General Cancer Markers

1. Alpha-Fetoprotein (AFP)
   • Sensitivity: ~60–80% for hepatocellular carcinoma (HCC).
   • Higher sensitivity in advanced disease; lower in early stages.
2. Carcinoembryonic Antigen (CEA)
   • Sensitivity: ~30–50% for colorectal cancer at early stages, up to 70–80% in advanced stages.
   • Limited utility for early detection.
3. Lactate Dehydrogenase (LDH)
   • Sensitivity: Low; not cancer-specific but can indicate tumor burden in lymphoma or leukemia.
4. Beta-Human Chorionic Gonadotropin (Beta-hCG)
   • Sensitivity: ~80–95% in germ cell tumors.
   • High sensitivity in trophoblastic diseases.

Markers by Cancer Type

Breast Cancer

1. HER2/neu (ERBB2)
   • Sensitivity: ~80–90% in HER2-positive breast cancers.
   • Not expressed in HER2-negative cancers.
2. CA 15-3 / CA 27-29
   • Sensitivity: ~70–80% for metastatic breast cancer.
   • Poor sensitivity for early-stage breast cancer (~20–30%).

Prostate Cancer

1. Prostate-Specific Antigen (PSA)
   • Sensitivity: ~70–80% for prostate cancer detection.
   • Higher sensitivity at lower specificity, leading to false positives in benign prostatic hyperplasia (BPH).
2. Prostatic Acid Phosphatase (PAP)
   • Sensitivity: ~60% in advanced prostate cancer.
   • Poor sensitivity in early-stage disease.

Colorectal Cancer

1. CEA
   • Sensitivity: ~30–50% in early-stage colorectal cancer; ~70–80% in advanced stages.
2. CA 19-9
   • Sensitivity: ~20–40% for colorectal cancer.
   • Higher sensitivity in pancreatic cancer.

Lung Cancer

1. Cytokeratin 19 Fragment (CYFRA 21-1)
   • Sensitivity: ~50–70% in non-small cell lung cancer (NSCLC).
   • Higher sensitivity for squamous cell lung cancer.
2. Neuron-Specific Enolase (NSE)
   • Sensitivity: ~60–80% for small cell lung cancer (SCLC).
   • Limited utility in NSCLC.
3. CEA
   • Sensitivity: ~30–50% in lung cancer.

Liver Cancer

1. AFP
   • Sensitivity: ~60–80% for hepatocellular carcinoma (HCC).
   • Poor sensitivity for detecting early-stage HCC (~20–30%).
2. Des-Gamma-Carboxy Prothrombin (DCP)
   • Sensitivity: ~60–90% for HCC.

Pancreatic Cancer

1. CA 19-9
   • Sensitivity: ~70–90% for pancreatic cancer.
   • Sensitivity drops in patients who are Lewis antigen-negative (5–10% of population).
2. CEA
   • Sensitivity: ~40–60% for pancreatic cancer.

Ovarian Cancer

1. CA 125
   • Sensitivity: ~80% for advanced ovarian cancer.
   • Poor sensitivity (~50%) in early stages.
2. HE4 (Human Epididymis Protein 4)
   • Sensitivity: ~70–80% in ovarian cancer.
   • Higher specificity when combined with CA 125.

Testicular Cancer

1. Beta-hCG
   • Sensitivity: ~80–95% in germ cell tumors.
   • High sensitivity in choriocarcinoma.
2. AFP
   • Sensitivity: ~60–80% in non-seminomatous germ cell tumors.
   • Not elevated in seminomas.
3. LDH
   • Sensitivity: ~50–70% in germ cell tumors.
   • Non-specific marker.

Stomach Cancer

1. CEA
   • Sensitivity: ~25–50% for gastric cancer.
   • Higher sensitivity in advanced stages.
2. CA 72-4
   • Sensitivity: ~40–46% for early-stage gastric cancer, up to ~60–80% in advanced stages.

Thyroid Cancer

1. Thyroglobulin (Tg)
   • Sensitivity: ~80–90% for differentiated thyroid cancer recurrence.
   • Dependent on thyroid ablation status.
2. Calcitonin
   • Sensitivity: ~90–100% for medullary thyroid cancer.

Bladder Cancer

1. NMP22 (Nuclear Matrix Protein 22)
   • Sensitivity: ~50–60% for bladder cancer.
   • Higher sensitivity in higher-grade tumors.
2. Bladder Tumor Antigen (BTA)
   • Sensitivity: ~50–70%.
   • Lower sensitivity for early-stage disease.

Melanoma

1. S-100 Protein
   • Sensitivity: ~50–70% in advanced melanoma.
   • Low sensitivity in early stages.
2. LDH
   • Sensitivity: ~50–60% in advanced melanoma.
   • Reflects tumor burden.

Emerging Markers

1. PD-L1
   • Sensitivity: Varies based on cancer type and cutoff values; used primarily for immunotherapy prediction.
2. EGFR Mutations (Lung Cancer)
   • Sensitivity: ~50–60% in lung adenocarcinoma patients (depends on prevalence of EGFR mutations).
3. ALK Rearrangement - Lung cancer.
4. BRAF Mutations (Melanoma and Colon Cancer)
   • Sensitivity: ~40–50% for melanoma patients (depends on prevalence of mutations).
5. Microsatellite Instability (MSI-H)
   • Sensitivity: ~95–99% in colorectal cancers with mismatch repair deficiency.
   • High sensitivity in Lynch syndrome-associated cancers.
6. KRAS Mutations - Colon, pancreatic, and lung cancers.
7. CTLA-4 - Response to immunotherapy.
8. TMB (Tumor Mutational Burden) - Biomarker for response to immune checkpoint inhibitors.

Key Points

• Sensitivity is often higher for advanced cancers than for early-stage disease.
• Combining markers or using them alongside imaging and clinical evaluation improves diagnostic accuracy.
• Many markers have limited specificity, leading to false positives in benign conditions.

For the most effective use of these markers, they are often combined with other diagnostic tools.