A generation ago, it was still a word to be whispered. Grandparents in scenes that resemble a Neil Simon play would say it under their breath, afraid that if the word escaped into the air it would tempt the evil spirits.

Newspapers would rarely print it on the obituary pages. People died "after a long illness."Even doctors would often keep the diagnosis from their patients and patients would often keep the word from their families. If they looked it up the dictionary, the very definition was shrouded in secrecy and even shame.

Cancer - it still states - is "a malignant growth anywhere in the body of a person or animal." Then Webster's adds for metaphorical measure, "anything bad or harmful that spreads and destroys."

But in past weeks, the word cancer was placed prominently and publicly in an entirely new context: presidential politics. No whispering allowed.

Paul Tsongas, who was diagnosed with cancer in 1983, announced his candidacy for president. Tsongas, who fought a difficult battle with lymphoma, is the first Democrat to throw his hat in the ring. Tsongas, whose cancer is said to be in complete remission, is making a bid for the White House.

Every national news story about the former senator from Massachusetts pointed out that he was a long shot, a Greek-American and a cancer survivor. Of course, they also said that he is a pro-business liberal; a pro-choice environmentalist who believes in the death penalty and nuclear power; a bright, engaging man with a subtle sense of humor, a strong sense of family, an 85-page pamphlet of ideas and a speaking style that makes Michael Dukakis look charismatic.

But it is the cancer that initially leaped off the page. We may have gotten immune to firsts in politics. The first Catholic, first black, first female. But the first cancer survivor to run for president must face down a lingering prejudice, a different heart of darkness.

Today in the United States there are some 6 million people who have been treated and survived. Cancer is no longer one disease but many, each with a separate treatment and prognosis. While some carry a swift death sentence, others have survival rates as high as 90 percent. About half of all those diagnosed with cancer in 1981 survived at least five years and 44 percent are still living. We are permitted now to even use the word "cured."

Times have changed since 1983 when Tsongas found a lump in his groin while taking a shower. The experimental bone marrow transplant that he underwent in 1986 has become almost common. Now the candidate's oncologist has pronounced the likelihood of a recurrence so remote as to be negligible.

But public attitudes are unpredictable. It is still harder for a survivor even of a "good" cancer to get life insurance or a job or a promotion. "Consciously or unconsciously," says Dr. Samuel Broder, the head of the National Cancer Institute. "Some aren't given the opportunity to return to the work force. People are passed over for promotion or forced out of a small business because of insurance issues."

Nobody has to hire you to run for president. It's an equal opportunity race, which, for Tsongas, is actually and mystically connected to his experience. It was cancer, he said sometime ago, that led him out of public life. Now, he calls his candidacy, "the obligation of my survival."

The question is how it will be seen by voters. Can people listen to ideas without looking for symptoms? Can a survivor be accepted as a leader for the future? If the long odds ever grow shorter, will those odds hinge on believing in Tsongas' oncologist as well as his agenda?

"I suspect he doesn't want to be known as `the cancer candidate,' " says his doctor, Tak Takvorian. But this 50-year-old father who has been through the tortures of cancer therapy - seen his hair fall out and grow back, his weight drop off and come back, his ambition recede and return in a changed form - will inevitably come to represent more than his ideas.

He will stand for, run for, speak for, a changed reality about cancer. And he will find out whether consciousness has kept up with oncology.