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Normal cells grow and multiply according to their genetic programming. Over time, genetic damage can occur that causes a cell to grow abnormally. Sometimes, this process is not harmful, producing a benign tumor that grows slowly, much like a skin wart. Other times, cells grow out of control, invading nearby tissues or other parts of the body. This type of malignant growth is commonly referred to as cancer. The medical study of cancer and its treatment is called oncology. Physicians who specialize in oncology are called oncologists. Cancer is primarily a disease of aging. In the United States, about 50% of all cancer occurs in people 65 years old and older. Cancer increases as we age for a number of reasons:
Cancer is second only to heart disease as the leading cause of death in the United States. Cancer and cancer survival are more in certain ethnic and racial groups than in others. Within the US population, cancer is most common among black Americans and least common among Native Americans. There are also more deaths from cancer among blacks than among whites, Asian Americans, or Native Americans. Some of these differences are due to genetics, while others are due to social (eg, poverty and access to health care) or behavioral (eg, smoking and diet) differences among cultures. Usually, the biology and clinical course of cancer is the same for younger and older adults. However, there are some exceptions. For example, acute leukemia and Hodgkin’s disease are more aggressive and less responsive to treatment in older adults than in younger ones. This may be due to age-related changes in the disease itself or to the poorer health often seen in older age. On the other hand, breast and lung cancers are usually less aggressive with advancing age. Cancer screening is designed to detect disease in an early stage before symptoms develop. This is usually when the cancer can be most easily treated. In some cases, screening tests are highly effective. For example, screenings for colon cancer (eg, colonoscopy), cervical cancer (Pap smear), and breast cancer (eg, mammography) have saved many lives. In other cases, screening tests are not very effective at identifying those who will develop cancer, or at increasing survival in those who are found to have cancer. This is why chest x-rays are not recommended as a screen for lung cancer, and why men older than 80 years of age are not screened for prostate cancer. In these cases, the benefit linked to early detection does not offset the risk of the diagnostic testing (eg, exploratory surgery, biopsy, etc) and treatment needed to address a positive screening test. Your healthcare provider can help you decide on the screening tests that are right for you. Principles of Cancer Treatment The main goals of cancer treatment are to prolong life, relieve symptoms, and improve quality of life. The main forms of treatment include the following: The choice of therapy is based on the type of cancer, its stage and severity, and your overall health. Often, a combination of treatments (eg, surgery and chemotherapy) is the most effective. Age-related diseases and conditions can complicate treatment and increase the risk of secondary problems and side effects. For example, many drugs used in cancer chemotherapy are given at lower dosages in older adults because of reduced liver and kidney function as we age. Surgery is a key part of many treatment plans for cancer. In some cases, surgery can remove a tumor and possibly cure the cancer. Other benefits of surgery include preventing future problems (such as blockage in colon cancer) or helping determine how far the cancer has spread. The biggest concerns in older adults undergoing cancer surgery are safety and the potential for full recovery. Older adults usually do reasonably well with elective surgery, but emergency surgery is a greater risk in older adults than in younger people. Length of hospital stay and time to full recovery generally increase with advancing age, which can increase the risk of complications and decreased quality of life. Advances in anesthesia and surgical technique have made surgery much safer in older adults with less risk of complications. For example, improvements in local and spinal anesthesia allow more extensive surgery without the risks of general anesthesia. Endoscopy procedures (eg, colonoscopy and laparoscopy), which use a flexible tube that is inserted into the body for examination or biopsy, are quicker and less invasive than traditional surgery. Radiation therapy uses high-energy beams to penetrate body tissues and kill cancer cells. This energy can be produced by machines (eg, x-rays) or by naturally occurring elements such as cobalt or radium. Radiation therapy can be used along with surgery or chemotherapy or by itself for some cancers. Radiation can kill healthy cells as well as malignant ones. Fortunately, cells that multiply rapidly, such as cancer cells, are more sensitive to the effects of radiation. Of course, healthy cells that multiply rapidly are also sensitive, including bone marrow and cells lining the gastrointestinal tract. The goal of radiation therapy is to focus the radiation on cancer cells only (as much as possible), while avoiding healthy tissue. Oncologists use several techniques to accomplish this, including the following:
Radiation therapy is both safe and effective in older adults, and it is often a safer choice than surgery. However, radiation safety is still questionable in certain situations. For example, irradiation of the entire brain may cause dementia, and irradiation of the pelvis may damage the bone marrow or gut. A major role of radiation is to control the spread of cancer. However, radiation is also used to control pain by targeting specific areas of cancer. Targeted radiation therapy can provide pain relief for many cancers, including lymphomas and cancers of the prostate, bladder, cervix, esophagus, breast, or head and neck area. Bone pain responds especially well to this targeted radiation therapy. While surgery and radiation have been used for over a century, cancer chemotherapy is relatively new. In chemotherapy, toxic chemicals are used to kill cancer cells. Because cancer cells are actively multiplying, they are very sensitive to the effects of toxic drugs. Unfortunately, some healthy body cells that are also rapidly multiplying are also affected. These include cells in the bone marrow, intestinal tract, and hair follicles. This can lead to low blood counts, nausea, vomiting, diarrhea, and hair loss, but these unwanted side effects can usually be controlled. Many cancer chemotherapy drugs have been used safely and effectively in older adults. The particular drug chosen depends on the cancer, its stage, and overall health. These drugs are given by mouth or intravenously, then circulate through the blood to reach cancer cells anywhere in the body, except the brain. The brain has a natural protective barrier against chemicals. Chemotherapy drugs are generally as effective in older adults as in younger adults. The biggest concern in older adults is safety. Older adults are generally given lower dosages, because of decreased liver and kidney function, which decrease drug metabolism and elimination. Chemotherapy also increases the chances that organ function will be lost, because older organs often do not have the ability to “bounce back” after tissue damage. Other safety issues that complicate chemotherapy in older adults include changes in the body’s chemical composition and interactions with commonly prescribed medications. Hormone-like drugs are effective against some types of cancer, including cancers of the breast, prostate, and uterine lining. For example, estrogen-like or anti-testosterone drugs are used to treat prostate cancer, while anti-estrogen drugs are used to treat breast cancer. Most of these hormonal therapies are often a treatment of choice in older adults with cancer. The most well known is probably tamoxifen, which is a treatment for breast cancer that has remarkably few side effects. Tamoxifen also has positive, estrogen-like benefits for heart disease and osteoporosis in postmenopausal women (see also Hormone Disorders and Osteoporosis). The immune defenses in older adults are often weaker than in younger people. For this reason, certain immune therapies are a particularly attractive treatment option in older adults. Only a limited number of immune therapies are currently available, but research is ongoing and the future looks bright. Alpha interferon is an effective immune therapy for some types of leukemia and some other cancers of the blood or lymph that are more common among older adults. Alpha interferon is also being tested as a treatment for melanoma, which is a malignant form of skin cancer. Potential side effects of alpha-interferon include depression of the bone marrow, severe fatigue, flu-like illness, fever, and nerve or liver problems. However, these side effects are generally seen at dosages higher than those commonly used for cancer treatment. Interleukin-2 is another immune therapy that is being used as a cancer treatment, specifically for melanoma and kidney cancer. Side effects can be severe, including low blood pressure, respiratory syndrome, irregular heart rhythms, swelling, kidney failure, liver disease, skin rashes, and bleeding problems. Side effects tend to show up gradually after high doses. Monoclonal antibodies are a different type of immune therapy. These antibodies are designed to target specific cancer cells, such as those found in some breast cancers or lymphomas. Usually, these antibodies are given along with chemotherapy to increase the effects of the chemotherapeutic drugs. Monoclonal antibodies generally have mild toxicities. Possible side effects include low blood pressure and shortness of breath, but these symptoms generally go away when the drug is administered more slowly. This is usually done by slowing down the rate of the intravenous (IV) drip. The most common cancers in the United States affect the prostate, breast, colon or rectum, and lung. Other common cancers in older adults include blood cell cancers (eg, leukemia and lymphoma) and skin cancer. (See also Prostate Disease, Skin Problems, and Disorders of the Digestive System). Breast cancer is the most common cancer in American women, and it becomes more common with age. More than 200,000 cases were diagnosed in 2004, with close to half of these among women 65 years old and older. Risk factors for breast cancer include the following:
Breast cancers generally grow slower in older women than in younger women. However, death caused by breast cancer is often higher among women diagnosed after age 75. This lower survival can be due to several reasons, including the poorer overall health of older women and economic or cultural factors (eg, limited access to healthcare or early screening). Breast cancer causes pain, illness, and death in postmenopausal women. It also causes a great deal of anxiety, including fears of mastectomy and rejection by sexual partners. Diagnosis: the best way to diagnose breast cancer early is through screening. Breast cancer screening by means of monthly breast self-examination, annual physical examination, and, for women over age 50, mammography every 1–2 years is recommended. The most effective screening tool is mammography, which can detect a lump that is too small to feel. If cancer is detected, additional procedures (eg, blood tests, x-rays, and lymph node biopsies) are recommended to help determine the severity of the cancer and if other organs (eg, bones, liver, or lungs) are involved. Routine diagnostic testing also assesses your state of health before treatment. Treatment and Prognosis: Surgery is the primary treatment for breast cancer. Research suggests that a lumpectomy (ie, removing just the tumor) can be as effective as a mastectomy (ie, removing the entire breast), especially when the lump is 2 inches or less in diameter. Many oncologists recommend a lumpectomy with removal of the lymph glands under the arm and/or radiation therapy. Treatment with a medication like tamoxifen is an alternative to surgery for women who have very small tumors or who have a short life expectancy due to other reasons. Tamoxifen is currently the most common form of hormonal treatment for breast cancer. It is usually given as a second-line treatment after surgery and/or radiation. Treatment with tamoxifen for at least 2 years has prolonged survival in postmenopausal women treated for breast cancer. Progesterone therapy is also an effective secondary treatment for breast cancer, but it is much more toxic than tamoxifen. A new class of drugs called aromatase inhibitors is also available as a second-line hormonal treatment. The value of chemotherapy that is more extensive than tamoxifen is controversial. Additional chemotherapy is used mostly in women with aggressive breast cancer that has spread to other parts of the body. In this situation, aggressive chemotherapy can cause the tumor to go into remission rapidly. The outlook for women with breast cancer depends on a number of factors, including the stage, extent, and type of disease. Approximately two-thirds of breast cancers in postmenopausal women contain hormone receptors, which generally indicate a better response to treatment and hormonal therapy (eg, tamoxifen). The chance of breast cancer coming back increases if there is a lack of hormone receptors, if the cancer cells are very immature, or if cell growth is rapid. The prognosis is also poorer for cancers that have spread to other tissues, such as lymph nodes or lung. Lung cancer is the leading cause of cancer death in both men and women. Almost 75% of all lung cancers are in older adults. Cigarette smoking causes 90% of lung cancers. People who stop smoking lower their risk immediately, and can eventually reduce their cancer risk to that of nonsmokers. Other risk factors for lung cancer include high-level exposures to soot, ionizing radiation, or asbestos, which are usually related to occupation. Lung cancer can develop in the cells that line the airways or the cells that form the lung tissue. Lung cancer is often aggressive and progresses to severe disease (and often death). Most of the initial symptoms are nonspecific, such as cough, fatigue, and loss of appetite. These symptoms may be ignored or considered to be part of another illness. For example, a persistent cough may be initially thought to be bronchitis. However, any new symptom in an elderly smoker raises the possibility of lung cancer. Diagnosis and Treatment: Lung cancer is diagnosed by chest x-ray, bronchoscopy, and other diagnostic tests directed at the lungs. Additional diagnostic tests (eg, brain x-rays, blood tests) are done to evaluate how far the cancer has spread and overall health before treatment. Early diagnosis and treatment provides the best chance for a cure. Radiation therapy can occasionally result in long-term remission in people who are not candidates for surgery. Chemotherapy is also used to treat lung cancer. Cancer of the blood cells (eg, leukemia, lymphoma, and myeloma) affected over 100,000 Americans in 2004, causing more than 50,000 deaths. More than half of these cases were among older adults. Leukemia is the malignant proliferation of abnormal white blood cells, ie, abnormal white blood cells multiply out of control. There are acute and chronic forms of leukemia. Acute leukemia is usually an aggressive disease that is often fatal for older adults. It usually results in signs of infection (sudden high fever, change in mental function), progressive weakness, fatigue, paleness, or easy bruising and bleeding (see also Blood Disorders). Chronic leukemia is the more common form among older adults, and it is generally more benign than acute leukemia. In fact, chronic leukemia is often found when routine blood screening tests are done. Adults with chronic leukemia may not have any symptoms, and they can live many years after diagnosis with few serious complications. The diagnostic evaluation for leukemia usually consists of a complete blood count and a bone marrow examination (eg, biopsy). Chronic leukemia does not require treatment unless it is causing symptoms. Treatment of acute leukemia consists of chemotherapy drugs to induce remission, followed by maintenance therapy. Remission is characterized by having no leukemia cells appear in the blood, and having less than 5% leukemia cells in the bone marrow. Older adults in poor health often cannot tolerate aggressive chemotherapy treatment because of the serious side effects. The lymph nodes and spleen form a major part of the immune system. Lymphoma is a malignancy of the lymph nodes. The spleen is also frequently involved. Lymphomas are classified as Hodgkin’s disease or non-Hodgkin’s lymphoma. Hodgkin’s disease causes lymph glands, usually in the neck, to enlarge. There is no pain. Lymph node enlargement often spreads in a predictable way from one lymph node to another. Other symptoms are more variable, including fever, weakness, itching, or weight loss. Anemia is often seen. In a small percentage of people, drinking alcohol results in pain in the tissues involved with Hodgkin’s disease. Non-Hodgkin’s lymphoma (NHL) is divided into low-grade (not very aggressive), intermediate-grade, and high-grade (aggressive) lymphomas. High-grade lymphomas are not very common in older adults. Low- to intermediate-grade lymphomas become more common with age. People with NHL usually notice large, painless lymph nodes in the neck or groin. Large lymph nodes around the elbow strongly suggest NHL. Problems can also be seen in the skin, liver, gastrointestinal tract, bones, and nervous system. People with low-grade NHL usually survive 7–10 years, even without treatment. However, low-grade NHL may change into a more aggressive form. Intermediate-grade NHL is the most common form in adults, with survival without treatment only 1–2 years. Lymphomas are diagnosed by lymph node biopsy. Another biopsy should be taken whenever the disease begins to progress more rapidly. Treatment is generally started in older adults when symptoms are significant or when the disease begins to progress rapidly. Treatment consists of chemotherapy, usually with a combination of drugs. The most common side effect of treatment affects the bone marrow and can lead to anemia, bleeding, and infection. In most older adults with Hodgkin’s disease, these side effects are not life threatening. However, these side effects in older adults with NHL are often serious, including bone marrow toxicity. Unfortunately, using lower, less toxic dosages of chemotherapeutic drugs are usually less effective. Multiple myeloma is a form of bone marrow cancer that is seen primarily in people older than 50 years. Multiple myeloma is diagnosed in about 14,000 Americans each year, with an average age at diagnosis of 68. Multiple myeloma is twice as common in black Americans as in white Americans. In multiple myeloma, growth of one family (clone) of the white blood cells that makes antibodies goes out of control. Antibodies can be produced by these cells in huge numbers, although they are not effective in the immune response. Symptoms often include weakness, loss of appetite, and weight loss. People with more advanced disease have bone pain, osteoporosis, anemia, high blood calcium, kidney problems, neurologic difficulties, and/or repeated infections. A classic feature of advanced disease is holes in the bone, which cause pain and fractures. Diagnosis involves blood and urine tests to look for abnormal antibodies, as well as x-rays to assess changes in the bones. Bone-marrow biopsies are often performed to confirm the diagnosis and to evaluate the potential for anemia, bleeding, or immune problems. Several diagnostic clues can help evaluate disease severity, including the presence or absence of holes in the bone, and the levels of antibodies, hemoglobin, and calcium in the blood. In older adults who do not have symptoms, treatment can be delayed. In a small number of these people, the disease may remain stable for many years and treatment is not needed. However, these people should be evaluated three or four times a year, so that chemotherapy can be started at the first signs of disease progression. Treatment is needed if painful holes in the bone develop, or if there are repeated infections, high blood calcium, or very high antibody levels. Standard treatment consists of intermittent chemotherapy every 4-6 weeks. Although there is no cure for multiple myeloma, treatment can relieve symptoms and prolong life. Supportive care includes drugs to fight osteoporosis and anemia, as well as antibiotics and other agents to fight infection. Fluid intake should be increased to 2–3 quarts a day to help protect kidney function. Bone pain is usually treated with radiation aimed at the holes in the bone that are causing pain. People with multiple myeloma should also remain active for as long as possible to help promote bone health. |
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Published: 10/28/2005