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Aims To examine the real-world safety of adding bevacizumab to first-line irinotecan-based chemotherapy for patients with metastatic colorectal cancer (mCRC). Materials and methods Patients diagnosed with CRC in three Canadian provinces (Ontario, Saskatchewan and British Columbia) who received publicly funded bevacizumab and/or irinotecan from 2000 to 2016 were identified from cancer registries. Propensity score 1:1 matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to contemporaneous and historical controls, adjusting for baseline demographic and clinical characteristics. Safety end points evaluated during first-line treatment plus 30 days included mortality within 30 days and all-cause-, chemotherapy- and bevacizumab-related hospitalisations. Chemotherapy- and bevacizumab-related visits were defined as hospitalisations for specific conditions commonly associated with chemotherapy (e.g. infections) or bevacizumab (e.g. arteriovenous thromboembolism) using most responsible diagnosis codes. In PSM and IPTW-weighted cohorts, we assessed event frequencies using odds ratios from logistic regressions and event rate ratios using negative binomial regression models. The results from each province and comparison were pooled using random-effects meta-analysis. Results We identified 16 250 mCRC patients who received first-line irinotecan-based treatment. In PSM cohorts, bevacizumab was associated with fewer deaths within 30 days of treatment compared with contemporaneous (pooled odds ratio = 0.62; 95% confidence interval 0.50–0.75) and historical controls (pooled odds ratio = 0.73; 95% confidence interval 0.58–0.93). Hospitalisations were more frequent among patients treated with bevacizumab compared with historical controls but similar to contemporaneous controls. As patients receiving bevacizumab were exposed to a longer average treatment duration, across their full treatment duration, patients receiving bevacizumab had significantly lower rates of hospitalisations (contemporaneous pooled rate ratio = 0.56; 95% confidence interval 0.47–0.67; historical pooled rate ratio = 0.73; 95% confidence interval 0.56–0.95). Similar trends were observed for chemotherapy- and bevacizumab-related hospitalisations and in IPTW-weighted cohorts. Discussion We did not observe any increase in rates of hospitalisation or death within 30 days of treatment among mCRC patients treated with bevacizumab plus chemotherapy versus chemotherapy alone; these findings should be interpreted with caution due to the risk of residual confounding.

Aims To compare the costs and effectiveness of intensity-modulated radiotherapy (IMRT) with three-dimensional conformal radiotherapy (3DCRT) for the radical treatment of localised prostate cancer at elevated doses (>70 Gy). Materials and methods A cost-effectiveness analysis model was developed using clinical effectiveness estimates from a systematic review. The base case analysis assumes equal biochemical survival for IMRT and 3DCRT, but lower frequency of gastrointestinal toxicity for IMRT. The costs of IMRT and 3DCRT were estimated through activity-based costing, incorporating input from radiation oncologists, physicists and treatment planners. Results The delivery of IMRT produced 0.023 more quality-adjusted life-years (QALY) than 3DCRT at an additional cost of $621 (QALY and costs discounted at 5% per year), yielding an incremental cost-effectiveness ratio of $26 768 per QALY gained. The treatment cost of IMRT was $1019 more than 3DCRT, but IMRT resulted in less frequent gastrointestinal toxicity, thus avoiding $402 in the treatment of toxicity. In the scenario that compared a higher dose of IMRT (75.6 Gy) to 3DCRT (68.4 Gy), IMRT improved disease control with equal toxicity incidence, and the IMRT strategy dominated (less costly and more effective). In the base case scenario (no survival difference), the cost-effectiveness of IMRT was most sensitive to the treatment cost difference between IMRT and 3DCRT. Conclusion For radical radiation treatment (>70 Gy) of prostate cancer, IMRT seems to be cost-effective when compared with an equivalent dose of 3DCRT.

Aims Intensity-modulated radiotherapy (IMRT) is an advanced radiation technique that is particularly suited to treating head and neck cancers because it can conform a high dose to the target volume while preserving the tissue function of neighbouring structures. The objective of this study was to compare the cost and effectiveness of IMRT with three-dimensional conformal radiotherapy (3DCRT) for the treatment of locally advanced oropharyngeal cancer. Materials and methods We developed a Markov model to estimate the incremental cost per quality-adjusted life-year (QALY) gained by IMRT from the perspective of the Ministry of Health. The costs of IMRT and 3DCRT were estimated through activity-based costing, incorporating input from radiation oncologists, physicists and radiation therapists. We obtained clinical effectiveness estimates from published studies and calculated the number needed to treat to avoid a case of severe long-term xerostomia using data from a randomised controlled trial. Results The delivery of IMRT produced 0.48 more QALYs than 3DCRT at an additional cost of $2447 (QALY and costs discounted at 5% a year), yielding an incremental cost-effectiveness ratio of $5084 per QALY gained. The cost-effectiveness of IMRT was sensitive to the costs of radiotherapy and the effect of IMRT on health-related quality of life. The cost of IMRT will probably decrease with the addition of volumetric modulated arc therapy, an increasingly used technology, because volumetric modulated arc therapy reduces treatment time. We need to treat less than two patients with IMRT to avoid a case of severe, long-term xerostomia (dry mouth), and the incremental cost to avoid a case of severe, long-term xerostomia was $4532. Conclusions In the treatment of locally advanced oropharyngeal carcinoma, the IMRT strategy appears to be cost-effective when compared with 3DCRT.