Peter Kubatka, Ludmila Filkova, Iva Slaninova, Tomas Kazda, Karel Smejkal, Dietrich Büsselberg, Olga Golubnitschaja
Routine tumor biomarkers remain among the most accessible tools in oncology. Yet, their clinical value is frequently weakened by a persistent specificity trap: abnormal results are often treated as cancer-specific signals, whereas normal results are sometimes used to reassure against malignancy. This critical narrative review develops a predictive, preventive, and personalized medicine (3PM)-guided clinical decision framework for interpreting routinely used tumor biomarkers. Evidence was mapped across six domains: validated indication, tumor type and disease phase, baseline marker status, longitudinal trajectory, false-positive and false-negative vulnerability, and analytical or pre-analytical limitations. The review covers classical circulating epithelial markers, organ-associated markers, neuroendocrine and neural-lineage markers, nonspecific markers of burden or proliferation, tissue-based therapeutic targets, immune-context biomarkers, and less standardized markers with nomenclature-sensitive interpretation. Across these groups, the central synthesis is that clinical usefulness rarely derives from an isolated threshold. It emerges when marker dynamics are interpreted in relation to pre-test probability, comorbidities, renal and liver function, inflammation, medication effects, assay platform, imaging, pathology, symptoms, and actionability. The proposed 3PM-guided workflow shifts routine biomarker use from reactive testing and diagnostic escalation toward context-corrected interpretation, prevention of low-value investigations, and personalized follow-up or treatment reassessment. Routine tumor biomarkers should therefore be reported and interpreted as conditional, trajectory-dependent clinical signals, not as stand-alone evidence for or against cancers. Finally, in primary care for protecting individuals against health-to-disease transition as well as for individualized rehabilitation programs in secondary care, a 3PM-guided holistic approach is strongly recommended utilizing multi-level diagnostics. This approach is based on comprehensive individualized patient profiles including phenotyping and biomarker panels essentially reflecting systemic effects. To this end, a non-invasive tear fluid test utilizing mitochondria as vital biosensors and AI-based multi-professional data interpretation has been established, followed by the cost-effective targeted disease prevention and individualized rehabilitation programs in primary and secondary care respectively.