Tumor grades and differentiation, cytogenetics and tumor markers

Cancer biology proved each tumor has a cellular grade and differentiation. The tumor grade depicts how abnormal the tumor cells and tissue appear under a microscope, indicating the likelihood for rapid growth or spread. There are three grades, low grade cells are closer to normal than high grade cells. The differentiation of the tumor also tells how abnormal the cells are. Again, there are three categories; well differentiated cells more closely resemble the normal cellular structure. Moderately differentiated is more disarrayed, and poorly differentiated cells are the furthest from the normal state. This knowledge is essential for predicting life expectancies. For instance, a low grade, well differentiated tumor has a better chance for longevity than a high grade, poorly differentiated tumor. A mitotic rate may also be provided, often with melanoma impairments. As the name suggests, a higher rate indicates faster cellular division and therefore, faster tumor growth.

Tumor markers are also used for identifying cancers and predicting the response to specific agents. Information about tumor markers is sometimes noted on the pathology of a biopsy. A common example is the marker CD20, which indicates the tumor will respond to Rituxan. The Ki67 marker identifies the rate of cell growth. The lower the number, the slower the growth. Lab tests can also identify tumor markers. Each cancer has a specific cellular marker that will be elevated. These markers can increase to indicate the presence of cancer, and they may track the efficacy of treatment as they gradually decrease. Prostate-specific antigen (PSA) screens for prostate cancer. An elevated carcinoembryonic antigen (CEA) can indicate cancer of the colon or lung, in addition to other cancers. CA125 may be elevated with ovarian cancer; CA15-3 and CA27.29 may increase with breast cancer. There are other markers currently used, and as science continues to learn, and guide oncology, more markers will certainly be discovered.
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Fairly new in the oncology field is cytogenetics: the study of chromosomes. This department of pathology identifies broken, missing, rearranged or extra chromosomes (mutated). The research in cytogenetics has provided key elements in cancer cause and treatment. Some tumor markers currently making an impact on identifying cancers are the KRAS gene and BRCA gene (BReast CAncer). All human cells have a KRAS gene. KRAS genes work to keep cell proliferation and differentiation normal (like a regulator). When the KRAS gene becomes mutated, cells will not be regulated and will begin to multiply, frequently out of control. There are several types of KRAS mutations, specific for specific cancers. BRCA1 or BRCA2 are two different genes found to indicate the chances of developing breast cancer. As cytogenetics, tumor markers, immunomolecular therapy and specific targeting agents continue to advance, the impact on conventional underwriting is obvious. It will take years before the statistics catch up with the analysis and treatment.