Date Published: April 22, 2019
Publisher: Public Library of Science
Author(s): Antonio Cuesta-Vargas, Jena Buchan, Bella Pajares, Emilio Alba, Cristina Roldan-Jiménez, Ali Montazeri.
Although breast cancer mortality is decreasing, morbidity following treatment remains a significant issue, as patients face symptoms such as cancer-related fatigue (CRF). The aim of the present study is to develop a classification system that monitors fatigue via integration of an objective clinical assessment with patient self-report. Forty-three women participated in this research. Participants were post-treatment breast cancer survivors who had been surgically treated for their primary tumour with no evidence of neoplastic disease at the time of recruitment. Self-perceived fatigue was assessed with the Spanish version of the Piper Fatigue Scale-Revised (R-PFS). Objective fatigue was assessed by the 30 second Sit-to-Stand (30-STS) test. Confirmatory factor analysis was done with Maximum Likelihood Extraction (MLE). Internal consistency was obtained by Cronbach’s α coefficients. Bivariate correlation showed that 30-STS performance was negatively-inversely associated with R-PFS. The MANOVA model explained 54.3% of 30-STS performance variance. Using normalized scores from the MLE, a classification system was developed based on the quartiles. This study integrated objective and subjective measures of fatigue to better allow classification of patient CRF experience. Results allowed development of a classification index to classify CRF severity in breast cancer survivors using the relationship between 30-STS and R-PFS scores. Future research must consider the patient-perceived and clinically measurable components of CRF to better understand this multidimensional issue.
While breast cancer is the most commonly diagnosed type of cancer in women, accounting for 30% of all new diagnoses, mortality rates have decreased by 38% in recent years . However, breast cancer still represents 15% of all cancer-related deaths in women . Despite decreasing mortality rates, morbidity following breast cancer remains a significant issue in the growing group of survivors. Survivorship starts at the time of cancer diagnosis and lasts throughout the lifespan, and it is commonly accompanied by treatment-related side effects . Cancer-related fatigue (CRF) is a symptom reported in about 70% of patients suffering from cancer, both during and shortly after treatment. Additionally, up to 30% of survivors develop CRF years post-treatment . However, these rates may be even higher given the difficulty in diagnosing and assessing CRF. For example, research has reported from 56% to 95% of breast cancer survivors experience CRF post-treatment .
Participants had undergone a lumpectomy (60%) or mastectomy (40%). Further, 93.3% of them had been treated with chemotherapy, radiotherapy and/or hormone therapy, with the vast majority (75%) still on hormone therapy. Additional demographic and clinical variables are presented in Table 1.
This study attempted to integrate objective and subjective assessments of fatigue,allowing more thorough classification of patient experience. Study aims were achieved, as results allowed development of an ambulatory index to assess CRF in breast cancer survivors. Results of the 30-STS were correlated with scores from total and each domain of the R-PFS to examine associations and relationships. Based on an observed relationship between the objective (30-STS) and subjective (R-PFS) tests, a scale was developed classifying CRF as one of five levels: Subclinical, mild, moderate, severe or extreme. As highlighted, CRF is multidimensional and includes physical and psychosocial components, necessitating an assessment that captures all domains. While PRO outcome tools such as the R-PFS  and Quick-Piper  are easy to access and provide an idea of how CRF affects the individual, combining an objective measure allows further assessment of how someone’s daily functional ability may also be impacted. Extensive research highlights the negative impact CRF has on quality of life through its impact on daily functioning ability [36–38].
This study integrated objective and subjective assessments of fatigue to better allow classification of patient experience. Results allowed development of an ambulatory index to assess CRF in breast cancer survivors using the relationship between 30-STS and R-PFS scores. By combining objective and subjective measures of fatigue and using these to classify the severity of an individual’s experience of the condition, management strategies can be better prescribed. Future research must consider the patient-perceived and clinically measurable components of CRF to better understand this multidimensional issue.