About 1.2 million Americans will be diagnosed with cancer this year, and more than half a million will die of the disease. For patients with many kinds and stages of cancer, existing treatments can shrink a tumor or slow its growth temporarily, but they offer little chance of a permanent cure.

Still, no more than 5 percent of the nation's adult cancer patients are enrolled in scientific studies that might lead to better treatments, according to a new survey.

Cancer doctors say they believe participation in such studies is the best way for their patients to get cutting-edge care, but most recruit very few of their adult patients for trials of experimental treatments, according to a survey of more than 9,000 specialists released last month at the annual meeting of the American Society for Clinical Oncology (ASCO).

Nationally, about 40,000 people with cancer are participating in clinical trials, which are scientific studies that typically compare two treatments or sometimes--if no treatment has been proved effective--test an experimental treatment against a placebo. The number enrolled in studies is thought to be between 3 and 5 percent of newly diagnosed cancer patients. Cancer specialists estimate that about 20 percent of adult cancer patients would be eligible for such studies.

Doctors who treat children with cancer are much more research-oriented, enrolling about 70 percent of their patients in clinical trials aimed at identifying better treatments with fewer side effects.

Enrolling more people in cancer trials would speed progress against the disease, said Ezekiel Emanuel, a physician and bioethicist at the National Institutes of Health's research hospital and primary author of the survey of cancer doctors. "We haven't cured cancer," he said. "We're only going to make a dent in that goal by doing clinical research, by knowing what works and what doesn't work."

A clinical trial is conducted only when there's no proven treatment for a condition, or when researchers don't know which of two effective treatments is superior. Cancer researchers say slow patient recruitment for such studies impedes scientific progress and lengthens the time it takes to answer critical questions.

For instance, several recent studies found that high-dose chemotherapy combined with a bone marrow transplant was no better than standard chemotherapy for women with advanced breast cancer. But that research took years to complete because about 15 women received bone marrow transplants outside studies for every woman who entered a clinical trial.

Of the estimated 40,000 cancer patients in studies, about 20,000 are enrolled in trials sponsored by the National Cancer Institute (NCI), about 13,000 in studies sponsored by drug companies and about 7,000 in studies paid for by teaching hospitals or comprehensive cancer centers.

Researchers, doctors and patients offer a variety of reasons why so few people with cancer enter treatment studies.

Emanuel said some patients may believe that a certain treatment is preferable and may be reluctant to be randomly assigned to a treatment, as is often required in clinical trials. He added that doctors aren't always willing to take the time to discuss the benefits and risks of entering a study with their patients and often aren't compensated for the hours it takes to complete the necessary paperwork.

Such tasks cost doctors between $2,000 and $3,000 per patient, he said, but the NCI pays doctors only $750 per patient. Drug companies typically pay $2,500 per patient. The survey found that doctors have increased their participation in drug company studies in recent years, perhaps in part because of the greater compensation. In response to the findings, Emanuel said, the NCI plans to increase the amount it pays per patient to $1,500.

Kenneth D. Miller, a Montgomery County cancer specialist who is chairman of the department of medicine at Shady Grove Adventist Hospital, said he tries to enroll patients in studies but has sometimes found it difficult to cut through the red tape required to get a patient accepted, especially at the NCI.

He recalled treating a patient four years ago who had a type of tumor called a sarcoma, located in his groin. Miller said he called an NCI researcher who was conducting a treatment trial on sarcomas of the extremities.

"He said, 'Nope, your patient's not eligible,' " Miller recalled. The researcher referred him to a different researcher who handled sarcomas of the trunk. That scientist told him, "No, he's not eligible--it's not the trunk."

"It leaves someone with the impression that you're only going to get someone [accepted for a trial] if it's the third Wednesday of the month and it's a full moon," Miller said.

He added that patients always worry about being randomly assigned to a treatment, even when he tells them that the study is being done because as far as anyone knows, the two alternatives being tested are equivalent.

"They will always ask, 'Which ones are better ? Why don't I just get that?' " Miller said. "I think that's a true barrier."

A Maryland woman who was treated with surgery and chemotherapy for an abdominal tumor two years ago said patients who are interested in entering studies frequently face strict deadlines for enrollment and often get little help from their doctors.

"You're recovering from surgery. You have the shock of a cancer diagnosis," said the woman, an FDA employee who asked not to be identified. "You have a very limited time frame in which to seek out these trials and get yourself in."

She recalled that her doctor mentioned two studies that he knew were being conducted on her type of cancer and handed her the telephone numbers of the NCI and Johns Hopkins Hospital. "At the NCI, they wouldn't even talk to me until my doctor had talked to them. But my doctor was on vacation" by the time she called, she said.

By making inquiries on her own, she finally located what sounded like a promising study at a comprehensive cancer center in another city and was accepted for treatment. Since then she has been satisfied with her care, but she believes she succeeded in locating the study only because she was particularly well informed.

"I was a very motivated person and one who knew that these trials exist," she said. "It's almost like you need an agent--and the agent needs to be your doctor. But if your doctor is some community doctor . . . they just can't do that job very well."

Mary S. McCabe, director of the office of clinical research promotion at the NCI, said her institute wants to make it easier for cancer patients to enroll in studies and has made considerable progress in that regard since the incidents described by Miller and the FDA employee.

She said the NCI's recently redesigned Web site on cancer trials highlights interesting studies, describes treatments under development and allows patients and doctors to send direct inquiries by electronic mail. Users can also get on a list to receive updates and announcements.

"People can actually ask us questions," she said. "It's answered by an individual."

She said researchers doing trials at the NIH research hospital in Bethesda have become more receptive to inquiries from outside doctors than they were four years ago, when Miller tried to refer his sarcoma patient. In addition, the cancer institute is setting up pilot studies that will allow cancer doctors around the nation to participate in NCI trials, submitting data on their patients electronically.

"We want physicians to participate so that patients, wherever they live, can stay with their community physicians and participate in trials," she said.

Finding Out About Cancer Treatment Studies

The National Cancer Institute (NCI) has several resources for cancer patients and their doctors.

The NCI operates a toll-free information line (1-800-4-CANCER or 1-800-422-6237; TTY 1-800-332-8615). English-speaking and Spanish-speaking information specialists will search the NCI's computer database to locate studies.

The NCI's clinical trials Web site (http://cancertrials.nci.nih.gov) contains research news and allows users to search the trials database. Another site (http://cancernet.nci.nih.gov) provides information on cancer screening, diagnosis and treatment.

The institute also sponsors cooperative groups of cancer specialists across the country who conduct treatment studies. See the Web site at http://ctep.info.nih.gov.

To find out about treatment studies taking place on the NIH's Bethesda campus, call 1-888-624-1937.

Many nongovernmental organizations for cancer patients have toll-free numbers and Web sites to assist with treatment decisions. Two examples are the National Coalition for Cancer Survivorship (1-888-937-6227; www.cansearch.org) and Cancer Care Inc. (1-800-813-HOPE; www.cancercare.org).

Pharmaceutical companies can also provide doctors and patients with information (by telephone or via the Internet) about company-sponsored studies.

Contact comprehensive cancer centers and academic medical centers directly to inquire about their treatment studies.