Cancer Therapy includes an ever-increasing array of tools at the disposal of clinicians in their treatment of this disease. However, cancer is a tough opponent in this battle, and current treatments, which typically include radiotherapy, chemotherapy and surgery, are not often enough to rid the patient of his or her cancer. Cancer cells can become resistant to the treatments directed at them, and overcoming this drug resistance is an important research focus.
Cancer can be treated by surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy (including immunotherapy such as monoclonal antibody therapy) and synthetic lethality. 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). 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 (that is, achieving cure with near-zero adverse effects) is the ideal goal of treatment and is often the goal in practice. Sometimes this can be accomplished by surgery, 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 nonnegligible 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 (for advanced-stage metastatic cancers).