Surgery is a traditional form of cancer treatment. It is the most effective in eliminating most types of cancer before it has spread to lymph nodes or distant sites (metastasized). Surgery may be used alone or in combination with other treatments, such as radiation therapy and chemotherapy. If the cancer has not metastasized, surgery may cure the person. However, it is not always possible to be sure before surgery whether the cancer has or has not spread. During surgery, doctors often remove lymph nodes near the tumor to see if the cancer has spread to them. If so, the person may be at a high risk of having the cancer recur and may need chemotherapy or radiation therapy after surgery to prevent a recurrence.
Surgery is not the main treatment once a cancer has metastasized. However, surgery is sometimes used to reduce tumor size (a procedure called debulking), so that radiation therapy and chemotherapy may be more effective, or to relieve symptoms such as severe pain or nausea or vomiting caused when a tumor blocks (obstructs) the intestine. Surgically removing metastases rarely results in a cure because finding all the tumors is difficult. Tumors that remain usually continue to grow. However, in certain cancers that have a very small number of metastases, particularly to the liver, brain, or lungs, surgical removal of the metastases can be beneficial.
Surgery is not the preferred treatment for all early-stage cancers. Some cancers occur in inaccessible sites. In other instances, removing the cancer might require removing a necessary organ, or surgery might impair the organ's function. In such cases, radiation treatment with or without chemotherapy may be preferable.
After a tumor has been removed, additional surgery may be needed to improve the person's comfort or quality of life (reconstructive surgery, for example reconstruction of a breast after mastectomy).