|This idea of palliative chemotherapy is relatively new. ItÃ¢â¬â¢s only in recent years that that alleviation of symptoms has become an important component of clinical trials for cancer research. Chemotherapy is a general term for the use of a chemical agent to stop cancer cells from growing. It can be administered in a variety of ways with the most common being: Orally-pills taken by mouth, IntravenouslyÃ¢â¬âinfused through a vein, TopicallyÃ¢â¬â applied to the skin. Chemotherapy usually refers to chemical agents such as alkylating agents, anti-metabolites, and anti-tumor antibiotics. These chemicals are designed to kill cancer cells and prevent them from growing but they arenÃ¢â¬â¢t biased. They attack healthy cells as well, causing side effects such as nausea, hair loss, and infections. While not technically considered chemotherapy, other drugs may be used palliatively to shrink tumor size and slow cancer growth. They include hormone therapy and immunotherapy. Hormone therapy is the use of hormones to slow cancer growth, such as estrogen to slow cervical cancer, tamoxifen to slow breast cancer, and anti-androgens for prostate cancers. Immunotherapy is designed to stimulate the immune system to better recognize and attack cancer cells. For palliative purposes, most oncologists prefer to try the treatment with the least risk of side effects that would negatively impact quality of life. This means that hormone therapy may be tried before toxic chemotherapies.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.