12 cancer screening tests India doctors recommend

11. Tumor marker blood tests — why doctors usually advise against routine use

Blood tests that measure tumour markers (for example CEA, CA‑125, AFP, PSA) can be helpful in monitoring known cancer or guiding diagnosis, but many experts warn they are not reliable for routine population screening. False positives and false negatives are common; a raised marker does not always mean cancer and a normal marker does not rule it out. An ex-AIIMS oncologist and others caution against using marker panels as a screening shortcut (Indian Express reporting). Doctors usually recommend these tests only when there is a specific clinical reason, a suspicious symptom, or for follow-up after cancer treatment.