Former Brazilian President Luiz Inacio Lula da Silva's cancerous tumor of the larynx has been shrunk 75 percent by his first two chemotherapy sessions, doctors treating the former head of state said.

An intensive battery of examinations on Monday, which included a laryngoscopy and a CAT scan, found an "extraordinary" reduction of the tumor, Dr. Roberto Kalil Filho, head of the medical team, told a press conference.

"The endoscopy showed a significant visual reduction (of the tumor)," the physician said.

The 66-year-old Lula was admitted Monday to the Sirio Libanes Hospital in Sao Paulo for the exams plus his third and last chemotherapy session, which he undergoes Tuesday.

The former president entered the hospital under his own power accompanied by two of his aides.

"The chemotherapy has achieved all the objectives we could hope for," Dr. Paulo Hoff told a press conference.

Together with the chemotherapy, Lula will begin radiation treatment that is scheduled to continue until mid-February, Kalil Filho said.

"We are undoubtedly on the way to a cure. The chemoradiation will continue until mid-February, and in March (Lula) will be able to return to his normal activities," the doctor said.

Lula's larynx is "apparently very healthy, absolutely normal" and the exams using imaging show only a "little ball," Dr. Rubens de Brito Neto said.

The former president, an inveterate smoker, on Oct. 29 was diagnosed with cancer of the larynx and two days later he began chemotherapy at the same hospital where his protege and successor, Dilma Rousseff, was cured of lymphatic cancer.