Breast Cancer Research and Treatment

, Volume 95, Issue 2, pp 125–129

The (mis)classification of chemo-fog – methodological inconsistencies in the investigation of cognitive impairment after chemotherapy

Authors

  • Val Shilling
    • Cancer Research UK Psychosocial Oncology GroupBrighton and Sussex Medical School University of Sussex
  • Valerie Jenkins
    • Cancer Research UK Psychosocial Oncology GroupBrighton and Sussex Medical School University of Sussex
  • Ivonne Solis Trapala
    • Centro de Investigacion en Matematicas, A.C
Clinical trial

DOI: 10.1007/s10549-005-9055-1

Cite this article as:
Shilling, V., Jenkins, V. & Trapala, I.S. Breast Cancer Res Treat (2006) 95: 125. doi:10.1007/s10549-005-9055-1

Abstract

Background

A growing number of studies report cognitive impairment after chemotherapy; indeed the phenomenon of chemo-fog is now almost universally accepted. We are concerned however that there is little if any consistency in the way in which patients are classified as showing cognitive impairment or not. We aim to demonstrate that different methods of analysis produce markedly different results, making the true extent of impairment unclear.

Methods

We analysed data from 92 breast cancer patients 4 weeks post-chemotherapy and from 42 healthy controls using 7 different methods, each taken from a different research paper in the area of cognitive impairment post-chemotherapy.

Findings

The extent of impairment was dependent on the method of analysis. Impairment ranged from 12 to 68.5% in the chemotherapy group and from 4.8 to 64.3% in the healthy control group.

Interpretation

This brief report highlights the contrasting degrees of cognitive impairment calculated by using legitimate statistical methods and demonstrates the need for a collaborative effort to standardise our methods that we might better understand the phenomenon of chemo-fog.

Keywords

breast cancerchemotherapycognitive impairment

Copyright information

© Springer 2005