A predictive marker is a particular

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

that indicates sensitivity or resistance to a specific

therapy A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a medical diagnosis. As a rule, each therapy has indications and contraindications. There are many different ...

. The use of predictive markers is becoming increasingly relevant in

cancer therapy Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal ble ...

as it allows for better identification of patients who will respond positively to the therapy. In the clinical setting, predictive markers are limited to use in

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

. Expression of

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...

and

progesterone receptor The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene resid ...

s can determine the benefits of

hormone therapy Hormone therapy or hormonal therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also be referred to as hormonal therapy or antihormone therapy. The most general classes of hormone therapy are oncologic horm ...

, whilst the benefit of treating breast cancer patients with herceptin (Trastuzumab) is determined by the expression of HER2. There are many advantages to utilizing a predictive marker in cancer therapy including better

patient management A patient is any recipient of health care services that are performed by Health professional, healthcare professionals. The patient is most often Disease, ill or Major trauma, injured and in need of therapy, treatment by a physician, nurse, opto ...

minimizing unnecessary suffering from side effects with ultimately the wrong treatment choice, reducing loss of precious time whilst determining whether a therapy will provide any benefit, and a reduction in cost to both the patient and the wider health community.

References

{{reflist Cancer treatments