Purpose: To evaluate the incremental benefits and costs of adding magnetic resonance (MR) imaging to digital mammography (DM) screening in BRCA carriers.
Method: We used a Markov Monte Carlo model to compare four screening strategies to clinical surveillance (no imaging): 1) annual DM beginning at age 25 [DM25], 2) annual DM beginning at age 30 [DM30], 3) DM/MR beginning at age 25 [DM/MR25], and 4) DM/MR beginning at age 30[DM/MR30]. For combined strategies, we examined DM/MR alternating at 6-month intervals. An excess relative risk model was used to incorporate radiation risk from DM. The primary outcomes were quality adjusted life years (QALYs), lifetime costs (2010 USD) and incremental cost-effectiveness ratios (ICERs).
Result: Adding MR to DM increased QALYs and costs in both BRCA1 and BRCA2 carriers (Table 1). The DM/MR25 and DM/MR30 strategies were equally effective; DM/MR30 was less costly. Compared to DM30, DM/MR30 resulted in 0.12 and 0.06 additional QALYs at a cost of $117,754 and $114,539 in BRCA1 and BRCA2 carriers, respectively. The ICERs for DM/MR30 vs DM30 were $70,105 (BRCA1) and $209,818 (BRCA2). For BRCA1 carriers, these results were most sensitive to MRI cost, lifetime breast cancer risk, age at prophylactic oophorectomy, and MR test performance. Varying MR cost in BRCA1 carriers resulted in the widest range of ICER values. As MR cost increased to $842 (base case: $619), the ICER for DM/MR30 vs. DM30 exceeded $100,000/QALY. As MR cost decreased to $363, the ICER fell below $50,000/QALY. The results in BRCA2 carriers were stable across the range of parameters examined in sensitivity analysis.
Conclusion: Combined DM/MR screening alternating at six month intervals beginning at age 30 is considerably more cost-effective in BRCA1 carriers than in BRC2 carriers.
| Table 1. Incremental cost-effectiveness of screening in BRCA1 and BRCA2 carriers. | ||||||
Clinical Surveillance | DM30 | DM25 | DM/MR30 | DM/MR25 | ||
| BRCA1 | Lifetime costs | $104,490 | $109,006 | $110,420 | $117,754 | $122,557 |
QALYs (y) | 43.96 | 44.25 | 44.25 | 44.37 | 44.38 | |
ICER ($/QALY) | - | $15,294 | Eliminated | $70,105 | $480,300 | |
| BRCA2 | Lifetime costs | $97,121 | $102,204 | $103,726 | $114,539 | $119,678 |
QALYs (y) | 45.22 | 45.52 | 45.51 | 45.58 | 45.58 | |
ICER ($/QALY) | - | $17,078 | Eliminated | $209,818 | Eliminated | |