A new analysis has found that breast cancer survivors may experience problems with certain mental abilities several years after treatment, regardless of whether they were treated with chemotherapy plus radiation or radiation only. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the study indicates that there may be common and treatment-specific ways that cancer therapies negatively affect cancer survivors' mental abilities.
Previous research suggests that chemotherapy can cause problems with memory and concentration in breast cancer survivors. To compare the effects of different types of cancer treatment on such mental abilities, Paul Jacobsen, PhD, of the Moffitt Cancer Center and Research Institute in Tampa, and his colleagues examined 62 breast cancer patients treated with chemotherapy plus radiation, 67 patients treated with radiation only, and 184 women with no history of cancer. Study participants completed neuropsychological assessments six months after completing treatment and again 36 months later, which is further out from the end of treatment than most previous studies of this type.
The study confirmed that chemotherapy can cause cognitive problems in breast cancer survivors that persist for three years after they finish treatment. In addition, the investigators found that breast cancer survivors who had been treated with radiation (and not chemotherapy) often experienced problems similar to those in breast cancer survivors treated with both chemotherapy and radiation. They did not find that hormonal therapy (such as tamoxifen) caused cognitive difficulties.
"These findings suggest that the problems some breast cancer survivors have with their mental abilities are not due just to the administration of chemotherapy," said Dr. Jacobsen. "Our findings also provide a more complete picture of the impact of cancer treatment on mental abilities than studies that did not follow patients as long or look at mental abilities in breast cancer survivors who had not been treated with chemotherapy," he added.
"Cognitive functioning after cancer treatment: A three-year longitudinal comparison of breast cancer survivors treated with chemotherapy or radiation and non-cancer controls." Kristin M. Phillips, Heather S. Jim, Brent J. Small, Christine Laronga, Michael A. Andrykowski, and Paul B. Jacobsen. CANCER; Published Online: December 12, 2011 (DOI: 10.1002/cncr.26432).