Older patients often suffer needlessly from cancer, depression, and heart disease because society's age bias gets in the way of treatment, according to a growing body of research.

Patients over 65 typically get less aggressive treatment for cancer than younger patients, less preventive care for high blood pressure and cholesterol, and double the dose they need of some psychiatric medicines, studies show.

While they represent the majority of patients with chronic illnesses and the major users of prescription drugs, they are frequently passed over for tests of new treatments and medicines, leaving doctors with little of the evidence they need to care for seniors properly.

''There is a persistent bias . . . that works against the best interests of older Americans," said Daniel Perry, executive director of the Alliance for Aging Research, a nonprofit based in Washington that advocates for improvements in the health of aging Americans.

Doctors and advocates are struggling to chip away at the ageism, which they said often springs from misguided attempts to protect seniors from being harmed by overly aggressive treatments. In the latest volley, published last week in the Journal of the American Medical Association, University of Vermont researchers showed that aggressive chemotherapy reduced deaths from breast cancer and recurrences in women over 65 as much as in younger women. Age alone should not rule doctors' and patients' decisions about cancer treatment, the researchers said.

Earlier studies of breast cancer treatment showed that many older women are not getting standard treatment, including life-saving chemotherapy. In fact, one study found that women over 65 with breast cancer that hadn't spread, and whose tumors didn't respond to antiestrogen therapy, were seven times less likely than younger women to get chemotherapy.

The researchers, from Ohio State University, controlled for factors such as the size of tumors and stage of cancer, and concluded that age bias was a major factor.

The problem is not limited to women. About half of all seniors with advanced colon cancer don't get chemotherapy after surgery to remove the tumor, although older patients who get the treatment live longer, according to researchers at Columbia University.

''Many older patients are not getting the optimal therapy for their cancer," said Dr. Edward Trimble, who heads efforts at the National Cancer Institute to improve cancer care for the elderly. ''Bias is part of it."

Other factors, he said, are real concerns about the ability of frail seniors or those with multiple illnesses to tolerate aggressive treatments. But those decisions should be made on a case-by-case basis in consultation with the patient, he and other doctors said, and not decided based on myths about what an ''average" old person can tolerate.

''Many physicians who take care of older people have not gotten the message that your chronological age is not your biological age," said Dr. Tamara Harris, a senior investigator at the National Institute on Aging. ''Physicians need to take into account that being 65 doesn't mean you're close to the end of your life."

Seniors' own internalized ageism also contributes to undertreatment, doctors said. Older patients sometimes dismiss health problems such as hearing loss, memory problems, or incontinence as symptoms of old age and don't even mention them during office visits.

Doctors are plagued by some of those same misconceptions, according to other research. In a survey published in the Journals of Gerontology, 35 percent of doctors erroneously considered an increase in blood pressure a normal process of aging.

''We've seen a dramatic underuse of cholesterol drugs, even blood pressure drugs, in older people," said Dr. Jerry Avorn, a professor of medicine at Harvard Medical School who studies use of drugs. ''The older you are, the more likely you are to have a chronic condition untreated with drugs."

A report by the Alliance for Aging Research found a particular problem in psychiatric care, suggesting that ''too many physicians and psychologists believe that late-stage depression and suicidal statements are normal and acceptable in older patients."

The suicide rate among older Americans is four times the national average, and 39 percent of older adults who commit suicide had been seen by their primary care physician in the previous week, according to the Alliance.

Many older patients also don't get screening and treatments to prevent disease. The federal Centers for Disease Control and Prevention reported in 2004 that six in 10 older adults hadn't gotten all recomended preventive services, including screening for common cancers and vaccines for flu and pneumonia. Seniors don't regularly get bone density tests either, although the tests can help assess risk for osteoporosis and fractures.

In some cases, the problem is at the other extreme -- seniors are overmedicated because doctors don't know the optimal dose. Many drugs have not been studied extensively in the elderly, who typically metabolize drugs differently from younger people.

The US Food and Drug Administration recommends, but does not require, drugs to be tested in the elderly.

A study of schizophrenia drugs in late 2003 found that seniors did well on about half the dose given to younger patients. The problem of overdosing is compounded, Avorn said, because some doctors dismiss symptoms of drug side effects, such as confusion or tiredness, as signs of aging.

Seniors have often been excluded from tests of new treatments for many of the illnesses that are most common among those over 65. For example, the Vermont doctors who analyzed research on breast cancer found that only 8 percent of the 6,487 women in four large studies were over 65, despite the fact that about 50 percent of all new breast cancer cases are diagnosed in older women.

''A lot of older people are shortchanged," said Dr. Hyman Muss, a professor of medicine at the Vermont Cancer Center at the University of Vermont College of Medicine.

The Food and Drug Administration, in fact, found that seniors represented about 36 percent of patients in clinical trials for six of the most deadly cancers, despite the fact that seniors account for 60 percent of the cases of cancer of the breast, lung, colon, pancreas, ovaries, and blood.

The gap is largely due to the failure of physicians to ask seniors to participate, according to a study by New York researchers. In addition, some seniors are excluded because of complicating illnesses, while others choose not to participate.

This contributes to a vicious cycle, Avorn noted. ''They get kept out of the studies and then people deny them the drugs because there's no evidence they work in the elderly," he said.

Change has begun, however.

The National Institute on Aging and the National Cancer Institute are spending millions of dollars on studies of disease and treatments in seniors.

Doctors' organizations are inviting Muss and other researchers who study age bias to speak about their results.

Medical schools are incorporating more teaching about geriatric care into the curriculum. Medicare is paying for more preventive care, and beginning to pay doctors on the basis of the quality of care provided to seniors.

But Perry, of the Alliance, suggests that the biggest push for equality in care will come as the baby boomers turn 65 in the next few years.

''Ageism in healthcare is still an underrecognized problem," he said. ''Reform will only come when the consumers of healthcare start demanding that their health needs are met with some urgency."

© Copyright 2005 Globe Newspaper Company.