Treatment-focused DNA testing for newly diagnosed breast cancer patients: Some implications for clinical practice
Publication Details
Lobb, E. A., Barlow-Stewart, K., Suthers, G., & Hallowell, N. (2010). Treatment-focused DNA testing for newly diagnosed breast cancer patients: Some implications for clinical practice. Clinical Genetics, 77(4), 350–354. doi:10.1111/j.1399-0004.2009.01307.x
Abstract
There is accumulating evidence that women with breast cancer due to a familial BRCA1 or BRCA2 mutation benefit from specific surgical and chemotherapeutic treatment strategies. However, the rapid identification of such patients during the acute phase of treatment raises a number of issues. This study investigated Australian opinion leaders' views on the issues arising from such ‘treatment-focused’ genetic testing. Semi-structured interviews with 34 opinion leaders working in cancer genetics were undertaken. Interviewees acknowledged the introduction of treatment-focused DNA testing has the potential to positively transform the management of breast cancer patients, but were concerned that certain ethical and logistical issues have yet to be addressed. These include decision-making and consent, the familial nature of genetic information, and the management of genetics services within familial cancer clinics in the public hospital system in Australia. Service providers will need to have policies and strategies for managing the increased demand. It will also be necessary to include genetic counseling services within familial cancer clinics in the care pathway for newly diagnosed patients prior to any DNA testing to determine adjuvant treatment; such services may be more cost-effective than expecting surgeons and medical oncologists to fulfill this role.
Women with a strong family history of breast/ovarian cancer are often referred to familial cancer clinics to discuss DNA testing for BRCA1 and BRCA2 mutations following completion of their treatment prior to testing. In this context, genetic testing and genetic counseling is undertaken to guide cancer risk-management decision-making for the patient and her family (1, 2). There is little urgency for this testing as test results do not usually influence disease outcomes or cancer management in the short term (3).
The indications for BRCA1 and BRCA2 testing are broadening as evidence accumulates of the benefit of tailoring surgery and adjuvant chemotherapy according to mutation status (4). Although breast-conserving surgery (lumpectomy) followed by radiotherapy is the treatment of choice for many, BRCA mutation carriers may consider undergoing uni- or bilateral risk-reducing mastectomy (RRM) (5) because of the increased risks of ipsilateral recurrence and/or a contralateral primary cancer in women diagnosed before 50 years (6–8). Some women prefer to have RRM simultaneously to avoid radiotherapy which can adversely impact on the cosmetic results of future breast reconstruction. Patients with a BRCA1 vs BRCA2 mutation may react differently to chemotherapy regimens (9, 10). Clinical trials are underway to determine the effects of treating breast/ovarian cancer in BRCA carriers with poly(ADP-ribose) polymerase (PARP) inhibitors, and emerging data looks encouraging (11). These developments suggest that there may be an increasing demand for treatment-focused genetic testing, namely, the rapid testing of newly diagnosed cancer patients to inform treatment decisions (12).
While treatment-focused genetic counseling and testing is undertaken in Australia and other countries to inform the surgical management of newly diagnosed women from high risk families, this has not occurred in any systematic way (13). Moreover, at the present time treatment-focused testing to aid decisions about adjuvant chemotherapy does not occur in any of these jurisdictions, except in the context of clinical trials. Such testing raises technical issues because the current method of mutation analysis in Australia, at least, is relatively slow and expensive. Methodological advances such as next-generation DNA sequencing will result in significant reductions in cost and turnaround time, but resolution of technical issues will still leave other matters unresolved.
Little is known about the views and experience of patients and clinicians regarding the use of treatment-focused genetic testing for adjuvant chemotherapy (13). A recent UK study reported that staff and patients expressed concern about newly diagnosed patients having to make a potentially difficult and emotionally charged decision about DNA testing at an already distressing time (14). In this short report, we describe Australian service providers' perceptions of the challenges generated by treatment-focused DNA testing.
Keywords
peer-reviewed, BRCA1 and BRCA2, breast cancer, DNA testing, newly diagnosed women
