Journal of Cancer Science and Research
Open Access

Cancer Genome Sequencing helps in determining which Cancer the Patient Exactly has for Determining the Best Therapy for the Cancer

Joseph Conrad^{* *}Correspondence: Joseph Conrad, Department of Cancer Immune Therapy at University of Gottingen, Germany,

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Introduction

Cancer can be treated by surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy (including immunotherapy such as monoclonal antibody therapy) and synthetic lethality, most commonly as a series of separate treatments (e.g. chemotherapy before surgery). The choice of therapy depends upon the location and grade of the tumor and the stage of the disease, as well as the general state of the patient (performance status). Cancer genome sequencing helps in determining which cancer the patient exactly has for determining the best therapy for the cancer. A number of experimental cancer treatments are also under development. Under current estimates, two in five people will have cancer at some point in their lifetime. Complete removal of the cancer without damage to the rest of the body but the propensity of cancers to invade adjacent tissue or to spread to distant sites by microscopic metastasis often limits its effectiveness; and chemotherapy and radiotherapy can have a negative effect on normal cells. Therefore, cure with no negligible adverse effects may be accepted as a practical goal in some cases; and besides curative intent, practical goals of therapy can also include suppressing the cancer to a subclinical state and maintaining that state for years of good quality of life that is, treating the cancer as a chronic disease, and palliative care without curative intent.

Because "cancer" refers to a class of diseases, it is unlikely that there will ever be a single "cure for cancer" any more than there will be a single treatment for all infectious diseases. Angiogenesis inhibitors were once thought to have potential as a "silver bullet" treatment applicable to many types of cancer, but this has not been the case in practice.

Radiation therapy

Radiation therapy also called radiotherapy, X-ray therapy, or irradiation is the use of ionizing radiation to kill cancer cells and shrink tumors by damaging their DNA the molecules inside cells that carry genetic information and pass it from one generation to the next, making it impossible for these cells to continue to grow and divide. Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA. Radiation therapy can be administered externally via External Beam Radiotherapy (EBRT) or internally via brachytherapy. The effects of radiation therapy are localised and confined to the region being treated. Although radiation damages both cancer cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue. Hence, it is given in many fractions, allowing healthy tissue to recover between fractions.

Chemotherapy

Chemotherapy is the treatment of cancer with drugs "anticancer drugs" that can destroy cancer cells. In current usage, the term "chemotherapy" usually refers to cytotoxic drugs which affect rapidly dividing cells in general, in contrast with targeted therapy see below. Chemotherapy drugs interfere with cell division in various possible ways, e.g. with the duplication of DNA or the separation of newly formed chromosomes. Most forms of chemotherapy target all rapidly dividing cells and are not specific to cancer cells, although some degree of specificity may come from the inability of many cancer cells to repair DNA damage, while normal cells generally can. Hence, chemotherapy has the potential to harm healthy tissue, especially those tissues that have a high replacement rate.