The paper presented at the American Society of Nephrology's 40th Annual Meeting and Scientific Exposition in San Francisco was headed by Dr. Germaine Wong and Dr. Kirsten Howard of the University of Sydney.
The researchers used a technique called Markov decision analytical modeling to weigh the benefits versus costs of breast cancer screening in two hypothetical groups of 50- to 69-year-old women on dialysis: one group who underwent mammography and one who did not. The mathematical simulation used research data from the Australian and New Zealand Data registry (ANZDATA) on breast cancer rates among women on dialysis, along with expected survival and mortality rates.
The cost of once-yearly mammograms—including the costs of diagnosing and treating detected breast cancers—averaged about $4,800 per patient per year. The simulation also suggested that yearly mammograms would prevent just one breast cancer death per 1,000 dialysis patients screened. The model estimated that, for each year of life saved, screening would add more than $500,000 to the total costs of care.
Several factors affected the costs and benefits of screening, including the rate of breast cancer, the accuracy of mammography, and the stage at which cancer was diagnosed. However, even under the most favorable assumptions, breast cancer screening for dialysis patients was unlikely to be cost-effective.
Regular mammograms to screen for breast cancer are recommended for most women aged 50 to 69. "Cancer screening is important because the overall cancer risk increases in renal transplant recipients and patients on dialysis," Dr. Wong explains. "Treatment options for cancers in these populations are limited because of co-existing illnesses."
Because patients with ESRD are at increased risk of death—not only from kidney disease, but also from other medical problems such as heart disease—it is unclear whether the costs of routine breast cancer screening are justified for women on dialysis.
"In contrast to most other cancers, the risk of breast cancer in the dialysis population is almost identical to the general population, but data on the effectiveness of screening for breast cancers in women on dialysis is relatively sparse," says Dr. Wong. "Even though they have the same risk, we are unsure whether women on dialysis would achieve the same benefits as in the general population. The best alternative is to model the benefits and harms of screening through decision analytical models. The model allows us to collate all evidence in a systematic way and to inform clinical decision making."
The results suggest that the benefits of performing routine breast cancer screening in women on dialysis are not likely to outweigh the costs. Dr. Wong and colleagues conclude, "Given the available data, at best, routine breast cancer screening in this population with a significantly reduced over survival does not appear good value for money."