Cancer & Tumor Marker Tests in California

Cancer and tumor marker tests are blood tests that measure substances often made by cancer cells or by the body in response to cancer. They are not used alone to diagnose cancer; instead, they help monitor treatment, detect recurrence, or assess prognosis in people already diagnosed.

What it measures

CA-125 — Often elevated in ovarian cancer, but also in non-cancerous conditions like endometriosis.
PSA (prostate-specific antigen) — A protein made by the prostate; high levels can indicate prostate cancer or benign enlargement.
CEA (carcinoembryonic antigen) — Commonly used to monitor colorectal cancer and some other cancers.
CA 19-9 — Often monitored in pancreatic cancer, though it can rise with other digestive issues.
AFP (alpha-fetoprotein) — Used in liver cancer and some testicular cancers; also elevated in pregnancy.
hCG (human chorionic gonadotropin) — A marker for certain testicular and gestational cancers; also high in normal pregnancy.

Who it is for

These tests are typically ordered by oncologists or other specialists to follow known cancer or monitor treatment response. They are not recommended for routine cancer screening in people without symptoms or a diagnosis.

Preparation

No fasting is usually required. Tell your clinician about any recent illness, pregnancy, or medications, as these can affect marker levels.

Results and what they mean

Results are reported as a number with a reference range from the lab. A single result is rarely meaningful on its own; your clinician interprets trends over time along with your history, imaging, and other tests. This is general information, not medical advice.

Requesting the Cancer & Tumor Marker Tests in California

Order online, choose a certified collection site in California, and review results through a secure portal. No referral is required, and orders are processed confidentially. Because the region is uneven, coastal metros, inland towns, and rural counties with very different access to testing — worth planning around when you book.

Frequently asked questions

Can a tumor marker test tell me if I have cancer?

No. It can be elevated for many reasons, including benign conditions, and normal results do not rule out cancer. Diagnosis requires a biopsy or other tests.

Why does my doctor repeat this test?

Changes over time are more useful than one result. Your doctor may repeat it to see if treatment is working or if cancer has returned.

What if my marker level is high?

A high level does not always mean cancer. Your doctor will consider other causes and may order more tests to understand what it means for you.

Are these tests used for screening in healthy people?

Generally no. They are not reliable for early detection in people without symptoms or a known cancer diagnosis.

Cancer & Tumor Marker Tests by city in California

All testing in California → Full Cancer & Tumor Marker Tests guide →