By Brian Ellsworth
CARACAS (Reuters) - Venezuelan President Hugo Chavez said on Friday he was preparing for a second round of chemotherapy in Cuba to eliminate the risk of malignant cells after completing what he called a successful first session.
The announcement by the 56-year-old socialist leader that he had surgery in Havana last month to remove a baseball-sized cancerous tumor has called into question his fitness to run for re-election next year in the OPEC nation of 29 million people.
Last weekend, Chavez flew back to the communist-led Caribbean island for chemotherapy after delegating limited powers to his finance minister and vice president.
"I have completed the first cycle of chemotherapy treatment ... this cycle was completed successfully," he said in a phone call to a televised meeting of his ruling Socialist Party.
"We are preparing for a second cycle ... to totally defeat and eliminate any risk of the presence of malignant cells."
Chavez has not said what type of cancer he has or for how long he will be abroad as the guest of his friend and political mentor, former Cuban leader Fidel Castro.
Before he flew out last Saturday he said his doctors had not found any malignant cells -- suggesting the cancer had not spread and thus become more dangerous and difficult to treat.
A former soldier whose workaholic leadership style and image of invincibility have helped him win numerous votes, Chavez is visibly weakened as he plans his re-election bid.
He had two operations last month that he described as complicated: the first for a pelvic abscess and another to remove the tumor. He was away almost a month until returning home a day before Venezuela's 200th independence celebration.
'GOING TO BED ON TIME'
On Friday, the president said he was putting on weight again and was back to 86 kilos (190 lbs).
"I'm at the ideal weight for me ... I was too fat. I'm doing exercise, rehabilitation, and I'm going to bed on time, by 11 o'clock at night at the latest," Chavez said.
"I want to tell the country, the Venezuelan people, that this battle for life continues, with the help of God."
In a message on Twitter, Chavez said Argentine soccer star Diego Maradona had visited him later on Friday. Maradona lived on-and-off in Cuba, undergoing drug rehabilitation, after retiring from professional sport in 1997.
"I am grateful to Diego Maradona for the fraternal visit he paid me this afternoon. We were together with Fidel. Thanks kid!" he wrote on his @chavezcandanga account.
State media in Venezuela then broadcast footage of Chavez meeting several of his senior government officials in Havana, including Oil Minister Rafael Ramirez. The president has been keen to show he is still fully in control despite his illness.
Parliamentary elections last September showed the South American country split down the middle between Chavez supporters and opponents. Now, a fractious opposition coalition senses a chance to unseat a convalescing Chavez in 2012.
Venezuelan pollster Datanalisis said on Friday its most recent poll showed his popularity at 50 percent -- lower than the 52 percent recorded in June, but within the margin of error of 2.42 percentage points.
The polling was conducted at the end of June and start of July, meaning some of the interviews took place before Chavez's June 30 announcement that he had been diagnosed with cancer.
It was not designed to measure how his illness would affect his popularity, said Datanalisis President Luis Vicente Leon.
"We cannot reach a conclusion, Leon told reporters, adding that a full recovery might improve his ratings. "The epic saga of Chavez cheating death could boost his popularity."
(Additional reporting and writing by Daniel Wallis; editing by Todd Eastham)