Q. Would you please explain why my doctor would be reluctant to do a Pap smear on an older woman? Have they done away with the annual Pap smear? I had to insist to get it done. In the past, I had a hysterectomy because of excessive bleeding due to fibroids. I'm a relatively healthy 78-year-old; shouldn't I continue to have Pap smears each year?

A. There are a couple of reasons why in your case it's reasonable to forgo further Pap smears: your age and the fact that you've had a hysterectomy.

There is no universally accepted age cutoff, but there are some general guidelines. The U.S. Preventive Services Task Force recommends stopping regular Pap smears after age 65 if yours have been consistently normal. The American Academy of Family Physicians concurs with that view.

The American Geriatrics Society says it's okay to stop Pap smears at age 70. The American College of Physicians recommends continuing to get them until age 65, but says you should continue up to age 75 if you've had none done between ages 55 and 65.

The American College of Obstetricians and Gynecologists, the American Cancer Society, the National Cancer Institute and the American Medical Association are among the organizations that have issued guidelines on Pap smear screening. They agree that young women should begin getting annual Pap smears at age 18 or when they begin sexual activity.

After a woman has had three normal Pap smears, the guidelines say, annual exams are not necessary. Tests should still be done at least once every three years, but individual schedules will depend on what a woman and her doctor agree on and whether she has any risk factors for developing cervical cancer.

Bear in mind that Pap smears are a screening test for cancer of the cervix, the portion of the uterus, or womb, that extends into the back of the vagina. Cancer of the cervix tends to develop in younger women--typically those in their thirties and forties. If you've gotten to age 70 without any signs of cervical cancer, it's unlikely that it will start developing.

However, if you've had abnormal Pap smears, or signs of pre-cancer known as dysplasia, your doctor will want to keep screening until it seems unlikely that cancer will develop.

One word of caution: There are a fair number of older women who haven't had regular Pap smears. This is the group that is at risk for developing cancer of the cervix later in life. It's not that the cancer starts in them all of a sudden. Instead, there are early warning signs that show up as abnormal Pap smears. These can precede the actual cancer by 10 years or more. If these women had had regular Pap smears, the warning signs would likely have appeared. They could have had treatment, and their cancers could have been prevented.

The next question you raise has to do with Pap smears in women who have had a hysterectomy--removal of the uterus. Many experts feel that if you don't have a uterus, there's no reason to do Pap smears. The U.S. Preventive Services Task Force recommends stopping Pap smear screening after a hysterectomy, unless cancer of the cervix was the reason for the hysterectomy. In that case, it makes sense to continue screening to check for the small chance of recurrence of the cancer inside the vagina.

In any event, if you understand the reasons for doing Pap smears and would still feel more comfortable having them, I would support your choice to do so. I also know that there are many physicians who continue to do Pap smears on older women and women who have had hysterectomies.

Jay Siwek, chairman of the department of family medicine at Georgetown University Medical Center, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician. Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, DC 20071. Questions cannot be answered personally.