DEAR DR. DONOHUE: I am a 73-year-old woman with two doctors who give me different answers on Pap smears. One tells me I don’t need them at my age. The other says I do. I don’t want to risk letting cancer go undetected, but I would like to stop having Pap smears. Is there a safe age when they can be stopped? — K.M.

ANSWER: Every woman needs to make a slight bow when she hears the words “Pap smear.” In 1943, Dr. George Papanicolaou (the “Pap” of Pap smear), a pathologist, devised this method for early detection of cervical cancer. The cervix is the necklike extension of the uterus into the vagina. It is one of the most common cancer sites in women.

Since introduction of the Pap smear, cervical cancer deaths have decreased by 75 percent. Few other medical tests have done so much for so many.

Your two doctors are not the only ones who disagree. Many cancer experts say that a woman is not courting danger by stopping Pap smears at age 65 if her previous Pap smears have been normal. Others say a woman should wait until 70 to stop the smears. They can be stopped then if the woman has had three or more smears in the previous 10 years and they were normal. If your smears have been normal, then both schools would let you stop testing now.

All women should be faithful to the schedule of Pap smears given to them by their doctors. Medicine is about to enter a new age when the detection of cervical cancer will be even more reliable than it has been so far. Tests for detection of the human papillomavirus are being perfected. The human papillomavirus is the cause of most cervical cancer. Detecting the virus clears up doubts that come from equivocal Pap smears, ones where the call between normal and abnormal is not clear.

Readers can find answers to their other questions about Pap smears and cervical cancer in the newly written pamphlet on those topics. To obtain a copy, write to: Dr. Donohue — No. 1102, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Please tell me what you know about a relatively new medicine called Forteo. I understand it is an injection-type product used for the treatment of osteoporosis. I am especially interested in side effects and what the side effects are in men. — M.B.

ANSWER: Forteo, the brand name for teriparatide, is a new medicine that attacks osteoporosis differently from previous osteoporosis drugs. It stimulates bone formation. The older osteoporosis drugs slow bone reabsorption.

Bones are active, ever-changing structures. Daily a demolition crew of bone cells gobbles up a section of bone. Immediately a construction crew moves in and rebuilds that bone section. It is a way to keep bones ever new. When osteoporosis strikes, the demolition crew works overtime, and the construction crew cannot keep pace.

Forteo is a synthetic version of parathyroid hormone, the hormone that controls the body’s calcium deposits.

Side effects include nausea, dizziness, leg cramps and headaches — things you can find listed for almost every medicine. In the laboratory, some animals given high doses of the drug for protracted periods of time developed bone cancer. That should not frighten you. The Food and Drug Administration has given Forteo its seal of approval, and that is not done with a casual flick of the wrist. The side effects are the same for men and women.

Forteo has two drawbacks. It is expensive, and it must be given in shots. The shots are similar to the insulin shots diabetics give themselves. They are not painful.

DEAR DR. DONOHUE: What’s the difference between the PSA test and the AMAS test for detecting prostate cancer? — F.B.

ANSWER: AMAS — anti-malignin antibody in serum — is a blood test that tracks down malignin, a protein produced by most cancer cells. It is not a specific test for prostate cancer, while the PSA (prostate-specific antigen) test is. The PSA test, therefore, is the one more commonly used.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.