Journal of Advanced Clinical & Research Insights (2016), 3, 60–63 60 Journal of Advanced Clinical & Research Insights ● Vol. 3:2 ● Mar-Apr 2016 REVIEW ARTICLE Oral cancer associated orofacial pain: An overview K. P. Mahesh, D. Nagabhushana JSS Dental College and Hospital, JSS university, Mysore, Karnataka, India Abstract Cancer pain is an ever-present public health concern. Most cancer patients will experience uncontrollable pain that creates a poor quality of life and limits normal function. Cancer-associated pain is associated with severe physical and psychological sufering. Unfortunately, pain associated with cancer or its treatment is frequently under-treated, probably due to several factors, including phobia of opioids, underreporting by patients, and under-diagnosis by health-care workers. The most common etiology of cancer pain is local tumor invasion (primary or metastatic) that involves infammatory and neuropathic mechanisms. Keywords Opioids, orofacial pain, squamous cell carcinoma Correspondence Dr. K. P. Mahesh, JSS Dental College and Hospital, JSS university, Mysore, Karnataka, India E-mail: mahesh_puttaraju@redifmail.com Received 1 January 2016; Accepted 27 February 2016 doi: 10.15713/ins.jcri.107 Introduction Oral cancer is unique in that it causes intense pain at the primary site and signifcantly impairs speech, swallowing, and masticatory functions. Oral cancer patients experience pain early in the disease. In fact, orofacial pain is the initial symptom that leads to the diagnosis of oral squamous cell carcinoma (SCC) in patients. The overall 5-year survival rate for oral cancer patients is 60%. With the improved survival rate, there is an increase in the burden of pain that oral cancer patients must bear. [1] The character, severity, and unique features of oral cancer pain likely refect the anatomy of the oral cavity, the continuous need for orofacial function, the biologic characteristics of oral SCC, and the interaction between the carcinoma and the peripheral nervous system. In a meta-analysis of 52 studies that calculated the prevalence of cancer pain, head and neck cancer (HNC) had the highest prevalence of pain, surpassing gynecological, gastrointestinal, lung, breast, and congenital cancer. The functional requirements and mechanical stimulation of oral structures during speech, mastication, and swallowing result in severe pain. [1] The pain is commonly associated with cancer, as it is the presenting symptom in 20-50% of all cancer patients and is signifcant in 75-90% of patients with advanced or terminal cancer. [1] In HNC patients, pain has been associated with both disease and cancer treatment. Large surveys of HNC patients found that pain was frequently associated with the tumor (87-92.5%), whereas in 17-20.8%, the pain was secondary to therapy, and many patients reported pain from both disease and treatment. Following treatment of HNC, 78% of patients reported pain in the head, face, or mouth and 54% in the cervical region or shoulder. As many as 70% of patients may sufer pain from more than one site that involves infammatory or neuropathic pain mechanisms. [2] Based on the current laboratory and clinical studies, there are 5 main causes that initiate or exacerbate oral cancer pain [Figure 1]: [1] a. Mediators in the cancer microenvironment, b. Lack of early palliative therapy, c. Dense trigeminal innervation and continuous oral function, d. Pain from cancer treatment, and e. Opiate tolerance. Pain in turn leads to other symptoms including anxiety, depression, and side efects of high-dose opiate use. Pain due to Tumor Pain due to primary head/neck tumor The orofacial pain may be a presenting symptom of HNC and may motivate patients to seek care from an oral and maxillofacial surgeon. Primary SCCs of the oral mucosa are often associated with pain and other sensory disturbances when at an advanced stage of disease, as they may interfere with oral function and induce nerve damage/dysfunction. [2]