Can we detect Cancer using Tumor Cell Markers by techniques like biopsy?
Cancer can be detected with the help of tumor cell markers, by visualization and biopsy. But before we read about the detection of tumors, we need to know about the staging of tumors:
Staging of tumors:
Tumors are classified or staged on the basis of TNM system, that includes the description of tumor size (T), involvement of the lymph nodes (N) and metastasis (M). The TNM system for tumor staging is given below:
T – If there is a primary tumor and if yes how big is it?
TX – Primary tumor cannot be assessed
TO – No evidence of primary tumor
Tis – Carcinoma in situ
T1-T4 – Increasing size of tumor
N – Involvement of the lymph nodes and finding out if the tumor has spread to the lymph nodes
NX –Regional lymph nodes cannot be assessed
NO – No evidence that the tumor has spread to the lymph nodes in the region of the primary tumor
N1-N3 – Progressive involvement of the regional lymph nodes
M – Distant metastasis, finding out if the tumor has spread to the distant parts of the body
MX – Distant metastasis cannot be assessed
MO – No evidence of distant metastasis
M1-M4 – Single or multiple sites of distant metastasis have been located
What are Tumor cell markers?
Tumor cell markers are the substances produced by the tumor cells or present on the surface of the tumor cells.
Tumor cell markers are used clinically for screening the presence of tumor cells in the body.
Drawbacks in using the tumor cell markers:
Drawbacks to the use of tumor cell markers in the diagnosis of cancer includes:-
- They are not specific for a certain type of cancer
- By the time the tumor cell markers are detected, the particular type of cancer may be well progressed
- Some of the noncancerous conditions may also be associated with the appearance of some of these markers in the blood
Examples of Tumor Cell Markers:
- α-Fetopotein – It is secreted by the embryonic liver cells. High levels of α-Fetopotein is seen in liver, ovarian and testicular cancers. This may also be observed with viral hepatitis.
- Prostate-specific antigen (PSA) – PSA increases markedly in prostatic cancer. It is elevated slightly in benign prostatic hypertrophy.
- CA 15-3 – CA 15-3 is elevated in the case of breast cancer. High levels of it often indicate the advanced or metastatic breast cancer. It may be elevated in liver disease or benign breast disease.
- CA 19-9 – CA 19-9 is elevated in the cancers of pancreas and gastro intestinal tract. It may also be elevated in pancreatitis and gall bladder diseases.
- CA 27-29 – CA 27-29 is elevated in breast cancer and many other cancers. It may also be elevated in benign breast disease, liver and kidney diseases.
- CA 125 – CA 125 is elevated in ovarian cancer, with pelvic inflammatory disease and in pregnancy.
- Human chorionic gonadotrophin – It is used as a marker for many different types of cancers and is elevated in pregnancy.
Detection of Cancer by Visualization:
Cancer can be detected by visualization by using methods like radiography, computer tomography (CT Scans) and magnetic resonance imaging.
Endoscopy may also be carried out to detect tumors visually in the bronchi and gastro intestinal tract.
By using visualization method, we not only can detect the presence of tumors but also we can evaluate matastasis.
Cancer detection by Biopsy:
Biopsy means the removal of a piece of suspect tissue for detailed histologic or histochemical analysis. It may be accomplished surgically by a needle biopsy, by preparing pap smear, by scraping cells from a surface or by endoscopic biopsy.