Cancer Markers in Diagnosis and Treatment

Diagnostic Markers

Alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (β-hCG) are used in males with suspected germ cell tumors, as recommended by the European Society for Medical Oncology 1, 2
Prostate-specific antigen (PSA) is used in males with possible prostate cancer, though its value in screening remains controversial, according to the American Urological Association 1
Carcinoembryonic antigen (CEA) is primarily used for monitoring colorectal cancer rather than diagnosis, as stated by the National Comprehensive Cancer Network 3
Cancer antigen 125 (CA125) is used in females with suspected gynecological malignancies, as recommended by the American College of Obstetricians and Gynecologists 1
Chromogranin A is used in patients with possible neuroendocrine malignancies, as suggested by the European Neuroendocrine Tumor Society 1

Lactate dehydrogenase (LDH) correlates with tumor burden and has established prognostic significance across multiple tumor types, with a moderate level of evidence, as reported by the American Society of Clinical Oncology 4
Elevated CEA levels (≥5 mg/mL) may correlate with poorer prognosis in colorectal cancer patients, with a high level of evidence, as stated by the National Comprehensive Cancer Network 3
Oncotype DX assay can predict recurrence risk in node-negative, estrogen-receptor positive breast cancer patients treated with tamoxifen, with a high level of evidence, as recommended by the American Society of Clinical Oncology 5, 6

CEA is the marker of choice for monitoring metastatic colorectal cancer during systemic therapy and should be measured at the start of treatment and every 1-3 months during active treatment, as recommended by the National Comprehensive Cancer Network 3
Despite non-tumor type-specific elevations of markers like CEA, CA19-9, CA15-3, and CA125, these can be used to determine disease course and monitor treatment response, as suggested by the European Society for Medical Oncology 1

Postoperative serum CEA testing should be performed every 3 months in patients with stage II or III colorectal disease for at least 3 years after diagnosis, as recommended by the National Comprehensive Cancer Network 3
The American Society of Clinical Oncology does not recommend using circulating tumor cell (CTC) measurements to make breast cancer diagnoses or influence treatment decisions, with a high level of evidence 5, 6

Gene expression profiling can be used to discover genes that may predict responsiveness to specific drugs in cancer cell lines, as reported by the American Association for Cancer Research 7
Multiparameter gene expression analysis, such as Oncotype DX, has emerged as a valuable tool for predicting recurrence risk and guiding treatment decisions in breast cancer, with a high level of evidence, as recommended by the American Society of Clinical Oncology 5
Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK) guidelines have been developed to improve the quality and transparency of tumor marker research, as stated by the National Cancer Institute 8, 9