Question

characteristics of an ideal tumour markers

Answer 1

A tumor marker is a substance found in your blood, urine, or body tissue. The term "tumor markers" may refer to proteins that are made by both healthy cells and cancer cells in the body. It may also refer to mutations, changes, or patterns in a tumor's DNA. Tumor markers are also called biomarkers.

Types of tumor marker

• Prostate-specific antigen (PSA)
• Prostatic acid phosphatase (PAP)
• CA 125
• Carcinoembryonic antigen (CEA)
• Alpha-fetoprotein (AFP)
• Human chorionic gonadotropin (HCG)
• CA 19-9
• CA 15-3
• CA 27-29

• Lactate dehydrogenase (LDH)
• Neuron-specific enolase (NSE)
• Bladder tumor marker studies

The three most important characteristics of an ideal tumor marker are

(a) it should be highly specific to a given tumor type,

(b) it should provide a lead-time over clinical diagnosis

(c) it should be highly sensitive to avoid false-positive results.

Additionally, the levels of the marker should correlate reliably with the tumor burden, accurately reflecting any tumor progression or regression, along with a short half-life allowing frequent serial measurements. The test used for detection should be cheap for screening applications at the mass level and should be of such nature as to be acceptable to the target population, In reality, an ideal tumor marker does not exist

some more characteristic of tumour marker are

Characteristics	Remarks
Highly specific	Detectable only in one tumor type
Highly sensitive	Non-detectable in physiological or benign disease states
Long lead-time	Sufficient time for the alteration of the natural course of the disease
Levels correlate with tumor	Prognostic and predictive utility of
burden	the tumor marker
Short half-life	Frequent serial monitoring of the marker levels after 5-6 half-lives
Simple and cheap test	Applicability as a screening test
Easily obtainable specimens	Acceptability by target population