(CNN) -- It started with an unscheduled phone call to an evening TV show.
The voice of Venezuelan President Hugo Chavez crackled over the state television speakers.
"I have some news that is not very good," he said on May 9, 2011, describing what he said was debilitating pain in his left knee that forced him to abruptly cancel a trip to Brazil and go on doctor-ordered bed rest.
"Surgery could be necessary," he continued. "They're evaluating that, but anyway, it is my responsibility to inform the country. Here I am, in battle."
A year later, the battle hasn't stopped.
Significant dates in Chavez health battle
Over a span of weeks, what started with announcements about a knee injury became something much more serious. First, an emergency surgery in Cuba for what government officials described as a pelvic abscess.
Then, days of silence from a leader known for lengthy speeches and rapid-fire Twitter posts.
Venezuelan officials went on the offensive when media reports suggested Chavez had cancer, describing the reports as vicious rumors that were part of a conspiracy by the president's political opponents.
Government reports summed up the situation with the same phrase, saying Chavez was "recuperating satisfactorily" in Cuba.
After weeks of speculation, the Venezuelan president broke his silence in a somber speech from Havana on June 30, revealing that doctors had removed a cancerous tumor.
He ended with a phrase that would become a constant refrain in his speeches in the coming months: "We shall overcome."
But the Venezuelan president did not disclose the type of cancer he was battling or how long he would be in Cuba for treatment.
After months of treatment, Chavez declared that he was cancer-free in October.
"There are no malignant cells in this body. They don't exist," he said on a visit to a religious site near Venezuela's border with Colombia.
In mid-January, he delivered a State of the Union speech that lasted more than nine hours.
On February 20, rumors swirled on social media after Venezuelan columnist Nelson Bocaranda, without naming sources, wrote that Chavez was in serious condition and doctors were treating him in Cuba.
The report drew ire from Venezuelan officials.
"Regarding the rumors, dirty war of swine," Information Minister Andres Izarra writes in a Twitter post.
The next day, while touring a tractor factory in Venezuela's Barinas state, Chavez announced that he would undergo surgery to remove a lesion from the same area where doctors removed a cancerous tumor from his body last year.
Soon afterward, he announced that tumor was also cancerous, and he has been regularly undergoing radiation treatment in Cuba since then.
Now, 10 months after Chavez first announced his cancer diagnosis, officials have released few details about his treatment. Neither Chavez nor anyone in his government have publicly discussed what kind of cancer he has or provided a detailed prognosis for the 57-year-old leader.
This year alone, Chavez has spent more than 50 days undergoing treatment in Havana, according to a CNN tally. Last year, he spent 45 days there.
Speaking to Venezuelan state TV in a phone interview from Cuba on Monday, Chavez said that he is governing his country even as he undergoes treatment in Havana.
"I am governing, fulfilling my duties as head of state and of the government, but in this special situation, which I will come out of in the coming days," he said. "Soon I will be there."
For answers on Chavez's health, many have turned to detailed media accounts, which, citing unnamed sources, paint a far more dire picture.
Among those reporting on Chavez's condition are Bocaranda and Venezuelan doctor Jose Rafael Marquina, who practices in Florida and has no direct connection with the case but says he has colleagues who know what is happening. Reporters from the Spanish ABC newspaper and the Brazilian O Globo daily publication also have filed reports on Chavez's condition.
According to these reports, thought to be reliable but which CNN has been unable to verify, Chavez's illness -- initially diagnosed as prostate cancer in January 2011 -- has spread to his colon and other internal organs and to some bones.
Top Venezuelan officials maintain Chavez is beating the disease, and Chavez has repeatedly said he plans to run for re-election on October 7.
But the Venezuelan president further fueled speculation last month when he teared up during a Holy Thursday Mass as he discussed his struggle with cancer.
"Christ ... give me life, because I still have things to do for the people and this country. Do not take me yet," the Chavez said.
Chavez announced in January that it was time to constitute a Council of State, stipulated in the Venezuelan Constitution as the highest circle of advisers to the president.
Last week, as speculation continued to surge over who would succeed if Chavez becomes to ill to govern or dies, he named 10 Venezuelans to the council.
CNN's Mariano Castillo and Arthur Brice contributed to this report.