Abstract P3-15-02: Treat ER+ight Canadian prospective observational study in HR+ advanced breast cancer: 2nd interim analysis
Authors: Dent S , Califaretti N , Doyle C , Ferrario C , Chouinard E , Kulkarni S , Roy J-A , Perri SR , Chia S 
Published: February 2018

Treat ER+ight is the 1st prospective observational study in Canadian postmenopausal women with HR+ HER2– advanced breast cancer currently receiving endocrine therapy (ET) alone or in combination with targeted therapy (TT) (NCT02753686).

Methods: This pre-planned interim analysis describes baseline characteristics, treatment sequence, monitoring patterns, patient-reported quality-of-life (QoL) and resource utilization of patients enrolled in ET and ET+TT cohorts within the 1st 3 months of therapy. At data cut-off (13Mar'17), 100 patients were enrolled from 24 sites since Mar'16.

Results:

Baseline Patient and Disease Characteristics ET (n=42)ET + TT (n=58)Median age, years (range)70 (37-88)63 (39-80)ECOG 0-1, (%)6072Median time since primary BC diagnosis, years (range)4.5 (0-37)5 (0-25)Median time with advanced BC diagnosis, years (range)1 (0-16)1 (0-7)Sites of metastases (%)  Bone only3829Visceral only3338Bone + visceral2924Last prior line of therapy included but not limited to (%)  Letrozole4131Anastrozole1219Tamoxifen1214Exemestane122Palbociclib+Fulvestrant07Line (L) of metastatic therapy (%)  1L19222L38433L4335

Enrollment therapy (%): everolimus+exemestane (35), fulvestrant (15), palbociclib + letrozole (15), tamoxifen (14), exemestane (7), palbociclib+fulvestrant (7), letrozole (4) and palbociclib+exemestane (1). Follow-up visits with physician after therapy initiation ET, ET+TT (%): week 2 (5, 47), month 1 (71, 67), month 3 (43, 31). Numerical differences were observed in EORTC QLQ C30 and BR23 global health status/QoL, functional and symptom scale scores between ET and ET+TT cohorts. Mean changes in transformed scores from baseline to month 3 were generally similar between cohorts however 'therapy side effects' symptom item worsened in ET+TT cohort (P = 0.031, Wilcoxon rank sum). Resource utilization in between scheduled visits during 1st 3 months of therapy was similar between cohorts for physician/radiology, hospitalizations and ER visits however patient calls to supportive care nurse was increased in ET+TT cohort (P = 0.008, Fisher's exact). Treatment discontinuation rate (20%) was similar between cohorts with progression as predominant reason for initiating next therapy. Chemotherapy (CT) was the most frequent subsequent therapy and represented 1st line metastatic CT for majority of patients.

Conclusions:

ET+TT patients were younger, had better ECOG, more visceral disease and 60% received everolimus+exemestane with &lt;10% receiving prior CDK4/6 therapy. Half of patients in ET+TT cohort returned for a follow-up visit with oncologist within 2 weeks of therapy initiation (compared to minority in ET cohort) and called the supportive care nurse in between scheduled visits. Patient-reported QoL within 1st 3 months of therapy was generally similar between cohorts. Therapy-related AEs impacted the patient-reported experience in ET+TT cohort however AEs did not lead to therapy discontinuation in over 85% of cases. These results highlight the importance of: (1) proactive AE patient education/management upon ET+TT initiation and at subsequent follow-up visits, (2) week 2 visit and (3) additional nursing telephone support in between visits.

Citation Format: Dent S, Califaretti N, Doyle C, Ferrario C, Chouinard E, Kulkarni S, Roy J-A, Perri SR, Chia S. Treat ER+ight Canadian prospective observational study in HR+ advanced breast cancer: 2nd interim analysis [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-15-02.