Tumor biomarkers, substances produced by tumors or the body's response to tumors, have significant value in screening, early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, advancements in molecular biology technologies have significantly promoted the discovery and development of novel, sensitive, specific, and accurate tumor biomarkers, advancing personalized medicine and improving cancer patient outcomes. This review summarizes the history, technologies, and applications of tumor biomarkers, highlighting recent advancements in biomarker-based anticancer therapies. It also discusses limitations and challenges, providing insights for future research and clinical applications. Key technologies for tumor biomarker detection include immunoassays, molecular hybridization, gene amplification, DNA sequencing, immunohistochemistry, liquid biopsy, electron microscopy, and CRISPR/Cas9 gene-editing technology. Tumor biomarkers are classified by tissue origin, with blood-based biomarkers being highly significant for tumor diagnosis and treatment. Examples of common blood biomarkers include AFP, CEA, SCCA, TPS, PSA, NSE, and AFU, each with specific roles in cancer management. The review emphasizes the importance of combining multiple biomarkers for improved precision medicine and highlights the potential of emerging technologies in advancing cancer research and therapy.Tumor biomarkers, substances produced by tumors or the body's response to tumors, have significant value in screening, early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, advancements in molecular biology technologies have significantly promoted the discovery and development of novel, sensitive, specific, and accurate tumor biomarkers, advancing personalized medicine and improving cancer patient outcomes. This review summarizes the history, technologies, and applications of tumor biomarkers, highlighting recent advancements in biomarker-based anticancer therapies. It also discusses limitations and challenges, providing insights for future research and clinical applications. Key technologies for tumor biomarker detection include immunoassays, molecular hybridization, gene amplification, DNA sequencing, immunohistochemistry, liquid biopsy, electron microscopy, and CRISPR/Cas9 gene-editing technology. Tumor biomarkers are classified by tissue origin, with blood-based biomarkers being highly significant for tumor diagnosis and treatment. Examples of common blood biomarkers include AFP, CEA, SCCA, TPS, PSA, NSE, and AFU, each with specific roles in cancer management. The review emphasizes the importance of combining multiple biomarkers for improved precision medicine and highlights the potential of emerging technologies in advancing cancer research and therapy.