Types of Cancer Tests: From Screening to Genetic Diagnosis
Numerous tests are available for the identification, diagnosis, and staging of various cancer types. These tests fall under several general categories, including genetic/molecular tests, imaging tests, diagnostic tests, laboratory tests, biopsy procedures, and screening tests.
1. Screening Tests (Early Detection)
These are used to identify cancer early in asymptomatic individuals:
- Mammogram – Breast cancer
- Pap smear & HPV test – Cervical cancer
- Colonoscopy, Sigmoidoscopy, Fecal tests – Colorectal cancer
- Low-dose CT scan – Lung cancer (for high-risk smokers)
- PSA test (Prostate-Specific Antigen) – Prostate cancer
- CA-125 blood test + Transvaginal Ultrasound – Ovarian cancer (for high-risk individuals)
- Skin checks / Dermoscopy – Skin cancer / Melanoma
- Oral visual inspection with acetic acid (VIA) – Oral cancer (in low-resource settings)
2. Blood and Laboratory Tests
These identify aberrant blood parameters or tumor markers:
- Tumor Markers:
- CEA (Carcinoembryonic antigen) – Colon, breast, pancreatic cancers
- CA-125 – Ovarian cancer
- CA 19-9 – Pancreatic cancer
- AFP (Alpha-Fetoprotein) – Liver cancer, germ cell tumors
- PSA – Prostate cancer
- hCG – Germ cell tumors
- LDH (Lactate Dehydrogenase) – Lymphoma, germ cell tumors
- Thyroglobulin / Calcitonin – Thyroid cancers
- Complete Blood Count (CBC) – May indicate leukemia, lymphoma
- Peripheral blood smear – Leukemia, lymphoma
- Urinalysis & Urine cytology – Bladder, kidney cancer
3. Imaging Tests
For the detection, diagnosis, and staging of cancer:
- X-ray (Chest X-ray) – Lung or bone cancer
- Ultrasound – Breast, abdomen, pelvic tumors
- CT scan (Computed Tomography) – Most solid organ cancers
- MRI (Magnetic Resonance Imaging) – Brain, spinal cord, breast, prostate
- PET scan (Positron Emission Tomography) – Detection of active cancer cells
- Bone Scan – Bone metastasis
- Mammography – Breast cancer
4. Biopsy Tests
Removal of tissue/cells for histopathology:
- Fine Needle Aspiration Cytology (FNAC)
- Core needle biopsy
- Excisional/Incisional biopsy
- Endoscopic biopsy (via bronchoscopy, colonoscopy, etc.)
- Stereotactic biopsy (image-guided)
- Bone marrow biopsy – Leukemia, lymphoma, myeloma
5. Genetic and Molecular Tests
Used for targeted therapy and personalized medicine:
- BRCA1/BRCA2 gene testing – Breast & ovarian cancer
- EGFR, ALK, KRAS, BRAF mutations – Lung, colorectal, melanoma
- HER2/neu amplification – Breast, gastric cancer
- Next-generation sequencing (NGS)
- PD-L1 expression – Immunotherapy eligibility
- Microsatellite Instability (MSI) / Mismatch Repair (MMR) – Colorectal, endometrial cancers
6. Specialized Endoscopic & Visual Exams
- Colonoscopy / Sigmoidoscopy – Colon and rectal cancer
- Bronchoscopy – Lung cancer
- Cystoscopy – Bladder cancer
- Laryngoscopy – Laryngeal/throat cancer
- Nasopharyngoscopy – Nasopharyngeal cancer
