Tsongas Turns 51; Health Outlook Good : Medicine: His doctor calls the candidate’s condition ‘excellent.’ But he says that he cannot be 100% certain lymph node cancer will not recur.

As Paul E. Tsongas celebrated his 51st birthday Friday, he could be reasonably confident that his health will remain excellent and that the life-threatening lymph node cancer that afflicted him in the mid-1980s will not recur.

There are no medical restrictions on the presidential candidate’s activities and he takes no medication on a regular basis, said his physician, Dr. Tak Takvorian of the Dana-Farber Cancer Institute in Boston.

But Takvorian and other experts in the treatment of lymph node cancers say that it is impossible to be 100% certain that the cancer has been eliminated forever. This is because the sophisticated treatments that restored the former Massachusetts senator to health in 1986 have been in wide use for less than a decade.

“I can’t swear for you and the public he’s cured,” Takvorian said in an interview. “On the other hand, I can attest to his excellent health now. There’s a very, very high likelihood” that the cancer won’t return.

“From a medical standpoint, I would be very comfortable with a person in this situation serving as President,” said Dr. John A. Glaspy of the UCLA Medical Center, who has not been involved in Tsongas’ care. “There is every reason to believe that Tsongas will be fit and capable of serving in a position of responsibility for at least the next five years.”

Tsongas’ medical condition has emerged as an issue with the approach of the New Hampshire primary Tuesday and his improved standing in the polls.

In 1983, while serving in the U.S. Senate, Tsongas developed swollen lymph nodes. Physicians removed a swollen node from his groin and diagnosed the cancer by examining the cells under a microscope.

The tumor belongs to a group of cancers known as non-Hodgkin’s lymphoma, which develop in about 40,000 Americans each year. Lymphoma is a tumor of the immune system cells, and their normal function is to protect the body against germs.

Tsongas’ tumor had spread to many of his lymph nodes but not to other organs, a relatively favorable situation, Takvorian said. Under the microscope, he said, the tumor consisted of small cleaved cells that had a nodular appearance. This was also considered a relatively favorable characteristic.

By 1985, the tumor was progressing and Tsongas was suffering flu-like symptoms. Under the microscope, the tumor appeared to be changing to a more virulent type.

Physicians concluded that a bold and aggressive therapy, still in its infancy, represented the best chance to save his life. In fact, Tsongas was one of the first several hundred people in the world to receive the therapy.

The treatment included intravenous chemotherapy and high dose radiation therapy to the entire body. It also involved a form of bone marrow transplant.

Tsongas’ own bone marrow cells were removed before the radiation treatment, stored frozen and then infused back into his body. This was necessary because the radiation necessary to kill the tumor cells also destroyed the bone marrow cells in the body.

The bone marrow transplant was performed in August, 1986. Since then, physicians have been unable to detect any evidence of a tumor in Tsongas’ body. The overwhelming number of lymphomas that recur do so within a year of the transplant. “To be without disease five years after transplant puts (Tsongas) in the statistical category that he is not going to relapse,” Takvorian said.

Tsongas has checkups every several months and a detailed evaluation once a year that includes many blood tests and X-ray studies.

The radiation treatment damaged tissues that moisten the throat; this contributes to the candidate’s need to frequently clear his throat.

In New Hampshire, Tsongas has had a relatively light public appearance schedule. Takvorian said the candidate has a “constitution that needs a certain amount of sleep” but that this was not related to his lymphoma or the subsequent treatment. He said Tsongas’ schedule is not related to any medical restrictions.

Tsongas insists that, while some voters are spooked by cancer, he wins sympathy with others for having beaten the disease. “On the one hand, some people say, ‘You’ve had cancer, I can’t vote for you.’ But more people say, ‘You’ve been through that, it gives you great wisdom.’ I think on balance it is a plus.”

Steinbrook reported from Los Angeles and Richter from Manchester, N. H.