A Retrospective Review of Clinical-Histological Characteristics, Treatment Modalities and Survival of Adult Patients with Oral Cancers Treated at Ocean Road Cancer Institute, Tanzania

Abstract

Oral cancer is the malignant neoplasm which arises from the oral cavity. The oral cavity includes; the upper and lower lips, gingivobuccal sulcus, buccal mucosa, upper and lower gingiva (including alveolar ridge), retromolar trigone, hard palate, floor of mouth, and anterior two-thirds of the tongue (“oral tongue”). The worldwide annual incidence of oral cancer is 354,864 with a mortality of 177,384. An increase in incidence of oral cancer has been seen worldwide, previously it was the disease of elderly over 60 years but currently seen in middle aged in 40’s. Trends over time in incidence vary by country and for different subgroups of the population. The treatment of oral cancer involves a multimodality approach which includes surgery, chemotherapy, and radiation resulting in increased disease control for locally advanced oral cancer. In Tanzania currently there is no information on the magnitude and trend of oral cancer so this study is going to fill up the gap by describing the disease in terms of social demographic data, risks factors, clinical presentation, histological types, stage, treatment modalities and overall survival for patients treated at Ocean Road Cancer Institute (ORCI). Objectives This study aimed to describe the epidemiology of oral cancer with regard to age, sex, histology and the clinical pathological profiles in adults presenting for treatment in Tanzania. Additionally, the study described the type of treatment applied and survival outcomes for adult patients seen at Ocean Road Cancer Institute (ORCI). Materials and Methods A descriptive retrospective study was carried out in adult oral cancer patients with a confirmed histological diagnosis who presented for treatment at Ocean Road Cancer Institute (ORCI) between January 2013 and December 2016. A proportionate quota sampling was applied to get the number of participants from each year followed by convenience sampling to collect 43 patients from each year. A sample size of 173 patients was gathered using a data extraction vii forms. The data was analyzed using the statistical package for the social sciences (SPSS) version 23 for windows. Continuous variables were summarized using frequency and percentages were used to summarize the categorical data. Table and figures were used to present summarized data. Kaplan Meir time to event analyses was used for survival status and log-rank tests to identify predictive factors. The potential predictors of survival were assessed using cox regression and p value of < 0.05 was considered significant. Results A total of 173 cases were reviewed, where 61.8% were males and 38.2% were females. The mean age at time of diagnosis was 59.95 ± 12.92 years (21 to 90 years) and half of participants were more than 60 years (51.1%). Tobacco use together with alcohol drinking was mostly commonly identified risk factor (39.2%) followed by tobacco use (37.6%). Smoking was the major route of tobacco use (68.4%). Pain was the leading clinical presentation (28.9%), followed by pain with an oral lump (20.8%), lump alone (11.6%) and others in minority. Tongue was the commonest site affected for adult oral cancer followed by buccal mucosa, gingiva, lip, mouth floor and palate by 47.4%, 15.1%, 12.7%, 11%, 9.2%, and 4.6% respectively. Histologically more than three quarter were squamous cell carcinoma type (95.3%) followed by minor salivary gland 2.3%, hematological 1.2% and others 1.2 % .Grade I was the leading tumor grade (65.3%) followed by grade II (22.5%) and grade III (7.5%). Majority of participants (86.2%) presented with a late stage disease at the time of diagnosis while minority of the cases (13.8%) were in their early stage disease. Concurrent chemoradiotherapy was mostly used as treatment modality to 61.8% of the participants while 37.6% were treated palliatively with either chemotherapy alone or radiotherapy alone for symptoms relief. viii The study found that overall survivals of study participants in 2 year and 3 year were 26.3% and 18.8% respectively. Factors found to be significantly associated with a better survival include stage of disease and treatment modality. Conclusion. This study showed that the clinico-histological characteristics and overall survival of adult oral cancer patients attended at ORCI present with similar findings of those in other regions of the world. Males are more affected than females and tobacco use and alcohol consumption being the commonest risk factors. The commonest site for adult oral cancer from the study is the tongue which is initially painless and later painful which brought the patients to seek medical attention with late stage disease. Disease stage is strongly related to treatment outcome with later stages of the disease having an overall poor outcome. 2 and 3 years overall survival is poor because of advanced stage of the disease at the time of diagnosis. Stage and treatment modalities are the most important outcome determinants of survival in adult oral cancer patients. This study provides the basis for future prospective studies and will potentially contributes to improve some of our daily practices