Lab Assessment of Tumor Markers

Question 1

A 63 yo Caucasian man has a PSA of 5.2 on routine physical exam. DRE reveals a smooth enlarged prostate w/out focal nodulatrity. What do you recommend as further work up? Diagnosis?

Answer 1

%free PSA is 28% suggesting he has a 16-25% probability of cancer

Dx: Prostate bx

Question 2

How do you explain rising PSA in patients with a UTI?

Answer 2

PSA peaks until UTI is treated

Question 3

What pre-analytical factors affect PSA?

Answer 3

1. Biologic variation
   - total PSA 6-30%
   - free PSA 13-15%
   - %fPSA 8-15%
2. Prostate manipulation
   - DRE delay 1 wk
   - needle bx has 5-50xincrase, wait 6 weeks
   - ejaculation - abstain 24-48 hours
3. Exercise (avoid biking)
4. Prostatitis (significant increase - treat with 4-6 wks with abx)
5. Drugs (Finasteride for treatment of BPH: 50% decrease of PSA)

Question 4

What is the purpose of a PCA3 assay?

Answer 4

aid in clinical decisions for when to re‐biopsy patients previously biopsy‐ negative for prostate cancer

Question 5

Should the PCA3 assay be used?

Answer 5

clinical validity is INADEQUATE to inform decisions on when to REBIOPSY previously biopsy negative pts for prostate cancer or to inform initial decisions on whether to biopsy.

Does not help in determining whether it is indolent or aggressive.

Question 6

A pt with known HCC who is a carrier of HBV has AFP conc which are high but stable in the 1000s. On most recent visit his AFP is 58.

What is the high dose hook (prozone) effect? How do you identify this effect?

Answer 6

• This is due to the excess amount of antigen biding to either capture or labeled antibody and prevent the formation of the “sandwich” complex.
• How to identify high dose hook effect ?

Assay specimens at TWO dilutions

Question 7

When should you use CA125?

Answer 7

indicated as a ONE TIME TEST for use as an aid in the detection of RESIDUAL OVARIAN CARCINOMA in patients who have UNDERGONE FIRST LINE THERAPY and would be considered for diagnostic second‐look procedures

Interpretation: At the time of second look, surgical procedures might be deferred in patients with CA125 levels which remain in the normal range.

Question 8

An assay value greater than _____ is indicative of residual disease

Answer 8

35 U/mL

Question 9

What causes elevation of CA125 in non-cancer conditions?

Answer 9

– Menstruation
– First trimester of pregnancy
– Congestive heart failure
– Tuberculosis
– Liver cirrhosis
– Uterine myofibroma
– Benign ovarian tumors
– Endometriosis

Question 10

What causes elevation of CA125 in non-gyn cancers?

Answer 10

– Liver cancer
– Lung cancer
– Breast cancer
– Pancreatic cancer

Question 11

What percent of healthy subjects have CA125 levels greater than 35U/mL?

Answer 11

2.5%

Question 12

What is HE4 used for?

Answer 12

monitor recurrence or progressive disease in pts with epithelial ovarian cancer

elevated less frequently than CA125 in benign disease so its BETTER

Question 13

Where does HE4 come from?

Answer 13

normally expressed in many tissues including the female reproductive tract

Question 14

What is the ROMA algorithm?

Answer 14

ROMATM (HE4 + CA125)

Question 15

What is ROMA used for?

Answer 15

ROMA is used to startify woman into LIKELIHOOD groups for finding cancer on surgery

it should only be used as an ADJUNCT test

Question 16

What is OVA1 algorithm?

Answer 16

OVA1TM: CA125 + Prealbumin + Apolipoprotein A‐1 + β2‐ microglobulin + Transferrin

Question 17

What is OVA1 used for? Who is the intended pt population?

Answer 17

Intended use: to further assess the likelihood that malignancy is present when the physician’s independent clinical and radiological evaluation does not indicate malignancy.

Intended patient population: women over age 18 with ovarian adnexal mass present, for which surgery is planned, and not yet referred to an gynecologic oncologist (GO).