Abstract Background: In 2024, colorectal cancer (CRC) emerged as the leading cause of cancer death in men under 50 and the second leading cause in women (referred to as early-onset CRC (EOCRC). The incidence of EOCRC is growing by 1. 4% annually. Understanding the “multidimensional spectrum of toxicities”, including the effects of the disease, treatments, and emotional and physical experiences of CRC at a young age, along with the indirect impacts on family and work life, remains poorly understood. The ColoCare Study is dedicated to investigating the interconnected factors that drive these complex toxicities. The goal is to identify high-risk EOCRC patients who could benefit from targeted strategies to improve their physical health, socioeconomic status, and overall quality of life during and after treatment. Methods: The ColoCare Study is an international, prospective cohort study including six U. S. sites and one site in Germany. Individuals ages 18 to 89 at diagnosis with newly diagnosed primary invasive CRC stage I-IV were enrolled (n=4, 442 patients (1, 238: age 50 y; 1, 718: age 50-64 y; and 1, 486: age 65+ y) ). We collected longitudinal, repeated assessments of patient-reported symptoms, health-related quality of life, and financial health, in addition to blood-, stool-, and tumor-derived biomarkers, and linked these to medical records for clinicopathological characteristics, toxicities, comorbidities, recurrence, and vital status. Results: In our cohort, more than half of EOCRC patients face treatment-related adverse events (AEs) both during and after their treatment. Compared to older patients, those with EOCRC experience more severe symptoms such as nausea/vomiting, fatigue, pain, and sleep disturbances. Among female EOCRC patients, 72% discussed reproductive and fertility-related challenges with their clinicians, yet only 19% proceeded with fertility preservation. Alarmingly, only 13% of all patients had insurance coverage for fertility preservation. Furthermore, employment and financial stability pose significant challenges for working-age EOCRC patients. They report greater financial difficulties than those over 65 (p0. 001). Individuals aged 18–49 also reported more frequent challenges in mental and physical function compared to their older counterparts. Additionally, EOCRC patients experience higher rates of material and psychological hardships. Further analyses are ongoing. Conclusions: These findings highlight the need for more targeted clinical management for many early-onset colorectal cancer (EOCRC) patients, especially during the first year following diagnosis and into survivorship. Addressing specific concerns related to ongoing toxicities—such as physical, socioeconomic, and emotional issues—could greatly benefit these patients. With approximately 1, 000 EOCRC patients involved, the ColoCare Study is uniquely positioned to conduct research focused on EOCRC survivorship. Citation Format: Jane C. Figueiredo, Nicole C. Loroña, Anne Kirchoff, Karely V T. Van Thiel Berghuijs, Heydon Kaddas, Mary Playdon, Patricia A. Erickson, Maria F. Gomez, Sheetal Hardikar, Mmadili N. Ilozumba, Jennifer Ose, Victoria Damerell, Vaia Florou, Mark A. Lewis, Shannon Christy, William M. Grady, Biljana Gigic, Doratha A. Byrd, Adetunji Toriola, Christopher I. Li, David Shibata, Cornelia M. Ulrich. Multidimensional assessment of toxicities and survivorship among people with early-onset colorectal cancer – Results from the ColoCare Study abstract. In: Proceedings of the AACR Special Conference in Cancer Research: The Rise in Early-Onset Cancers—Knowledge Gaps and Research Opportunities; 2025 Dec 10-13; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2025;31 (23Suppl): Abstract nr PR015.
Figueiredo et al. (Wed,) studied this question.