TAMPA, Fla. (AP) - With much of her lower body consumed by cancer, Leslee Flasch finally faced the truth: The herbal supplements and special diet were not working.

"I want this thing cut out from me. I want it out," she told her family.

But it was too late. Her rectal cancer - potentially curable earlier on - had invaded bones, tissue, muscle and skin. The 53-year-old Florida woman could barely sit, and constantly bled and soiled herself.

"It was terrible," one doctor said. "The pain must have been excruciating."

Flasch had sought a natural cure. Instead, a deadly disease ran its natural course. And the herb peddlers who sold her hope in a bottle?

"Whatever money she had left in life, they got most of it," said a sister, Sharon Flasch. "They prey on the sick public with the belief that this stuff can help them, whether they can or can't."

Some people who try unproven remedies risk only money. But people with cancer can lose their only chance of beating the disease by skipping conventional treatment or by mixing in other therapies. Even harmless-sounding vitamins and "natural" supplements can interfere with cancer medicines or affect hormones that help cancer grow.

Yet they are extremely popular with cancer patients, who crave control over their disease and want to do everything they can to be healthy - emotional needs that make them vulnerable to deceptive claims. Studies estimate that 60 percent of cancer patients try unconventional remedies and about 40 percent take vitamin or dietary supplements, which do not have to be proved safe or effective and are not approved by the federal Food and Drug Administration.

None has turned out to be a cure, although some show promise for easing symptoms. Touch therapies, mind-body approaches and acupuncture may reduce stress and relieve pain, nausea, dry mouth and possibly hot flashes, and are recommended by many top cancer experts. A recent study found that ginger capsules eased nausea if started days before chemotherapy.

Many hospitals offer aromatherapy, massage, meditation, yoga and acupuncture because patients want them and there is little risk of physical harm. They call this complementary or integrative medicine because it is in addition to - not in place of - conventional treatments.

At the other end of the spectrum are quacks selling fringe therapies and supplements through testimonials, not proof. Laetrile, "detoxifying" coffee enemas, shark cartilage - the miracle cures change but the bogus claims remain the same.

"What I am noticing in the last year or two is a resurgence of these things. It's coming back," said Barrie Cassileth, integrative medicine chief at Memorial Sloan-Kettering Cancer Center in New York and a longtime adviser to the American Cancer Society.

The Internet fuels this trend by letting people buy direct and bypass doctors who could help them see through scams and misleading claims of scientific proof. Sadly, some Web sites are run by quacks - a "doctor" title doesn't mean the remedy is safe or effective.

"A lot of these doctors prey on people's insecurities and need for hope," said Dr. Roy Herbst, lung cancer chief at the University of Texas M.D. Anderson Cancer Center.

About 7 percent of cancer patients go straight to an alternative approach, sometimes traveling to Mexico, the Bahamas or a "spa" in Europe for treatments not allowed in the United States, Cassileth's research found. Most cancers spread slowly, so people can be temporarily fooled into thinking herbs or special diets are keeping it at bay.

"After they've been there some months they'll realize things are not working. But with cancer, you get one chance. By the time they get back to a reasonable hospital, they're dead. Nothing can be done for them," she said.

Getting nutrients from pills is different than getting them from a balanced diet, nutrition experts say.

"So many people think, ÔWell, if a little bit is good, then more is better,' and that's definitely not true with most dietary supplements," said Kathy Allen, a Moffitt Cancer Center dietitian.

Herbals and dietary supplements can undermine cancer treatments in ways that patients can't feel and doctors can't measure. When a treatment fails, it's impossible to say whether it was due to the person's cancer or because a supplement subtly interfered.

"We know that there's some harm going on. We just don't know the magnitude of it," said Dr. Jeffrey White, the National Cancer Institute's complementary and alternative medicine chief.

Studies show that as many as two-thirds of cancer patients who use unproven remedies do not tell their doctors. Sometimes it is because they fear disapproval, but often they do not realize this can harm their care.

"I didn't think they were medications. They're not prescription, they're not drugs. This is all natural substances," said Vince Palella, a Bradenton, Fla., prostate cancer patient.

A Moffitt dietitian, Diane Riccardi, discovered that Palella was taking dozens of pills a day, including a saw palmetto extract. That supplement might have interfered with his hormonal cancer treatments or the monitoring to see if  those treatments were working.

"There's absolutely no way of knowing" if it did, Riccardi said.

Another supplement that can pose a risk for prostate cancer patients is DHEA, which can affect testosterone levels, said Phyllis Matthews, a urology nurse practitioner at a group of Veterans Affairs clinics in the Denver area.

Cancer doctors also worry about isoflavones and other soy-related supplements; some research suggests they might stimulate breast tissue. Breast cancer patients on tamoxifen or aromatase inhibitors like Femara or Arimidex should not use red clover, dong quai or licorice because of estrogen-stimulating components, say guidelines from the Society for Integrative Oncology.

In June, the FDA sent 25 warning letters to sellers of teas, pills and other products sold on the Internet that falsely claim to cure, treat or prevent cancer. They included bloodroot, shark cartilage, coral calcium, cesium, ellagic acid, cat's claw, Essiac tea and various mushrooms.

In September, the Federal Trade Commission charged five companies with making false and misleading claims for cancer cures and reached settlements with six others. The agency also started a bogus cures Web site to help consumers. A statement explained its reasoning:

"When you're battling cancer, the last thing you need is a scam."