Absence of adverse quality of life outcomes of radiation therapy in breast conservation therapy for early breast cancer

Abstract

The shared decision making process involved in selection of local therapy for early breast cancer requires women to have an understanding of the potential adverse effects of radiation therapy (RT) and subsequent impact on quality of life(QoL). This study aims to prospectively assess the QoL of women in the 12 months following breast conservation therapy(BCT) and determine the factors associated with impaired QoL; including whether the experience of a higher grade of acute RT toxicity is associated with worse QoL at 12 months. Women managed with breast conservation therapy in four NSW radiation oncology departments were enrolled onto a prospective longitudinal clinical study assessing acute RT toxicity and QoL endpoints. Eligible women were those who received adjuvant breast tangential RT to a total dose ≥50Gy after wide local excision of breast cancer. Women receiving cytotoxic chemotherapy were specifically excluded from study entry. Physician and patient assessment was performed prior to RT and then at fixed timepoints (end RT, Week+6, month+6 and month+12 post RT). Acute toxicity outcomes assessed included RTOG skin score, moist desquamation, breast edema, breast discomfort and lethargy. QoL instruments used were the European Organization of Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-30) and Perceived Adjustment to Chronic Illness Scale (PACIS). Non-parametric tests were used in analysis of the endpoints. Difference in QoL between the timepoints was assessed by Wilcoxon Signed Ranks Test. Potential patient, tumour and treatment related factors associated with QoL were assessed by Mann-Whitney analysis. 194 women were enrolled in the study between October 1998 to March 2001. All women had complete data collection at 12 months post RT. The median age was 56 years (36–81 yrs), 84% of women had invasive breast cancer and 11% had node positive disease. 54% of women received adjuvant tamoxifen. Peak toxicity by end RT included 4% of women with RTOG skin score of 3 or 4; 20% had moist desquamation mostly limited to the inframammary fold; 27% described “quite a bit” of daily breast discomfort and 40% had breast edema at the end of RT. 22% of women described lethargy leading to a significant disruption to normal activity during RT, though only 2% described the need for prolonged rest. By Week+6(W6) and Month+12(M12) this had reduced to 7% and 4% respectively and were equivalent to preRT assessment. At M12 the rate of breast discomfort was 6% and breast edema was 24%. Global QoL parameters were analysed at each timepoint to M12 and compared with baseline measures. No negative effects on QoL were noted over the time period of RT, with EORTC demonstrating no difference (p = .79) whilst PACIS recorded a significant improvement in functioning (p < .01) from baseline to W6 and then remained unchanged. The fatigue domain in EORTC QoL was worse at end of RT but had returned to baseline by W6. Older age (p < .05), tamoxifen use (p < .01) and lethargy (p < .01) were associated with worse global EORTC QoL at M12. RT acute toxicity outcomes, other than lethargy, were not associated with worse QoL. This prospective longitudinal study of the QoL effects in women receiving RT in BCT confirms the minimal impact of RT on patient functioning at 12 months post treatment. Acute RT toxicity and its impact had resolved by 6 weeks post RT and was not associated with adverse QoL outcome at 12 months. This data should provide confidence to women and breast surgeons in the decision making process of breast conservation therapy