After a definitive diagnosis has been made and the cancer has been staged, treatment can begin. Treatment of oral cancers is a multidisciplinary approach involving the efforts of surgeons, radiation oncologists, chemotherapy oncologists, dental practitioners, nutritionists, and rehabilitation and restorative specialists. Before beginning treatment, other oral health needs will be addressed to decrease the likelihood of developing post therapeutic complications. Teeth with poor prognosis from periodontal problems and caries may need to be extracted to avoid any post-radiotherapy surgery as this can induce osteonecrosis, a condition which can develop when tissue damaged by radiation exposes the underlying bone. The bone, which has lost its ability to efficiently repair itself due to reduced blood supply, again from radiation exposure, becomes a chronic and difficult situation to treat.
Surgery is the oldest form of treatment and most people with cancer will have some type of surgery. It also has an important role in diagnosing and staging (finding the extent) of cancer. The goal is less invasive operations to remove the tumor but to also preserve as much normal oral cavity structure and function as possible. Surgery offers the greatest chance for cure for many types of cancer, especially those that have not yet spread to other parts of the body. When the disease is localized, a surgical procedure can remove the cancer in its entirety.
Radiotherapy is the treatment of cancer with ionizing radiation that deposits energy and destroys cells in the area being treated (the target tissue) by damaging the genetic material (DNA) in the individual cells, making it impossible for them to continue to grow. Although radiation damages both cancer cells and normal cells, normal, healthy cells are able to repair and return to proper functioning. Prior to starting radiation therapy, markings are placed on the patient’s skin to help with positioning during the actual treatments and a porous mesh mask is made so that radiation is only delivered to the designated areas. The total dose of radiation therapy prescribed is broken down into small fractions which are given on a daily basis, usually five days in a row with a two day break each week. The daily dose must also be great enough to destroy the cancer cell while sparing the normal tissues of excessive levels of radiation and allowing for repair. This balancing act forms the basis of modern radiation therapy. Like all forms of cancer treatment, radiation therapy can have side effects like loss of hair in the area being treated, skin irritation, change in skin color, nausea, and tiredness. It also causes loss of salivary function, dry mouth (xerostomia), and mucositis, making the interior of the mouth sore.
Chemotherapy is one of the three main methods used to treat cancer and the use of chemicals to destroy cancer cells. What makes chemotherapy very effective, is that it has the ability to treat widespread (metastatic) cancer, that is in more than one location in your body. This ability makes chemotherapy very important in a patient’s fight to overcome cancer, because radiation therapy and surgery are only suitable for treating cancer in localized areas. When these three treatments are used in conjunction, their complimentary avenues of attacking the disease usually offer the patient the best chance to beat cancer. Chemotherapy targets the cell cycle by altering the DNA structure in the nucleus of the cell preventing replication. The most common means of administering chemotherapy drugs are orally or intravenously through a catheter that is left in place during the course of treatment. Chemotherapy is very effective in killing cancer cells, but it also affects normal cells as well. Side effects include gastrointestinal tract problems like nausea, diarrhea, constipation, and loss of appetite. Since it affects normal cells as well, there can be low blood cells counts leading to anemia, inability to fight infections, and impaired clotting. It affects hair follicles causing hair loss. There are also mouth sores, skin rashes, fatigue, and infertility.
TARGETED, BIOLOGICAL, AND IMMUNOTHERAPY
The conventional therapies used to treat cancer such as radiation, chemotherapy, and surgery, work effectively but are not without significant side effects. Healthy surrounding tissues, and even parts of the bodies remote from the area of the cancer are affected. Ideally science would like to find methods of treatment that are specific to killing just the cancer cells while not affecting healthy tissues through targeted therapies. These interfere with some aspect of cellular life by focusing on proteins that are involved in the signaling process, without harming healthy cells. Biological therapies use the body’s immune system, either directly or indirectly, to fight cancer or to lessen the side effects that may be caused by some cancer treatments. Biological response modifiers (BRMs) are antibodies, cytokines, and other immune system substances produced in the laboratory that alter the interaction between the body’s immune defenses and cancer cells to boost, direct, or restore the body’s ability to fight the disease. Gene therapy involves introducing genetic material into a person’s cells to improve a patient’s immune response to cancer.
Proper nutrition is a vital part of cancer treatment to get the essential nutrients needed for body healing, immune system, body weight, and the percentage of lean body mass (muscles) maintenance during treatments. A healthy diet including proteins, fats, vegetables, carbohydrates, and ample hydration, makes cancer treatment easier and recovery time shorter. As treatments progress, there can difficulty chewing and swallowing solid food, altered saliva and taste, and mucositis sores in the mouth. It can become necessary to blend meals and drink them orally or use protein shake supplements. If even liquid nutrition taken orally is not enough and body weight begins to drop radically, a feeding tube may be necessary. This can be a frightening step for cancer patients and techniques for usage and adaptation will need to be covered by the cancer care team. There are different ways of feeding such as bolus feeding (using a large syringe to put food in your tube), gravity feeds (using a drip bag) or utilizing a pump. A patient will need to regularly vent, flush, and clean out the tube every time it is used. There are numerous support groups for cancer patients and tube feeding issues.
COMPLICATIONS OF TREATMENTS
The likelihood is high that cancer treatments will have toxic effects on normal cells as well as cancer cells. The most common oral complications occurring after radiation and chemotherapy are mucositis (an inflammation of the mucous membranes in the mouth), infection, pain, and bleeding. Other problems are dehydration and malnutrition, commonly brought on by difficulties in swallowing (dysphagia). Radiation therapy to the head and neck may injure the glands that produce saliva (xerostomia) or damage the muscles and joints of the jaw and neck (trismus). These treatments may also cause hypo vascularization (reduction in blood vessels and blood supply) of the bones of the maxilla or mandible (the bones of the mouth). In addition, treatments may affect other forms of dental disease (caries, or soft tissue complications), or even cause bone death (osteonecrosis). Long term problems can be lowered blood counts leading to anemia, lower immunity, and impaired clotting. By identifying patients at risk, doctors can start preventive measures before cancer therapy begins. This includes identifying the patient’s age, overall health and preexisting medical conditions pre-treatment, the type of cancer, the chemotherapy type and schedule used, the area irradiated and how much radiation is given, and how much low blood counts are decreased and for how long.
While all these types of scans are still used largely for confirmation or measuring extent, the best indicator of tumor involvement is still the clinical assessment, relying on both direct examination of the area as well as biopsy. The ability to detect cancer at the earliest stages, as well as its precise location in the body, can improve the survival rate of this disease, and allow for less disfiguring ways to address the tumors and lesions associated with oral cancer. If the pathologist examining the cells from a patient finds oral cancer, the patient’s doctor needs to know the stage, or extent, of the disease in order to plan the best treatment. Staging a cancer involves establishing the degree to which the cancer has spread, and to what extent it involves other areas of the mouth and neck, or even distant locations elsewhere in the body. This is described using the terms well differentiated, moderately differentiated, or poorly differentiated. A well-differentiated cancer is not overly aggressive in the rate it is spreading; a moderately differentiated cancer is intermediately aggressive; and a poorly differentiated is much more aggressive in its extent and the speed with which it is spreading.