Evaluating the effects of adding chemotherapy to trastuzumab treatment on mental functioning in older patients with HER2-positive breast cancer.

This study investigated the effects of adding chemotherapy to trastuzumab (Herceptin) treatment on cognitive (thinking and reasoning) functioning in older patients with HER2-positive (HER2+) breast cancer (BC). The data showed that the addition of chemotherapy did not impact cognitive functioning in these women.

BC is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). HER2+ is a subtype of BC in which cancerous cells contain high levels of the HER2 protein that helps cancer cells grow and spread. Patients with this subtype of BC commonly receive targeted therapy such as trastuzumab that specifically targets the HER2 protein.

Cognitive function is a person’s ability to process thoughts. It includes functions such as memory, the ability to learn new information, speech, and reading comprehension. There are conflicting reports of cognitive functioning deficits in patients treated with chemotherapy. There are very few studies evaluating the effects of chemotherapy on cognitive impairment in older patients with BC. Whether adding chemotherapy to trastuzumab treatment has a negative effect on the cognitive functioning of older patients with HER2+ BC is not known.

This study involved 55 women aged 70-80 years with HER2+ BC. Patients were divided into 2 groups. Group 1 included 29 patients who received trastuzumab alone. Group 2 included 26 patients who received trastuzumab plus chemotherapy. The cognitive functioning of the patients was tested using the Mini-Mental State Examination (MMSE). MMSE includes tests of orientation, attention, memory, and language.

The average change in the total MMSE score between the 2 groups was 0.6 at 1 year and 0.9 at 3 years. After 3 years, 41.7% of the patients in group 1 had mild cognitive impairment compared to 28.6% of the patients in group 2. This difference was not considered significant.

This study concluded that adding chemotherapy to trastuzumab treatment led to similar cognitive functioning impairment compared to trastuzumab alone for older patients with HER2+ BC.

Different chemotherapy regimens were allowed in this study. The follow-up period was too short and the number of participants was small. This study did not consider the education level of the patients which could affect the MMSE test results.