Abstract P1-12-01: Clinical impact of internet-based tools to help guide therapeutic decisions for metastatic breast cancer (MBC)

Background: Clinical practice guidelines are an important resource to help guide management of patients with MBC. However, guidelines are sometimes difficult to apply to individual patients, particularly when there are 2 or more treatment options with similar levels of evidence. We sought to determine whether expert recommendations on MBC treatment, delivered via an interactive, online decision support tool, would change or confirm the treatment decisions of community practitioners. We further sought to analyze changes in practice patterns and expert recommendations over time by comparing data from the current tool (2013) with data from a similar tool developed previously (2012).

Methods: Both online decision support tools were developed based on input from a panel of 5 experts. Each expert provided treatment recommendations for more than 400 patient scenarios based on a simplified set of variables: disease phenotype (HR status, HER2 status), previous therapy, visceral crisis (yes/no), and rate of disease progression. Users of the tool are prompted to enter specific patient criteria, and are asked to state their intended management approach for that particular patient case. The tool then shows the recommendations of the 5 MBC experts for the specific patient case that the user entered. Finally, the user is prompted to indicate whether the experts’ recommendation confirmed or changed their intended management approach. An analysis of expert recommendations and user-selected treatments was performed to compare results of the 2013 and 2012 tools.

Results: The 2012 decision support tool was utilized by 697 individuals who entered more than 1000 patient case scenarios. Users indicated that the experts’ recommendations changed their intended management approach for 30% of the cases, confirmed their approach for 36%, and did not impact their intended approach for 34%. Utilization data for the 2013 tool are pending. Expert recommendations in the 2012 vs 2013 tools changed to reflect emerging developments in guidelines, evidence, and clinical practice. For example, in 2012 there was no expert consensus on use of everolimus + hormonal therapy for HR+, HER2- patient cases, whereas in 2013, everolimus-based therapy was recommended by the majority of experts (3 out of 5) for 12 different HR+, HER2- cases. There was no consensus among the experts on the use of pertuzumab + trastuzumab and a taxane for HER2+ MBC in 2012, whereas in 2013 at least 3 out of 5 experts recommended it for a total of 36 HER2+ cases. At least 3 of 5 experts recommended trastuzumab emtansine for 96 different HER2+ cases in 2013 vs 0 in 2012. In both 2012 and 2013, the greatest variability in expert treatment recommendations was observed for HR-, HER2- cases.

Conclusions: An online tool providing expert advice on specific MBC patient scenarios either confirmed or changed the clinical approach for a majority of community practitioners. Decision support tools may increase the number of clinicians who make optimal treatment decisions for patients with MBC, especially when new data, agent indications, and guideline updates must be incorporated. Detailed comparisons of expert and user responses from the 2012 and 2013 decision support tools will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-12-01.

Predominant p53 G-->A transition mutation and enhanced cell proliferation in uterine sarcomas of CBA mice treated with 1,2-dimethylhydrazine

Mouse uterine tumors were examined for genetic alterations in the ras proto-oncogene and p53 tumor suppressor gene and for other biologically relevant immunohistochemical markers that may increase our understanding of the events that occur in uterine cancer. Fourteen dimethylhydrazine (DMH)-induced uterine sarcomas, including 3 primary malignant fibrous histiocytomas (MFH), 7 transplanted MFH, 3 stromal sarcomas, and 1 undifferentiated sarcoma, were first screened by immunohistochemistry for p53 missense mutations, followed by single strand conformation polymorphism analysis and DNA sequencing for the identification of point mutations. There was 100% correlation between p53 protein immunopositivity and subsequent detection of p53 mutations in DMH-induced malignant fibrous histiocytomas. All MFH had a characteristic p53 G:C-->A:T transition mutation, consistent with O6-methylguanine mispairing with thymine, the most common DNA lesion caused by alkylating agents. DMH-induced uterine MFH with p53 mutations also had a higher proliferative rate (qualitatively evaluated by immunohistochemical detection of proliferating cell nuclear antigen) when compared with other DMH-induced sarcomas. Uterine sarcomas were further evaluated for biological end points, such as estrogen receptor and desmin. Neoplastic cells from stromal sarcomas (SS), undifferentiated sarcomas (US), and MFH did not stain for desmin. The estrogen receptor was detected in normal uteri and a small portion of MFH, SS, and US. Our data suggest that DMH-induced uterine sarcomas are not consistent with smooth muscle cell origin and that a subset of these tumors, specifically DMH-induced malignant fibrous histiocytomas, have unique p53 G:C-->A:T transitions and a high proliferative rate.