Exploring the Epidemiology and Survival Trends in Pediatric Major Salivary Gland Malignancies: Insights from the National Cancer Database.

OBJECTIVE: To investigate the clinicopathological, therapeutic, and survival data on pediatric major salivary gland cancers. MATERIALS AND METHODS: National Cancer Database (NCDB) query from 2004 to 2018. RESULTS: In total, 967 cases of individuals under the age of 21 were identified. Most cancers affected the parotid gland (86%). Mucoepidermoid carcinoma (41.3%) and acinic cell adenocarcinoma (33.6%) were the most common. Tumors occurred more often from age 11 to 21, and females were more affected. Histology varied by age, gender, and race. In the 0-5 age group, mucoepidermoid carcinoma and myoepithelial carcinoma/sarcoma/rhabdomyosarcoma were the most common pathologies. In patients over 5 years old, mucoepidermoid carcinoma was the most frequent tumor in boys, while acinic cell adenocarcinoma was more common in girls. African American patients had a higher incidence of mucoepidermoid carcinoma, while White patients in the 0-5 age group had a higher incidence of myoepithelial carcinoma/sarcoma/rhabdomyosarcoma tumors. Low-grade tumors were commonly diagnosed at stage I, but the 0-5 age group had a high frequency of stage IV tumors. The overall 5-year survival rate was 94.9%, with 90% for the 0-5 years age group and 96% for the 11-15 years age group. Negative margins were associated with higher 5-year survival rates in high-stage tumors (93%) compared to positive margins (80%). Submandibular malignancies had worse 5-year survival rates across all age groups. CONCLUSIONS: Major salivary gland malignancies in pediatric patients exhibit variations in histopathologic characteristics by age, gender, and race. Negative margins impact 5-year survival rates, especially in high-stage tumors.

Intraoral Minor Salivary Gland Tumors: A Retrospective, Clinicopathologic, Single-Center Study of 432 Cases in Japan and a Comparison with Epidemiological Data.

BACKGROUND: Intraoral minor salivary gland tumors are relatively rare lesions with histological subtypes not commonly found in major salivary glands. This study aimed to retrospectively evaluate the clinicopathologic features of intraoral minor salivary gland tumors from the Tokyo Dental College Hospital, Japan, and compare them with findings from other epidemiological studies. METHODS: We conducted a retrospective clinicopathologic evaluation of 432 cases of intraoral minor salivary gland tumors [161 male (37.3%) and 271 female (62.7%) patients; mean age: 52.5 and 48.6 years for males and females, respectively; age at diagnosis: 7-87 (mean: 50.1) years] from the Tokyo Dental College Hospital between 1975 and 2022, including 283 benign tumors (65.5%) and 149 malignant tumors (34.5%). RESULTS: The most common benign tumor was pleomorphic adenoma (n = 239), whereas mucoepidermoid carcinoma was the most common malignant tumor (n = 74). The mean age of patients with benign and malignant tumors was 48.4 and 53.2 years, respectively, with patients with malignant tumors being significantly older (P = 0.0042). The mean age of patients with malignant tumors was significantly higher in males (56.7 years) than in females (50.9 years) (P = 0.0376), although the mean age of patients with benign tumors did not differ by sex. Tumors were commonly located in the palate [250 cases (57.9%)]. Benign tumors were more frequent in the palate, upper lip, and buccal mucosa, whereas malignant tumors were more frequent in the palate, floor of the mouth, buccal mucosa, and retromolar area. CONCLUSIONS: Understanding the features of intraoral minor salivary gland tumors is useful for diagnosis. Our study provides important epidemiological data (patient differences in age at occurrence, sex, and site of origin) that will inform clinicians and researchers.

Epidemiological and clinical characteristics of synchronous lung metastasis in major salivary gland mucoepidermoid carcinoma.

OBJECTIVES: To analyze the risk factors for synchronous lung metastases (LM) in patients with major salivary gland mucoepidermoid carcinoma (MaSG-MEC). METHODS: MaSG-MEC patients were extracted from the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2014. Descriptive statistics were used to examine the baseline characteristics of the patients. We examined the association between risk factors and synchronous LM using Chi-squared tests. The primary study outcomes were overall survival (OS) and cancer-specific survival (CSS). Kaplan-Meier survival curves were compared using the log-rank test. Hazard analysis was conducted using the Cox proportional hazards model. RESULTS: A total of 701 patients were analyzed, which including 8 patients (1.1%) with synchronous LM, and 693 patients without synchronous LM (98.9%). Lower T or N classification, and highly differentiated disease were associated with a significantly lower risk of LM and multivariate logistic regression analysis showed that lower T classification were associated with a significantly lower risk of LM (P < 0.05, respectively). Elderly Caucasian male patients with poorly differentiated disease, multiple sites of metastases and no surgical therapy to primary tumor were more likely to reduce life expectancy. CONCLUSION: By analyzing data from a large cohort, lower T or N classification and highly differentiated disease were associated with a significantly lower risk of LM. Elderly Caucasian male patients with poorly differentiated disease, multiple sites of metastases and no surgical therapy to primary tumor were more likely to reduce life expectancy. More accurate assessments of LM will be imperative for early diagnosis and treatment in patients who harbored with higher T or N classification and poorly differentiated disease.

Salivary gland tumours: an epidemiological review of non-neoplastic and neoplastic pathology.

Salivary gland tumours (SGT) demonstrate geographical variation. The primary objective of this study was to determine the types, frequency, distribution, and demographics of non-neoplastic and neoplastic salivary gland pathology at Waikato Hospital, New Zealand (NZ) over a 10-year period. Following this we conducted a 10-year retrospective review of SGT epidemiology from international literature. In total 825 patients were identified, 31% (256/825) with non-neoplastic salivary gland pathology, 34% (284/825) with benign neoplastic pathology, 14% (118/825) with primary malignant lesions, 18% (146/825) with metastatic SGTs, and 3% (21/825) with lymphoma. Patients had a mean (range) age of 58 (3-102) years, were predominantly male (58%, 476/825), and NZ European (65%, 536/825). Tumours were most prevalent in the parotid gland (85%, 484/569), of which 44% (211/484) were malignant. Pleomorphic adenoma was the most common benign (71%, 203/284) and overall (36%, 203/569) tumour, while mucoepidermoid carcinoma (25%, 29/118) and squamous cell carcinoma (SCC) (73%, 106/146) were the most common primary malignant and metastatic SGTs, respectively. Our literature review identified 18 studies consisting of 33,933 patients, of whom 71% (24,013/33,933) had benign SGTs. Pleomorphic adenoma (68%, 16404/24013) and mucoepidermoid carcinoma (29%, 2826/9621) were the most common benign and malignant SGTs, respectively. Low numbers of non-neoplastic and metastatic SGTs were reported in the literature. This research provides a greater understanding of differences in their global distribution. Consistent with previous literature, pleomorphic adenoma and mucoepidermoid carcinoma were the most common benign and malignant SGTs. In NZ, we found high rates of malignant SCC to the parotid gland, consistent with the epidemiology of non-melanoma skin cancer in the country.

Twenty-seven years of primary salivary gland carcinoma in Wales: an analysis of histological subtype and associated risk factors.

OBJECTIVE: Risk factors for salivary gland carcinoma are poorly understood. Although links between background radiation, smoking and obesity have been previously suggested, no studies have so far established any significant results. This study aimed to establish correlations between common environmental and lifestyle risk factors and different subtypes of salivary gland carcinoma. METHOD: A study of population data in Wales spanning 27 years was conducted; 2 national databases were used to identify 356 cases of primary salivary gland carcinoma over this period. Histological subtype of cancer and geographical location of each case was recorded. Public health data was used to establish radon levels, smoking, obesity and activity levels of populations in each geographical location. A population matched multivariate analysis of variance analysis was performed using histological subtype and risk factor data for each geographical location. RESULTS: A significantly higher incidence of mucoepidermoid cancer in populations with higher background radon levels (p = 0.006), epithelial-myoepithelial cancer in populations with higher smoking levels (p = 0.029) and adenoid cystic cancer in populations with higher obesity levels (p = 0.028) was found. CONCLUSION: To the authors' knowledge, this is the first study to establish significant links between background radiation, smoking and obesity with different subtypes of salivary gland carcinoma.

Prognostic analysis and nomogram establishment in patients with mucoepidermoid carcinoma of the tongue: a population-based study using the SEER database.

OBJECTIVES: To describe the clinicopathological characteristics and determinants of survival of patients with mucoepidermoid carcinoma (MEC) of the tongue. METHOD: Retrospective population-based study was conducted using the data of patients diagnosed with MEC of the tongue from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016. RESULTS: A total of 200 cases of MEC of the tongue were identified. The cohort was composed of 56.5% females. The mean age at diagnosis was 58.8 years. The base of the tongue was the most common primary site (72.5%). Most cases (80.9%) presented with T1 and T2. Lymph node metastases was present in 40.9% of cases, while distant metastases only observed in 2.2% of cases. Overall survival (OS) at 2, 5, and 10 years was 80.2%, 69.8%, and 52.4%, respectively. 77.5 percent of cases (155/200) underwent surgery, and 66 cases received both surgery and radiation therapy. Patients with post-operative radiation had much longer disease-specific survival (DSS). Advanced T stage, distant metastasis contributed independently to shorter OS, while the use of surgery is an independently favorable prognostic factor for OS. In addition, an OS-specific nomogram was established, and the C-index for OS prediction was 0.74 (95% CI 0.67-0.81). CONCLUSION: This rare malignancy is associated with a generally favorable prognosis, and T stage, distant metastasis as well as surgical therapy are independent predictors of OS.

Epidemiological and clinical characteristics of 407 salivary glands neoplasms in surgically treated patients in 2010-2020.

INTRODUCTION Tumors of the salivary glands account for approximately 3 to 4% of all head and neck neoplasms. It is estimated that 10-15% of them are malignant. The most common benign tumor is pleomorphic adenoma, while the most common malignant tumors are adenoid cystic carcinoma and mucoepidermoid carcinoma. Neoplasms of the salivary glands are extremely histologically diverse, which results from the complex embryogenesis of the salivary glands. The identified risk factors for tumors of the salivary glands are: ultraviolet radiation, ionizing radiation, viral infections, nicotine and alcohol. MATERIAL AND METHOD The aim of the study was an epidemiological analysis of patients with salivary gland neoplasms, the distribution and histopathological characteristics of individual neoplasms treated at the Department of Otorhinolaryngology of the Medical University of Warsaw in 2010-2020. The diagnoses were analyzed according to the latest WHO 2017 histological classification of salivary gland tumors. In addition, the material was supplemented with data on the 5-year survival rates of patients with malignant neoplasms obtained from the Registry of Marital Status. RESULTS AND DISCUSSION The material contained 407 neoplasms of the salivary glands over a 11-year period, of which malignant neoplasms accounted for 17.4%. The malignant tumors were dominated by: adenoid cystic carcinoma (28,2%), mucoepidermoid carcinoma (12,7%), and acinic cell carcinoma (9,9%). Lymphomas (15,5%) were also a large group. The benign neoplasms were dominated by pleomorphic adenoma (54.1%) and Warthin's tumor (36%). Tumors of the salivary gland the most often affected the parotid gland (92%). CONCLUSIONS The obtained data are consistent with the general epidemiological data described in the current literature.

Salivary gland tumours in Iceland 1986-2015: a nationwide epidemiological analysis over a 30-year time period.

Salivary gland tumours (SGT) are a vast and heterogenous group of neoplasms. There is a relative lack of comprehensive nationwide epidemiological studies on the subject. The aim of this nationwide analysis was to gain insight into epidemiological traits, such as site, incidence and histological subtypes of SGT in general. Patients diagnosed with a primary SGT between 1986 and 2015 were identified from The Icelandic Cancer Registry and registries from all pathology departments in Iceland. Information on age, sex, tumour location and histology was retrieved from pathology reports. A total of 687 patients were diagnosed with a SGT, 609 (89%) were benign and 78 (11%) malignant. 9% of parotid gland tumours, 22% of submandibular gland tumours and 26% of minor SGT were malignant. The most common malignant tumours were mucoepidermoid carcinoma, acinic cell carcinoma and adenoid cystic carcinoma. The incidence of benign SGT was 4.9 per 100 000 among men and 7.0 per 100 000 among women. The incidence of malignant tumours was 0.59 per 100 000 for men and 0.79 per 100 000 for women. The proportion of malignant SGT is lower than most often reported. Only 10% of parotid gland tumours, 20% of submandibular gland tumours and 25% of minor salivary gland tumours are malignant.

Prognostic factors in patients with salivary gland malignancy: a retrospective cohort study.

Our objective was to determine the factors affecting the prognosis in patients with major salivary gland malignancy presenting to Aga Khan University Hospital in Karachi. Retrospective cohort study was carried out at our center on patients diagnosed and treated for salivary gland cancers. Presentation and treatment offered was reviewed from medical charts. Telephonic interviews were conducted to assess the survival of patients who were lost to follow-up. Log rank test was used to compare the mean survival times. A total of 36 patients were included in the study. The mean age was 45.1 +/- 14.6 years. Majority were male 21 (58.3%). The most common malignancy was mucoepidermoid carcinoma (36.1%) followed by adenoid cystic carcinoma (22.2%). Node positivity, grade of tumor, radiotherapy and chemotherapy were a significant indication of survival times on log rank test.

Mucoepidermoid carcinoma. An update and review of the literature.

OBJECTIVE: Mucoepidermoid Carcinoma (MEC) is the most common malignant salivary gland neoplasm, representing 10 to 15% of all salivary neoplasms. A review of the literature was conducted in order to determine trends in presentation, diagnostic features, treatment, and outcomes. METHODS: A PubMed, Embase, and Scopus search was carried out. The search process was performed by 2 independent reviewing authors and inclusion criteria included systematic reviews, meta-analyses, case-controls studies, cohort studies, comparative studies, clinical trials, cross-sectional studies, descriptive studies, experimental studies, case reports, case series studies, and human studies evaluating MEC. RESULTS: Females were more affected (54.5%) and the average age was 48.8 years. The most common location of MEC was the parotid glands (56.8%) followed by hard palate (18%). The most frequent clinical presentation was mass (65.2%) followed by ulcer (29.4%) with pressure as their main symptom (64.4%). The most frequent histologic presentation was Low grade (46.7%) followed by Intermediate grade (27.3%) and the most used treatment was surgery (76.2%). The average follow up was 138.5months, and recurrence was reported at 8.5%. CONCLUSION: MEC showed a strong predilection for the parotid glands is frequently painful, most frequently presents as a mass and most commonly has a low-grade histologic presentation.

Prevalence of mucoepidermoid carcinoma among intraoral minor salivary gland tumors: A systematic review and meta-analysis.

This study aimed to synthetize and critically appraise available evidence regarding mucoepidermoid carcinoma (MEC) prevalence among intraoral minor salivary gland tumors (MiSGT). Five main electronic databases and three grey literature databases were searched. The risk of bias (RoB) was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Proportion meta-analyses were performed. From 1321 studies identified, 82 were included in qualitative synthesis and 80 in meta-analyses. Sixteen were classified as high, 33 as moderate, and 33 as low RoB. A total of 12 774 MiSGT were found, of which overall MEC prevalence was 16.5% (95% Confidence Interval [95% CI] = 14.8%-18.4%). Most MiSGT were found in the palate (n = 7115), although MEC pooled prevalence in this anatomic location was only 13.6% (95% CI = 11.7%-15.6%). The retromolar area presented the highest pooled prevalence (58.9%; 95% CI = 47.0%-70.3%), followed by gingiva (28.8%; 95% CI = 22.7%-35.4%) and tongue (27.2%; 95% CI = 21.2%-33.6%). Regarding geographic location, Middle East presented the highest pooled prevalence (20.8%; 95% CI = 14.8%-27.6%), followed by America (20.0%, 95% CI = 17.2%-23%) and Europe (15.6%; 95% CI = 9.2%-23.5%). Among MiSGT, the MEC overall prevalence was approximately 16.5%. Although most MiSGT were found in the palate, the retromolar area was proportionally more affected by MEC.

Incidence and survival trends of parotid malignancies over 42 years.

BACKGROUND: There is a paucity of information regarding the incidence and survival of parotid malignancies over time. METHODS: The Surveillance, Epidemiology, and End Results population-based cancer registry was queried for parotid malignancies from 1973 to 2015. RESULTS: The age-adjusted incidence of parotid malignancies has increased by 58.1% (7.87-12.44 per 1 000 000). Analysis of histologic type revealed an increased annual percent change (APC) of acinar cell carcinoma (1.38) and squamous cell carcinoma (1.58), but decreased APC of adenoid cystic carcinoma (-1.63) and adenocarcinoma NOS (-0.86) (P < .05). The disease-specific survival of mucoepidermoid carcinoma, adenocarcinoma NOS, and squamous cell carcinoma significantly improved (P < .05) over time. CONCLUSION: The incidence of parotid cancer is rising steadily since 1973, while the incidence of overall head and neck cancer has decreased. Further research is necessary to understand the etiology, risk factors, and pathophysiology of parotid cancer to curb its rising incidence. LEVEL OF EVIDENCE: 4.

Clinicopathological analysis of parotid masses: six-year experience of a tertiary center.

OBJECTIVE: To analyse the clinical and histopathological characteristics of parotid gland masses at a tertiary referral centre and to compare the results with those cited in literature. METHODS: The retrospective study was conducted at Adana Numune Training and Research Hospital, Adana, Turkey, and comprised data of patients undergoing parotid surgery between January 2011 and December 2016. They were evaluated in terms of age, gender, surgery method, fine-needle aspiration biopsy results, specimen reports and complications after the surgery for one year. SPSS 20 was used for data analysis. RESULTS: Of 170 parotidectomies, 97(57.1%) had been performed on males and 73(42.9%) on females. There were 145(85.3%) benign and 25(14.7%) malignant tumours. Pleomorphic adenoma 67(39.4%) and Warthin's tumour 56(32.9%) were the two most common benign tumours. Mucoepidermoid carcinoma 7(4.1%) and adenoid cystic carcinoma 6(3.5%) were the two most prevalent malignant tumours. Superficial parotidectomy 133(78.2%) was the main type of surgical intervention. The sensitivity of fine needle aspiration cytology for identifying malignant tumours was 64.71%, the specificity was 100% and overall accuracy of the procedure was 94.92%. CONCLUSIONS: Repeated aspirations for sampling different parts of the lesion should be performed on suspicion of malignancy, especially if fine needle aspiration cytology reported pleomorphic adenoma.

Sinonasal mucoepidermoid carcinoma: a review of the National Cancer Database.

BACKGROUND: Primary sinonasal mucoepidermoid carcinoma (SN-MEC) is a malignancy arising from seromucinous glands of the nasal cavity and paranasal sinuses. Given its rarity, few large-scale studies have been performed. In this study we describe the incidence and determinants of survival of patients with SN-MEC leveraging the National Cancer Database (NCDB). METHODS: This was a retrospective, population-based cohort study of patients diagnosed with SN-MEC between 2004 and 2012 within the NCDB. The main outcome measure was overall survival (OS). RESULTS: A total of 164 patients were identified. The cohort was composed of 47.6% males. Mean age at diagnosis was 59.7 years. The maxillary sinus was the most common primary site, accounting for 45.7% of cases. Eleven percent of patients presented with nodal disease, whereas 2.1% had distant metastases. Stage IV disease was seen in 30.4% of cases. A total of 79.8% of the patients underwent surgery, 61.0% received radiation therapy, and 15.1% had chemotherapy. OS at 1, 2, and 5 years was 83%, 77.0%, and 57%, respectively. On multivariate analysis, Medicaid insurance status (hazard ratio [HR], 7.29; 95% confidence interval [CI], 1.74-30.57), advanced tumor size (HR, 4.94; 95% CI, 1.19-20.5), and advanced nodal disease (N1: HR, 9.48; 95% CI, 1.66-54.23; N2B: HR, 19.3; 95% CI, 1.07-350.64) were associated with worse OS. CONCLUSION: Mucoepidermoid carcinoma is the most common salivary gland malignancy but a rare sinonasal malignancy, with 5-year survival for SN-MEC approximating 50%. A significant proportion of patients present with advanced disease. Both socioeconomic factors and tumor characteristics are associated with survival.

Minor salivary gland tumors of the head and neck-Memorial Sloan Kettering experience: Incidence and outcomes by site and histological type.

BACKGROUND: Minor salivary gland carcinomas of the head and neck are rare cancers with variable clinical behavior. This study explored the incidence, pathology, clinical behavior, and factors predictive of outcomes in a large cohort of patients treated at Memorial Sloan Kettering Cancer Center over a 30-year period (1985-2015). METHODS: Clinical, pathological, treatment, and outcome data were collected. Unadjusted and adjusted hazard ratios for each variable were calculated with univariate and multivariable Cox regression for survival and recurrence outcomes. RESULTS: Four hundred fifty patients were included: 55% were female, 56% were younger than 60 years, and the median follow-up was 74 months (range, 1-364 months). The most common site was the oral cavity with 305 tumors (68%), which was followed by the oropharynx with 96 (21%), the sinonasal cavity with 38 (8%), the trachea with 7 (2%), and the larynx with 4 (1%). The most common histological types were mucoepidermoid carcinoma (180 tumors [40%]), adenoid cystic carcinoma (141 tumors [31%]), and polymorphous low-grade adenocarcinoma (54 tumors [12%]). The 5-year predicted overall survival rate was 86%, and the disease-specific survival rate was 94% at 5 years. Pathology and tumor stage were significant variables on multivariate analysis for overall survival, disease-specific survival, recurrence-free survival, local recurrence-free survival, regional recurrence-free survival, and distant recurrence-free survival. CONCLUSIONS: American Joint Committee on Cancer stage and pathology were the most predictive variables across all outcomes. Tumor site, postoperative radiotherapy, and margin status were not statistically significant variables after tumor stage and pathology were controlled for in most outcomes.

Risk of malignancy associated with cytomorphology subtypes in the salivary gland neoplasm of uncertain malignant potential (SUMP) category in the Milan System: A bi-institutional study.

BACKGROUND: Salivary gland neoplasm of uncertain malignant potential (SUMP) is a diagnostic category in the Milan System for Reporting Salivary Gland Cytopathology. The objective of this study was to assess the risk of neoplasm (RON) and the risk of malignancy (ROM) in SUMP cases by evaluating them based on their prominent cytomorphology. METHODS: The pathology databases were searched for cases of fine-needle aspiration-diagnosed SUMP at The Johns Hopkins Hospital and Northwestern University from 2013 to 2018. Only cytopathology cases diagnosed as SUMP that had available surgical follow-up were included. RESULTS: Sixty-five patients with SUMP were identified, including 31 men and 34 women who ranged in age from 15 to 87 years (mean age, 55.2 years). Sixty-five cases had histologic follow-up, including 13 (20%) with basaloid features, 13 (20%) with oncocytic features, and 39 (60%) with unspecified features. No cases with clear cell features were found. Overall, the RON in the SUMP category was 95.4% (62 of 65 cases), and the ROM was 33.8% (22 of 65 cases). The RON in SUMPs with basaloid, oncocytic, and unspecified subtypes was 92.3%, 100%, and 94.9%, respectively, whereas the ROM was 38.5%, 7.7%, and 41%, respectively. The most common benign neoplasm was pleomorphic adenoma (23.1%), whereas mucoepidermoid carcinoma (9.2%) was the most common malignant neoplasm. CONCLUSIONS: This study shows that the ROM differs significantly based on cytomorphology subtypes, whereas the overall ROM is approximately the same as the target rate in the Milan System for Reporting Salivary Gland Cytopathology. Moreover, the RON remains high in the SUMP category among different cytomorphology subtypes. Adequate sampling, immunohistochemical staining, and familiarity with metaplastic and reactive changes may improve the diagnosis.

Salivary gland carcinoma in Shanghai (2003-2012): an epidemiological study of incidence, site and pathology.

BACKGROUND: Salivary gland carcinoma ranks the sixth in head and neck cancers while it is relatively rare in its incidence. Epidemiological studies have been based mostly on institutional data, leading to selection bias in incidence evaluation. Most population-based cancer registries have grouped cancers of the minor salivary glands with oral cancer instead of with salivary gland carcinoma as a whole, because of the international disease coding. Thus, the incidence of salivary gland carcinoma has not been well assessed. The aim of the study is to evaluate the incidence of both minor and major salivary gland cancers in Shanghai during the years 2003-2012, and to analyse the site and histological distributions. METHODS: Data from the Shanghai Cancer Registry system were extracted for patients diagnosed with malignancies of the major or minor salivary glands for the year 2003 to 2012. Pertinent socio-demographic data were obtained from the Shanghai Municipal Bureau of Public Security. The age-standardized incidence rates were calculated directly according to the world standard population. The change in incidence during the study period was analysed by comparing the rates during the first and next five years. The distributions of anatomic subsites and histology were also analysed. RESULTS: A total of 1831 cases were identified, representing 0.35% of all malignancies during the study period. The median age was 59 and 57 years for men and women, respectively. The age-standardized incidence was 7.99 per 1,000,000 person-year, with a male-to-female ratio of 1.10. There was no significant change in the incidence during the 10-year period. The anatomic distribution confirmed the 4:1:2 rule for the parotid, submandibular, and minor glands. In men, adenocarcinoma not otherwise specified was the most common histological type followed by mucoepidermoid; in women, the mucoepidermoid was the most common histotype, followed by the adenoid cystic. CONCLUSION: Salivary gland carcinoma is relatively rare in incidence. However, the variations in age and sex distribution in sites and histology types suggest differences in aetiology which warrants further investigation.

[A retrospective clinical study of 3 382 cases of malignant oral maxillofacial tumors].

To investigate the incidence of malignant tumors in oral and maxillofacial region and the pathological features of various tumors, a total of 3 382 cases of malignant tumors in oral and maxillofacial region admitted to Jilin University from Januarary 2000 to December 2017. The characteristics of age, sex, location and pathological types of all kinds of tumors were analyzed. The median onset age is 57 years old, 51 to 70 years old is a high-risk age group, the ratio of male to female was 1.9∶1. The primary tumor location is tongue, gingiva and floor of mouth. Epithelial, lymphatic hematopoietic system, bone and soft tissue were the three major sources of tumor tissue, and squamous cell carcinoma was the most common pathological type (65.1%), followed by mucoepidermoid carcinoma and adenoid cystic carcinoma. In summary, oral and maxillofacial malignancies have a high incidence in elderly men, and tongue is the most common site of disease. Epithelial-origin and squamous cell carcinomas are the first of their origins and pathological types, respectively.