Adding Palbociclib Did Not Diminish QOL in Metastatic Breast Cancer

According to an analysis of the PALOMA-2 trial, adding palbociclib to letrozole offers similar health-related quality of life (QOL) and better pain scores in postmenopausal women with estrogen receptor–positive/HER2-negative metastatic breast cancer, compared to letrozole alone.

“Improving response and prolonging the duration of response to endocrine-based therapy while maintaining or improving QOL is an important treatment goal,” wrote study authors led by Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center. “The addition of agents targeted to pathways contributing to resistance may improve response and delay progression, but it is critical to understand both the safety profile and the impact of these therapies on QOL.”

The investigators analyzed QOL outcomes in the PALOMA-2 study, which randomized postmenopausal women with metastatic breast cancer to receive either palbociclib plus letrozole (444 patients) or placebo plus letrozole (222 patients). The median follow-up period was 23 months, and QOL was assessed using the Functional Assessment of Cancer Therapy–Breast (FACT-B) and –General (FACT-G), and Euro-QOL-5 Dimension (EQ-5D) questionnaires. The results were published online ahead of print in Annals of Oncology.

The mean age in the palbociclib and placebo arms was 62 and 61 years, respectively. At baseline, the mean FACT-B total scores were similar, at 101.5 and 103.2 for the palbociclib and placebo arms; the authors noted that these scores are comparable to those seen in healthy individuals.

The overall change from baseline was –0.11 with palbociclib and 0.22 with placebo, which was not significantly different (P = .782). That change did not reach a threshold (7 points change), which would indicate that addition of palbociclib had a clinically meaningful adverse impact on QOL.

Baseline scores on the FACT-G were also similar (77.7 with palbociclib and 79.1 with placebo), and the overall change from baseline was –0.39 with palbociclib and –0.53 with placebo (P = .883). The EQ-5D showed no differences between the groups either. Most subscales of the FACT-B were also similar with regard to change from baseline, and an analysis of time to deterioration on the FACT-B favored palbociclib but was not significant.

There was, however, a difference in the subscale that assessed pain in body parts, with a significantly greater improvement from baseline with palbociclib, at –0.256 compared with –0.098 (P =.018).

“This analysis shows that women on endocrine therapy are doing exceedingly well as evaluated by patient-reported outcomes, comparable to healthy individuals,” the authors wrote. “More importantly, results of outcomes assessed using FACT-B showed maintenance of QOL in both arms, without detriment from the addition of palbociclib.”