MONDAY, Dec. 12 (HealthDay News) -- Breast cancer survivors can experience memory and concentration problems several years after treatment with radiation and/or chemotherapy, a new study says.

The findings suggest that there may be common and treatment-specific ways that these cancer therapies impair cancer survivors' mental abilities, according to Paul Jacobsen, of the Moffitt Cancer Center and Research Institute in Tampa, Fla., and colleagues.

The study included 62 breast cancer survivors treated with chemotherapy plus radiation, 67 patients treated with radiation only and 184 women with no history of cancer. The breast cancer patients underwent neurological assessments six months and three years after completing treatment.

The researchers found that chemotherapy can cause cognitive, or thinking, problems that persist for three years after breast cancer survivors finish treatment. This pattern of changes is often called "chemo brain." They also found that patients who were treated with radiation alone often had cognitive problems similar to those treated with both radiation and chemotherapy.

There was no indication that hormonal therapy, such as tamoxifen, caused cognitive problems.

The study was published online Dec. 12 in the journal Cancer.

"These findings suggest that the problems some breast cancer survivors have with their mental abilities are not due just to the administration of chemotherapy," Jacobsen said in a journal news release.

"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.

More information

The American Cancer Society offers an overview of chemotherapy-related cognitive problems commonly referred to as chemo brain.