Outcomes of testing with cancer patients suggest chemotherapy may lead to cognitive impairment such as learning, memory, and attention deficits. However, several limitations appear evident in the research to date.
First, studies of chemotherapy and cognitive impairment have mainly focused on patients with breast cancer, limiting the generalisability of results beyond this group. Second, most studies have not taken pre-chemotherapy baseline measurements for comparison or studied patients over time, limiting knowledge about long-term effects. Third, other possible factors that may affect cognitive function have not been taken into account including the type of chemotherapy treatment, self-perceived cognitive changes, and psychological factors known to affect cognitive function including depression, anxiety, and fatigue.Finally, inappropriate control groups or no control groups have been used for comparison.
The purpose of the current study is to implement a national long-term study of cognitive impairment with patients undergoing chemotherapy, other than breast cancer patients, taking into account a range of factors. Patients diagnosed with testicular cancer appear especially appropriate as most patients undergo surgery, yet only some continue on with chemotherapy.
The patients who do not receive chemotherapy therefore provide an appropriate control group for comparison. Many tests used to assess cognitive function are not suitable for ongoing assessment because of the possibility of learning the test over time.
Importantly, valid and reliable computerised assessments of cognitive function (CogHealth) taking as little as 10 minutes are now available to allow repeated measurements over time without burdening patients attempting to deal with chronic illness. Research on the extent of cognitive impairment after chemotherapy has implications for the way future trials are investigated, especially with cancer survivors living longer due to advances in medical care.
Professor Ian Olver (SA), Associate Professor Guy Toner (Vic), Professor Villis Marshall (SA), Associate Professor Michael Boyer (NSW) & Associate Professor Paul Maruff (Vic)