A leading Soviet dissident, buoyed by last week's release of Anatoly Shcharansky, has launched a public campaign in support of his wife's request to go abroad for cancer treatment.

Naum Meiman, 74, a former member of the group monitoring compliance with the 1975 Helsinki accords here, held an unusual news conference for western reporters yesterday to publicize his wife Inna's fruitless efforts to obtain a visa for medical treatment in the West.

Meiman praised Shcharansky's release from Soviet prison and his departure for Israel last week and said that the treatment of his wife's case will demonstrate whether the new Kremlin leadership is interested in improving its human rights record further.

Meiman said he told Sen. Edward M. Kennedy (D-Mass.) about his wife's case in a meeting here two weeks ago. During a three-day visit here, Kennedy met with Soviet leader Mikhail Gorbachev and several "refusedniks," or persons whose visa requests have been denied.

At the news conference, Meiman distributed copies of a letter in which he asked Kennedy to intercede with Gorbachev on his wife's behalf.

Despite invitations from four foreign governments, admission in a treatment program at New York's Memorial Sloan-Kettering Cancer Center, and appeals on her behalf by various foreign political leaders, Soviet authorities have denied Inna Meiman, 53, a visa to travel to the West since she was diagnosed as having cancer in 1983.

After four operations here, Soviet doctors have exhausted their capacity to treat his wife, Meiman said. In recent days, her health has deteriorated, he added.

"Refusal to let her go dooms her to slow death," he added. "We may be losing the last chance to save her life."

Meiman said his request to emigrate to the West was rejected in 1976 because his academic work had given him access to state secrets.

Meiman told reporters Soviet authorities had denied his wife a visa to travel abroad on the grounds that her marriage to him made her a security risk. But his classified academic work ended in 1955, he said.