NEW YORK (AP) _ A woman whose fiance broke off their engagement faked terminal breast cancer for two years to get sympathy, fooling co-workers and even a cancer support group, a report says.

The woman shaved her head to mimic a side effect of chemotherapy, dieted away 20 pounds or so and feigned listlessness and loss of appetite as part of the ruse, said Dr. Marc Feldman, co-author of the report in the journal Psychosomatics.

''She felt that the process of rebuilding a social life for herself was simply overwhelming. She needed a shortcut,'' Feldman said.

She had what psychiatrists call a factitious disorder, in which a person consciously fakes an illness for some psychological gain. A well-known variant is Munchausen syndrome, in which a person virtually makes a career of being a patient.

Nobody knows how common factitious disorder is, said Dr. David Folks, a professor in the department of psychiatry and behavioral neurobiology at the University of Alabama School of Medicine in Birmingham.

But ''on any one day, you could probably go into your local hospital and find one patient who either had factitious disorder or was a Munchausen patient. So it's not rare by any stretch of the imagination,'' he said.

Feldman, a psychiatrist in private practice in Birmingham, Ala., treated the woman after her ruse was discovered. He was then director of psychosocial programming at the Duke University Medical Center's cancer center in Durham, N.C.

The woman, who by then was 35, began the charade while working as a corporate secretary. She told co-workers that the cancer had spread and that her prognosis was grim. She modeled her symptoms on the genuine cancer of an acquaintance.

After experiencing a gratifying outpouring of warmth from her officemates, she joined the support group because it was a ready-made social network, Feldman said in a telephone interview.

''The groups there really work to be unconditionally supportive, very nurturing and warm,'' he said. ''The very first day she showed up she was embraced and welcomed.''

She built up a network of close friends, Feldman said.

Yet ''she was quite confrontative at times in group with other cancer patients, saying that they needed to face their illness head on, needed to be much more direct in dealing with the issue of cancer,'' he said.

The charade was uncovered when a routine check of medical records showed that she had never seen the cancer specialist she claimed was treating her.

When confronted, the woman confessed immediately, which is unusual for factitious disorder, Feldman said. Then, distraught and remorseful, she contacted Feldman and agreed to be hospitalized, he said.

She was diagnosed with major depression and a personality disorder. She made good progress during four weeks in the hospital, Feldman said. When she was discharged, she said she would move to a new state to start her life over.

Feldman said he has not had any contact with her since that time, about 18 months ago. She apparently did not get back with her boyfriend, he said.

An official of an organization that runs breast cancer support groups in 12 states said she had never heard of an imposter in such a group.

''I can see where she wouldn't be detected,'' said Sharon Green, executive director of the Y-ME National Organization for Breast Cancer Information and Support.

''If she did her reading and did her homework and watched for signals from other women, I suspect she could do that.''