RIO DE JANEIRO - Former Brazilian President Luiz Inacio Lula da Silva was confirmed Wednesday to be cancer-free, a year after doctors first detected a cancerous tumor in his larynx, his press advisor said.

Earlier in March, Lula's doctors said that the cancer treatments appeared to be successful, but they had to wait a few months to confirm the result.

The ex-president underwent medical tests on Wednesday at a hospital in Sao Paulo, which confirmed there was no trace of the tumor found in October 2011, according to the advisor.

The edema in Lula's throat, which impeded his speech recently, has disappeared as well following three chemotherapy and 33 radiotherapy sessions during a five-month treatment.

Last Sunday, Lula tirelessly campaigned for party candidates in municipal elections, and Fernando Haddad, handpicked by Lula, won the mayorship of Sao Paulo.

Lula is one of five South American leaders who have battled cancer. The other four are Colombian President Juan Manuel Santos, Venezuelan President Hugo Chavez, Argentine President Cristina Fernandez and former Paraguayan President Fernando Lugo.

Lula's successor, Dilma Rousseff, underwent treatment for a lymphoma when she was Lula's chief of staff.