Oral adverse effects during and after treatment in patients and survivors of cancers outside the head and neck region

Abstract

Better cancer treatment has led to an increasing number of cancer survivors in Norway, but cancer is still the second most common cause of death. New treatment regimens and increased survival often imply longer treatment time and more cycles of chemotherapy. In many cases, this leads to increased risk of both short and long-term adverse effects. The primary aim of this thesis was to investigate oral adverse effects in Norwegian cancer patients treated with chemotherapy for cancers outside the head and neck region at different phases of the disease trajectory. It also aimed to investigate if patients had received any information about oral complications or care, and if long-term survivors of childhood cancer experienced higher annual expenses for dental treatment compared to references. Three study populations with current or previous cancer diagnoses were investigated: outpatients receiving chemotherapy, inpatients receiving palliative care, and adult survivors of childhood acute lymphoblastic leukemia. All three studies had a cross-sectional design and included an oral examination with registration of clinical findings such as caries, gingival health, mucosal disease/alterations, and dental developmental disturbances as well as oral symptoms. In the studies of the outpatients and palliative care patients, a self-report registration form including items regarding information received, a symptom assessment tool, and an evaluation tool for the patient’s general condition was used. The survivors filled out a mailed questionnaire that included various questions relating to oral health and oral health expenses, which enabled a comparison of self-reported oral health and oral health expenses to a matched reference population. Oral discomfort was highly prevalent in the outpatients receiving chemotherapy and the palliative care patients. Xerostomia, mucositis and a high number of systemic drugs were associated with oral discomfort in patients receiving chemotherapy. Xerostomia and taste alterations were associated with oral discomfort in the palliative care patients. Few patients in both groups remembered receiving information about oral complications or care. In the survivors, dental developmental defects such as microdontia, arrested root development, and enamel hypoplasia were prevalent. Receiving a cancer diagnosis at the age of five years or less and high cumulative doses of anthracyclines were associated with increased severity of dental developmental defects. Diagnosis at a higher age was associated with higher caries experience. No significant difference was found when comparing survivors to a reference population regarding annual expenses for dental treatment. The results from this thesis indicate that there is a need for a continuous focus on how to inform about, prevent, diagnose, and manage oral cancer-related adverse effects at all stages of the disease trajectory. A systematic collaboration with dental professionals may increase the detection of oral adverse effects at an early stage; facilitate prevention and/or early treatment of oral adverse effects, thereby improving symptom management.