A population study comparing tracheal and lung adenoid cystic carcinoma.

BACKGROUND: Thoracic adenoid cystic carcinoma (ACC) is rare, and the differences between tracheal and lung lesions have not been fully understood. METHODS: Patients were identified from a Chinese cancer center (FUSCC) (2005-2022) and the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019). Incidence was calculated and trends were quantified. Clinicopathological features and overall survival (OS) were analyzed. Nomograms predicting OS were constructed. RESULTS: Totally, 55 tracheal adenoid cystic carcinoma (TACC) and 25 lung and bronchus adenoid cystic carcinoma (LACC) were included in a Chinese cohort, 121 TACC and 162 LACC included in the SEER cohort. There were larger tumor sizes, more lymph nodes and distant metastases for LACC than TACC patients. TACC patients are more likely to get local treatments. Patients with LACC had significantly worse median OS than patients with TACC (SEER cohort: 68.0 months vs. 109.0 months, p = 0.001, Chinese cohort: 62.9 months vs. 124.8 months, p = 0.061). Age, lymph node metastasis, distant metastasis and local treatment were identified as independent prognostic factors for OS of TACC. Distant metastasis and local treatment were identified for LACC. Specifically, surgery alone or in combination with radiotherapy is crucial for improving survival in both TACC and LACC. Only TACC benefits from radiotherapy alone, while chemotherapy does not improve survival for either. The nomograms constructed using these factors revealed good prognostic accuracy. CONCLUSIONS: LACC is more aggressive and has a worse prognosis than TACC. TACC patients have more opportunities for local treatment, which is important for the prognosis of both TACC and LACC. Nomograms were created for TACC and LACC to aid in personalized survival predictions and clinical decisions.

Prognosis of primary breast salivary gland-type carcinoma: a propensity score-matching analysis with invasive carcinoma of no special type based on the SEER database for years 2010-2020.

BACKGROUND: Primary breast salivary gland-type carcinoma has weak evidence to support its management due to its rare occurrence and limited data regarding its clinicopathological features and prognosis. Therefore, this study aimed to assess clinicopathological features and prognosis for this type of carcinoma diagnosed over the past decade and compared those to the common breast invasive carcinoma of no special type (NST). METHODS: This study used the Surveillance, Epidemiology, and End Results (SEER) database to extract data regarding primary breast salivary gland-type carcinoma. Using a propensity score-matching approach, the prognosis was compared with invasive carcinoma, NST. RESULTS: This study included 488 cases of salivary gland-type carcinoma and 375,660 cases of invasive carcinoma, NST, giving an occurrence ratio of 1 to 770. Adenoid cystic carcinoma (81%) formed the majority of salivary gland-type carcinoma, followed by secretory carcinoma (13%). For salivary gland-type carcinoma, acinic cell carcinoma histological type, tumor grade 3, HER2-overexpressed status, and higher AJCC stage groups were significant worse prognostic factors for breast cancer-specific survival in univariate analyses (p < 0.05). Nonetheless, tumor grade 3 and higher AJCC stage groups remained as significant independent prognostic factors in multivariate analysis (p < 0.05). The apparent better breast cancer-specific survival of salivary gland-type carcinoma as compared to that of invasive carcinoma, NST, was diminished following adjustment for differences in baseline clinicopathological features and treatment-related variables. CONCLUSIONS: This study suggests that when managing primary breast salivary gland-type carcinoma, greater emphasis should be given to the tumor grade and AJCC stage group in addition to acinic cell carcinoma histological type and HER2 overexpression. Conventional prognostic factors are important as salivary gland-type carcinoma had similar prognosis as invasive carcinoma, NST, following adjustment for confounding variables.

Prognostic factors for sublingual gland carcinoma: a population-based Surveillance, Epidemiology and End Results database study.

OBJECTIVE: To identify the clinical features and prognostic factors for sublingual gland carcinoma. METHODS: This was a case-control study. Patients with surgically treated sublingual gland carcinoma were retrospectively included in the Surveillance, Epidemiology and End Results database and divided into adenoid cystic carcinoma (ACC) and non-ACC groups. Primary outcome variables were disease-specific survival (DSS) and overall survival (OS). Prognostic factors for each group were analyzed using Cox models. RESULTS: We included 251 patients (115 men and 136 women). Compared with the non-ACC group, the ACC group had a larger average tumor size and received more adjuvant radiotherapy. In patients with ACC, the pathologic grade had an independent impact on DSS and OS, and patients who were undergoing adjuvant chemotherapy had worse DSS than those who were not receiving chemotherapy. In the non-ACC group, pathologic grade IV, lymph node metastasis, and adjuvant chemotherapy were associated with poor DSS and OS, and tumor extension predicted worsening DSS. CONCLUSIONS: In sublingual gland carcinoma, the pathologic grade and adjuvant chemotherapy were the most important prognostic factors, whereas lymph node metastasis had a negative impact in non-ACC patients but not in ACC patients.

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.

Clinical and demographic features of minor salivary gland tumors: A collaborative study of 480 cases.

OBJECTIVE: To describe the frequency, clinical, and demographic features of minor salivary gland tumors and possible associated factors. MATERIALS AND METHODS: A cross-sectional study was conducted. Clinical and demographic data were collected from biopsy records of two oral pathology services. Chi-square test, Fisher's exact test, and descriptive statistical analysis were performed. RESULTS: A total of 480 (0.89%) minor salivary gland tumors were retrieved, 272 (56.7%) benign and 147 (30.7%) malignant. Sixty-one (12.6%) had no subtype specification. Most patients were women (307/64.0%), in sixth decade of life (80/16.7%), with a mean age of 45.32 years. Palate was the most common site (336/70.1%). Pleomorphic adenoma (PA; 245/51.1%), mucoepidermoid carcinoma (MEC; 70/14.6%), and adenoid cystic carcinoma (ACC; 43/8.9%) were the most frequent tumors. Symptomatic case, recurrence, and tobacco use were associated with malignancy (p < 0.05). PA and MEC were more frequent in palate (p < 0.05). No association between the three most frequent histological types and gender or age group was observed (p > 0.05). CONCLUSIONS: This represents one of the largest exclusive series of minor salivary gland tumors in Brazil and worldwide. PA, MEC, and ACC were the most frequent tumors. Clinical and demographic data are similar from Brazilian studies or from other countries.

Differences in clinical features and prognosis between orbit adenoid cystic carcinoma and adenocarcinoma: a study from the SEER 18 database.

PURPOSE: To analyze the differences in clinical features, treatment methods, prognosis, and etiological factors between lacrimal gland, adenoid cystic carcinoma (LGACC), and orbit adenocarcinoma. MATERIAL AND METHODS: All cases of LGACC and orbit adenocarcinoma between 1975 and 2016 were obtained from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. RESULTS: The 3-, 5-, and 10-year overall survival (OS) rates for 118 LGACC cases were 82.2%, 70.2%, and 51.7%, respectively. The 3-, 5-, and 10-year OS rates for 29 orbit adenocarcinoma cases were 76.3%, 51.2%, and 51.2%, respectively. There was no statistically significant difference in the overall survival rate between LGACC and adenocarcinoma (P=0.566). Univariate analysis showed that the proportion of deaths was higher with increased age and year of diagnosis in LGACC (P=0.010 and P=0.000), while the death rate was higher for poorly differentiated adenocarcinoma (P=0.020). The survival rate for LGACC was lower in patients ⩾60 years of age than in those <60 years of age (P=0.035). There was no significant difference in survival rate between adenocarcinoma patients ⩾60 years and <60 years old (P=0.102). There was no significant correlation between the degree of tumor differentiation and the survival rate for LGACC or adenocarcinoma (P=0.401 or P=0.098, respectively). CONCLUSION: There is no significant difference in prognosis between LGACC and adenocarcinoma. The degree of tumor differentiation is not associated with prognosis for either LGACC or adenocarcinoma.

[Salivary gland carcinomas - Monocentric experience on subtypes and their incidences over 42 years]. / Speicheldrüsenkarzinome ­ Monozentrische Erfahrung zu Subtypen und deren Inzidenz über 42 Jahre.

OBJECTIVE: Salivary gland carcinomas are rare and heterogeneous. More than 20 subtypes are recognized and risk factors are diverse. The aim of this work was to evaluate the subtype and other risk factors in a monocentric population from more than four decades. MATERIAL AND METHODS: 205 cases (diagnosis period 1972-2014) were retrospectively collected and analyzed with regard to the distribution of risk factors and their influence on overall survival (OS). RESULTS: 19/24 (79.2%) of the subtypes listed in the WHO classification occurred rarely in the cohort (< 5%). 10/24 (41.7%) of all subtypes were never diagnosed. With a total of 145/205 cases (70.7%), squamous cell carcinoma (PEC), adenocarcinoma (AdenoCa), acinar cell carcinoma (AcinarCa), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) were by far the most common subtypes. Risk factors are significantly different in these groups (e.g., lymphogenic metastasis and degree of differentiation in AdenoCa and age, T and UICC stage in PEC). The 5-year overall survival of all patients was 66.9% and differed significantly within the most common subtypes. An independent impact on overall survival was detectable for patient age (p<0.001), and T- (p=0.003) and N-stage (p=0.046) in multivariate analysis. CONCLUSIONS: Most subtypes occurred markedly rarely or not at all within decades. The most common diagnoses differ with respect to risk factors as well as OS and 3 risk groups can be defined based on histology. In conclusion, considering TNM alone is insufficient for prognosis estimation in salivary gland carcinoma.

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.

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.

Analysis of local invasion and regional spread in malignant sublingual gland tumour: Implications for surgical planning.

Malignant tumours arising from the sublingual glands are very rare, and the extent and frequency of local invasion or regional spread in malignant sublingual gland tumour (MSLT) has not been fully studied due to the disease rarity. To provide comprehensive features of local and regional spread of MSLT, we reviewed 20 surgical cases for detailed pathological analyses among 26 cases diagnosed as having primary MSLT. Adenoid cystic carcinoma (ACC) was the most common pathological subtype, followed by mucoepidermoid carcinoma. Disease-free and overall survivals at 5 years were 76.1 % and 77.7 %, respectively. High-grade malignant tumours and grade 2-3 ACC accounted for 41.7 % and 85.7 %. Clinical and pathological extraparenchymal extensions were found in 34.6 % and 80.0 %, respectively. Tumour invasion to the lingual nerve and submandibular gland/ductal system were also detected in 40.0 % and 28.6 %. The incidences of lingual nerve invasion in ACC and ACC ≥4 cm were 30.8 % and 42.9 %. Regional nodal involvement occurred in seven of 26 cases, and all metastatic lymph nodes were found in neck levels Ib and IIa. In summary, a significant portion of MSLT cases consisted of high-grade tumours and grade 2-3 ACC; therefore local invasion into adjacent structures should be cautiously evaluated in cases of MSLT.

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.

Salivary gland carcinoma in Denmark: a national update and follow-up on incidence, histology, and outcome.

PURPOSE: Salivary gland carcinoma is a rare disease and studies on epidemiology and outcome require data collection over many years. The aim of this study is to present an update of incidence rates, anatomical sites, histological subtypes, and survival rates based on the Danish national cohort of salivary gland carcinoma patients. METHODS: Data from all Danish patients with salivary gland carcinoma diagnosed from 1990 to 2015 (n = 1601) were included and analyzed following histological reevaluation and reclassification. Overall, disease-specific, and recurrence-free survival were evaluated. Prognostic factors were analyzed with multivariate Cox Hazard Regression. RESULTS: The study population consisted of 769 men and 832 women, median age 62 years (range 6-102). The most frequent anatomic site was the parotid gland (51.8%). Adenoid cystic carcinoma was the most common subtype (24.7%). The majority had tumor classification T1/T2 (65.3%). The mean crude incidence was 1.2/100.000/year with an increase of 1.5% per year. There was no increase in age-adjusted incidence. The 5-, 10-, and 20-year survival rates were for overall survival 68, 52, and 35%, for disease-specific survival, 77, 69, and 64%, and for recurrence-free survival, 75, 64, and 51%, respectively. Age, high-grade histological subtype, advanced T-classification, cervical lymph node metastases, vascular invasion, and involved surgical margins had significantly negative impact on survival rates. CONCLUSION: The age-adjusted incidence has been stable for a period of 26 years. Multivariate analysis confirmed that histological grade, advanced stage, involved surgical margins and vascular invasion are independent negative prognostic factors. Survival rates were stationary compared to earlier reports.

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.

Sublingual Gland Tumors Worldwide: A Descriptive Retrospective Study of 839 Cases.

PURPOSE: Sublingual gland tumors are rare. We sought to define the general features of sublingual gland tumors for clinical reference. In addition, we evaluated whether it would be safe to speculate that ∼90% sublingual gland tumors will be malignant and that ∼90% of those malignant tumors will be adenoid cystic carcinoma. MATERIALS AND METHODS: In the present study, we have reported data from a pleomorphic adenoma case of the sublingual gland and a case series of sublingual gland tumors. Global data of sublingual gland tumors were retrieved. The cases pathologically identified as either benign or malignant tumors of the sublingual gland were included. The demographic, pathologic, and treatment features were analyzed. RESULTS: Data from 1 recent case of pleomorphic adenoma of the sublingual gland and a 21-case series of sublingual gland tumors were retrieved. A total of 839 cases of sublingual gland tumors were analyzed in the present study. The most commonly encountered age group was 40 to 59 years (47.6%). Of the 367 patients with gender specified, 178 were men (48.5%) and 189 were women (51.5%). Malignant tumors predominated (n = 722 cases; 86.1% of 839). Most malignant tumors were adenoid cystic carcinoma (n = 376), just greater than one half (52.1%) of all malignant tumors. Surgery was the only reported treatment method for the benign tumors. The most common treatment methods for the 164 explicit malignant tumors were surgery plus radiotherapy for 82 patients (50%), followed by surgery alone for 70 patients (42.7%). CONCLUSIONS: To date and to the best of our knowledge, the present study is the most comprehensive study on the demographic, pathologic, and treatment features of global sublingual gland tumors. These findings have shown that ∼90% of sublingual gland tumors will be malignant. However, the assumption that ∼90% malignant sublingual gland tumors will be adenoid cystic carcinoma is incorrect, which could be a new critical clinical reference.

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.

A prospective multicentre REFCOR study of 470 cases of head and neck Adenoid cystic carcinoma: epidemiology and prognostic factors.

BACKGROUND: Adenoid cystic carcinoma (ACC) accounts for 1% of malignant head and neck tumours [1] and 10% of salivary glands malignant tumours. The main objective of our study is to investigate the prognostic factors influencing the event-free survival (EFS) of patients with ACC. PATIENTS AND METHODS: A multicentre prospective study was conducted from 2009 to 2018. All 470 patients with ACC whose survival data appear in the REFCOR database were included in the study. The main judgement criterion was EFS. Both a bivariate survival analysis using log-rank test and a multivariate using Cox model were performed using the R software. RESULTS: Average age was 55 years. Females accounted for 59.4% of the cohort. The body mass index (BMI) was normal in 86% of cases. Tumours were located in minor salivary glands in 60% of cases. T3/T4 stages represented 58%; 89% of patients were cN0. histological grade III was observed on 21% of patients. The EFS and overall 5-year survival rates were 50% and 85%, respectively. After adjustment, the most significant pejorative prognostic factors were age ≥65 years (hazard ratio [HR] = 1.67), BMI<16.5 (HR = 2.62), and lymph node invasion cN (HR = 2.08). CONCLUSION: Age, BMI and N stage are the three main clinical prognostic factors determining EFS identified in this prospective series of patients with ACC. Such findings open new research perspectives on the influence of these components on initial patient care.

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.

Should a neck dissection be performed on patients with cN0 adenoid cystic carcinoma? A REFCOR propensity score matching study.

BACKGROUND: Patterns of nodal involvement in adenoid cystic carcinoma (ACC) of the head and neck have not been sufficiently assessed to guide a decision of prophylactic neck dissection (ND). The objective of this study is to analyse the influence of ND on event-free survival (EFS) for patients with cN0 ACC. PATIENTS AND METHODS: A multicentre prospective study was conducted between 2009 and 2018. Patients presenting cN0 non-metastatic ACC on any site, and who received surgery on the tumour, were included. EFS was the main judgement criterion. A comparative survival analysis between the groups that received a ND versus those that did not was performed, using a propensity score. Analyses were carried out using the R software. RESULTS: Between 2009 and 2018, 322 patients with cN0 ACC were included, out of which 58% were female. The average age was 53 years. Tumours were in minor salivary glands in 58% of cases, and 52% had T3/T4 stages. ND was performed on 46% of patients. Out of them, seven had histological lymph node invasion, out of which six had tumour infiltration in the mucosa of oral cavity. After propensity score, the median EFS for N0 patients with ND was 72 months (95% Confidence Interval (CI) [48-81]), compared to 73 months (95% CI [52-85]) for patients without ND (HR = 1.33; 95% CI [0.82-2.16]; p = 0.2). CONCLUSION: ND of cN0 patients does not provide any benefit on EFS, which suggests that its application on such patients is not necessary.