Biological and psychological predictors of cognitive function in breast cancer patients before surgery.

PURPOSE: Research suggests that cancer-related cognitive impairment (CRCI) can occur before breast cancer (BC) treatment. The limited extant evidence suggests the underlying mechanisms could be stress-related. Potential psychological and biological predictors of CRCI prior to any BC treatment were examined. METHODS: 112 treatment-naïve women with BC and 67 healthy controls (HC) completed a neuropsychological test battery to assess cognitive impairment and a self-report battery to assess cognitive complaints, cancer-related stress, depressive and anxiety symptoms. Morning and evening cortisol and α-amylase were collected from saliva. Multilinear regressions were conducted. RESULTS: Treatment-naïve BC patients were more frequently impaired in verbal memory and processing speed and reported more cognitive complaints (all p < .001) than HC. BC patients and HC did not differ in overall cognitive impairment (p = .21). Steeper α-amylase, lower cancer-related stress and younger age was associated with better overall cognitive function in treatment-naïve BC patients. Higher depressive symptoms predicted higher levels of cognitive complaints in BC patients. CONCLUSION: Overall, these findings suggest that stress plays a role in CRCI. This study is the first to associate α-amylase with cognitive function in cancer patients, informing future research. The findings on impairment in processing speed and verbal memory among treatment-naïve BC highlight the need to screen for such impairments among BC patients and indicate that future studies on CRCI should include baseline assessments prior to BC treatment. If replicated, these findings could inform the development and testing of appropriate interventions to decrease CRCI among cancer patients. CLINICAL TRIALS REGISTRATION NUMBER: NCT04418856, date of registration: 06.05.2020.

The microphthalmia-associated transcription factor (Mitf) gene and its role in regulating eye function.

Mutations in the microphthalmia-associated transcription factor (Mitf) gene can cause retinal pigment epithelium (RPE) and retinal dysfunction and degeneration. We examined retinal and RPE structure and function in 3 month old mice homo- or heterozygous or compound heterozygous for different Mitf mutations (Mitfmi-vga9/+, Mitfmi-enu22(398)/Mitfmi-enu22(398), MitfMi-Wh/+ and MitfMi-Wh/Mitfmi) which all have normal eye size with apparently normal eye pigmentation. Here we show that their vision and retinal structures are differentially affected. Hypopigmentation was evident in all the mutants while bright-field fundus images showed yellow spots with non-pigmented areas in the Mitfmi-vga9/+ mice. MitfMi-Wh/+ and MitfMi-Wh/Mitfmi mice showed large non-pigmented areas. Fluorescent angiography (FA) of all mutants except Mitfmi-vga9/+ mice showed hyperfluorescent areas, whereas FA from both Mitf-Mi-Wh/+ and MitfMi-Wh/Mitfmi mice showed reduced capillary network as well as hyperfluorescent areas. Electroretinogram (ERG) recordings show that MitfMi-Wh/+ and MitfMi-Wh/Mitfmi mice are severely impaired functionally whereas the scotopic and photopic ERG responses of Mitfmi-vga9/+ and Mitfmi-enu22(398)/Mitfmi-enu22(398) mice were not significantly different from wild type mice. Histological sections demonstrated that the outer retinal layers were absent from the MitfMi-Wh/+ and MitfMi-Wh/Mitfmi blind mutants. Our results show that Mitf mutations affect eye function, even in the heterozygous condition and that the alleles studied can be arranged in an allelic series in this respect.