Carcinoembryonic antigen (CEA) is more abundant in feces than in serum; however, evidence for the role of fecal CEA (FCEA) in the detection of colorectal cancer (CRC) is limited. We conducted a systematic review of studies that evaluated FCEA for the noninvasive detection and diagnosis of CRC. PubMed and Web of Science were searched for relevant studies published until 18 January 2023. Information on publication year, study design, country, study population characteristics, FCEA and serum CEA (SCEA) concentrations, and diagnostic performance was summarized. Two authors independently extracted data and assessed the risk of bias and applicability of each included study. Seven studies published between 1979 and 2021, all conducted in clinical settings and together involving 399 CRC patients and 889 controls, were identified. Significant differences in FCEA concentrations were observed between CRC and control groups in all studies. Methods for detecting FCEA varied, with the electronic chemiluminescence immunoassay (ECLIA) being used in the most recent studies. Reported sensitivities, specificities, and area under the curves of FCEA ranged from 50.0% to 85.7%, 73.0% to 100.0%, and 0.704 to 0.831, respectively. In direct comparisons, the diagnostic performance of FCEA was better than that of SCEA. The potential role of FCEA as a novel, noninvasive, easily measurable biomarker for the diagnosis of CRC requires further evaluation in screening settings.

Cachexia is a major challenge throughout cancer treatment. Unintentional weight loss, the principal diagnostic criterium of cancer cachexia, is usually assessed through self-reported body weight change, which may be prone to bias. Other aspects of cancer cachexia include altered body composition (e.g., loss of muscle mass) and impaired physical activity. The central aim of the ‘Patient-Recorded Indexing MeasurementS’ (PRIMS) study is to improve the accuracy of the diagnosis of cachexia in patients with cancer. The primary objectives are to compare self-reported and objectively measured pre-treatment weight changes, and to assess their respective association with treatment-related adverse events and survival. Secondary objectives are to define host phenotypes based on combinations of objectively assessed cachexia-related data that are predictive of treatment-related adverse events and survival, and to investigate longitudinal associations between body weight and physical activity patterns. This prospective observational cohort study will be conducted in two Dutch referral centers specialized in treatment of patients with upper gastrointestinal, hepatobiliary, pancreatic, colorectal, and ovarian cancer. We will include 300 cancer patients scheduled for either neoadjuvant chemo(radio)therapy or upfront elective surgery. Patients will undergo a baseline assessment consisting of nutritional screening (anthropometry, body weight assessment), body composition analysis, and physical fitness tests. Patients will be provided with an accelerometer and weight scale for continuous/daily at-home measurements before, throughout, and after treatment. Treatment-related adverse events will be assessed according to the Common Terminology Criteria for Adverse Events or Clavien-Dindo classification. Response to chemo(radio)therapy will be assessed according to ‘Response Evaluation Criteria in Solid Tumors’ (RECIST) criteria. Disease-free and overall survival will be recorded. Relationships between cachexia-related parameters and outcomes will be investigated using multivariable logistic regression analysis. The PRIMS protocol comprises a core assessment set of objective measurements to improve the diagnosis of cancer cachexia. It will help to identify patient phenotypes associated with treatment-related adverse events and survival. This approach is expected to advance cachexia diagnostics and enhance future clinical and translational research on the prevalence, severity, and impact of cancer cachexia. PRIMS will also aid clinicians in providing personalized counseling on treatment options and their expected outcomes. Medical Ethics Committee of the Academic Hospital Maastricht/Maastricht University (azM/UM) (METC18012, version 4.0, June 2024), Netherlands Trial Register (NL65402.068.18). The trial is registered in the ClinicalTrials.gov register (NCT05899205).