DEAR ABBY: Imagine if, by applying what we already know, we could save the majority of lives that are lost to the third-leading cause of cancer in men and women. That's no pie-in-the-sky dream. I'm talking about colon cancer. Regular testing can help prevent this disease or detect it at its earliest, most treatable stage.

This year, colon cancer will claim the lives of more than 56,000 Americans. That's more than 150 deaths a day, many of them preventable. The tests allow doctors to remove polyps before they can become cancerous, and prevent colon cancer from happening. These same tests can also detect early signs of the disease as effectively as mammography detects breast cancer. So why aren't Americans over the age of 50 getting tested?

Many people simply do not realize they're at risk beginning at age 50. Some people think they don't need to be tested because they have no family history of the disease or symptoms. The truth is, symptoms often don't appear until colon cancer has progressed, and no matter what a person's family history or how someone feels, if you're 50 or older you're at risk for colon cancer.

There is also the perception that the test will be embarrassing or painful. While some of the tests may be uncomfortable, colon cancer is far worse.

Bottom line: If you're 50 or older, now is the time to get tested for colon cancer. People with a family history of the disease or other risk factors should discuss with their doctors getting tested even earlier.

Abby, March marks the sixth annual National Colorectal Cancer Awareness Month. It's a perfect time to start raising this important subject and making sure that Americans get the test that could save their lives. Do it NOW. Don't put it off. It's one of the few cancer tests that can actually prevent the disease. -- STEPHEN F. SENER, M.D., PRESIDENT, AMERICAN CANCER SOCIETY

DEAR DR. SENER: I am pleased to help publicize this important message. Readers, if there is a history of colon cancer in your family, please discuss it with your doctors, regardless of your age. If you're lucky and there isn't one, but you're 50 or nearly there, recognize that adulthood brings with it certain responsibilities. So don't be childish, don't be embarrassed and don't be afraid. The exam isn't painful. The biggest "inconvenience" is the preparation for it. Consider it an initiation into a special club -- the long-life club.

The American Cancer Society offers a free information kit to help you discuss colon cancer testing with your physician. To get one, call toll-free: (800) 227-2345 and stop colon cancer before it starts.

DEAR ABBY: I am a 28-year-old, American-born Asian woman, whose tradition-bound, first-generation mother insists that I, or another person in our family, share a portion of our meal with her even though she has already eaten and we have not. This is acceptable behavior in her home, but is it appropriate for her to continue this behavior in public?

For example, my mother, my aunt, my cousin's three children and husband and I went out to dinner at a steakhouse, and my mother insisted that I slice a portion of my steak and share it with my cousin, who had already started to eat her entree of pasta. Not wanting to create a scene, I obliged. Mother becomes angry with me when I try to explain that this is not proper etiquette. She calls me selfish for not wanting to share. What do you suggest I do? -- FRUSTRATED DAUGHTER IN CALIFORNIA

DEAR FRUSTRATED: You will spare yourself a lot of heartburn if you realize that you cannot change your mother. So, when you are at a restaurant with her, order a larger portion than you normally would, beat her to the punch and offer to share.

Abby shares more than 100 of her favorite recipes in two booklets: "Abby's Favorite Recipes" and "More Favorite Recipes by Dear Abby." Send a business-size, self-addressed envelope, plus check or money order for $10 (U.S. funds)

to: Dear Abby -- Cookbooklet Set, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included in price.)

DEAR ABBY: I need advice with a problem I have regarding our basset hound, "Sherlock." I bought Sherlock for my husband, "Ken," a year and a half ago. Ken loves the dog, and so does my 18-year-old daughter, "Gretta," who lives with us.

When I bought Sherlock, the understanding was that he would be cared for by my husband and daughter. This is not what happened. I do 90 percent of the feeding, cleaning up after him, taking him to the groomer, the veterinarian, etc. We also have a cocker spaniel, "Lulu," we have had since our Gretta was 3. Lulu has also been my responsibility for the most part. Ken and Gretta play with the dogs, and I "get" to do almost everything else.

Abby, I am not a dog lover; I am a dog "liker." I feel used and resentful. I want to give Ken an ultimatum: Care for Sherlock or find another home for him. Am I being unreasonable? I feel guilty thinking about doing this, because Sherlock was a Christmas gift to my husband, but I just don't want to continue this way. Ken works full time, as do I, but he commutes two hours each day. Asking him and Gretta to share in the care of the dogs has done no good. Any advice would be appreciated. -- USED AND RESENTFUL IN SOUTHERN CALIFORNIA

DEAR USED AND RESENTFUL: Stop feeling used and resentful and look in the mirror. Why did you buy a second dog after seeing that your husband and daughter didn't care for the one you already had? You put yourself in this pickle.

Please reconsider shrugging off the responsibility for Sherlock. There are alternatives to getting rid of him. A neighborhood teen could be hired to walk him. A pet service could provide transportation to the vet or the groomer. Finding another home for him should be only your last resort.

Focus on the bright side. Since you and your husband have full-time jobs, and your daughter is busy with her own schedule, it's just as well that you have two dogs because they have each other for companionship.

DEAR ABBY: Thirty years ago my mother-in-law, "Grace," suddenly changed. She began accusing her husband of cheating on her and trying to poison her. She made his life miserable until he passed away. After the funeral, we moved Grace into a house next door to ours.

Things were OK for a while, then she started up again. According to Grace, everyone has been trying to kill her. She has alienated almost the entire family because of her accusations, and she has called the police several times because she thinks everyone is stealing from her.

A few months ago, Grace had surgery. I stayed with her until she was back on her feet. Now she says I am trying to poison her, and have people come in and steal her stuff when she's outside.

My husband, her only child, is very upset and has forbidden me to go over there anymore. Grace is 83, but age has nothing to do with it. This started when she was in her early 50s.

Can somebody suggest what we can do? We love her dearly and we're at our wits' end. -- TEARFUL IN TENNESSEE

DEAR TEARFUL: Your mother-in-law needs a psychiatric evaluation. Her son should make sure her doctor understands what's been going on before she goes for the exam. The symptoms you describe indicate she may be mentally ill.

CONFIDENTIAL TO AFRAID TO FALL: Please don't give up yet. Keep in mind that every failure is a stepping-stone to success.

What teens need to know about sex, drugs, AIDS, and getting along with peers and parents is in "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $5 (U.S. funds only) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: I am a 36-year-old married woman. "Vern" and I have been married for 10 years and are childless by choice. We have had our share of problems, but for the most part, I've learned to put them in perspective.

Eight months ago, I started flirting with a guy at work. "Jason" is married with two small children. At first the flirtation seemed harmless. The next thing I knew, we were having a hot-and-heavy affair.

I have never been so drawn to any man. I became convinced that feeling this way about Jason meant I was no longer in love with Vern, so I left my husband.

Vern was devastated. I didn't tell him there was someone else. I said I was unhappy, which was the truth. I got my own place, and the affair continued until Jason's wife became suspicious. Then Jason started pulling back. He said he was worried about not being able to see his kids.

Finally, Jason told me he thought it would be a good idea for me to go back to Vern. I begged him to change his mind and said I'd be his other woman for as long as it takes. I was so in love. He made me laugh, listened to me, and made me feel special. He was everything my husband wasn't.

I am now back with Vern. I care for him, but the spark is long gone. He goes out of his way to make things right for me, but he no longer trusts me because he's heard rumors. I want our marriage to work, but all I do is think about Jason. What should I do? -- CONFUSED IN ALASKA

DEAR CONFUSED: While you're thinking about Jason, please remember that although he was amusing and a good listener, and the chemistry was strong, he was also a liar and a cheater. He may have made you feel special, but when the chips were down, his wife and children were more important to him.

Your husband wasn't born yesterday. He still loves you. Vern took you back in spite of the rumors. You now have a second chance -- but only if you reorganize your priorities. If you want your marriage to work, you and Vern will have to admit that you had issues before you moved out, and seek professional counseling to work on them.

DEAR ABBY: I have known "Jerry" for four years. We met through my ex-boyfriend, "Paul." We have been dating for about nine months.

Paul and I have a child together; our daughter, "Elise," just turned 5. My ex and I rarely speak to each other, and when we do, it's only about Elise.

I love Jerry with all my heart and would never cheat on him. How can I convince him that I am no longer interested in Paul? Whenever we have an argument, he says, "Go back to Paul -- maybe he can make you happy."

Would I be out of line if I told Jerry, "If you don't like the idea of my talking to my child's father, there's the door, and don't let it hit you on your way out"? We don't even live together, and he's trying to control me. How do you think it would be if we started living together -- which we have discussed? -- ANGRY IN PENNSYLVANIA

DEAR ANGRY: Jerry is insecure. Since you love him, do not give him an ultimatum. Because you share a child with Paul, there will always be contact of some sort. If Jerry is going to build a future with you, he will have to accept that fact. Do not live with him until he is mature enough to do so.

What teens need to know about sex, drugs, AIDS, and getting along with peers and parents is in "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $5 (U.S. funds only) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)