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. 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.