When Sarasota nurse Kim Laning started having severe backaches last October, she dismissed them. The office manager of a thriving endoscopy practice, Laning thought she must have wrenched her back helping a patient.

Her doctor ordered physical therapy, but by November, with pain spreading to her hips and left arm, Laning was in agony, curling up with heat pads and relying heavily on pain medication for relief. The shoulder rubs from her 21-year-old son, Joshua, and 26-year-old daughter, Kariann, became a nightly ritual.

Eventually, Laning quit physical therapy and turned to a chiropractor. Disturbed by her lack of progress, he ordered a spinal MRI. "That was Dec. 22," remembers the 46-year-old Chicago native. The next day the chiropractor ordered another MRI, then a CT scan the day after.

Three months after Laning first complained of an unrelenting backache, her doctor called to tell her that she had inoperable lung cancer, which had spread to her liver, adrenal glands and bones. With that phone call, Laning became one of more than 172,000 people who will be diagnosed with lung cancer this year. Nearly 80,000 of those will be women (Christopher Reeve's widow, Dana, is one recent high-profile example), and Laning hopes she will not be among the 92 percent of them who will die from it.

Of all the cancers that afflict human beings, lung cancer may be the sneakiest and least comprehensible. While deaths from lung cancer continue to decline in men by about 2 percent each year, the National Center for Health Statistics says that between 1979 and 2002, the death rate for women skyrocketed by 163 percent.

Today, lung cancer kills more women than breast and ovarian cancer combined.

Many researchers attribute that astronomical increase to the number of women smoking today, and tobacco is still linked to nearly 90 percent of the cases for either gender. Over the last several decades, female smoking rates have caught up to those of men.

But Laning smoked only socially in her late teens. She hasn't touched a cigarette in more than 20 years.

That doesn't surprise Dr. Bruce Fleegler, a pulmonologist at Sarasota's Lung Associates, who explains, "About 15 percent of people who get lung cancer are non-smokers." Plus, he adds, quitting when you're young does wonders for the rejuvenation of lung tissues. "If you haven't smoked for 20 years, it's as if you never smoked at all," he claims.

Laning says her doctor, Kirk Voelker (who practices with Fleegler at Lung Associates), believes she must have been exposed to a chemical like asbestos or radon. And although no clinical studies have linked them to cancer in medical workers, numerous medical products are made with compounds (like nickel, the acrylonitrile used in some medical gloves, and silica) that have been linked to lung cancer. So Laning believes she'll never know for sure what caused it.

But something else may be afoot. A number of studies indicate that estrogen may cause nicotine and tobacco to virulently attack women's bodies. A recent article in the New England Journal of Medicine reports that estrogens may play a particular role in the development of adenocarcinoma, the type of cancer Laning has, which strikes women much more often than men.

Researchers have found that early onset of menopause (at less than 40 years of age) decreases the risk of adenocarcinoma, while the use of estrogen replacement therapy raises the risk.

But Fleegler is not yet convinced there is a physiological link. "I think we just don't know yet. I know it's intriguing, but the fact is that everyone who smokes is at risk."

Unfortunately, treatments for lung cancer have not kept pace with those for breast, colon and even ovarian cancer. Six out of 10 lung cancer patients still die within one year of diagnosis. Between seven and eight patients don't survive two years. The five-year survival rate (at which most doctors consider a patient cured) for all stages of lung cancer is still just 15 percent, compared to 64 percent for colon, 88 percent for breast and 99.8 for prostate cancer.

Following up the surgical removal of lung tumors with chemotherapy can raise the five-year survival rate to 69 percent, on average from 73 months overall to 94 months. But only 16 percent of lung cancers are diagnosed before they spread too far for this type of treatment to be useful.

By the time Laning was diagnosed, her cancer was so widespread that her PET scan resembled a Rorschach inkblot. "It was just everywhere," she says softly, as she flips through the notebook she's kept since her diagnosis. Every test result lies protected in clear plastic sheet holders. "Nodal, bone, liver and adrenal metastasis," she reads from one report.

Surprisingly, says Fleegler, few people experience lung cancer's classic symptoms of chronic cough, hoarseness, shortness of breath or chest pain. For most, he says, the first sign is bone pain, and by then it's just too late.

Since Laning's tumors were inoperable, she started chemotherapy within a week of her diagnosis. Chemotherapy inflicts the same side effects in both genders, but the hair loss takes a greater psychological toll on women. And since women are at greater risk of developing osteoporosis later in life, radiation that could relieve pain puts their delicate bones at risk for fracture.

Laning's pelvis was too riddled with tumors to start the radiation that doctors said would finally ease her pain. First she had to undergo orthopedic surgery to shore up the thighbone and hip joint. Doctors proceeded with radiation on her arm despite fears that the bone was so fragile it might shatter if she lifted anything too heavy.

Early detection seems to hold the greatest promise for treating the disease, so researchers are exploring new tests that can detect cancer cells in sputum samples, and experimenting with ways to alter the DNA of lung cancer cells. The American Cancer Society reports that new drugs are being tested that may stop the formation of the blood vessels that feed lung cancer cells. A vaccine may even be on the horizon.

But chemotherapy remains the best line of defense against advanced lung cancer, and Laning's first round of chemo had excellent results. A PET scan in February showed her tumors were shrinking, but two months later the news wasn't so good. "It figures out how to get around the medicine," she notes.

In May, Laning and her husband of 27 years, Dave, took their families to Europe, where she visited the lush tulip fields of Keukenhof Gardens near Amsterdam, and Dave, an amateur chef, learned to bake torta di cioccolata in Italy. Upon her return, she started a new chemo regimen with Taxol. If that doesn't work, she'll consider entering a clinical trial.

"But I'm feeling more back pain, and the pain in my arm has come back," she says. "I don't know what that means yet."

Although she asked for one, Laning never received a prognosis. "It could be months. It could be years," she says. "You can't really put a number on it for anyone." Beside, she adds, "I think, overall, that there's a better place than this. I know heaven is waiting for me."

SMOKE SIGNALS

The surest way to prevent lung cancer is to stop smoking-or to avoid developing the habit in the first place. But that's not the easiest thing to do when you're part of a demographic that has been specifically targeted by cigarette manufacturers.

The World Health Organization has culled 6 million documents from seven of those manufacturers that became available to the public in 1998. Said one British scientist working for American Tobacco in 1976, "Smoking behavior of women differs from that of men.Women are more neurotic than men and more likely to need to smoke in stressful situations, presumably because they are less well able to deal with stress.Given that women are more neurotic than men it seems reasonable to assume that they will react more strongly to smoking and health pressures.There may be a case for launching a female-oriented cigarette with relatively high deliveries of nicotine."

Similar internal memos detail the tobacco industry's efforts to appeal to women's insecurities about body image by marketing "light" and "mild" cigarettes often labeled as "slim" or "thin."

The campaigns seem to be working. Female smoking rates now equal those of men, and according to the American Lung Association, nearly 22 percent of all high school females smoke on a regular basis.

NEWSBRIEF U.S. News and World Report ranks Sarasota Memorial Hospital 37th in the country in cancer care, and with good reason. In addition to its affiliation with H. Lee Moffitt Cancer Center in Tampa, the nonprofit, public hospital is finalizing a program to offer genetic screening for breast, ovarian and uterine cancers. If an initial counseling visit points to the potential for any of these cancers, patients can opt to have themselves fully screened for about $4,500.

SCREEN SAVERS

The simple blood test can allay fears of women with female relatives who have contracted the diseases, or it can help make life-saving decisions. An abnormality in one of two gene markers, for example, can raise a woman's risk for ovarian cancer by as much as 50 percent. In that case, the patient can make a determination whether to keep or remove her ovaries as a preventive measure.

Breast, ovarian, uterine and colon cancers are the first types of cancer to be screened at Sarasota Memorial. The hospital hopes to eventually expand the program to include thyroid and pancreatic cancer screening and skin cancers like melanoma.

OFF THE MARKET One of the most promising drugs on the market for the treatment of end-stage lung cancer has been pulled by the U.S. Food and Drug Administration after it failed to live up to expectations. Iressa will still be available to those currently using it, but as of last month, new patients have to qualify for strict clinical trials.

Some patients who had been given months to live credit the drug, which came on the market in 2003, with extending their lives by years. A recent NBC Nightly News segment profiled one female patient who'd been cancer-free for two years since taking Iressa.

Scientists believe the drug works by blocking a molecule that fuels cancer cell growth, but only in patients who already have a particular gene mutation-a mutation found most often in women and nonsmokers.

The manufacturer, AstaZeneca, says about 4,000 people currently use Iressa, but despite its promise, only 10 percent of overall patients have shown any response. AstaZeneca says it will continue testing its theory that a specialized set of patients may still be suitable to receive the drug in the future.