Retrospective investigation of clinical and pathological characteristics of patients with malignant salivary gland tumor

Introduction: Salivary gland tumors are a rare, heterogeneous group of neoplasms classified within head and neck tumors that differ significantly in terms of both their pathological features and anatomical origins, histology and biological behavior. They constitute approximately 6% of head and neck tumors. The different biological behavior of salivary gland masses and the fact that they have wide histopathological origins customize the treatment of these masses. In our study, we aimed to retrospectively scan the clinical and pathological features of patients diagnosed with salivary gland tumors, who are being followed up in our department. Method: Our study included 72 patients with a diagnosis of malignant salivary gland tumor who applied to Gaziantep University, Şahinbey Training and Research Hospital between January 2013 and December 2020. Our research is a retrospective cohort study. Age, gender, additional disease status, pathological subtypes, diagnosis dates, recurrence dates, operation dates, treatments, last control dates and/or death dates of all patients included in the study were determined and comparative analyzes were planned. Results: Seventy-two patients, forty-three (59.7%) male and twenty-nine (40.3%) female, were included in our study. While 62.5% of the patients were under the age of 65, 27% were aged 65 and over. While 21 patients (29.2%) did not have an additional disease, 51 patients (71.8%) had an additional disease. Fifty-four patients were reached and their smoking histories were learned. While 57.4% (31 patients) of the patients were non-smokers, 42.6% (23 patients) were smokers. While 38.1% (24 patients) of 63 patients whose data could be accessed during their follow-ups were in remission, 19% (12 patients) had never been in remission. 42.9% of the patients (27 patients) relapsed after entering remission. While 47.1% (32 patients) of the patients in our study were still alive, 52.9% (36 patients) died. At the time of diagnosis, 36% (26 patients) of the patients had metastatic disease. While 87.5% (63 patients) of our patients were diagnosed with parotid malignant neoplasm, 8.3% (6 patients) submandibular gland malignant neoplasm, 2.8% (2 patients) minor salivary gland malignant neoplasm, 1% .4 (1 patient) were diagnosed with submental gland malignant neoplasm. The most common pathological subtype in the patients in our study was squamous cell carcinoma with 25% (18 patients). The second most common subtype was mucoepidermoid carcinoma with 18.1% (13 patients). Lymph node metastasis was observed in 61.6% (24 patients) of the patients in our study who were found to have metastasis at the time of diagnosis. Metastases to bone, liver, lung, breast, scapula, adrenal gland and other lymph nodes were detected less frequently. The overall survival time (GSS) of the patients in our study was 101.33±15.71 (70.55-132.11 95% HR) months, and the disease-free survival time (HSS) was 81.0 ± 5.18 (70.84-91, 16 95% HR) months. Considering the general survival of the patients in our study according to the metastasis status at the time of diagnosis; The overall survival of patients with metastasis was 25.46±8.18 months, whereas it was 161.68±16.79 months in patients without metastasis (p=0.001). While the overall survival of patients under the age of 65 was 133.00± 24.12 months, the overall survival of patients aged 65 and over was 12.00±2.04 months (p=0.001). While the overall survival of patients with comorbidity was 63.27±8.26 months, the overall survival of patients without comorbidity was 168.93±22.12 months (p=0.010). While the overall survival of smokers was 13.00± 35.57 months, the overall survival of non-smokers was 103.00±31.60 months (p=0.024). In our study, a statistically significant difference was found between the number of affected areas and overall survival (p=0.001). A statistically significant difference was found between chemotherapy history and overall survival (p=0.001), but no statistically significant difference was found between radiotherapy history and overall survival (p=0.648). SCC; A statistically significant difference was found in overall survival when compared with ACC, MEK, PAEK and other subtypes (p<0.05). A statistically significant difference was found between stages 1, 2 and 3 in terms of overall survival between stages 2 and 3 and 4 (p<0.05). In terms of HSS; A statistically significant difference was found between patients younger than 65 years of age and patients aged 65 and over, stage 4 patients compared with stage 1 patients, patients with and without metastasis at the time of diagnosis, and patients who received or did not receive chemotherapy (p<0, 05). Conclusion: Considering the results of our study; Additional studies examining the relationship between smoking and survival are needed. The number of cigarettes used, age, gender, pathological subtype, etc. components need to be developed. At the same time, more prospective studies are needed to examine the data we obtained regarding the relationship between SCC, the number of sites involved, and survival. Keywords: salivary gland tumors; overall survival time; disease-free survival time; squamous cell carcinoma; mucoepidermoid carcinoma