Cross-cultural adaptation of the Functional Assessment of Cancer Therapy-Breast (FACT-B) in Malaysian breast cancer survivors

Introduction: The survival rate of female breast cancer survivors has been reported to be higher than other types of cancer in Malaysia. Nonetheless, breast cancer survivors face new challenges from unwanted side effects of treatment or management such as fatigue, psychological disturbance, or arm swelling, which can lead to the decline of quality of life (QOL). This study aims to adapt the Malay version of the Functional Assessment of Cancer Therapy-Breast (FACT-B) to evaluate the QOL and to test its reliability and validity in Malaysian breast cancer survivors. Methods: The Malay version of the FACT-B, with Disabilities of Arms, Shoulders and Hands (DASH), and Patient Health Questionnaire Anxiety-Depression Scale (PHQ-ADS) were distributed to female breast cancer survivors which were recruited on a voluntary basis, from cancer support groups based in selected states in Malaysia. Reliability was assessed based on internal consistency (Cronbach’s α), whereas concurrent validity was examined by comparing domains in FACT-B with DASH and PHQ-ADS. Finally, total scores of each domain were analysed between lymphedema and without lymphedema groups for known-group validity. Results: A total of 113 breast cancer survivors agreed to participate (response rate = 100%) in the study. Our results showed that the Cronbach’s α value for Malay FACT-B is 0.88, and each domain ranged from 0.62 to 0.88. A strong correlation was found between the physical well-being domain of FACT-B with DASH. Meanwhile, the breast cancer scale (BCS) displayed significant correlation with the instrument, Patient Health Questionnaire- Anxiety Depression Scale (PHQ-ADS), indicating that multiple factors including psychological distress were measured in the BCS domain. Furthermore, the instrument was able to detect differences in physical, functional and QOL between participants from lymphedema and without lymphedema groups. Conclusion: The Malay version of the FACT-B demonstrated reliable properties and is effective in assessing QOL and can be applied in Malaysian breast cancer survivors.