Surgery — an operation to repair or remove part of your body to diagnose or treat a condition — remains the foundation of cancer treatment. Your doctor may use cancer surgery to achieve any number of goals, from diagnosing your cancer to treating it to relieving the symptoms it causes. Cancer surgery may be your only treatment, or it may be supplemented with other treatments, such as radiation and chemotherapy.

Cancer surgery may be used to achieve one or more goals. Common reasons you might undergo surgery include:

• Cancer prevention. If your doctor suspects you'll develop cancer in certain tissues or organs, he or she may recommend removing those tissues or organs before cancer develops. For example, if you have a genetic condition called familial polyposis, your doctor may use cancer surgery to remove your colon and rectum because you have a high risk of developing colon cancer in the future.
• Diagnosis. Your doctor may use a form of cancer surgery to remove (biopsy) all or part of a tumor — allowing the tumor to be studied under a microscope — to determine whether the growth is cancerous (malignant) or noncancerous (benign).
• Staging. Cancer surgery helps your doctor define how advanced your cancer is, called its stage. Surgery allows your doctor to evaluate the size of your tumor and determine whether it's traveled to your lymph nodes. Additional tests might be used to gauge your cancer's stage.
• Primary treatment. For many tumors, surgery is the best chance for a cure, especially if the cancer is localized and hasn't spread. If your doctor believes your cancer hasn't spread, he or she may recommend surgery to remove the cancerous tumor as your primary treatment.
• Debulking. When it's not possible to remove all of a cancerous tumor — for example, because doing so may severely harm an organ — your doctor may remove as much as possible (debulking) in order to make chemotherapy or radiation more effective.
• Relieving symptoms or side effects. Sometimes surgery is used to improve your quality of life rather than treat the cancer itself — for example, to relieve pain caused by a tumor that's pressing on a nerve or bone. Another example might include removing a tumor that's obstructing your intestine.

Surgery is often combined with other cancer treatments, such as chemotherapy and radiation. Whether you opt for additional cancer treatment depends on your cancer and its stage.

The primary purpose of cancer surgery is to cure your cancer by physically removing all of it from your body. The surgeon usually does this by cutting into your body and removing the cancer along with some surrounding tissue to ensure that all of the cancer is removed. Your surgeon may also remove some lymph nodes in the area to determine if the cancer has spread. This helps your doctor assess the chance of your being cured, as well as the need for any further treatment.

In a traditional cancer operation, your doctor attempts to completely remove the cancer by using a scalpel or other cutting instruments. Your doctor might also remove a surrounding margin of tissue or nearby lymph nodes. For example, in the case of breast cancer, your doctor may remove the breast cancer by removing the whole breast (mastectomy) or by removing the cancer and some of the surrounding tissue (lumpectomy). Or in the case of lung cancer, your doctor may remove one lung lobe (lobectomy) or the entire lung (pneumonectomy) in an attempt to ensure that all the cancer has been removed.

Many other types of surgical methods for treating cancer and precancerous conditions exist, and investigators are always researching new methods. Some common types of cancer surgery include:

• Cryosurgery. During this type of surgery, your doctor uses very cold material, such as liquid nitrogen spray, or a cold probe to freeze and destroy cancer cells or cells that may become cancerous, such as irregular cells in your cervix that could become cervical cancer.
• Electrosurgery. By applying high-frequency electrical currents, your doctor can kill cancer cells, for example, in your mouth or on your skin.
• Laser surgery. Laser surgery, used to treat many types of cancer, uses beams of high-intensity light to shrink or vaporize cancer cells. In some cases, the heat of the laser accomplishes this. In other cases, the laser is used to activate a previously administered chemical that cancer cells absorb. When stimulated by light, the chemical kills the cancer cells.
• Mohs' surgery. Useful for removing cancer from sensitive areas such as near the eye and for assessing how deep a cancer goes, this method of surgery involves carefully removing cancer layer by layer with a scalpel. After removing a layer, your doctor evaluates it under a microscope, continuing in this manner until all the abnormal cells have been removed and the surrounding tissue shows no evidence of cancer.
• Laparoscopic surgery. A surgeon uses a laparoscope to see inside your body without making large incisions. Instead, several small incisions are made and a tiny camera and surgical tools are inserted into your body. The surgeon watches a monitor that projects what the camera sees inside your body. The smaller incisions mean faster recovery and a reduced risk of complications. Laparoscopic surgery is used in cancer diagnosis, staging, treatment and symptom relief.
• Image-guided surgery. In some instances, surgeons can rely on real-time images of your body to guide them when operating. For instance, rather than opening your skull to physically see inside your brain, a surgeon may use magnetic resonance imaging (MRI) to visualize the surgery. MRI images allow the surgeon to be very precise. Many other cancers can be treated using image-guided surgery, which is less invasive than traditional surgery. Other imaging techniques are used as well, including computerized tomography (CT) and ultrasound.
• Robotic surgery. In robotic surgery, the surgeon sits away from the operating table and watches a screen that projects a three-dimensional image of the area being operated on. The surgeon uses hand controls that tell a robot how to maneuver surgical tools to perform the operation. Robotic surgery helps the surgeon operate in hard-to-reach areas. But robotic surgical systems are expensive and require specialized training, so robotic surgery is only available in specialized medical centers.

Cancer surgery continues to evolve. Researchers are investigating other surgical techniques with an eye toward less invasive procedures.

Preparation and healing from cancer surgery varies greatly based on the operation you're undergoing. But in general, you can expect certain similarities, including:

• Preparation. In general, expect to undergo certain tests, such as blood tests, urine tests, X-rays and other imaging tests, in the days preceding your surgery. These tests will help your doctor assess your surgical needs, such as your blood type should you need a transfusion, and identify potential risks, such as infections, that may influence your surgery.
• Anesthesia. If you're having surgery, you'll likely need some type of anesthetic — a medication that blocks the sensation of pain. Your options for anesthesia will be based on what type of surgery you're receiving.
• Recovery. Depending on your surgery, you may stay in the hospital for a time before going home. Your health care team will give you specific directions for your recovery, such as how to care for any wounds, what foods or activities to avoid and what medications to take.

As with any surgery, cancer surgery does carry risks. What side effects you might experience after cancer surgery will depend on your specific surgery. In general, most cancer operations carry a risk of:

• Pain. Pain is a common side effect of most operations. Some cause more pain than others do. Your health care team will tell you how to keep your pain to a minimum and will provide medications to reduce or eliminate the pain.
• Infection. The site of your surgery can become infected. Your health care team will show you how to care for your wound after surgery. Follow this routine closely to avoid infection, which can lengthen your recovery time after surgery. Doctors treat infections most often with antibiotics.
• Loss of organ function. In order to remove your cancer, the surgeon may need to remove an entire organ. For example, your kidney may need to be removed (nephrectomy) if you have kidney cancer. For many such operations, the remaining organ can function sufficiently to compensate for the loss, but in other situations you may be left with impairments. For instance, removal of a lung (pneumonectomy) may cause difficulty breathing. Cancer surgery may also leave you without an arm or leg.
• Bleeding. All operations carry a risk of bleeding. Your surgeon will try to minimize this risk.
• Blood clots. While you're recovering from surgery, you're at an increased risk of developing a blood clot. Though the risk is small, this complication can be serious. Blood clots most commonly occur in the legs and may cause some swelling and pain. If the blood clot breaks off and travels to the lung (pulmonary embolism), the clot can be very dangerous and even deadly. Your surgeon will take precautions to prevent blood clots from developing, such as getting you up and out of bed as soon as possible after your operation.
• Altered bowel and bladder function. Immediately after your surgery you may experience difficulty having a bowel movement or emptying your bladder. This typically resolves in a few days, depending on your specific operation.

Whatever cancer treatment your doctor recommends, you're likely to feel some anxiety about your condition and the treatment process. Knowing what to expect can help. Use this information to help you talk with your doctor and ask informed questions.