Purpose Many patients with hormone receptor-positive (HR+) breast cancer do not adhere to endocrine therapy (ET), and treatment-related side effects are often discussed by participants in online breast cancer forums. Our aim was to survey this unique group of patients about their ET-related experiences. Methods We partnered with patients active in breast cancer social media communities to develop a survey assessing ET-related side effects and medical team communication. Patients with a history of HR+ breast cancer who had received a recommendation to take ET were eligible to participate in the anonymous, online survey. Results Respondents included 2353 women and 54 men. Aromatase inhibitors were the most commonly used medication. Side effects were reported by 91.2%, were more often experienced by women than men (p < 0.001), and were primarily related to medication type. Approximately one-third of respondents discontinued therapy early. While most felt supported by their medical team, 31.5% reported that their side effects were dismissed or minimized. Survey respondents most frequently reported that a healthy diet and exercise, yoga/acupuncture, and vitamins/supplements were helpful in managing ET-related side effects. Conclusions ET-related side effects are very common, and one-third discontinued treatment early. Lifestyle changes and complementary therapies can be important tools for side effect management. One-third of patients did not feel that their side effects were taken seriously. Implications for Cancer Survivors This is the largest survey of ET use by participants in online breast cancer communities. Further research is needed to identify strategies to improve treatment adherence and to better manage ET-related side effects.

ObjectiveSystemic sclerosis (SSc) is a multifactorial autoimmune fibrotic disorder involving complex rewiring of cell‐intrinsic and cell‐extrinsic signaling coexpression networks involving a range of cell types. However, the rewired circuits as well as corresponding cell–cell interactions remain poorly understood. To address this, we used a predictive machine learning framework to analyze single‐cell RNA‐sequencing data from 24 SSc patients across the severity spectrum as quantified by the modified Rodnan skin score (MRSS).MethodsWe used a least absolute shrinkage and selection operator (LASSO)–based predictive machine learning approach on the single‐cell RNA‐sequencing data set to identify predictive biomarkers of SSc severity, both across and within cell types. The use of L1 regularization helps prevent overfitting on high‐dimensional data. Correlation network analyses were coupled to the LASSO model to identify cell‐intrinsic and cell‐extrinsic co‐correlates of the identified biomarkers of SSc severity.ResultsWe found that the uncovered cell type–specific predictive biomarkers of MRSS included previously implicated genes in fibroblast and myeloid cell subsets (e.g., SFPR2+ fibroblasts and monocytes), as well as novel gene biomarkers of MRSS, especially in keratinocytes. Correlation network analyses revealed novel cross‐talk between immune pathways and implicated keratinocytes in addition to fibroblast and myeloid cells as key cell types involved in SSc pathogenesis. We then validated the uncovered association of key gene expression and protein markers in keratinocytes, KRT6A and S100A8, with SSc skin disease severity.ConclusionOur global systems analyses reveal previously uncharacterized cell‐intrinsic and cell‐extrinsic signaling coexpression networks underlying SSc severity that involve keratinocytes, myeloid cells, and fibroblasts.image

e18533 Background: Prior studies have shown that when patients with cancer engage with social media, they have positive outcomes, including clinical trial participation, volunteerism and advocacy, and diminished levels of anxiety. However, active users of social media tend to be white, well-educated, and of higher socioeconomic status. Little is known about the use of technology and social media by underserved oncology populations, particularly patients with limited English proficiency (LEP). We sought to characterize current technology use by patients at Olive View—UCLA Medical Center (OVMC), a safety net hospital in Los Angeles County. Methods: We developed an anonymous online survey (Qualtrics, Provo, UT) comprised of 39 questions. The survey was administered, via touchscreen tablets from January 2020 through January 2021, to a convenience sample of patients seen in OVMC’s outpatient medical oncology clinic. The survey was available in English and Spanish, and we excluded patients who were not fluent in either language. Patients were categorized as having LEP versus English proficiency (EP) by self-assessment, on a 5-point Likert scale, of their comfort in speaking English. Differences between the LEP and EP groups were assessed using Pearson’s chi-squared test and Fisher’s exact test. Results: Of 113 patients who were offered the survey, 10 (9%) declined participation because of illiteracy in their primary language or inability to use a tablet. Reponses were recorded for 50 patients with LEP and 53 with EP. The LEP and EP groups, respectively, were similar in their representation of women (62% and 64%) and mean age (58 years and 51 years). High school completion rates were 32% for the LEP group and 70% for the EP group. A higher proportion of the LEP group identified as Hispanic/Latinx (84%) compared to the EP group (58%). The LEP group was less likely than the EP group to have internet access (63% vs. 98%, P< 0.01). However, among patients with internet access, social media use was similar in the LEP and EP groups (65% vs. 71%, P= 0.7). Facebook was the most used platform by the LEP (22%) and EP (32%) groups; other platforms (e.g., Twitter, Instagram) were used by very few respondents. The LEP group was less likely than the EP group to have activated the OVMC online patient portal (19% vs. 47%, P< 0.01) and less likely to perceive websites as helpful for learning about clinical trials (30% vs. 53%, P= 0.03). Conclusions: A notable proportion of safety net oncology patients at OVMC do not engage with tablet technology because of illiteracy or lack of comfort with touchscreens. Patients with LEP are less likely to have internet access, but those with access use social media about as often as patients with EP, and prefer Facebook over other platforms. For patients with LEP, engagement efforts, including clinical trial outreach, should continue to include non–internet-based resources in patients’ native languages.

83 Background: Oncologic clinical trial enrollment is low, particularly in underserved populations. Increasing enrollment of public safety-net hospital patients is important to ensure representation of the general population and reduces cancer outcome disparities. To tailor clinical trial outreach, we sought to characterize attitudes towards trial participation of oncology patients at Olive View—UCLA Medical Center (OVMC), a public safety-net hospital in Los Angeles County. Methods: We developed a 39-question survey (Qualtrics, Provo, UT). It was administered via tablets to a convenience sample of patients in OVMC’s medical oncology clinic and infusion center during 2020—2021. The survey was offered to patients fluent in English or Spanish. Results: Of 165 patients who were offered the survey, 11 declined due to illiteracy in any language, 4 did not finish the survey. Median age was 54 (range: 20-81); 63% were female. The majority (76%) reported an annual income below $25,000; 39% did not complete high school. Self-identified ethnicity was Hispanic/Latino (73%), non-Hispanic White (12%), Asian-Pacific Islander (9%), and Black (4%). Based on a 5-point Likert scale of comfort speaking English, 48% had English proficiency (EP). Overall, 69% of patients expressed interest in trials. When considering participation, patients would seek advice from their physician (86%), family (32%), other medical staff (14%), alternative medicine practitioner (7%), friend (6%), or religious leader (4%). Concerns regarding trial participation were lack of knowledge regarding trials (47%), fear of side effects (43%), frequent visits (25%), cost (20%), transportation (14%), wage loss (9%), and inability to determine own treatment (4%). Patients found the following modalities useful for learning about trials: website (43%), paper handout (39%), video (37%), discussion with prior participants (34%). Patients with annual income > $25,000 were significantly more concerned about cost (33.3% v. 15.8%, p = 0.04) and treatment side effects (61.1% v. 36.8%, p = 0.02). EP patients were more likely to find a website (54.2% vs. 32.1%, p = 0.01) or discussion with prior participants (45.8% v. 23.1%, p < 0.01) helpful compared to low EP patients. Conclusions: There is considerable interest in oncologic clinical trials in this predominantly Hispanic/Latino population. This population had significant trust in physicians for guidance on trial enrollment, and had minimal concern for out-of-pocket cost, wage loss, or transportation issues. The majority of patients did not find additional informational resources helpful. Structural barriers rather than patient-level variables are likely the primary drivers of low oncologic trial enrollment. Future efforts should focus on improving access to appropriate trials and leveraging the physician-patient relationship for increasing trial participation.