Thymic Cancer Health Article

Clinical staging, treatments, and prognosis

Clinical staging

There is more than one type of staging system for thymic cancer but the Masaoka system is used most often. This staging system was developed for thymoma, however, it is sometimes used to stage the other thymic cancers as well. Thymic carcinoma is graded (low or high) based on the cell type present in the tumor. Thymoma is categorized into four stages (I, II, III, and IV) which may be further subdivided (A and B) based on the spread of cancerous tissue. The Masaoka staging system is as follows:

• Stage I. The thymoma lies completely within the thymus.
• Stage II. The thymoma has spread out of the thymus and invaded the outer layer of the lung (pleura) or nearby fatty tissue.
• Stage III. The thymoma has spread to other neighboring tissues of the upper chest including the outer layer of the heart (pericardium), the lungs, or the heart's main blood vessels.
• Stage IVA. The thymoma has spread throughout the pericardium and/or the pleura.
• Stage IVB. The thymoma has spread to organs in other parts of the body.

Treatments

The treatment for thymic cancer depends on the type and stage of cancer and the patient's overall health. Because thymic cancers are so rare, there are no defined treatment plans. Treatment options include surgery, radiation therapy, and/or chemotherapy. Surgical removal of the tumor is the preferred treatment. Surgery is often the only treatment required for stage I thymic cancers. A treatment that is intended to aid the primary treatment is called adjuvant therapy. For instance, chemotherapy may be used along with surgery to treat thymic cancer. Stages II, III, and IV thymic cancers are often treated with surgery and some form of adjuvant therapy.

SURGERY.

Thymic cancer may be treated by surgically removing (resecting) the tumor and some of the nearby healthy tissue. Removal of the entire thymus is called a thymectomy. Surgery on the thymus is usually performed through the chest wall by splitting open the breast bone (sternum), a procedure called a median sternotomy. When complete removal of the tumor is impossible, the surgeon will remove as much of the tumor as possible (debulking surgery, sub-total resection). In these cases, If the tumor has spread, surgery may include removal of other tissues such as the pleura, pericardium, blood vessels of the heart, lung, and nerves.

RADIATION THERAPY.

Radiation therapy uses high-energy radiation from x rays and gamma rays to kill the cancer cells. Radiation given from a machine that is outside the body is called external radiation therapy. Radiation therapy is often used as adjuvant therapy following surgery to reduce the chance of cancer recurrence. Radiation may be used to kill cancer cells in cases in which the tumor was only partially removed. It may be used before surgery to shrink a large tumor. Radiation therapy is not very effective when used alone, although it may be used alone when the patient is too sick to withstand surgery.

The skin in the treated area may become red and dry and may take as long as a year to return to normal. Radiation to the chest may damage the lung causing shortness of breath and other breathing problems. Also, the tube that goes between the mouth and stomach (esophagus) may be irritated by radiation causing swallowing difficulties. Fatigue, upset stomach, diarrhea, and nausea are also common complaints of patients having radiation therapy. Most side effects go away about two to three weeks after radiation therapy has ended.

CHEMOTHERAPY.

Chemotherapy uses anticancer drugs to kill the cancer cells. The drugs are given by mouth (orally) or intravenously. They enter the bloodstream and can travel to all parts of the body. Chemotherapy may be given before surgery to shrink a tumor, which is called neoadjuvant therapy. Thymic tumor cells are very sensitive to anticancer drugs, especially cisplatin, doxorubicin, and ifosfamide. Generally, a combination of drugs is given because it is more effective than a single drug in treating cancer.

The side effects of chemotherapy are significant and include stomach upset, nausea and vomiting, appetite loss (anorexia), hair loss (alopecia), mouth sores, and fatigue. Women may experience lose of appetite (anorexia) vaginal sores, menstrual cycle changes, and premature menopause. There is also an increased chance of infections.

Prognosis

The approximate five-year survival rates are 35% for thymic carcinomas and 60% for thymic carcinoids. The five-year survival rates for thymomas are 96% for stage I, 86% for stage II, 69% for stage III, and 50% for stage IV.

Thymomas rarely spread (metastasize) but thymic carcinomas frequently spread to distant organs. Thymic carcinomas spread most often to the pleura, lung, local lymph nodes (bean-sized structures that contain lymphocytes), bone, and liver. Thymic carcinoid tumors commonly spread to local lymph nodes.

Thymomas are prone to recurrence, even 10 to 15 years following surgery. For thymomas, recurrence rates are drastically reduced and the five-year survival rates are drastically increased in patients who receive adjuvant radiation therapy. Recurrence of thymic carcinoid tumors is common.

Alternative and complementary therapies

Although alternative and complementary therapies are used by many cancer patients, very few controlled studies on the effectiveness of such therapies exist. Mind-body techniques such as prayer, biofeedback, visualization, meditation, and yoga, have not shown any effect in reducing cancer but they can reduce stress and lessen some of the side effects of cancer treatments. Gerson, macrobiotic, orthomolecular, and Cancell therapies are ineffective treatments for cancer.

Clinical studies of hydrazine sulfate found that it had no effect on cancer and even worsened the health and well-being of the study subjects. One clinical study of the drug amygdalin (Laetrile) found that it had no effect on cancer. Laetrile can be toxic and has caused deaths. Shark cartilage, although highly touted as an effective cancer treatment, is an improbable therapy that has not been the subject of clinical study. Although the results are mixed, clinical studies suggest that melatonin may increase the survival time and quality of life for cancer patients.

Selenium, in safe doses, may delay the progression of cancer. Laboratory and animal studies suggest that curcumin, the active ingredient of turmeric, has anticancer activity. Maitake mushrooms may boost the immune system, according to laboratory and animal studies. The results of laboratory studies suggest that mistletoe has anticancer properties, however, clinical studies have not been conducted.

For more comprehensive information, the reader should consult the book on complementary and alternative medicine published by the American Cancer Society listed in the Resources section.