Impact of symptoms and toxicity on quality of life: Exploratory analysis of gemcitabine plus docetaxel vs capecitabine plus docetaxel in metastatic breast cancer

Abstract

682 Background: A recent phase III trial comparing gemcitabine-docetaxel (GD) with capecitabine-docetaxel (CD) for metastatic breast cancer (MBC) found comparable progression-free survival but patients (pts) on GD had less toxicity (Chan, ASCO 2005). To better understand how quality of life (QoL) is impacted by toxicity and symptoms, we conducted an exploratory analysis. Methods: The study had 305 pts who relapsed after anthracycline-based treatment either in (neo)adjuvant or first-line MBC. Pts were randomized to GD or CD for 21-day cycles until PD or unacceptable toxicity. QoL was assessed every cycle with Rotterdam Symptom Checklist (RSCL). Only pts with RSCL data were included in the QoL analysis. Comparison between arms of changes from baseline in RSCL dimensions at each cycle were analyzed using analysis of co-variance (ANCOVA). Because the physical symptom distress scale (PSDS) includes symptom- and toxicity-related items, distributions of responses to each item were explored. Results: 302 pts received treatment (GD 152; CD 150); median number of cycles was 6 for both arms. 267 pts (88%) had baseline RSCL data; compliance ranged from 79%-88% for the first 6 cycles. Baseline RSCL scores were comparable between arms. No statistical differences between arms were seen for any of the RSCL dimensions (p>.05 at all cycles). Both arms had worsening in the PSDS (median increases of 3–6.8 on 69-point scale). Numerical differences were seen in some PSDS items rated as “quite a bit” or “very much.” By cycle 3, more GD pts reported tiredness (58% v 47%), lack of energy (45% v 38%), back pain (19% v 9%), and by cycle 2, alopecia (76% v 66%). By cycle 1, more CD pts reported tingling hands/feet (15% v 7%) and burning/sore eyes (14% v 3%). Conclusions: Preliminary analysis indicated no QoL differences between GD and CD; however, further exploration shows that physical distress is explained by different symptoms and toxicities in each arm. Results, particularly at later cycles, should be cautiously interpreted because of pt attrition and different reasons for discontinuation (eg, more CD than GD pts discontinued due to serious adverse events [28% v 13%]). Further analysis incorporating clinical outcomes may better explain QoL outcomes [Table: see text]