Abstract PO5-12-06: Minimization of treatment toxicity/side effects and their impact on quality of life (QoL) in patients (pts) with ER+/HER2- metastatic breast cancer (mBC)

Abstract Introduction: Treatment toxicity and side effects may be underreported (Basu Roy. J Thorac Oncol 2018:13:1815-17) and can negatively impact QoL. As such toxicities can influence pts’ treatment decisions, we surveyed pts with ER+/HER2- mBC to better understand the impact and patient reporting accuracy of treatment toxicities/side effects. Methods: The EQUALS 3 (ESR1 QUAlity of Life Survey 3), 55-question survey was designed by the EQUALS Steering Committee, trialed by pt advocates, emailed to US subjects (Cure Media Group and authors’ contacts), and posted to private BC Facebook and Twitter groups for 2 wks in June 2023. Eligible pts had ER+/HER2- mBC and treatment changes due to disease progression. Pts received a $10 gift card at survey completion. Survey answers were descriptively summarized. Results: 213 pts completed the survey. Most were < 60 yrs of age (77%), White (44%) or Hispanic/Latino (48%), peri-/postmenopausal (54%), and college-educated (71%); had income >$50,000 (66%); lived in urban (51%)/rural areas (22%); and had therapy lines of 1st (8%), 2nd (36%), or 3rd+ (51%). Current mBC treatments were endocrine therapy (ET) ± targeted therapies (70%), antibody drug conjugate (8%), chemotherapy (11%), and other (10%). Most pts had a female oncologist (65%) who worked in an academic hospital (61%); 68% had >1 oncologist. Surveyed pts reported toxicity concerns for side effects ranging from serious to nuisance. Side effects most frequently reported as extremely/moderately concerning were respiratory symptoms (51%), blood clots in lungs (49%) or heart/brain (47%), cognitive dysfunction (47%), infections (46%), nausea/vomiting (44%), cardiac adverse effects (44%), diarrhea (42%), gait instability (41%), fatigue (39%), joint pain (39%), hair loss (33%), or sexual dysfunction (27%). Although 49% of pts felt comfortable speaking to their medical team (MT) about side effects, 62% reported having minimized side effects to their MT due to fears/concerns of being seen as a complainer (70%), dose reduction (66%), being taken off drug (65%), not accessing other drugs with similar toxicities (61%), reduced efficacy with lower dose (59%), or coming off trial (47%). Almost half (47%) did not report treatment side effects, mostly due to fear of being seen as a complainer (63%), being taken off drug (57%), reduced efficacy with lower dose (51%), dose reduction (50%), not accessing other drugs (50%), or coming off trial (41%). QoL was poor/very poor in 20% of pts and QoL was the most common (68%) important/very important factor for making a treatment decision based on risks. Most common side effects that negatively impacted QoL were sexual dysfunction (45%), joint pain (38%), vaginal atrophy/dryness (36%), fatigue (33%), bone pain (31%), and hair loss (26%). Toxicities/side effects also impacted pts’ anxiety (49%), career (46%), marriage (42%), finances (32%), housework (30%), and relationships (19%). Regret after taking a cancer medication due to side effects was reported by 46% of pts. Conclusion: In this survey of pts with ER+/HER2- mBC on ET predominantly, many treatment side effects caused concern, not necessarily related to their seriousness, and most pts had minimized or hid side effects at some point due to fear of negative perceptions from their MT, reduced treatment efficacy, or clinical trial changes. Although QoL was overall good for most, 20% had poor QoL (largely impacted by sexual dysfunction, joint pain, and vaginal issues). Regret about toxicities was also common and should be explored. Provider awareness of pts’ toxicity experience, fears, and impacts on daily lives opens the door for educational tools to improve MT communications for treatment decisions, informed consent, and more accurate toxicity reporting in clinical trials. Citation Format: Sarah Sammons, Jane Meisel, Kelly Shanahan, Timothy Pluard, Fumiko Chino, Dario Trapani, Dominic Carroll, Monica Kozlowski, Elizabeth Attias, Nicole Kuderer. Minimization of treatment toxicity/side effects and their impact on quality of life (QoL) in patients (pts) with ER+/HER2- metastatic breast cancer (mBC) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-12-06.