Testing for BRCA1 mutations: a cost-effectiveness analysis

Breast carcinoma is the most common type of cancer affecting women in the Western world. The hereditary forms, which amount from 5 to 10% of all the cases of breast cancer, mainly involve BRCA1 or BRCA2 mutations. Due to the diagnostic strategy used by the patent owner, Direct DNA sequencing (DS) may become the only BRCA1/2 test procedure available, although there exist several alternative strategies. A cost-effectiveness study was carried out using BRCA1 testing as a model. The main techniques available for performing mutation searches were assessed: DS, denaturing high performance liquid chromatography (DHPLC), single-strand conformation polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE), heteroduplex analysis (HA), fluorescent assisted mismatch analysis (FAMA) and the protein truncation test (PTT). Twenty strategies involving the use of one or more techniques were then devised for performing the complete genetic analysis. DS was adopted as the 'gold standard' for effectiveness. All the strategies except for DS involved a two-step procedure. The first step consisted of pre-screening the 22 coding exons of BRCA1. The second step consisted of performing DS only on the variations detected in the coding sequence. The cost of the strategies tested, including a pre-screening stage, turned out to be 30 to 90% lower than that of DS, whatever annual use was made of the equipment. The most cost-effective strategy, ie, that corresponding to the lowest cost per mutation detected, was found to be a combination between PTT on exon 11 (60% of the coding sequence) and HA on the remaining 21 exons (PTT(11)+ HA(21)). However, since a high false negative rate is associated with this strategy, at least four other strategies are worth mentioning: PTT(11)+ DHPLC(21), DHPLC alone, FAMA(11)+ DHPLC(21) and FAMA alone. Our results on genetic testing for breast cancer show that DS is not the most cost-effective method available. The monopolist approach of the firm which owns the patents on the BRCA1/2 genes, may, therefore limit the use of the most cost-effective strategies.