Relationship between time elapsed since completion of radiotherapy and quality of life of patients with breast cancer

Globally, breast cancer is the most common malignancy and the leading cause of cancer-related deaths among women [1, 2]. In the United States, one in eight women will develop breast cancer during their lifetime [3]. Management of breast cancer includes surgery followed by radiotherapy (RT). Other treatment approaches include chemotherapy, endocrine therapy, and molecular targeted therapy [4]. Breast cancer remission in most cases is accompanied by concomitant short and/or long term damage to the physiological structure and function [5‐10]. This could ultimately limit the patients’ activities of daily living and represent a source of long term impairment [8‐14].

Advances in early diagnosis and treatment of breast cancer have helped improve patient survival. Consequently, the number of people living with disease sequelae is projected to increase over time. Providing long-term health care to these patients and measuring the impact of these services are pragmatic approaches. Assessment of cancer-specific quality of life (QOL) is an ideal approach towards this end. The European Organization Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire is a widely used instrument to assess the QOL of cancer patients [15]. Its specific module on breast cancer is the EORTC QLQ-BR23 [16]. Several studies have focused on the association between various treatment modalities (such as, surgical approach, radiation and chemotherapy regime or endocrine therapy) and QOL of patients with breast cancer [17]. However, few studies have investigated the temporal changes in QOL of these patients after completion of radiotherapy.

In the present study, we assessed the QOL of breast cancer patients at different time intervals after completion of RT using EORTC QLQ-C30 and EORTC QLQ-BR23 questionnaires. The objective was to assess whether time elapsed since completion of RT has a bearing on the QOL of these patients.

The present study is among the few studies which have evaluated the effect of time elapsed since completion of radiotherapy on the QOL of breast cancer patients following breast surgery using the EORTC QLQ-C30 and EORTC QLQ-BR23 instruments. We found that the patients’ social function, as measured with the EORTC QLQ-C30, improved significantly with passage of time during the 2.5 to 4.5 year time window after completion of RT. Social function refers to the patient’s self-awareness about his/her own health status and the impact on family’s daily life and social activities. A previous study revealed poor QOL of family caregivers of patients with cancers [18]. Strain imposed by cancer associated pain and discomfort, impaired capacity for work, and the dependence on drugs and adjuvant therapy can affect the physical condition of family caregivers, and render them vulnerable to cognitive dysfunction and sleep disorders. The major causes that impair post-treatment social life of patients with breast cancer include physical changes (such as removal of mammary gland), pain, and psychological factors such as depression, irritability and anxiety [19‐21]. With passage of time after completion of radiotherapy, patients tend to gradually accept the reality, which helps improve their social adaptability [22‐24].

Breast, arm, and shoulder pain are commonly experienced by breast cancer patients after treatment [25, 26]; these were shown to significantly impair the long-term QoL of these patients [27]. These symptoms may be attributable to tumor metastasis, anti-cancer therapy or to social-psychological factors. Previous studies have identified age, axillary lymph node dissection, and postoperative RT as significant risk factors [25, 28]. In the present study, only time elapsed since completion of RT was found to be associated with reduction in pain, after adjusting for age, educational level of patients, operation method, surgical staging and number of chemotherapy cycles; pain relief was especially noticeable after 2.5 to 4.5 years post-radiotherapy.

Scores pertaining to concerns about future state of health showed improvement from 2.5 to 3.5 years post-radiotherapy and a slight decline was also observed during the 3.5 to 4.5 year time window post-radiotherapy. The diagnosis and cure of breast cancer are both typically life-changing events which affect the patient’s psychological health [29]. At initial diagnosis, the patient typically experiences the psychological phenomenon of denial, anger, acceptance, depression, fear and survival, short-term lack of confidence and even fear for future health. Although the negative effects of disease on the patient exist, the positive effects of post-traumatic growth, however, helps augment patient’s confidence and reduces their worries about future [30]. More importantly, the confidence of patients is reinforced by the negative results of the annual cancer re-examination. Additionally, the recovery of functions in various aspects promotes the normal activities of daily living, which enable the patients to look forward to the future [24].

The cross-sectional study design is the main limitation of this study. The design does not allow for causal inferences, but only describes the factors associated with self-reported QoL outcomes.

In this study cohort, time elapsed since completion of RT had significant impact on social function, pain symptoms, and concerns about future state of health of patients with breast cancer. These scales improved with passage of time after RT. Our results have profound guiding significance for QOL of patients with breast cancer after RT. Of note, breast cancer is a heterogeneous disease and these results are limited to the cross-sectional study. Further studies are needed to elucidate the possible impact of time elapsed since completion of RT on breast cancer patients.