Full Name

Cancer Antigen 125 (CA 125)

Sample Type

Blood (serum)

Fasting Required

❌ Not required

Test Category

Tumor marker

Primary Organs

Ovaries, also uterus, fallopian tubes, peritoneum, pleura, liver

Main Use

Monitoring ovarian cancer, and assessing pelvic masses

<35 U/mL

✅ Normal

35–200 U/mL

May be elevated in benign conditions

>200 U/mL

Suspicious for malignancy, especially in postmenopausal women

>500 U/mL

Often seen in advanced ovarian cancer

🧬 Monitor ovarian cancer

Track response to therapy or recurrence

🩺 Pelvic mass evaluation

Helps differentiate benign vs malignant mass (esp. in older women)

👩 Assess high-risk women

Not for screening in general population, but used in high-risk cases (e.g., BRCA mutation)

❗ Track tumor burden

Higher levels often correlate with tumor size or spread

Pelvic ultrasound / CT scan

For structural assessment of ovaries or pelvis

CEA, CA 19-9, HE4

For other tumor types or to improve specificity

Beta-hCG, AFP, LDH

If suspecting germ cell ovarian tumors

BRCA1/2 mutation testing

For hereditary ovarian/breast cancer risk

Endometriosis

Inflammation of uterine lining

Uterine fibroids

Benign smooth muscle tumors

Pelvic Inflammatory Disease (PID)

Infection of female reproductive organs

Pregnancy

Especially first trimester

Menstruation

Normal cyclic elevation

Liver disease or cirrhosis

Due to impaired clearance

Sample

Blood (serum)

Fasting

Not required

Normal Range

0–35 U/mL

Primary Use

Monitor ovarian cancer, assess pelvic masses

High Levels

Possible ovarian, endometrial, or peritoneal cancers

Paired Imaging

Pelvic ultrasound, CT scan

Limitations

Not reliable for early screening or in premenopausal women due to false positives