Research studies

So far, the ACS has been included in more than 35 projects in the Netherlands and internationally, of which many are still ongoing. These projects cover a wide range of topics, including cross-sectional or longitudinal evaluations of cognitive functioning in healthy and clinical populations, validation and feasibility studies, and collection of normative data.

Although the ACS was originally developed to assess cognitive functioning in oncology, the ACS has successfully been implemented in studies to assess cognitive functioning in other clinical populations, for example, in patients with psychiatric or neurological disorders.

Research studies using the ACS

The Netherlands Cancer Institute (NKI) has conducted several studies in which the ACS was implemented to assess cognitive function in oncological populations. Some examples of these studies and their results are:

Cognitive effects of physical exercise during and after chemotherapy

The ACS was used in three studies to assess cognitive effects of exercise interventions during or after chemotherapy. The PAM study found positive effects of a 6-month exercise intervention on cognitive function in highly fatigued chemotherapy-exposed breast cancer patients (Koevoets et al., 2022). The PACT-PACES-HEART study found no long-term effects of exercising and being overall more physically active during or after adjuvant chemotherapy for breast cancer on objective or self-reported cognitive functioning, approximately 8.5 years after the exercise intervention (Naaktgeboren et al., 2024). The OptiTrain trial found no long-term effects five years after a 16-week supervised exercise program during chemotherapy for breast cancer on objective and subjective cognitive function (Anandavadivelan et al., 2024).

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Koevoets et al. (2022). Effect of physical exercise on cognitive function after chemotherapy in patients with breast cancer: a randomized controlled trial (PAM study).

Naaktgeboren et al. (2024). Effects of physical exercise during adjuvant chemotherapy for breast cancer on long-term tested and perceived cognition: results of a pragmatic follow-up study.

Anandavadivelan et al. (2024). Five-year follow-up of the OptiTrain trial on concurrent resistance and high-intensity interval training during chemotherapy for patients with breast cancer.

Long-term cognitive effects of risk-reducing salpingo-oophorectomy (RRSO)

The ACS was used in HARMOny study to compare cognitive function between women that had undergone pre- versus post-menopausal RRSO at least ten years prior. Women with premenopausal RRSO did not report more cognitive problems nor performed worse on objective cognitive tests compared to women with postmenopausal RRSO (Terra et al., 2023).

Terra et al. (2023). Long‐term effects of premenopausal risk‐reducing salpingo‐oophorectomy on cognition in women with high familial risk of ovarian cancer: A cross‐sectional study.

Cognitive functioning in working cancer survivors

Thirty percent of occupationally active non-central nervous system cancer survivors with cognitive complaints had lower than expected performance on the ACS. Performance was associated with work ability and work functioning (Klaver et al., 2024).
An internet-based therapist-guided extensive cognitive rehabilitation program was effective in achieving personalized work-related goals in working cancer survivors with and without cognitive impairment Klaver et al. (2024).

Klaver et al. (2024). Neuropsychological test performance and self-reported cognitive functioning associated with work-related outcomes in occupationally active cancer survivors with cognitive complaints.

Klaver et al. (2024). Internet-based cognitive rehabilitation for working cancer survivors: Results of a multicenter randomized controlled trial.

Cognitive effects of endocrine therapy for breast cancer

The TOTAM trial used the ACS to investigate the adverse effect of tamoxifen on cognitive function and was the first to investigate and demonstrate that tamoxifen’s effects may be exposure-dependent (Luijendijk et al., 2024). A prospective follow-up study including baseline cognitive assessments is currently being carried out.

The SONIA trial found worse cognitive function on all cognitive domains in hormone receptor positive breast cancer patients upon diagnosis of advanced disease. Nine months of treatment with endocrine therapy with or without CDK4/6 inhibitors did not further worsen cognitive function (Luijendijk et al., 2024).

Luijendijk et al. (2024). Effects of tamoxifen on cognitive function in patients with primary breast cancer.

Luijendijk et al. (2024). Cognitive function in patients with HR+ advanced breast cancer treated with endocrine therapy with or without CDK4/6 inhibitors in the SONIA trial.