CEA is the most widely used

marker for gastrointestinal cancer.

Although CEA is primarily associated with colorectal

cancers, other malignancies that can cause elevated levels

of CEA include breast, lung, stomach, pancreas, ovary and

other organs. Benign conditions that cause significantly

higher than normal levels include inflammation of lung

and gastrointestinal (GI) tract and benign liver cancer.

Heavy Smokers, as a group, have higher than normal

baseline concentration of CEA.

Expected Ranges of Values

Nearly 99% of non-smokers have CEA concentrations

less than 5 ng/mL. Similarly 99% of smokers have

concentrations less than 10 ng/mL.

Expected Values for the CEA ELISA Test System

Non-smokers < 5 ng/mL

Smokers < 10 ng/mL

Increased

Cancer (breast, esophageal, gastrointestinal, ovarian,

pancreatic, prostate, pulmonary), chronic ischemic heart

disease, cirrhosis, hypothyroidism, inflammatory bowel

disease, inflammatory processes, leukemia, neuroblastoma,

pancreatitis (acute), pneumonia (bacterial), pulmonary

emphysema, radiation therapy (recent), renal failure (acute),

tobacco smokers (chronic), and trauma. Drugs include

antineoplastics and hepatotoxic drugs.

Decreased

Not clinically significant.

PROSTATE-SPECIFIC ANTIGEN (PSA)

TOTAL PROSTATE SPECIFIC ANTIGEN (TPSA)

ELISA, MFD: MONOBIND

(Courtesy: Lilac Medicare)

Prostate Specific antigen (PSA) is a serine protease with

chymotrypsin-like activity. The protein is a single chain

glycoprotein with a molecular weight of 28.4 kDa. PSA

derives its name from the observation that it is a normal

antigen of the prostrate but is not found in any other normal

or malignant tissue.

PSA is found in benign, malignant and metastatic

prostrate cancer. Since prostate cancer is the second

most prevalent form of male malignancy, the detection

of elevated PSA levels plays an important role in the early

diagnosis. Serum PSA levels have been found to more useful

than prostatic acid phosphatase (PAP) in the diagnosis and

management of patients due to increased sensitivity.

Interpretation

PSA is elevated in benign prostrate hypertrophy (BPH).

Clinically, an elevated PSA value alone is not of diagnostic

value as a specific test for cancer and should only be

used in conjunction with other clinical manifestations

(observations) and diagnostic procedures (prostate

biopsy). Free PSA determinations may be helpful in

regard to the discrimination of BPH and prostrate cancer

conditions.

Expected Ranges of Values

Healthy males are expected to have values below 4 ng/mL.

Expected values for the PSA ELISA Test System Healthy

Males < 4 ng/mL.

686 Concise Book of Medical Laboratory Technology: Methods and Interpretations Usage

Assists in the identification, differentiation, clarification,

staging, and localization of tumor; monitoring

preoperatively, postoperatively, and for recurrent tumor;

assists in the selection of therapeutic interventions or cytotoxic drug therapy; and assists in assessment of tumor

response to treatment protocols.

Increased

Benign prostatic hypertrophy, cirrhosis, impotence,

osteoprosis, prostate cancer or infarct, prostatic needle

biopsy, prostatitis, transurethral resection (TUR), urethral

instrumentation, and urinary retention.

PROSTATIC ACID PHOSPHATES (PAP), BLOOD

METHOD: BIOCHEMICAL ANALYSIS

Normal: Values are dependent upon laboratory method

SI unit

Fishman-Lerner 0-0.7 U/dL

Bessey, Lowry, and Brock (BLB)

Female 0.02–0.55 U at 37°C 0.3–9.2 U/L

Male 0.15–0.65 U at 37°C 2.5–10.8 U/L

Bodansky 0–3 U/dL 0–16.1 U/L

King-Armstrong 0–3 U/dL 0–5.3 U/L

RIA 2.5–3.7 ng/mL

Increased

Bone cancer (metastatic), hyperparathyroidism, metastatic

prostatic carcinoma, multiple myeloma, osteogenesis

imperfecta, Paget’s disease, prostatic carcinoma (10–25%),

and prostatic infarct.

Decreased

Down syndrome. Drugs include estrogen therapy for

prostatic carcinoma, and ethanol.

Description

Prostatic acid phosphatase, an isoenzyme of acid

phosphatase, is a lysosomal enzyme that hydrolyzes

phosphate esters. It is found mainly in the prostate, but

is also present in erythrocytes and the kidneys, liver,

and spleen. Prostatic tissue has a concentration of acid

phosphatase 100 times greater than other tissues. Serum

activity of the prostatic isoenzyme is greatly increased in

metastatic cancer of the prostate in which the tumor has

extended beyond the capsule surrounding the prostate

gland. Therefore, this test is used as both a marker for

and a monitor of the disease course. For Method refer to

Enzymology section.