Real-world Patient Characteristics Research Articles

Provider Burden Associated With Apremilast Adverse Events

Introduction: In December 2021, the US Food and Drug Administration (FDA) expanded its initial approval for apremilast to include moderate and severe cases of psoriasis. However, real-world epidemiology data regarding the use of apremilast, the influence of adverse events (AEs), and the burden of AEs on managing physicians, has been lacking. This retrospective, observational, multisite study aimed to describe real-world patient characteristics, AEs (including diarrhea, nausea, and headache), and healthcare provider-level burden associated with the psoriasis treatment apremilast in the US. Methods: Dermatologists abstracted medical record data for adults treated with apremilast on or after January 1, 2018, who had ≥3 months of data available. Dermatologist and patient characteristics, including demographics and clinical characteristics, AEs, and provider burden in managing AEs were summarized using descriptive statistics. Results: Forty-seven dermatologists nationwide responded to a survey and conducted a chart review of 308 patients. Dermatologists practiced in various US geographic regions. The most common practice setting was in a private community with 2 to 5 physicians (34.0%). Most patients were White (74.4%), non-Hispanic (86.0%), and male (55.2%). The mean age at diagnosis was 43.6 years (SD, 16.8 years). AEs occurred in 29.2% of patients, with the most common being diarrhea (16.2%), followed by nausea (13.6%) and headache (4.9%). Diarrhea mostly occurred ≤30 days into treatment (87.2%) and resulted in 1 additional office visit (39.5%) and 3 phone calls per patient to their providers (34.9%). Nausea mostly occurred within 30 days (70.2%) and resulted in 1 additional visit (29.7%) and 1 phone call per patient (35.1%). The burdens of managing both diarrhea and nausea were similar, although diarrhea resulted in more phone calls to the healthcare provider. Conclusion: Diarrhea and nausea were common and resulted in an additional time and resource burden on dermatologists and their staff. Future research on the AE burden on providers and patients related to apremilast is needed.

Real-World Outcomes of Selective RET Inhibitor Selpercatinib in the United States: Descriptive, Retrospective Findings from Two Databases.

This study described real-world patient characteristics and outcomes among selpercatinib-treated patients in the United States, using the Flatiron Health electronic health record-derived deidentified database (FHD) for advanced/metastatic non-small cell lung cancer (a/mNSCLC) and Optum's de-identified Clinformatics® Data Mart Database (CDM). Patients initiating selpercatinib treatment between 08MAY2020 and 30JUN2023 were included. We evaluated real-world time to selpercatinib treatment discontinuation or death (rwTTDd) and time to next treatment or death (rwTTNTd) using Kaplan-Meier analyses. Medication possession ratio (MPR) was estimated as a measure of medication adherence in CDM patients. In a/mNSCLC patients from the FHD (N = 68), the median rwTTDd and rwTTNTd were 22.4 [95%CI: 13.3-NR] and 21.0 [95%CI: 11.6-NR] months, respectively. In CDM, these durations were 12.1 [95%CI: 9.6-NR] and 16.2 [95%CI: 9.6-NR] months for lung cancer (n = 43), while these were not reached for thyroid cancer (n = 24) patients. The median MPR was 0.98 [IQR: 0.84-1.00] among all patients in the CDM (N = 75), with 77.3% of patients adhering (MPR ≥ 0.80) to selpercatinib. Real-world outcomes in this older and frailer patient cohort align with phase 3 trial results, further supporting selpercatinib as the standard of care for patients with RET-altered cancers. Early testing for the detection of RET alterations remains essential.

Real-World Patient Characteristics and Outcomes in China Multiple Myeloma Patients with Unmet Needs

Real-World Patient Characteristics and Outcomes in China Multiple Myeloma Patients with Unmet Needs

Real-World Patient Characteristics and Outcomes in Patients with Relapsed or Refractory Multiple Myeloma Receiving Teclistamab across Community Oncology Practices in the US

Real-World Patient Characteristics and Outcomes in Patients with Relapsed or Refractory Multiple Myeloma Receiving Teclistamab across Community Oncology Practices in the US

Real-World Patient Characteristics and Treatment Patterns in Patients with Chronic Graft-Versus-Host Disease Receiving Belumosudil in the United States

Real-World Patient Characteristics and Treatment Patterns in Patients with Chronic Graft-Versus-Host Disease Receiving Belumosudil in the United States

Real-world patient characteristics and survival outcomes in patients with advanced or recurrent endometrial cancer in England: a retrospective, population-based study

ObjectiveThis study defined a retrospective cohort of patients in England with primary advanced or recurrent (A/R) endometrial cancer (EC) who may have been eligible for clinical trials evaluating immune checkpoint...

S1197 Early Real-World Patient Characteristics and Treatment Patterns in Upadacitinib-Treated Patients With Ulcerative Colitis: A U.S. Claims Database Study

S1197 Early Real-World Patient Characteristics and Treatment Patterns in Upadacitinib-Treated Patients With Ulcerative Colitis: A U.S. Claims Database Study

569P Mismatch repair deficient, stage II/III rectal cancer: Real-world patient, tumour, and treatment characteristics in the Netherlands

569P Mismatch repair deficient, stage II/III rectal cancer: Real-world patient, tumour, and treatment characteristics in the Netherlands

OA01.07 Real-World Patient Characteristics, Biomarker Testing, and Adjuvant Therapy for Resected NSCLC at U.S. Oncology Clinics, 2019-2023

OA01.07 Real-World Patient Characteristics, Biomarker Testing, and Adjuvant Therapy for Resected NSCLC at U.S. Oncology Clinics, 2019-2023

Real-world characteristics of patients with asthma initiating fluticasone furoate/umeclidinium/vilanterol single-inhaler triple therapy in Japan

BackgroundReal-world data assessing characteristics of patients with asthma initiating inhaled corticosteroid/long-acting muscarinic antagonist/long-acting β2-agonist (ICS/LAMA/LABA) triple therapy in Japan are limited. MethodsDescriptive, observational study of patients with asthma aged ≥15 years newly initiating single- or multiple-inhaler triple therapy (SITT: fluticasone furoate/umeclidinium/vilanterol [FF/UMEC/VI], SITT: indacaterol/glycopyrronium bromide/mometasone furoate [IND/GLY/MF] or MITT) or ICS/LABA using JMDC/Medical Data Vision (MDV) health insurance databases from February 2021–February 2022 (first prescription date: index date). Patients were assigned to three non-mutually exclusive cohorts: A) new FF/UMEC/VI initiators; B) new FF/UMEC/VI, IND/GLY/MF, or MITT initiators; C) new FF/UMEC/VI, IND/GLY/MF, MITT or ICS/LABA initiators as initial maintenance therapy (IMT). Patient characteristics were assessed descriptively for 12-months pre-treatment initiation (baseline period). ResultsCohort A: among new FF/UMEC/VI initiators, 12.8% and 0.1% (JMDC) and 21.7% and 0.9% (MDV) of patients had ≥1 moderate and severe exacerbation; 52.0% (JMDC) and 79.2% (MDV) had ICS/LABA use. Cohort B: most patients initiated FF/UMEC/VI and IND/GLY/MF over MITT (JMDC: 91.3% vs 8.7%; MDV: 67.8% vs 32.2%), with fewer exacerbations and lower rescue medication use. Cohort C: a greater proportion of FF/UMEC/VI initiators as IMT experienced a moderate exacerbation at index versus ICS/LABA initiators as IMT (JMDC: 17.8% vs 10.7%; MDV: 8.0% vs 5.1%). ConclusionsPatient characteristics were generally similar between treatment groups; SITT initiators had fewer exacerbations and lower rescue medication use than MITT initiators, represented by the greater proportion of IMT among SITT versus MITT initiators. Physicians may have prescribed triple over dual therapy as IMT in response to an exacerbation.

Abstract PO2-17-06: Real world treatment patterns and clinical outcomes by germline BRCA (gBRCA) mutation status in patients with HER2-negative early breast cancer in the US community oncology setting: a retrospective observational chart-review study

Abstract Background: Women with early-stage breast cancer (eBC) who have inherited BRCA1 or BRCA2 mutations (gBRCAm) are typically diagnosed at a younger age and often require more intensive treatment. In the randomized, double-blind OlympiA trial of HER2-negative (HER2–) gBRCAm patients, olaparib, a targeted poly (ADP-ribose) polymerase inhibitor (PARPi), significantly improved invasive disease free survival (IDFS), distant disease free survival (DDFS) and overall survival (OS) and was subsequently approved for adjuvant treatment of gBRCAm HER2– high-risk eBC patients. This study examined the real-world patient characteristics, treatment patterns and clinical outcomes by gBRCA status among patients with HER2– eBC in a US community oncology setting prior to olaparib US approval for treatment of eBC. Methods: This retrospective observational study used chart review data from The US Oncology Network's iKnowMed database to examine adult patients diagnosed with HER2– eBC (stage I-III) initiating systemic neoadjuvant or adjuvant therapy with chemotherapy and/or endocrine therapy between January 1, 2012 and December 31, 2018. Patients with valid gBRCAm test results (all gBRCAm and randomly selected BRCAwt patients) were included and followed through December 31, 2021. Patients were excluded if they had HER2+ tumors and progressed to stage IV within 6 months after initiation of neoadjuvant therapy or were diagnosed with another primary cancer. Descriptive analyses assessed patient characteristics. Kaplan Meier methods and multivariate Cox proportional hazard models (CPHM) were used to evaluate IDFS, DDFS and OS by gBRCA status and by HR+/HER2– or TNBC eBC subsets. Results: Among 298 BC patients meeting initial criteria, 42% had gBRCAm (n=124, 43% hormone receptor positive [HR+], 56% triple-negative BC [TNBC], 1% unknown), and 58% had gBRCAwt (n=174, 74% HR+, 22% TNBC). Median (interquartile) age at surgery was numerically lower in gBRCAm (45 [36,55] years) than gBRCAwt (48 [41,55] years) patients. A numerically higher proportion of gBRCAm patients received neoadjuvant therapy compared with gBRCAwt (Neoadj: gBRCAm 37.1% vs gBRCAwt 12.6%) but the reverse was true for adjuvant (Adj: gBRCAm 42.7% vs gBRCAwt 65.5%) and neoadjuvant + adjuvant use was numerically similar (Neoadj+Adj: gBRCAm 20.1% vs gBRCAwt 21.8%). The majority of TNBC patients received neoadjuvant therapy while the majority of HR+ patients received adjuvant therapy (Neoadj: TNBC 51.4% vs HR+ 6.6%, Adj: TNBC 29.0% vs HR+ 71.4%, Neoadj+Adj: TNBC 19.6% vs HR+ 22.0%). Median IDFS, DDFS, and OS in both study cohorts were not reached. Median follow-up from surgery was < 5 years (overall 59.0 months; gBRCAm 50.6 months; gBRCAwt 61.3 months). At 60 months, in gBRCAm and gBRCAwt respectively, estimated IDFS were 85.5% and 90.9%, estimated DDFS 88.1% and 92.2%, and estimated survival 91.9% and 95.2%. At 60 months, in HR+/HER2– and TNBC respectively, estimated IDFS were 92.4% and 81.2%, estimated DDFS 93.9% and 85.7%, and estimated survival 96.3% and 90.9%. CPHM results showed that risks of invasive disease (HR 1.74; 95% CI 0.83-3.64; p=0.15), distant disease (HR 1.24; 95% CI 0.50-3.07; p=0.65) and death (HR 1.79; 95% CI 0.52-6.13; p=0.353) were similar between gBRCAm and gBRCAwt patients. Between HR+/HER2– and TNBC patients, risks of invasive disease (HR=0.63; 95% CI 0.21-1.89; p=0.41), distant disease (HR=0.42; 95% CI 0.11-1.67; p=0.22) and death (HR 0.48; 95% CI 0.09-2.70; p=0.41) were similar. Conclusions: This real-world chart review study of data through 2021 (before PARPi approval for eBC) with limited follow up of 5 years found that gBRCAm patients had a numerically shorter survival (IDFS, DDFS and OS) than gBRCAwt, but this difference was not statistically significantly different. Given that the follow-up period was too short to draw conclusions, further studies examining clinical outcomes over a longer follow-up period after approval of PARPi may be of interest. Citation Format: Jay Andersen, Jagadeswara Earla, Nicole Fulcher, Juliet Ndukum, Nicholas J Robert, Mark Robson, Weiyan Li, Jaime Mejia. Real world treatment patterns and clinical outcomes by germline BRCA (gBRCA) mutation status in patients with HER2-negative early breast cancer in the US community oncology setting: a retrospective observational chart-review study [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 PO2-17-06.

Real-world utilization, patient characteristics, and treatment patterns among men with localized prostate cancer tested with the 17-gene genomic prostate score® (GPSTM) assay.

Descriptive study focusing on real-world utilization and characteristics of men with prostate cancer tested with the 17-gene Genomic Prostate Score® (GPS™) assay by linking administrative claims and electronic health record (EHR) data with GPS results. This retrospective, observational cohort study (January 1, 2013 to December 31, 2020) included men aged 40-80 years with localized prostate cancer claims, continuous enrollment in Optum's Integrated Claims data set, ≥1 day of EHR clinical activity, and a GPS result. Men were classified as undergoing definitive therapy (DT) (prostatectomy, radiation, or focal therapy) or active surveillance (AS). AS and DT distribution were analyzed across GPS results, National Comprehensive Cancer Network® (NCCN®) risk, and race. Costs were assessed 6 months after the first GPS result (index); clinical outcomes and AS persistence were assessed during the variable follow-up. All variables were analyzed descriptively. Of 834 men, 650 (77.9%) underwent AS and 184 (22.1%) DT. Most men had Quan-Charlson comorbidity scores of 1-2 and a tumor stage of T1c (index). The most common Gleason patterns were 3 + 3 (79.6%) (AS cohort) and 3 + 4 (55.9%) (DT cohort). The mean (standard deviation) GPS results at index were 23.2 (11.3) (AS) and 30.9 (12.9) (DT). AS decreased with increasing GPS result and NCCN risk. Differences between races were minimal. Total costs were substantially higher in the DT cohort. Most men with GPS-tested localized prostate cancer underwent AS, indicating the GPS result can inform clinical management. Decreasing AS with increasing GPS result and NCCN risk suggests the GPS complements NCCN risk stratification.

Progress in methodological research on bridging the efficacy-effectiveness gap of clinical interventions(2): to improve the extrapolation of efficacy

Objective: Randomized controlled trials (RCT) usually have strict implementation criteria. The included subjects' characteristics of the conditions for the intervention implementation are quite different from the actual clinical environment, resulting in discrepancies between the risk-benefit of interventions in actual clinical use and the risk-benefit shown in RCT. Therefore, some methods are needed to enhance the extrapolation of RCT results to evaluate the real effects of drugs in real people and clinical practice settings. Methods: Six databases (PubMed, Embase, Web of Science, CNKI, Wanfang Data, and VIP) were searched up to 31st December 2022 with detailed search strategies. A scoping review method was used to integrate and qualitatively describe the included literature inductively. Results: A total of 12 articles were included. Three methods in the included literature focused on: ①improving the design of traditional RCT to increase population representation; ②combining RCT Data with real-world data (RWD) for analysis;③calibrating RCT results according to real-world patient characteristics. Conclusions: Improving the design of RCT to enhance the population representation can improve the extrapolation of the results of RCT. Combining RCT data with RWD can give full play to the advantages of data from different sources; the results of the RCT were calibrated against real-world population characteristics so that the effects of interventions in real-world patient populations can be predicted.

Analysis of Real-world Characteristics of Patients with CDKL5 Deficiency Disorder Enrolled for Ganaxolone Treatment (P6-1.010)

Analysis of Real-world Characteristics of Patients with CDKL5 Deficiency Disorder Enrolled for Ganaxolone Treatment (P6-1.010)

Real-world patient characteristics and treatment patterns in US patients with advanced non-small cell lung cancer

BackgroundPatients from non-small cell lung cancer (NSCLC) controlled clinical trials do not always reflect real-world heterogeneous patient populations. We designed a study to describe the real-world patient characteristics and treatment patterns of first-line treatment in patients in the US with NSCLC.MethodsThis was an observational, retrospective cohort study based on electronic medical records of US adults with locally advanced or metastatic disease in the ConcertAI Patient360 NSCLC database who initiated first-line treatment with anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) therapy between July 2016 and December 2020. The analysis used patient attributes, clinical characteristics, and treatments from each patient’s medical records.ResultsA total of 2175 patients were eligible for analysis. The median age was 68 years, and 26.2% of the patients were ≥75 years old. At treatment initiation, 96.4% and 3.6% of the patients had Stage 4 and Stage 3 (B or C) NSCLC, respectively. The most common histology type was nonsquamous adenocarcinoma (66.4%), and 19.8% had Eastern Cooperative Oncology Group performance status ≥2. Immunosuppressive medications were being used by 17.7% of patients, and 11.0% were immunocompromised. Almost all patients had metastases: 64.6% had 1, 23.2% had 2, and 8.0% had ≥3 metastatic sites. Brain metastases were present in 22.9% of patients. Treatment evolution was observed with first-line standard of care shifting from single-agent immunotherapy in 2016 (90.2%) to combination immunotherapy and chemotherapy in 2020 (60.2%).ConclusionBetween 2016 and 2020, the first-line treatment paradigm for advanced NSCLC in the US shifted from anti–PD-1/PD-L1 monotherapy to combination chemoimmunotherapy, with increasing biomarker testing. Further research in heterogeneous patient populations to characterize treatment strategies is warranted.

Real-world patient characteristics, treatment patterns, and treatment outcomes of patients with diffuse large B-cell lymphoma by line of therapy.

Although initial treatment of diffuse large B-cell lymphoma (DLBCL) with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) can be effective, up to 50% of patients will develop refractory or relapsed (R/R) disease. This study aimed to provide contemporary data on characteristics, treatment patterns, and outcomes for R/R-DLBCL. Patients with incident (January 2016 to March 2021) DLBCL age ≥18 years who initiated first-line (1L) therapy were identified from the COTA real-world database. Baseline characteristics, treatment patterns, and real-world outcomes, including time to next treatment (rwTTNT) and overall survival (rwOS), were assessed for the study population and by line of therapy (LOT). A total of 1347 eligible DLBCL patients were identified. Of these, 340 (25.2%) proceeded to receive 2L, of whom 141 (41.5%) proceeded to receive 3L, of whom 51 (36.2%) proceeded to receive 4L+. Most common treatments were R-CHOP in 1L (63.6%), stem cell transplant (SCT) in 2L (17.9%), polatuzumab vedotin, bendamustine, and rituximab (Pola-BR) in 3L (9.9%), and chimeric antigen receptor T-cell therapy (CAR-T) in 4L (11.8%). Treatment patterns were more variable in later LOTs. One- and 3-year rwOS from 1L initiation were 88.5% and 78.4%, respectively. Patients who received later LOTs experienced numerically lower 1- and 3-year rwOS (from 2L initiation: 62.4% and 46.4%, respectively). In this real-world analysis, 25.2% of patients experienced R/R-DLBCL after 1L with poor outcomes. Given the findings of this study, there is a high unmet need for novel, safe, and effective treatment options for patients with R/R DLBCL.

Mainstream Model of Genetic Testing for Prostate Cancer at a Large Tertiary Cancer Centre

BackgroundAn estimated 20% to 30% of men with advanced prostate cancer carry a mutation in DNA damage repair genes, of which half are estimated to be germline. Eligibility criteria for germline genetic testing expanded significantly for Ontario patients in May 2021 and many centers adopted a “mainstream” model, defined as oncologist-initiated genetic testing. MethodsWe conducted a retrospective chart review to report on the first-year mainstream experience of a large tertiary oncologic center, the Sunnybrook Odette Cancer Centre. All patients who underwent mainstream at the discretion of their treating physician were included. A subset underwent somatic profiling as part of clinical trial screening. Descriptive statistics were used to report baseline clinicopathologic characteristics and treatments received. ResultsBetween May 1, 2021, and May 30, 2022, 174 patients with prostate cancer underwent mainstream germline genetic testing with a 19-gene panel. Median age was 75 (IQR 68-80), and 82% of patients were diagnosed with either de novo metastatic or high-risk localized prostate adenocarcinoma. Fourteen patients (8%; 95% CI 4%-12%) were found to have a deleterious germline mutation, including pathogenic or likely pathogenic variants in BRCA1/2, ATM, CHEK2, PMS2, RAD51C, HOXB13, and BRIP1. Forty-nine patients (28%; 95% CI 21%-35%) were found to have a variant of uncertain significance. Thirty-four patients also had next-generation sequencing (NGS) of their somatic tissue. Among this subset, 8 of 34 (23%) had an alteration in homologous recombination repair (HRR) genes. Of the 14 patients with a germline mutation, none had a prior personal history of malignancy and 6 (43%) did not have any first- or second-degree relatives with history of prostate, pancreatic, breast, or ovarian cancer. ConclusionWe report on the real-world characteristics of prostate cancer patients who underwent mainstream germline genetic testing. Personal history and family history of cancer cannot reliably stratify patients for the presence of pathogenic germline variants.

Real-world treatment patterns and unmet need in patients with previously treated metastatic colorectal cancer that is not MSI-H or dMMR.

53 Background: Regorafenib and trifluridine/tipiracil (TAS-102) are standard of care (SoC) systemic anticancer treatments (SACT) for metastatic colorectal cancer (mCRC) patients perviously treated with fluoropyrimidine (5-FU), irinotecan, & oxaliplatin-based chemotherapy. However, evidence is limited on post-chemotherapy & later SACT for patients with mCRC that is not microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR). This study assessed real-world patient characteristics and treatment patterns in community oncology practices among previously treated, not MSI-H/dMMR mCRC patients. Methods: This retrospective cohort study utilized The US Oncology Network (iKnowMed) electronic health record database, supplemented by chart review. The study cohort comprised adult, not MSI-H/dMMR mCRC patients treated with chemotherapy (5-FU/capecitabine, irinotecan, and oxaliplatin) who initiated subsequent SACT or received best supportive care (BSC) between 1/1/2016 & 12/31/2021. Index date for SACT users was the regimen start date. For patients on BSC and no subsequent SACT/BSC, index date was last chemotherapy administration date. Patients were followed from index date through 8/31/2022, date of death or last contact date, whichever occurred first. Descriptive statistics were used to report patient and treatment characteristics. Results: The study consisted of 292 mCRC patients, with a median age of 57 (range: 49, 68) years. The predominant histology was adenocarcinoma (n = 237, 81.2%) with 1.7% other histology and rest missing, 198 (67.8%) patients had Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 and 206 (70.5%) had primary tumors located in the colon. Liver (n = 207, 70.9%) and lung (n = 78, 26.7%) were the most common metastasis sites. Diabetes (n = 33, 11.3%) and peripheral vascular disease (n = 18, 6.2%) were the most common comorbidities. Eighty-seven (29.8%) patients received at least one chemotherapy in the adjuvant/neo-adjuvant setting, while majority (70.2%) patients received chemotherapies in the metastatic setting. Overall, 203 (69.5%) received SACT post-chemotherapy, 84 (28.8%) received BSC and 5 (1.7%) did not receive SACT/BSC. Among the SACT post-chemotherapy users, 30 (14.8%) received regorafenib, 25 (12.3%) received TAS-102 and 148 (72.9%) received other SACT. Other SACT included irinotecan-based (n = 76, 37.4%), oxaliplatin-based (n = 30, 14.8%), irinotecan and oxaliplatin-based (n = 6, 3.0%) chemotherapy, and anti-EGFR (n = 15, 7.4%) or anti-VEGF (n = 8, 3.0%) targeted therapies. Conclusions: Overall, only 27.1% of previously treated mCRC patients with tumors that were not MSI-H or dMMR received SoC. The real-world variability in choice of treatments and the high percentage of patients rechallenged with chemotherapy in subsequent lines, highlights an unmet need in this population.

Real-World Patient Characteristics, Treatment Patterns, and Outcomes Among Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated with Cemiplimab at US Oncology Clinical Practices

Real-World Patient Characteristics, Treatment Patterns, and Outcomes Among Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated with Cemiplimab at US Oncology Clinical Practices

Real-world clinical profile, RET mutation testing, treatments, and PROs for MTC in Europe.

This study aimed to describe real-world patient and physician characteristics, rearranged during transfection (RET) mutation testing and results, treatment patterns, and patient-reported outcomes (PROs) in advanced or metastatic medullary thyroid cancer (aMTC) across five populous European countries. Cross-sectional physician and patient surveys were used to collect quantitative and qualitative data in France, Germany, Italy, Spain, and the UK from July to December 2020, prior to the introduction of selective RET inhibitors in Europe. Physicians completed patient record forms and a survey about their specialty and practice site. Patients were asked to provide PRO data using four validated instruments, including the EuroQol 5 Dimension (EQ-5D) questionnaire. The physician-reported sample included 275 patients with aMTC, including 79 patients with RET mutation-positive disease; median age was 60 and 56 years, respectively. Overall, 75% were tested for RET mutation (35% germline only, 21% somatic only, 44% both). Common physician-cited barriers to RET mutation testing included high cost, difficulty accessing latest tests, and time delay for results. First-line systemic therapy (most commonly vandetanib or cabozantinib) was prescribed for 69% of patients overall and 82% of the RET mutation-positive subgroup. Second-line therapy was prescribed for 12% of patients who received first-line therapy; most patients remained on first-line therapy at data capture. PROs revealed substantial disease/treatment burden. Patients with aMTC report substantial disease/treatment burden. Outcomes could be improved by identifying patients eligible for treatment with selective RET inhibitors through more optimal RET mutation testing.