Cancer-Related Cognitive Impairment or “Chemobrain:” Emerging Assessments, Treatments, and Targets for Intervention

A systematic review of rehabilitation programs for cognitive impairment related to breast cancer: Different programs at different times?

BACKGROUND

"Cancer Related Cognitive Impairment" (CRCI) defines cognitive disorders related to cancer and its treatments. Many people with breast cancer experience signs of CRCI (incidence between 20 and 30 %) and, although several intervention options exist, there is no established standard of care. Our main objective was to provide a detailed description of the methods and results of randomized controlled trials of interventions for CRCI in breast cancer survivors, paying particular attention to the timing of the interventions within the care pathway.

METHODS

We conducted a systematic literature review following the PRISMA guidelines from 01 to 01-2019 to 16-07-2023 and included randomized controlled trials of interventions for CRCI after breast cancer with at least one objective cognitive assessment as a primary or secondary outcome.

RESULTS

Among 228 identified studies, 35 (including 2821 participants) were retained for inclusion. The interventions were classified into 4 categories: cognitive rehabilitation, physical activity, complementary therapy and pharmacological treatment. Our analysis revealed that pharmacological interventions have no effect, whereas physical activity interventions proposed in the months following the initial cancer treatment improve Quality of Life and Speed of Information Processing while interventions proposed later improve Memory and Attention (Cognitive Rehabilitation) and Perceived Cognitive Function and Depression/Anxiety/Mood (Complementary Therapies).

CONCLUSION

CRCI is multifactorial and affected individuals frequently experience high levels of fatigue, pain, anxiety and depression and are most likely to benefit from holistic approaches that include cognition, physical activity, relaxation, psychoeducation, group support and/or psychological counselling. Thus, rehabilitation programs should be designed on multi-modal approaches, using innovative, cost-effective delivery methods that increase access to treatment, and intervention outcomes should be evaluated using measures of participation.

DATABASE REGISTRATION

The review was recorded on Prospero (01-03-2020), with the registration number 135,627.

Chemotherapy-induced cognitive impairment in breast cancer survivors: A systematic review of studies from 2000 to 2021

BACKGROUND

Studies have indicated that apart from enhancing patient survival, chemotherapy has adverse side effects on the psychological, social, and cognitive functions of breast cancer survivors.

AIMS

This study was conducted to understand chemotherapy's impact on breast cancer survivors' cognitive functions.

METHODS AND RESULTS

Our study is a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched English databases, including PubMed/MEDLINE, PsycINFO, and Web of Science, and Persian databases, such as Irandoc and Elmnet, using Persian keywords of cancer, breast cancer, chemotherapy, cognitive functions, executive functions, and neuropsychological functions. Two reviewers independently evaluated the full text of the articles according to predefined criteria. Among the 937 available studies, 26 were selected based on the inclusion and exclusion criteria, of which 17 (65%) were longitudinal and 9 (35%) were cross-sectional. The findings indicated a significant relationship between the use of chemotherapy and cognitive impairments, most notably attention, working and short-term memory, and executive functions. However, the studies differed in their findings regarding the long-term persistence of cancer-related cognitive impairment (CRCI), which could be due to the wide range of tools used, different methods to measure cognitive functions, and the difference in the sample size of the studies.

CONCLUSION

Chemotherapy, affecting cortical and subcortical brain structures, causes a set of cognitive impairments that can lead to impairments in social responsibility acceptance, daily functioning, and quality of life of women. Therefore, rigorous and extensive research design is required to understand the causes and consequences of CRCI using standardized and sensitive measures of cognitive functions. Specifically, studies comparing the effects of different chemotherapy regimens on cognition and potential mechanisms and/or moderators of CRCI would be instrumental in designing more effective therapy regimens and evaluating the efficacy and cost-effectiveness of cognitive rehabilitation and supportive care programs.

CanCOG®: Cultural Adaptation of the Evidence-Based UCLA Cognitive Rehabilitation Intervention Program for Cancer Survivors in Portugal

Cognitive difficulties are highly prevalent and negatively impact cancer survivors' quality of life. The UCLA Cognitive Rehabilitation Intervention Program (in short, UCLA program) is an evidence-based intervention developed and tested in the US to address the cognitive complaints of cancer survivors. Since there are no cognitive rehabilitation programs available for Portuguese cancer-related settings, this study aimed to culturally adapt the UCLA program to Portugal. Nine steps were implemented for this cultural adaptation: needs assessment, initial contacts, translation, cultural adaptation, independent review by a panel of experts (n = 6), focus group discussions with cancer survivors (n = 11), systematization of inputs and improvement of the final materials, fidelity check, and preliminary acceptability assessment. The findings suggested that changes to the original materials were needed. A Portuguese name, "CanCOG^®-Reabilitação Cognitiva no Cancro" (in English "CanCOG^®-Cognitive Rehabilitation in Cancer"), and a logo were created to make it more memorable and appealing for the Portuguese population. The language was adjusted to ensure content accessibility and semantic and conceptual equivalence. Finally, references to several cultural aspects, such as habits, customs, and traditions, were adapted to fit the new cultural context. The UCLA program may be a promising tool to help alleviate the cognitive difficulties reported by cancer survivors in different cultural contexts. Future research is needed to confirm the feasibility, acceptability, and preliminary efficacy of its Portuguese version, "CanCOG^®-Reabilitação Cognitiva no Cancro".

Loneliness as a risk factor for cancer-related cognitive impairment: a secondary data analysis from the Haze study

PURPOSE

The purpose of this study was to investigate the association between loneliness and cancer-related cognitive impairment (CRCI) in a cohort of breast cancer survivors.

METHODS

Female breast cancer survivors (stage I-III) reporting cognitive impairments 2 months to 5 years after chemotherapy (n = 61) participated in a prospective, nonblinded, waitlist-controlled pilot study. The intervention was a tailored cognitive rehabilitation program. Data were collected pre-/post-intervention. Loneliness was measured using the UCLA Loneliness Scale. Perceived cognitive function was measured using two subscales of the FACT-Cog and two PROMIS - Applied Cognition short forms. Spearman correlation coefficients were calculated to determine the relationship between loneliness and perceived cognitive function (PCF).

RESULTS

Participants' loneliness severity was correlated with diminished PCF across all cognitive measures (Spearman r= -0.63 FACT-Cog Perceived Cognitive Impairment, p < 0.0001; r= -0.6 FACT-Cog Perceived Cognitive Abilities, p < 0.0001; r= -0.49 PROMIS Cognitive Ability, p = 0.0002; r = 0.50 PROMIS General Concerns, p = 0.0002). Loneliness scores significantly decreased following participation in the cognitive rehabilitation program in intervention participants as compared to wait-list controls [-5.0 ± 7.24, 95% CI (-8.06, -1.94), p = 0.0025].

CONCLUSIONS

Perceived loneliness was significantly and consistently correlated with PCF. The intervention may have served a dual purpose in both addressing cognitive deficits and loneliness. Additional research dedicated to understanding the association between loneliness and cognitive function, as well as screening for and addressing loneliness in clinical oncology settings, may be warranted. IMPLICATIONS FOR REHABILITATIONScreening for and addressing loneliness in oncology rehabilitation settings is warranted.Rehabilitation professionals are well-positioned to screen for and address loneliness during clinic visits as part of routine cancer rehabilitation care.Group settings may be appropriate for addressing cancer-related cognitive impairment in rehabilitation, as these groups may serve the dual purpose of addressing cognitive impairment and loneliness simultaneously.