The Deadliest Cancer; Lung cancer kills more Americans than any other type of malignancy--and some of the victims never smoked. But despite grim statistics there is some good news: fresh research offers hope for earlier diagnosis and more-effective treatments.(Cover Story)

Byline: Geoffrey Cowley and Claudia Kalb (With Karen Springen, Anna Kuchment and Vanessa Juarez Graphic by Josh Ulick)

With the news last week that former smoker Peter Jennings had succumbed to lung cancer at 67 and Dana Reeve, who never smoked, was diagnosed with the disease at 44, millions of Americans grasped a terrible truth--the deadliest form of cancer doesn't strike just the pack-a-day crowd. Suddenly lung cancer was everyone's concern. And rightly so. Lung cancer may not inspire walkathons or pink-ribbon awareness campaigns, but after three decades of the War on Cancer and four decades of surgeon generals' reports, it remains the most devastating of all malignancies. The disease kills some 160,000 Americans a year--more than breast cancer, colon cancer and prostate cancer combined. The burden has grown steadily in recent decades, thanks to the rising incidence among women, and survival rates have scarcely budged. Nearly 60 percent of patients still die within a year of diagnosis, and 85 percent die within five.

The vast majority of cases are smoking-related, but curbing the use of tobacco isn't the only challenge we face. America's 46 million former smokers still constitute a huge reservoir of risk. And people who smoke don't all suffer the same consequences. Why do some stay healthy, even as nonsmokers are stricken? Are women more susceptible than men? And what are the prospects for earlier detection and more-effective treatment? Can science save other former smokers from Peter Jennings's fate? Researchers are the first to acknowledge the daunting challenges they face. But health officials are making new commitments--the National Cancer Institute unveiled a new research initiative last week--and after decades of discouragement, some researchers are voicing cautious optimism. Geneticists are zeroing in on mutations that may make some people vulnerable. Biologists and radiologists are devising new ways to detect small, localized tumors. And new treatments are beginning to extend survival times, even for advanced-stage patients. "That's not a home run," says Dr. David Johnson of the Vanderbilt-Ingram Cancer Center in Nashville, Tenn., "but it's hardly a bunt single."

The causes of lung cancer are no great mystery: some 87 percent of all cases result directly from smoking. Whatever your age, sex, race, occupation or family history, the surest way to protect yourself is to avoid smoking or to quit. Unfortunately, quitting doesn't completely negate the genetic damage that tobacco smoke…