Cancer survivors' knowledge of personalized medicine diagnostics

Gene expression profiling assays and other molecular diagnostics are increasingly being used to help guide decision-making for adjuvant therapy. Little is known about cancer survivors' knowledge about the use and adoption of personalized medicine diagnostics. This study was aimed at determining breast and colorectal cancer patients' knowledge and preferences for personalized medicine diagnostics. We measured patients' knowledge and preferences using a previously developed survey instrument. A web-based cross-sectional survey was administered to newly diagnosed (n=100) and survivors (n=68) of breast and colorectal cancer. The sample was drawn from a nationally representative panel of respondents. The mean age of patients with a breast cancer diagnosis was 54.5 years and of colorectal cancer patients 42.0 years. Study participants exhibited a wide range of educational attainment. Sixteen per cent of breast cancer and 29% of colorectal cancer patients had obtained a bachelor's degree. We also observed a range of income levels, with a mean annual household income of USD $65,000 among breast cancer patients, and a mean annual household income of $100,000 among colorectal cancer patients. Among all respondents, 76.5% of breast cancer patients and 70.0% of colorectal cancer patients were diagnosed with early-stage cancers. The majority of respondents 44.3% of breast cancer and 53.0% of colorectal cancer respectively, received their diagnosis within two to five years prior to this study. Among cancer survivors, 38% of breast cancer and 33% of colorectal cancer were in remission; whereas 9% and 26% respectively were actively monitored. New cancer patients were more knowledgeable about specific genes influencing cancer treatments (p< 0.05). Among those with colorectal cancer, 34% of new patients were aware of UGT1A1 and 17% for KRAS mutation testing compared with 10% and 3% respectively of cancer survivors (p<0.001). Similarly, 23% of new breast cancer patients were knowledgeable about their HER2 status versus 5% of survivors (p<0.05). Knowledge of specific pharmacogenomic-based genes and diagnostics was highest among younger patients (<49 years old) and among those from upper income groups (USD $100,000 and over). Early stage cancer patients preferred higher degrees of test sensitivity and specificity over survivors (p<0.05). Important knowledge deficits exist among adult survivors of breast and colorectal cancer regarding novel personalized medicine genomic diagnostics. Such deficits could impair survivors' ability to seek and receive long-term follow-up and care.