Time-to-Treatment in Oral Cancer: Causes and Implications for Survival

SIMPLE SUMMARY: Stage of the disease at diagnosis has been recognized as one of the most important prognostic markers for oral cancer. Unfortunately, still two thirds of patients are diagnosed at an advanced stage of disease with a 5-year survival rate of 50% or less. Although the detection of oral cancer at an early stage is the most effective means to improve survival and reduce morbidity, in the past years, there has been little change in the diagnosis of oral cancer at early stages, which is believed to be a result of delays in diagnosis and treatment of oral cancer, among other independent factors. Following the Aarhus statement, developed in effort to standardize the design, methods and reporting of studies concerning time-intervals in early diagnosis research, the review assessed the causes that influence the patient, diagnosis and pre-treatment intervals in the pathway of time-to-treatment in oral cancer and its impact on survival. ABSTRACT: The purpose of this review was to identify and describe the causes that influence the time-intervals in the pathway of diagnosis and treatment of oral cancer and to assess its impact on prognosis and survival. The review was structured according to the recommendations of the Aarhus statement, considering original data from individual studies and systematic reviews that reported outcomes related to the patient, diagnostic and pre-treatment intervals. The patient interval is the major contributor to the total time-interval. Unawareness of signs and/or symptoms, denial and lack of knowledge about oral cancer are the major contributors to the process of seeking medical attention. The diagnostic interval is influenced by tumor factors, delays in referral due to higher number of consultations and previous treatment with different medicines or dental procedures and by professional factors such as experience and lack of knowledge related to the disease and diagnostic procedures. Patients with advanced stage disease, primary treatment with radiotherapy, treatment at an academic facility and transitions in care are associated with prolonged pre-treatment intervals. An emerging body of evidence supports the impact of prolonged pre-treatment and treatment intervals with poorer survival from oral cancer.