PATERSON, N.J. — Sen. Frank Lautenberg, at 86 the nation's second oldest U.S. senator, has curable lymphoma of the stomach, his office said Friday.

Doctors for the Democrat found B-cell lymphoma that will require treatment over the next few months, spokesman Caley Gray said in a news release. He will not resign, Gray said.

Independent doctors agree that Lautenberg's type of lymphoma is usually treatable.

Lautenberg will undergo six to eight chemotherapy treatments and should make a "full and complete recovery," said Dr. James Holland of New York City's Mount Sinai Medical Center.

Lautenberg is expected to return to work at the Senate between treatments, Holland said.

A resignation could hurt the Democratic Party. Under New Jersey law, Gov. Chris Christie, a Republican, would be able to appoint a replacement if a senator left office.