Background: Cancer patients experience numerous disease-related symptoms and side effects of treatment, such as pain, nausea, anorexia, anxiety, among others. Despite the use of the current drugs of first choice, many patients continue to suffer intractably from a number of symptoms. This impacts negatively on their quality of life, functional status, and their desire to continue with disease altering therapies. The synthetic cannabinoid, nabilone (Cesamet), is officially indicated for the treatment of refractory chemotherapy-induced nausea and vomiting. Pre-clinical studies and preliminary findings from clinical trials suggest cannabinoids may be useful for the management of multiple symptoms and side effects in cancer patients. Nabilone offers the opportunity to optimize pain and symptom management while reducing overall polypharmacy.
Material and Methods: Data were retrospectively collected from the charts of patients referred to a specialist consultative palliative medicine program in a large urban centre between May 1, 2005 and June 30, 2006. The decision to prescribe nabilone was based on the presence of severe pain and symptom distress. The sample was selected on the basis that they had completed an Edmonton Symptom Assessment System (ESAS) questionnaire on the initial consultation, and then, at least one thereafter. Data from a total of 139 patients were reviewed, of which nabilone was prescribed to 82. All patients were followed by a specialist team consisting of a palliative medicine physician and nurse practictioner. ESAS questionnaires were completed on their initial consultation and serially thereafter. Although 17 patients discontinued nabilone owing to side effects or based on the recommendation of other treating physicians, their follow-up continued. In addition, serial performance status, measured by the Palliative Performance Scale, version 2 (PPSv2), and a recording of all other medications employed was documented. Data analysis was carried out by an academic biostatistical consultant using MS Windows based S-Plus 6.2 software. The change in ESAS score on all 10 items was compared between the cannabinoid and non-cannabinoid subjects.
Results. The mean baseline PPSv2 was 56.7 ( 15.4) in the cannabinoid subjects and 53.9 ( 14.8) in the non-cannabinoid subjects; duration of follow-up (mean) was similar between the two groups (nabilone, 52.8 [ 80.3] days; non-nabilone, 51.6 [ 72.5] days). Compared with non-cannabinoid subjects, the nabilone subjects experienced significant (P<.0001) reductions in pain, markedly so in subjects with a PPS.v2 score of 60 or higher. For drowsiness, tiredness, appetite, and well-being, ESAS scores remained stable in the nabilone group but deteriorated in the non-nabilone group. While subjects in the nabilone group had significantly (P<.0001) greater nausea at baseline, they experienced a significant reduction (P<.0001), in contrast to non-cannabinoid subjects. Depression and anxiety were significantly (P<.0001) more prevalent in the nabilone group; however, reductions in both symptoms were significant (P<.0001) with use of the cannabinoid. Conversely, anxiety and depression increased in the non-cannabinoid group. Item No. 10 on the ESAS, Other, allows patients to rate a particularly bothersome symptom. Two symptoms emerged as important in nabilone subjects: insomnia and fever/night sweats. For both these symptoms, nabilone appeared to be efficacious. Distress, which is derived from scores on the first nine items of ESAS, improved significantly (P<.0001) in subjects receiving nabilone in contrast to non-cannabinoid subjects.
Discussion: The study findings are limited by potential biases. Imbalances between the two groups in baseline scores were not adjusted, and the time to the last measurement, from which change in scores was calculated, was variable. The standard of care in the two groups also was not documented. Nonetheless, nabilone, when added to standard of care and taken longer-term, appears to offer significant alleviation of several symptoms in cancer patients, including pain, nausea, depression and anxiety, insomnia, fever/night sweats, and overall distress.