Clinicopathological Features and Treatment Outcomes in Parotid Malignancies at Ocean Road Cancer Institute, Dar-es-Salaam, Tanzania

Abstract

Background: Neoplasms that arise in the salivary glands are relatively rare, yet they represent a wide variety of both benign and malignant histologic subtypes. Tumors of the salivary glands form one of the most heterogeneous groups of oncological pathology. Head and neck tumors represent ∼5% of human neoplasms, and out of these, salivary gland neoplasms constitute 10%. Aim: The challenges faced for parotid gland malignancy are numerous and these factors determine the treatment modality, prognosis and outcome, overall survival, sociodemographic features affecting Tanzanian residents and there is very little knowledge on clinicopathological aspects of parotid gland malignancies diagnosed at a tertiary health center and this study can compare the findings with epidemiologic data from different geographic locations. Methods: A Retrospective study design was used among all patients who had been diagnosed and confirmed histologically with malignant Parotid tumor referred to and treated at Ocean Road Cancer Institute (ORCI) from January 2009-December 2016. Analysis of this retrospective study determined the sociodemographic factors, clinico-pathologic features, treatment outcomes of surgery, radiotherapy, chemotherapy and assessment of 2 years overall survival of parotid malignancies from January 2009 to December 2014. The study was conducted at ORCI in Dar es Salaam. Results: Out of 94 patients with histologically confirmed parotid gland malignancy, more males were affected compared with females with the ratio of 1.18:1 and the mean SD age of patients was 51.9 years. Adenocarcinoma was the most common malignant tumor n = 37 (40%) followed by squamous cell carcinoma n = 18 (19.1%) and the left parotid gland being the most affected site. 44 cases (46.8%) had pathologic grading, grade IV accounting for majority of the grades (27.3%). Stage IV was presented the most n=72 (76.5%) and 8.5% presented with metastasis at diagnosis. 31% of patients were subjected to surgery while 69.1% were deemed to be unfit for surgery due to advanced disease. Radiotherapy was received by n = 82 (95.2%) with 13 patients (14%) subjected to curative intent and 69 patients (86%) subjected to palliative intent. 2 year overall survival for the curative cohort from 2009-2014 is 23% and 11% for the palliative arm. The 2 year overall survival of parotid gland malignancy treated at ORCI is 12%. Conclusion: Clinico-pathologic presentation of parotid gland malignancy seen in this study differs from other studies probably due to geographical variations. More males are affected than women, especially in the middle ages. Adenocarcinoma was the most frequent histology. Two years overall survival from 2009 to 2014 was 12%. Late stage presentation was seen as a problem that needs to addressed to maximize the effectiveness of the treatment, and improve the overall survival. Treatment modalities need to be standardized across health facilities in Tanzania.