 80 studies were included in the analysis. The positive rates of HER2 ranged from 3.3% to 84.0% and 1% to 9% in malignant and benign subtypes, respectively. The highest HER2 overexpression rate among malignant tumors was in salivary ductal carcinomas (SDC), with a 45% positive rate (CI 95%: 21.9-70.3%). Mucoepidermoid carcinoma (MEC) had the highest positive rate of 84% (CI 95%: 74.1-90.0%). Among benign salivary gland tumors, the highest rate was found in myoepithelioma, with a positive rate of 9% (CI 95%: 1.7-33.6%). The highest rate of HER2 overexpression is present in malignant subtypes of salivary gland tumors, more specifically in salivary ductal carcinoma, mucoepidermoid carcinomas, salivary duct carcinoma in situ, and carcinoma ex pleomorphic adenoma.

Prognostic Significance of Cancer Stem Cell Markers in Patients With Salivary Gland Carcinomas

OBJECTIVES

Cancer stem cells (CSCs) are a small group of cells resistant to therapy and play a major role in tumor progression, recurrence, and poor clinical outcomes of patients. This study aimed to evaluate the association of CSC markers with clinicopathologic features and survival in patients with salivary gland carcinomas (SGCs).

MATERIALS AND METHODS

The medical records of 48 patients affected by mucoepidermoid carcinoma (MEC) and 47 patients with adenoid cystic carcinoma (AdCC) were reviewed retrospectively. SOX2, CD133, and CD44 expression was appraised by immunohistochemistry and statistically analyzed to weigh the correlation between these markers and patients' clinicopathologic features and tumor outcomes.

RESULTS

In AdCC patients showing poor outcomes, a trend toward a high expression of CD133 and CD44 and low expression of SOX2 was observed, while in MEC patients experiencing the same outcomes, there was a trend toward a high expression of CD44 and low expression of CD133 and SOX2. Only the increase of MEC histopathologic grade was statistically significant with decreased SOX2 expression. Distant metastasis in AdCC patients, tumor grade, lymph node involvement, and local recurrence in MEC patients had significant correlations with patients' survival.

CONCLUSION

Besides the significant association between low SOX2 expression and higher grades of MEC, we found no statistically significant correlation between the studied CSC markers and patients' survival or clinicopathologic features. Therefore, a larger sample size with long-term follow-up is beneficial for thorough investigations toward the main role of CSCs in patients with SGCs.

Surgical Navigation, Augmented Reality, and 3D Printing for Hard Palate Adenoid Cystic Carcinoma En-Bloc Resection: Case Report and Literature Review

Adenoid Cystic Carcinoma is a rare and aggressive tumor representing less than 1% of head and neck cancers. This malignancy often arises from the minor salivary glands, being the palate its most common location. Surgical en-bloc resection with clear margins is the primary treatment. However, this location presents a limited line of sight and a high risk of injuries, making the surgical procedure challenging. In this context, technologies such as intraoperative navigation can become an effective tool, reducing morbidity and improving the safety and accuracy of the procedure. Although their use is extended in fields such as neurosurgery, their application in maxillofacial surgery has not been widely evidenced. One reason is the need to rigidly fixate a navigation reference to the patient, which often entails an invasive setup. In this work, we studied three alternative and less invasive setups using optical tracking, 3D printing and augmented reality. We evaluated their precision in a patient-specific phantom, obtaining errors below 1 mm. The optimum setup was finally applied in a clinical case, where the navigation software was used to guide the tumor resection. Points were collected along the surgical margins after resection and compared with the real ones identified in the postoperative CT. Distances of less than 2 mm were obtained in 90% of the samples. Moreover, the navigation provided confidence to the surgeons, who could then undertake a less invasive and more conservative approach. The postoperative CT scans showed adequate resection margins and confirmed that the patient is free of disease after two years of follow-up.

Oral Cancer Stem Cells: Therapeutic Implications and Challenges

Head and neck squamous cell carcinoma (HNSCC) is currently one of the 10 most common malignancies worldwide, characterized by a biologically highly diverse group of tumors with non-specific biomarkers and poor prognosis. The incidence rate of HNSCC varies widely throughout the world, with an evident prevalence in developing countries such as those in Southeast Asia and Southern Africa. Tumor relapse and metastasis following traditional treatment remain major clinical problems in oral cancer management. Current evidence suggests that therapeutic resistance and metastasis of cancer are mainly driven by a unique subpopulation of tumor cells, termed cancer stem cells (CSCs), or cancer-initiating cells (CICs), which are characterized by their capacity for self-renewal, maintenance of stemness and increased tumorigenicity. Thus, more understanding of the molecular mechanisms of CSCs and their behavior may help in developing effective therapeutic interventions that inhibit tumor growth and progression. This review provides an overview of the main signaling cascades in CSCs that drive tumor repropagation and metastasis in oral cancer, with a focus on squamous cell carcinoma. Other oral non-SCC tumors, including melanoma and malignant salivary gland tumors, will also be considered. In addition, this review discusses some of the CSC-targeted therapeutic strategies that have been employed to combat disease progression, and the challenges of targeting CSCs, with the aim of improving the clinical outcomes for patients with oral malignancies. Targeting of CSCs in head and neck cancer (HNC) represents a promising approach to improve disease outcome. Some CSC-targeted therapies have already been proven to be successful in pre-clinical studies and they are now being tested in clinical trials, mainly in combination with conventional treatment regimens. However, some studies revealed that CSCs may not be the only players that control disease relapse and progression of HNC. Further, clinical research studying a combination of therapies targeted against head and neck CSCs may provide significant advances.

Histopathological Review of Diagnostic Categories of the Milan System for Reporting Salivary Gland Cytopathology - An Institutional Experience of 6 Years

Introduction:

Salivary gland malignancies account for 2 to 4% of head and neck cancers. Fine needle aspiration cytology (FNAC) is used in preoperative diagnosis of salivary gland lesions. Although FNAC is a highly reliable technique for preoperative diagnosis, there were no consensus on salivary gland cytopathology reporting. Recently, an international group has recommended a classification system for salivary gland FNAC reporting titled “Milan System for Reporting Salivary Gland Cytopathology” (MSRSGC). In this study, we aimed to evaluate the usability of the Milan System, its ability to determine the risk of malignancy for each category, with comparisons of inital cytologic and final histopathological diagnosis.

Materials and Methods:

We performed a retrospective analysis of salivary gland lesion FNAC in our department from 2013 to 2019. A total of 578 FNACs were performed in 514 patients. Of these, 85 cases had surgical follow-up (parotid gland, n = 73, submandibular gland, n = 12). The cytological samples were categorized according to the MSRSGC into six categories by two pathologists. The risk of malignancy (ROM) and diagnostic accuracy values were calculated for each diagnostic categories.

Results:

A total of 85 aspirates of the patients with follow-up, the MSRSGC diagnostic categories were as follows: non-diagnostic in 7 aspirates (8.2%), non-neoplastic in 3 (3.5%), atypia of undetermined significance (AUS) in 9 (10.5%), benign neoplasm in 43 (50.5%), salivary gland neoplasm of undetermined malignant potential in 7 (8.2%), suspicious for malignancy in 10 (11.7%), and malignant in 6 (7%). The ROM for each category was 28, 5%, 0%, 33%, 0%, 28.5%, 90%, and 100%, respectively.

Conclusion:

FNAC plays a critical role in the evaluation of patients with salivary gland lesions. The MSRSGC helps in the standardization of the process of diagnosis and clinical management of salivary gland lesions, especially of AUS and SUMP categories that are indeterminate categories in nature.

Mutational and immunologic Landscape in malignant Salivary Gland Tumors harbor the potential for novel therapeutic strategies

Salivary gland carcinomas (SGC) are rare (3-6 % of all head and neck cancers) and show biological heterogeneity depending on the respective histological subtype. While complete surgical resection is the standard treatment for localized disease, chemotherapy or radiation therapy are frequently insufficient for the treatment of unresectable or metastasized SGC. Therefore, new therapeutic approaches such as molecularly targeted therapy or the application of immune checkpoint inhibition enhance the treatment repertoire. Accordingly, comprehensive analyses of the genomic landscape and the tumor-microenvironment (TME) are of crucial importance in order to optimize and individualize SGC treatment. This manuscript combines the current scientific knowledge of the composition of the mutational landscape and the TME in SGCs harboring the potential for novel (immune-) targeted therapeutic strategies.

Immunohistochemical analysis of proliferating cell nuclear antigen and minichromosome maintenance complex component 7 in benign and malignant salivary gland tumors

Background:

Proliferation markers have been used to determine the behavior and prognosis of benign and malignant tumors; this study was aimed to compare the immunohistochemical (IHC) expression of proliferating cell nuclear antigen (PCNA) and novel marker minichromosome maintenance complex component 7 (MCM7) in common salivary gland tumors including pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (AdCC), to find a possible significant correlation between benign and malignant tumors.

Materials and Methods:

In this cross-sectional study, a total of 90 cases, including 30 PAs, 30 MECs, and 30 AdCCs, were collected. The IHC expressions of PCNA and MCM7 were evaluated. Their expressions were compared with each other and between benign and malignant tumors. Statistical analysis was performed by Chi-square and Tukey's test. P value was considered 0.05.

Results:

Out of 30 cases of PA, 28 cases (93.3%) were PCNA positive and 28 cases (93.3%) were MCM7 positive. In the AdCC cases, 29 cases (96.6%) were PCNA positive and 29 cases (96.6%) were MCM7 positive. In the MEC cases, all cases (100%) were PCNA positive and 23 cases (76.6%) were MCM7 positive. The labeling index (LI) of MCM7 and PCNA was evaluated, and this index was lower in MCM7 LI than PCNA in all tumors. The MCM7 and PCNA expression showed a significant difference in PA and MEC (P < 0.001).

Conclusion:

PCNA expression was higher than MCM7 expression in salivary gland tumors. However, more studies are needed to evaluate the malignant activity of these tumors with group of markers such as MCM family members.

Clinicopathological characteristics and outcomes of 23 patients with secretory carcinoma of major salivary glands

This retrospective study investigated the clinicopathological characteristics of secretory carcinoma of salivary glands (SCSG) in 23 patients with histopathologically confirmed SCSG between January 2010 and December 2020. In total, 13 males and 10 females (ratio, 1.3:1) aged 10 − 69 years (median, 45 years) were enrolled in this study; the average disease duration was 2.44 years (0.25–20 years). Twenty-one patients (91.3%) had SCSG in the parotid gland, and two (8.7%) in the submandibular gland. All patients had single nodules of diameters 0.8–4.8 cm (average 2.6 cm); five with lymph node metastases, and two with distant metastases. Immunohistochemically, tumors stained positive for S-100, mammaglobin, CK7, GATA3 and pan-Trk, and negative for DOG1, P63, and calponin, with Ki-67 positivity from 1 to 50%. ETV6 gene rearrangement was confirmed in 15 patients. All patients underwent oncological resection, four had radioactive particles implanted postoperatively, one received chemotherapy, and seven underwent chemoradiotherapy. Six patients had regional recurrences, two distant metastases, and one died before the last follow-up. SCSGs are typically indolent, with a low locoregional recurrence rate and excellent survival. Prognosis is correlated to clinical stage, pathological grade, and surgical procedures.

Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS) spectra of salivary glands carcinoma, tumor and healthy tissues and their homogenates analyzed by chemometry: Towards development of the novel tool for clinical diagnosis

In this study, two approaches to salivary glands studies are presented: Raman imaging (RI) of tissue cross-section and surface-enhanced Raman spectroscopy (SERS) of tissue homogenates prepared according to elaborated protocol. Collected and analyzed data demonstrate the significant potential of SERS combined with multivariate analysis for distinguishing carcinoma or tumor from the normal salivary gland tissues as a rapid, label-free tool in cancer detection in oncological diagnostics. Raman imaging allows a detailed analysis of the cell wall's chemical composition; thus, the compound's distribution can be semi-quantitatively analyzed, while SERS of tissue homogenates allow for detailed analysis of all moieties forming these tissues. In this sense, SERS is more sensitive and reliable to study any changes in the area of infected tissues. Principal component analysis (PCA), as an unsupervised pattern recognition method, was used to identify the differences in the SERS salivary glands homogenates. The partial least squares-discriminant analysis (PLS-DA), the supervised pattern classification technique, was also used to strengthen further the computed model based on the latent variables in the SERS spectra. Moreover, the chemometric quantification of obtained data was analyzed using principal component regression (PCR) multivariate calibration. The presented data prove that the PCA algorithm allows for 91% in seven following components and the determination between healthy and tumor salivary gland homogenates. The PCR and PLS-DA methods predict 90% and 95% of the variance between the studied groups (in 6 components and 4 factors, respectively). Moreover, according to calculated RMSEC (RMSEP), R2C (R2P) values and correlation accuracy (based on the ROC curve), the PLS-DA model fits better for the studied data. Thus, SERS methods combined with PLS-DA analysis can be used to differentiate healthy, neoplastic, and mixed tissues as a competitive tool in relation to the commonly used method of histopathological staining of tumor tissue.