What cancer are you at risk to develop at your age? Cancer risk is different for women with each decade of life.

Women are diagnosed with more new cases of cancer each year than men. However, men have more cancer mortality. For both genders a lot of these cases are preventable. The American Cancer Society estimates that out of the 555,000 Americans who will die of cancer this year, approximately 170,000 will die because of tobacco use, and 19,000 will die of causes related to excessive alcohol consumption. In addition, approximately one-third of the cancer deaths are related to poor nutrition, obesity, inactivity, and other lifestyle factors and could be prevented. A healthy lifestyle lowers your lifetime risk of cancer dramatically. Research suggests that only about 20 percent of all cancers are caused primarily by genetic factors.

The most common-occurring cancers among women (other than skin cancer) are those of the breast, lung, and colon. The order changes when you consider cancer deaths. In females, lung cancer is the leading cause of cancer death, followed by breast and then colon cancer. Although most people fear cancer, few people realize that an individual's risk of certain types of cancer changes with each decade of life.

20s Most women during their 20s are thinking primarily about their career and finding a life mate. Cancer is usually not a primary concern. However, cervical cancer is a foremost risk during this decade. Most women are familiar with the Pap test, the most widely used screening test for cervical cancer. It can detect precancerous changes in cervical cells; these can be treated before aggressive cancer develops. The American Cancer Society recommends annual Pap smears to screen for cervical cancer when women become sexually active or at age 18 (whichever comes first).

Cervical cancer is caused by an infection with human papillomavirus (HPV). This common virus is passed from person to person during sex. The main risk factor for cervical cancer is having multiple sexual partners or having sex with men who have had many partners. Other risk factors include smoking, poor socioeconomic status, non-Caucasian race, and HIV infection. Cervical cancer risk peaks during the decades of the 20s and 30s. Although the risk decreases as women age, older women still need Pap smears. Although only 25 percent of all cervical cancer cases are in women age 60 or older, 40 percent of all the cervical cancer deaths occur in this population. Cancer that is limited only to the cervix is treated locally with freezing, laser burning, or removal of the diseased cervix. Rarely a hysterectomy is performed. Cervical cancer that spreads outside of the cervix and uterus is frequently very aggressive and possesses few treatment options; this underscores the importance and effectiveness of screening.

30s The decade of thirtysomething carries two main cancer risks--a continuing risk for cervical cancer, and a developing risk for lymphoma, a common malignancy from age 30 to 50.

Lymphoma typically presents as painless, enlarged lymph nodes. Nonspecific symptoms such as fatigue, weight loss, and low-grade fevers may also be present. Many factors can cause lymph nodes to swell, including trauma, infection, irritation, and inflammation. However, in all of these situations the lymph nodes will likely be very tender to touch, and given a small amount of time, will return to normal size. In lymphoma they tend to remain enlarged and painless. Unfortunately, there is no blood test for detection of this disease. Individuals are encouraged to see a physician if any lymph nodes remain enlarged longer than two weeks.

There are two types of lymphoma: Hodgkin's disease and non-Hodgkin's lymphomas. Regardless, the cure rates are generally very good among both. As with most cancers, the earlier the disease is detected and treated, the better the chance of survival. Radiation and, if more advanced, chemotherapy are used for treatment. There are a limited number of very advanced, aggressive lymphomas that carry a poor prognosis.

40s Although lymphoma is still a significant possibility during this period, this is the decade to start screening for breast cancer. Women fear breast cancer more than any other cancer (even more than heart disease, the number one killer of women). Out of the expected 647,000 new cases of cancer diagnosed in women this year, 203,000 will be breast cancer.

Breast cancer usually presents as a painless, rock-hard lump in the breast. The most common location is the upper outer quadrant of both breasts. A breast cancer lump will double in size approximately every three months. If a suspicious lump is found, usually a mammogram and frequently a biopsy are performed. If the lesion is cancerous, additional surgery is required. Depending on the stage and location of the cancer, women undergo either a lumpectomy or a modified radical mastectomy. With either surgery, lymph nodes are removed from under the arm, to look for any spread of disease. In most cases chemotherapy after surgery is recommended. The prognosis is greatly affected by finding breast cancer before it has spread.

Screening mammograms are recommended by the American Cancer Society to start for all women at age 40. Women with a strong family history of breast cancer may choose to start earlier. Mammograms have been proven to reduce mortality as a result of breast cancer after age 50. By this time the breasts are less dense and the mammogram can find very small lumps. The data on women in their 40s is more confusing. During this decade the breasts are denser, and a mammogram has more difficulty finding small lumps. A study showing that mammograms lower mortality from breast cancer in 40-year-olds does not exist. Current recommendations for women in their 40s call for a mammogram every two years, self-exam every month, and a professional exam every year. It is interesting to note that few people know that about 1 percent of breast cancer cases occur in men. This disease is typically very aggressive in men and causes higher rates of mortality than in women.

50s The three most common cancers for women are all-important risks during this decade. Women should be screened annually for breast cancer during this entire decade. In addition, colon and lung cancer become significant risks at this age.

More than 95 percent of all lung cancers occur in current or past smokers. Unfortunately, lung cancer produces few or no symptoms until there is significant growth. This is because lung tissue itself is void of pain receptors. Only when the tumor has grown to the chest wall or the bronchus, both of which possess sensory nerve fibers, do individuals develop symptoms. Common symptoms are weight loss, fatigue, and a bloody cough. Lung cancer can rapidly spread to bone, lymph nodes, liver, and brain. Diagnosis can usually be made with just a chest X-ray.

If there is limited disease, surgical removal of a lobe of the lung can be performed. Otherwise radiation and chemotherapy are the mainstays of treatment. Prognosis is poor, because the disease is frequently not caught early. The five-year survival rate is only 15 percent. Although there is no recommended screening test for lung cancer, there is currently research into using spiral CAT scans to find early lung tumors. However, near complete prevention can be obtained unequivocally by not smoking.

There are more than 105,000 new cases of colon cancer diagnosed in the U.S. each year. One in 20 persons develops this disease in their lifetime. A diet high in fat and red meat and low in vegetable fiber is associated with a greater risk. In addition, any family history of colon cancer increases lifetime risk of developing this malignancy by threefold.

Colon cancer originates from colon polyps, which are mushroom-shaped growths that develop in the intestine. Although there are many types of colon polyps, colon cancer originates from just one type of polyp, called a villous adenoma. No other polyps become cancerous. Screening, starting during the 40s for high-risk individuals, involves the use of a flexible sigmoidoscope by a physician to examine the colon. This should be done every five years to screen for polyp formation. A less invasive, but also less accurate, test for colon cancer is an annual screening for microscopic blood in the stool. However, this test assumes that all colon cancers bleed, which unfortunately is not realistic.

Symptoms of colon cancer can range from none to intestinal bleeding, obstruction, and weight loss. This cancer commonly spreads to lymph nodes and the liver. Treatment involves surgery to remove the primary cancer and regional lymph nodes. Chemotherapy is also used to treat any disease that may have spread. Colon cancer diagnosed early carries a great prognosis (greater than a 95 percent cure), while late-stage cancer is difficult to overcome (less than a 5 percent survival at five years).

60s The seventh decade of life continues the significant risk of colon, breast, and lung cancer, and screening measures for them continue. But along with these three major cancer risks, ovarian cancer becomes a significant risk during this decade.

Ovarian cancer is the fifth most common cause of cancer death in women. The chance of a cure is good if it is diagnosed early. Cancers found and treated before they spread outside of the ovary have a five-year survival rate of 75 percent. Unfortunately, only 25 percent of ovarian cancers are found at this early stage, because the disease rarely produces symptoms until it has spread to other organs. But these symptoms of ovarian cancer may include swelling of the abdomen and pelvic pain or pressure. These symptoms are not specific to ovarian cancer and are more commonly caused by something else. When the disease is suspected, an ultrasound or CT scan of the pelvis is commonly ordered; however, the diagnosis can be confirmed only by biopsy.

Since early detection and treatment greatly increase survival rates for ovarian cancer, it would be an ideal disease for a screening test. Unfortunately, to date, no effective screening test has been identified. There is no known cause of ovarian cancer. A few risk factors have been identified, including increasing age, long-term use of fertility drugs without pregnancy, a family history of ovarian cancer, and increased number of menstrual cycles (early menarche, late menopause). Factors that lower your risk for ovarian cancer include pregnancy, breast feeding, hysterectomy, and birth control pills.

Although it's becoming less common, the American Cancer Society estimates that 39,000 women will be diagnosed with cancer of the uterine lining (endometrial cancer) this year. Risk factors for uterine cancer either increase the amount of estrogen a woman's uterus is exposed to or increase the duration of the exposure. Known risk factors include obesity, infertility, diabetes, menstrual periods prior to age 12, menopause after age 52, treatment with tamoxifen (a breast cancer drug), certain types of estrogen replacement (particularly estrogen alone without progesterone). The primary symptom of uterine cancer is unexplained, irregular vaginal bleeding that does not stop. Diagnosis is easy, commonly with an endometrial biopsy. Treatment is either radiation or a hysterectomy. Prognosis is very good as long as the cancer has not spread outside the uterus.

70s As women reach their life expectancy, the risk of developing cancer reaches its peak. Cancers of the breast, colon, and lung continue to be very significant risks. A personal physician should screen for multiple diseases on an annual basis.

Although there is already enough cancer risk to be concerned about, there are several relatively rare cancers that become more common at this time. Included in this group are cancers of the urinary bladder, throat, esophagus, kidney, and pancreas. The majority of the risk from these entities can be substantially reduced by never smoking.

Leukemia is a cancer of the white blood cells and occurs commonly in the later decades of life. White blood cells normally fight infections. There are two types of leukemia, acute and chronic. In both types of leukemia there is a proliferation of immature white blood cells. Although there are exceedingly increased amounts of white blood cells, these immature cells have limited infection-fighting ability. In the acute leukemias, all of the white blood cells are immature and nonfunctional, thus making the risk of infection very high. Chronic leukemias are characterized by both mature and immature white blood cells. The mature white blood cells make infection risk much lower, thus individuals can frequently live multiple years with a chronic leukemia.

Screening for this disease can be obtained with a complete blood count, which is usually performed at an annual physical exam. Symptoms can include abdominal pain from an enlarged spleen, fatigue, lymph node enlargement, and weight loss. Diagnosis is made by a bone marrow biopsy. Treatment is chemotherapy followed by a bone marrow transplant.

Vaginal cancer occurs during the 70s and 80s. It is a rare disease; only 2,000 cases occurring per year, and it results in very few cancer deaths.

Your Risk

Although there will be significant improvements in the diagnosis and treatment of most of these feared illnesses, cancer will continue to be a major health issue for the twenty-first century. Individual choices make a big difference. A healthy lifestyle lowers or eliminates your risk of nearly every cancer. Screening can catch most of the remaining cancers at an early, treatable stage.

Cancer risk is different for each decade of life. It is important for each person to understand how the risk changes over time. Proper screening includes considering your family history, personal habits, and occupational exposures. The American Cancer Society recommends screening plans for individuals at normal risk levels. Discussing your risks, along with developing a screening plan with your personal physician, should prove beneficial.

Prevention and Screening of the Most Common Cancers in Women

Type of Cancer     High Prevalence  Screening Test  Prevention
                   Age

Lung Cancer        age greater      none, spiral    no smoking
                   than 50          CAT scan        maybe vitamin E
                                    shows promise

Breast Cancer      age greater      mammography     avoid alcohol
                   than 40                          avoid estrogen

Colon Cancer       age greater      stool test      high-fiber diet
                   than 45          for blood       vitamin E
                                    sigmoidoscopy   low-fat diet

Cervical Cancer    age greater      pap smear       monogamy
                   than 15

Leukemia           age greater      complete blood  avoid radiation
                   than 50          count

Throat Cancer      age greater      none            no smoking
                   than 50

Ovarian Cancer     age greater      none            avoid fertility
                   than 40                          drugs

Lymphoma           age 35-50        regular exam    none
                                    of lymph nodes
                                    and spleen

Skin Cancer        age greater      yearly exam of  avoid ultraviolet
                   than 30          moles           light

Pancreatic Cancer  age 50-70        none            no smoking

Uterine Cancer     age greater      none            avoid obesity,
                   than 50                          diabetes

Vaginal Cancer     age greater      none            none
                   than 70

Cancer Statistics at Specific Sites

Lung Cancer

* Most common cause of cancer death.

* Cigarette smoking causes more than 90 percent of cases in males and more than 80 percent in females.

* Lung cancer risk 20 times higher for smokers of one pack per day than for nonsmokers.

* Lung cancer risk for a nonsmoker married to a smoker increases 30 percent.

Breast Cancer

* Most common cancer (excluding skin cancer).

* Hard, painless lump in breast, doubles in size every three months.

Colon Cancer

* Develops from colon polyps.

* High cure rates if found early.

* Sigmoidoscopy is a good screening test.

Ovarian Cancer

* Rarely found early.

* No good screening test.

* Only a few known risk factors.

Lymphoma

* Common during the decades of the 30s and 40s.

* Presents with enlarged, painless lymph nodes.

* High cure rates.

Skin Cancer

* Three types: basal cell, squamous cell, and melanoma.

* Only melanoma is life-threatening.

* Risk directly related to the amount of ultraviolet light exposure.

Cervical Cancer

* Typically occurs in young, sexually active women.

* Directly related to transmission of human papillomavirus.

* Treatment is local and effective and is limited to the cervix.

Throat Cancer

* Limited only to past and present smokers.

* Poor cure rates.

* Spreads to other sites quickly.

Leukemia

* Cancer of the white blood cells.

* Two types: acute and chronic.

* Treatment is chemotherapy and a bone-marrow transplant.

Pancreatic Cancer

* Usually presents as painless jaundice.

* Has usually spread by the time it is diagnosed.

* Poor prognosis.

Scott E. Woods, M.D., M.P.H., M.Ed., is the director of epidemiology at Bethesda Family Practice in Cincinnati, Ohio.