Evaluation of Brain Function Before and After Standard Chemotherapy for Early Breast Cancer

As the survival rate and prognosis of cancer improve, there is increasing recognition of the presence of a long term negative impact of standard chemotherapy on cognition, namely in the domains of attention, memory, psychomotor speed and executive functions. The purported incidence varies between 10-50%, the mechanism is unknown and it is unclear who is at risk. This impact has also not been studied and documented in the Asian population.

This proposal outlines a study that intends to prospectively (1) investigate and document the incidence and severity of cognitive impairment following systemic chemotherapy for breast cancer in Asian women in the acute and prolonged setting, and (2) to relate these cognitive changes to damage to DNA and lipids (two major targets of attack by toxic agents) as indicated through tests conducted on blood and urine samples.

Thirty breast cancer patients who will be required to undergo standard chemotherapy will be recruited for a pilot study to determine the acceptability of the procedure and to establish the size of the effects under investigation. A 45-minute neurocognitive assessment will be administered at three time points: before commencement of chemotherapy, and at 6 months and 1 year following completion of chemotherapy. Blood and urine samples will be collected just prior to the commencement of chemotherapy, after the first cycle of chemotherapy, and also at 6 months and 1 year post completion of chemotherapy.

It is hypothesized that (1) there will be decrements in performance on the neurocognitive measures post-chemotherapy; (2) the presence of cognitive decline will correlate with the presence of markers of oxidative damage in the blood and urine samples. The benefits of this project are two fold. Firstly, it will allow research into and documentation of the possible presence of cognitive decline following chemotherapy in Asian women, which is important in allowing patients to make fully-informed consent with regard to treatment. Secondly, if a relationship between the presence of cognitive decline and the presence of biochemical markers of oxidative damage can be established, this can potentially lead to new treatment methods that may reduce the cognitive decline that has been associated with the chemotherapeutic process.