Background: Sentinel lymph node biopsy (SLNB) is less invasive than axillary lymph node dissection (ALND) for staging early breast cancer, and has a lower risk of arm lymphoedema and similar rates of locoregional recurrence up to 8 years. This study estimates the longer-term effectiveness and cost-effectiveness of SLNB. Methods: A Markov decision model was developed to estimate the incremental quality-adjusted life years (QALYs) and costs of an SLNB-based staging and management strategy compared with ALND over 20 years' follow-up. The probability and quality-of-life weighting (utility) of outcomes were estimated from published data and population statistics. Costs were estimated from the perspective of the Australian health care system. The model was used to identify key factors affecting treatment decisions. Results: The SLNB was more effective and less costly than the ALND over 20 years, with 8 QALYs gained and $883 000 saved per 1000 patients. The SLNB was less effective when: SLNB false negative (FN) rate >13% 5-year incidence of axillary recurrence after an SLNB FN>19% risk of an SLNB-positive result >48% lymphoedema prevalence after ALND <14% or lymphoedema utility decrement <0.012. Conclusion: The long-term advantage of SLNB over ALND was modest and sensitive to variations in key assumptions, indicating a need for reliable information on lymphoedema incidence and disutility following SLNB. In addition to awaiting longer-term trial data, risk models to better identify patients at high risk of axillary metastasis will be valuable to inform decision-making.

Objectives: To apply the most recent evidence from randomised trials of prostate‐specific antigen (PSA) screening and explore the potential value of risk assessments to guide the use of PSA screening in practice. Design: A decision model that incorporated a Markov process was developed in 2012 to estimate the net benefit and cost of PSA screening versus no screening as a function of baseline risk. Main outcome measures: Quality‐adjusted life‐years (QALYs) and costs. Results: The harms of screening outweighed the benefits under a number of plausible scenarios. Conclusions were sensitive to the estimated quality‐of‐life impacts of prostate cancer treatment as well as the incidence of cancers not detected by screening tests (poorer prognosis) and those that were detected by screening tests (better prognosis). The base‐case incremental cost‐effectiveness ratio of PSA screening was $168 611 per QALY for men with average risk, $73 452 per QALY for men with two times the average risk, and $22 938 per QALY for men with five times the average risk. Conclusions: PSA screening was not found to be cost‐effective for men at an average‐to‐high risk of prostate cancer, but may be cost‐effective for men at very high risk. Inexpensive approaches for identifying men at very high risk are needed, as is further research on the size of clinical benefit of early detection in this population. The potential for the costs of risk assessment to be offset by reduced costs of PSA screening also warrants investigation.

CORRECTIONError in calculating costs of screening: In "Risk assessment to guide prostate cancer screening decisions: a cost-effectiveness analysis" in the 3 June 2013 issue of the Journal (Med J Aust 2013; 198: 546-550), there was an error in the way screening costs were calculated. These corrections do not alter the study conclusions. The corrected figures are in bold as follows.Results section of the abstract (page 546): "The base-case incremental cost effectiveness ratio of PSA screening was $168 611 per QALY for men with average risk, $73 452 per QALY for men with two times the average risk,