Though heart disease is a more common disease among American women, cancer is one of the most feared. Cancer is the second leading cause of death in the United States; nearly four of every ten Americans will have some kind of cancer at some point during their lives, and about 75 percent of those diagnosed with cancer are age fifty-five or older. One-third of all women in the United States will develop cancer during their lifetimes, so as you approach menopause, it's important that you understand which cancers have age-related risk factors for women.

Cancer isn't one disease, but a family of diseases, all of which occur when cell growth goes out of control in some part of the body. Contributing factors include environmental pollutants, heredity, occupation, nutrition, and lifestyle. Different cancers produce very different illnesses, each with its own symptoms, causes, and risk factors. The following sections discuss some of the most common cancers women face as they move into middle age.

Lung Cancer

Lung cancer is the leading cause of cancer death for women in the United States, and tobacco smoke is the leading cause of lung cancer. Though neither menopause nor age is a contributing factor in this disease, most women are diagnosed with lung cancer at age fifty — right around the time they hit menopause, and often after many years of tobacco smoke exposure. Women are one and a half times as likely as men to develop cancer from tobacco smoke, including secondhand smoke; the vast majority of nonsmokers who contract lung cancer are women.

Why not start this new phase smoke-free? Smoking increases your chances of developing cervical cancer, emphysema, and other life-threatening chronic lung conditions. Smoking is a sure way to derail an active, healthy passage into middle life. In fact, smokers tend to have earlier menopause than nonsmokers, so quitting early can delay menopause in some women.

Breast Cancer

Breast cancer is the second most common form of cancer for American women, and advancing age appears to be a major risk factor in its development. Nearly 80 percent of all breast cancers are found in women over fifty, and the incidence of diagnosis and fatality both seem to rise with age. The American Cancer Society (ACS) reports that 163 per 100,000 women in the United States in their forties are diagnosed with breast cancer each year, and 29 die of it; 374 per 100,000 women in their sixties will be diagnosed, and 90 of those will die from the disease.

If your mother, sister, or daughter has had breast cancer, your risks of getting it go up two to three times (depending on how many of these first-degree relatives are involved). And, if you've had breast cancer before, you have a higher risk of developing it again. If you've never had a child, or had your first child after age thirty, your risk goes up as well. But what about risk factors that you can change? The ACS lists the following risk factors for breast cancer that are specifically linked to lifestyle choices:

• Menopause hormone therapy. MHT does appear to increase the risk of certain types of breast cancer in some women. In 2006, it was reported that after the Women's Health Initiative (WHI) study results were made public, millions of women stopped MHT. The following year, the incidence of breast cancers, especially estrogen-sensitive breast cancers, had dropped by 7 percent. This is the largest drop in breast cancer rates since records were first kept in the 1970s. This strongly suggests a link between MHT and breast cancer.

  In the Nurses Health Study of 121,700 women patients, those using estrogen alone had a 23 percent increase in breast cancer over women who never used hormone therapy. Estrogen with progesterone was even more concerning, with a 58 percent increased risk of breast cancer. The most alarming was the 77 percent higher risk for women taking estrogen plus testosterone. Based on these results as well as the WHI study, it would be fair to say that using any sort of MHT has a chance of increasing your breast cancer risk.

• Alcohol. Women who have one alcoholic drink a day have a slightly increased risk of contracting breast cancer; two to five drinks daily can up your risk to one-and-a-half times that of nondrinkers.

• Diet. The connection between obesity and breast cancer risk is still being studied, but research indicates that after menopause your risk of contracting breast cancer is greater if you are overweight. How much of this risk is linked to your body fat versus specific dietary fat content is still not clear. Another issue may be that more breast tissue (obese women tend to have bigger breasts) makes it harder to find an early, small cancerous lump, both on exam and on mammogram.

• Exercise. Although research has begun only recently, early findings reported by the ACS seem to indicate that even moderate physical activity can lower breast cancer risk. And maintaining good overall physical condition certainly improves your chances of having fewer complications related to medical and surgical treatment for any disease — including breast cancer.

Survival rates for breast cancer are highest when the cancer is detected early. The five-year survival rate (your chance of being alive five years after the diagnosis of cancer is made) is 96 percent for women whose cancer is caught at an early stage. Early detection helps keep the surgery or other treatment that follows diagnosis as noninvasive and conservative as is possible. Techniques for incorporating breast cancer detection into your general health maintenance plan appear later in this chapter.

Endometrial Cancer

In the United States, cancer of the endometrium — the lining of the uterus — is the most common cancer of the female reproductive organs. The ACS estimates that this cancer has a five-year survival rate of about 84 percent.

Your risk of developing endometrial cancer increases as you age. The average age of diagnosis for this cancer is sixty, and 95 percent of all endometrial cancer occurs in women age forty or older.

A number of risk factors can contribute to the development of endometrial cancer:

• Total number of years of anovulatory cycles. Your body's total lifetime exposure to estrogen, without the balancing hormone progesterone, can have an impact on your likelihood of developing endometrial cancer. The more cycles you have had without ovulation, the more you have been exposed to unopposed estrogen, and the higher your risk. If you began having periods at a young age (before the age of twelve), continued having periods past age fifty, and have had few or no children (which gives your body a break from the constant estrogen production), your ovaries have been producing estrogen for a greater number of years than the average woman. The more estrogen (and less progesterone) your body has experienced over the years, the higher your risk of developing endometrial cancer.

• Obesity. Depending upon how obese you are, your excess body fat can increase your chances of developing endometrial cancer two to five times. Body fat can convert other hormones into estrogen, and having excess body fat contributes to a woman's estrogen levels — and risks of developing this cancer. Diets high in animal fats also may contribute to this risk factor, as can diabetes — a disease common among obese women. Women who are overweight are also more likely to have abnormal menstrual periods, because their ovaries fail to ovulate — thus not producing enough progesterone to balance their estrogen.

• Estrogen therapy (ET). ET — hormone therapy that doesn't include progesterone — can increase a woman's chance of developing endometrial cancer. Though doctors used to prescribe ET for relief from hot flashes, osteoporosis, and heart disease, today doctors almost exclusively combine estrogen with progesterone in MHT, which eliminates the increased risk of endometrial cancer. Of course, if you have had a hysterectomy, you do not need a prescription for progesterone added to your estrogen, since your risk of endometrial cancer is zero.

If endometrial cancer is diagnosed early, it has an excellent survival rate. Precancerous changes, such as endometrial hyperplasia, often become known through unusual spotting, bleeding, or discharge. Often, these symptoms are apparent for years before actual cancer develops. Sometimes women who have had irregular periods for their entire lives forget to report this to their health care practitioner. Besides, when you're entering menopause, irregular bleeding, spotting, and discharges aren't supposed to be unusual occurrences at all, so how do you know when to worry that your irregularity is signaling endometrial cancer?

If you suffer from unusual bleeding that lasts more than two weeks, consult your doctor right away — no matter what your medical history. An endometrial biopsy can determine whether or not your symptoms point to endometrial cancer or some other cause.

Ovarian Cancer

One in 70 women will develop ovarian cancer over the course of her life; it's the fourth leading cause of cancer deaths in women in the United States. Every year, U.S. doctors diagnose over 23,000 cases of this cancer, and more than 14,000 women die from it. Ovarian cancer occurs most often in women who are approaching the age of menopause. This cancer is a silent killer with symptoms that can be mild, vague, and similar to those of many other conditions and diseases. If detected early, while still in the ovary (called stage I), this cancer is curable about 90 percent of the time. But if the cancer spreads to the pelvis or beyond (stage III or IV), the five-year survival rate drops dramatically. Taking all stages into consideration, this cancer's overall five-year survival rate is somewhere around 40 percent.

Sadly, early ovarian cancer has few symptoms, so it makes sense to know your risk factors and your family history. Risk factors for ovarian cancer include:

• A family history of ovarian, breast, colon, rectal, endometrial, or pancreatic cancer increases a woman's risks considerably. The severity of increased risk is higher if there has been one of these cancers in a first-degree relative, such as a mother, sister, or daughter.

• A woman's risk of developing ovarian cancer also rises with the total number of times she has ovulated; again, exposure to estrogen has an impact on the woman's overall risks. In other words, not having had any children or not taking birth control pills at any point in your life means your ovaries have been working overtime, compared to women in the average population.

Symptoms of ovarian cancer are vague, especially in the early stage, but can include pain, pressure, or swelling in your abdomen; gas, nausea, and indigestion; unexplained changes in your bowel movements; changes in your weight; fatigue; or pain during intercourse. If you exhibit any of these symptoms, talk to your doctor. He or she can perform a sonogram (ultrasound examination of the pelvis) to determine if your ovaries have any abnormalities. In addition, your health care provider may choose to obtain a blood test called CA-125 to check for a certain protein that can point to the presence of ovarian tumors. It is not a perfect test. A negative result does not rule out ovarian cancer, since about half of tests are negative in stage I of the disease; an elevated result does not always mean ovarian cancer — it can point to liver problems, colon conditions such as diverticulitis, and other illnesses. Inaccurate results with this blood test (a false positive) are highest in premenopausal women, so check with your doctor about the usefulness of taking the test and with your insurance company about whether it is covered.

Of course, your health care provider physically palpates (feels) your ovaries every year during your pelvic examination to detect any changes in their size or shape. In most cases, a combination of symptoms and physical examination findings lead to a series of diagnostic tests for ovarian cancer. That's why now, more than ever, it's critical that you report any unusual physical symptoms or changes in your normal menstrual cycle to your health care provider.