Types of cancer

 

 

All neoplasms that occur in human are similar in their ability to excessive growth, which can not be controlled by organism of the sick. This phantom has its source in loss of balance between coexisting cells of the body. These cells, which, in time, will compose a visible tumor, become resistant to regulating systems of neighbouring healthy cells. The cause of their ability to independent and uncontrolled growth are changes in their genetic material. One improper cell, which additionally can multiply itself, is enough to become the first of millions daughter cells, which finally form a neoplasm.

 

There are many types of neoplasms distinguished in oncology. The main division is made on the base of a human body tissue (organ) being the source of the cells that formed the tumor, which was, in example, removed by a surgeon. Such tissue sample is then examined by a pathologist, which, with usage of microscope and many other special techniques, is able to assess which kind of neoplasm is found in a particular case.

 

It is worth of noticing that not each neoplasm is a cancer. It has become customary to name every kind of malignant neoplasm as a cancer, but the truth is that in medical nomenclature a cancer is a name given to a malignant neoplasm coming from epithelial cells. This kind of cells cover or line different organs in human body. That is why e.g. larynx cancer comes from epithelium of larynx, colon cancer comes from epithelium which lines the large bowel, breast cancer comes from epithelial cells of mammary gland, prostate cancer comes from glandular epithelium of prostate, skin cancer comes from basal cells of epidermis, etc.

 

 

Malignant - what does it mean?

 

Malignancy of the neoplasm is caused by so called atypic cells, which differ from healthy cells of the body. Atypic cells are improper, can divide quickly and effectively, independently of suppressing signals sent by healthy tissues. The consequence of the above can be the phantom of infiltrating of healthy tissues and ability to give recurrences in treated site – it is so called local malignancy. There is also possibility of detachment of a single or clustered cells from primary tumor, their transfer along the blood or lymph stream and settling in distant tissues, e.g. lungs, bones, brain, liver or lymph nodes. This is how metastases occurs. From this point forward we talk about disseminated malignant neoplastic disease.

 

Malignant neoplasms can be also divided due to individual characteristics of growing tumor. One of the most important issues is to assess the source organ of the neoplasm. Assessing of the source organ is crucial in making a treatment modality decision and gives answers if surgery, radiotherapy, chemotherapy, combined treatment or implementing of additional therapies (e.g. immune therapy, bone marrow transplantation, hyperthermia) would be the best treatment option.

Next, the nature of tumor cells have to be revealed. It is about the maturity grade of the cells forming the tumor. The less mature the cells are and the less similar they are to those that they are coming from, the greater probability of malignancy is and the more aggressive treatment has to be undertaken to fight the disease.

The second important element of classification is stage of the disease on time of diagnosis. The grater stage, the less chance for cure. The stage is assessed on the base of size of malignant tumor, its relation to surrounding tissues (presence of separating capsule or direct infiltration), presence of metastases in local or regional lymph nodes and presence of distant metastases.

 

It is also worth to mention precancerous lesions. They are considered benign, nevertheless, having ability to transform, in time, into form of active malignant neoplasm. In this group dysplasia of cervix epithelium, karatosis actinica, skin horn or adenomas (polyps) of large bowel can be listed.