For 13 years, Ken Kercheval played Cliff Barnes, J.R. Ewing's ambitious yet hapless brother-in-law and persistent rival on the television series Dallas. Despite their on-air enmity, the two men were friends away from the set, and Hagman, an anti-smoking crusader, used to warn Kercheval and the rest of the Dallas crew about the dangers of tobacco. "Larry was very dogmatic about not smoking on the set," says Kercheval, 59, who went through two to three packs a day during the show's run. "Most of the smokers did quit. I was just too bloody stubborn."

That proved unfortunate. Last February, doctors found a spot on Kercheval's left lung during a routine physical exam. It turned out to be two malignant tumors.

The diagnosis of lung cancer didn't come as a complete surprise to the actor. His father, Dr. John Marine Kercheval, a smoker, died of emphysema at the age of 67, and Kercheval realized that he too might someday be stricken with a smoking-related illness.

Now, four months after surgery to remove the lung's cancerous lower left lobe, he is free of the disease. "Usually the cure rate for lung cancer is about 10 percent, "says Kercheval's pulmonary doctor, Martin Gordon, "but because Ken's was detected early and hadn't spread, his chance of recovery is closer to 90 percent." Kercheval, who has four children from two marriages, credits his recovery to the love of his fiancée, Cheryl Ann Paris, 33, an actress with whom he also has a 13-month-old daughter, Maddie. At his home in Northridge, Calif, Kercheval recently discussed his illness with correspondent Lyndon Stambler.

EACH JUNE, AT THE BEGINNING OF the new Dallas season, I would traipse off to my doctor for an annual physical and a chest X-ray. My doctor would say to me, "Kenny, you're foolish. By the time we find a spot on an X-ray, it's usually too late." I continued to go every year after the show went off the air. I felt relieved when the results came back and there was nothing wrong.

Last February was different. My doctor found a spot on my lung. He told me it looked like adenocarcinoma, a cancer he attributes to smoking. He didn't need to biopsy it. Certainly I had apprehensions as I went for a variety of tests with two different specialists. But when they said the spot was isolated and therefore looked curable, I felt optimistic that I'd be okay. I didn't walk around with a cloud of impending doom. There wasn't going to be a conclusion until they operated.

I didn't tell anyone at first, even my fiancée, Annie, because I didn't want her to worry. About two weeks later, I went for a second set of X-rays, then had an MRI and nuclear bone scan done to make sure the malignancy hadn't spread. I asked the second pulmonary specialist how soon I'd need surgery. He said 10 days to two weeks. I said, "This is serious." I had lung cancer, for criminy's sake. There were some things I needed to take care of. The doctors' time frame lit a fire under me to get them done: I wanted to get my will in order, I've got kids. I've got people in my life I've got to take care of.

I told Annie after meeting with the second doctor. I didn't let on that I was terrified. I tried to make it sound very routine. Of course, Annie didn't believe my nonchalance and insisted that she go to the doctor with me. She's so honest and practical, which is what drew me to her when I met her while we were both filming a TV series in Texas two years ago. Annie's mother had died of cancer. We both knew it was a fact we had to deal with. She went to the doctor with me to help me emotionally prepare for the operation.

I had never had any kind of major surgery in my life. When I was a kid I had serious athlete's foot and nosebleeds. I was in a car accident once and broke my nose. I had to have some plastic surgery for a scar. But that was it.

I knew the severity of the situation. From what I had been told about the surgery, there was nothing to look forward to. Nothing. I was told it was one of the more painful operations. One doctor referred to it as "mutilating surgery." I thought that that was a dire word to use. Even though I knew I probably had lung cancer, I hadn't given smoking up yet. In fact, I had a cigarette as I walked up the sidewalk to the hospital. I think it was the realization I didn't have any choice. I had to quit. It was one for the road.

The surgery was scheduled for March 28 at Century City Hospital. We didn't know if it would take 45 minutes or five hours. The surgeons opened me up and found two tumors on my left lung: the first was about the size of a walnut. The second, alongside it, was smaller. They took a section of the larger tumor and biopsied it. When they learned it was cancerous, they removed the entire lower lobe, 55 percent of my left lung.

Annie didn't see me until eight hours later in the intensive care unit. I was admitted under another name, and she couldn't remember the name. I had checked in under an alias to avoid the tabloids; there are sources within some hospitals that call the tabloids every time a celebrity checks in and get paid for it. I wanted to avoid that, because I hadn't even told my 91-year-old mother, Christine.

When Annie saw me afterward she said I looked like I was 100 years old. I was in uncontrollable pain. I was heavily drugged. There could have been seven blue elephants and six zebras there, and I wouldn't have noticed. The incision ran from my left nipple under my arm all the way up around to my shoulder blades. I couldn't move without someone helping me. I needed a shot of painkiller every three hours. I was there for a week. On the third day, I felt the craving for a cigarette. I thought, "This is insane."

I was able to walk when I left the hospital, but I couldn't get in and out of bed by myself. Annie was with me full time. About 10 days after I came home, she had to go to the grocery store. Maddie was in her crib. I went to change her diaper. She probably weighed 22 pounds then. I reached down and picked her up and took her over to the changing table. I paid for that move for about four days. Everything hurt. That taught me to back off.

The doctors said I wouldn't be myself for a year. It took 2½ months. Another very encouraging thing was the fact that I didn't need radiation or chemotherapy. I had breathing exercises to do when I got home, but as far as lung capacity goes, I haven't noticed much of a difference.

I wanted to get back to work. I think it's really important that I get out there and do some stuff. I have a marvelous idea for a series I'm developing. And this week I'll be filming an episode of Perry Mason.

I grew up in a small midwestern town, Clinton, Ind. My mother's family were farmers and coal miners. My dad was a doctor and surgeon. He was the fifth generation of his family to become a doctor. Dad smoked Lucky Strikes. Once, a patient told him if he wanted to quit, he should go out and buy a pack of Picayunes. They were strong, nasty-smelling cigarettes. But Dad wound up liking them. He smoked Picayunes for the rest of his life. There were even two cigarette machines in Clinton that stocked Picayunes simply because Doc Kercheval liked them.

Smoking is a powerful addiction. I know about powerful addictions because I was a practicing alcoholic for 20 years. I've been sober for the last 14½ with the help of a 12-step program. At first you don't know how you're going to live without it. You think, if I don't drink, what in the world am I going to do with my time? Your time gets filled up quickly. The point is you do learn to live without it.

So far, I'd say I've been 99 percent successful at quitting smoking. I still have the urge, especially when I get anxious. I've had about 16 cigarettes since my surgery in March, about one or two a week. I don't feel good about myself when it happens, but I don't beat myself up about it.

What gives me strength is thinking about my children. My oldest, Aaron, is 36, and my youngest, Maddie, is 13 months. I realize that, being 59, I probably won't know my younger children when they're 36.1 feel lucky that I've been given my life back so I can enjoy my kids for as long as I'm supposed to be here.

If you're a smoker, the odds increase greatly that you'll get cancer. You should pray that you'll be as lucky as I was. But even if you don't have the desire or will to quit, at least have a regular checkup. It only takes about half an hour to get a chest X-ray. It's what I did, and I feel like a blessed man.