Tumor removal is a surgical procedure to remove an abnormal growth.
A tumor can be either benign, like a wart, or malignant, in which case it is a cancer. Benign tumors are well circumscribed and generally are easy to remove completely. In contrast, cancers pose some of the most difficult problems in all of surgery.
Currently 40% of all cancers are treated with surgery alone. In 55% of cases, surgery is combined with other treatments—usually radiation therapy or chemotherapy.
The doctor needs to decide if surgery should be done at all. Because cancers spread (metastasize) to normal tissues, sometimes at the other end of the body, the ability of surgery to cure must be addressed at the outset. As long as the cancer is localized, the initial presumption is that cure should be attempted by removing it as soon as possible.
Non-curative surgery may make other treatments more effective. "Debulking" a cancer-making it smaller-is thought to assist radiation and chemotherapy to get to the remaining pieces of the cancer and be more effective. Physicians apply standards and guidelines based on research to the specific situation of a given patient s situation to decide the best approach. For example, reports released in 2003 said a study of patients with a common form of brain tumor called glioma had a more favorable outcome if their tumors were removed than if a biopsy were just performed.
Another important function surgery performs in cancer treatment is accurately assessing the nature and extent of the cancer. Most cancers cannot be adequately identified without a piece being placed under a microscope. This piece is obtained by surgery. Surgery also is the only way to determine exactly how far the tumor has spread. There are a few standard methods of comparing one cancer to another for the purposes of comparing treatments and estimating outcomes. These methods are called "staging." The most universal method is the TNM system.
- "T" stands for "tumor" and reflects the size of the tumor.
- "N" represents the spread of the cancer to lymph nodes, largely determined by those nodes removed at surgery that contain cancer cells. Since cancers spread mostly through the lymph system and this is a useful measure of their ability to disperse.
- "M" refers to the metastases, how far they are from the original cancer and how often they have multiplied.
Other methods of staging include Duke's method and similar systems, which add the degree of invasion of the cancer into the surrounding tissues to the above criteria.
Staging is particularly important with such lymphomas as Hodgkin's disease. These cancers may appear in many places in the lymphatic system. Because they are very radiosensitive, radiation treatment often is curative if all the cancer is irradiated. Therefore, it must all be located. Surgery is a common, usually essential, method of performing this staging. If the disease is too widespread, the staging procedure will dictate chemotherapy instead of radiation.
Curative cancer surgery demands special considerations. There is a danger of spreading or seeding the cancer during the process of removing it. Presuming the cancer cells can grow almost anywhere in the body to which they spread, the surgeon must not "spill" cells into the operating field or "knock them loose" into the blood stream. Special techniques called "block resection" and "no touch" are used. Block resection means taking the entire specimen out as a single piece. "No touch" means that only the normal tissue removed with specimen is handled; the cancer itself is never touched. This prevents "squeezing" cancer cells out into the circulation. Further, in this technique pains are taken to clamp off the blood supply first, preventing cells from leaving by that route later in the surgery.
There are four types of biopsy techniques. The physician will choose the appropriate technique depending on the tumor type, location, size, and other factors. Some types of biopsy are more invasive than others.
- Aspiration biopsy. A needle is inserted into the tumor and a sample is withdrawn.
- Needle biopsy. A special cutting needle is inserted into the core of the tumor and a core sample is cut out.
- Incisional biopsy. A portion of a large tumor is removed, usually before complete tumor removal.
- Excisional biopsy. A whole lesion is removed along with surrounding normal tissue.
Complete tumor removal
Once surgical removal has been decided, an oncologic surgeon will remove the tumor whole, taking with it a large section of the surrounding normal tissue. The healthy tissue is removed to minimize the risk of possible seeding.
When surgical removal of a tumor is unacceptable as a sole treatment, a portion of the tumor is removed to "debulk" the mass. Debulking aids radiation and chemotherapy treatments.
Retesting and periodical examinations are necessary to ensure that a tumor has not reformed after total removal.
The possibility of mestastasis and seeding are risks that have to be considered in consultation with an oncologist. The advancement in imaging techniques has led to some tumor staging by techniques like positron emission tomography (PET) scanning. A needle biopsy may still be required to confirm a diagnosis or staging decision, but in some cases, imaging can replace an initial need for biopsy.
"PET Scan, Endcoscopic Ulrsound Show Promise in Staging for Lung Cancer Surgery." Biotech Week July 9, 2003: 181.
"Study of Brain Tumors Points to Resection Over Biopsy as One Key to Survival." Cancer Weekly October 28, 2003: 20.