CHICAGO (Reuters) - As Hugo Chavez heads to Cuba to have surgery on a second lesion in his pelvis, medical experts say the Venezuelan president still has a chance to be cured, but he may have to battle fatigue as he campaigns for re-election in October.
After declaring himself cancer-free last October, Chavez now says he has a 2 centimeter (0.79 inch) lesion in the same pelvic area where doctors in Cuba removed a baseball-sized tumor during his original treatment last year.
Doctors say the fact that Chavez' cancer has returned is worrisome, but the second surgery will give him one more chance at a cure.
"If it is localized and they can get it out and they get good, clean surgical margins, there is a 20 to 25 percent chance that he could be cured," said Dr. Richard Schilsky, a specialist in gastrointestinal cancers at University of Chicago Medicine who is not treating Chavez.
It is still not clear what kind of cancer the Venezuelan leader has, but comments made by Chavez and his handlers suggest he may have rectal or bladder cancer, or possibly soft tissue sarcoma. Schilsky said colon or rectal cancers sometimes come back in the pelvis or abdomen.
"It's hard to know without knowing what the primary tumor was. Local occurrence of colon cancer is less common than rectal cancer," Schilsky said.
Dr. Charles Fuchs, director of the gastrointestinal oncology program at the Dana-Farber Cancer Institute in Boston, said rectal cancer is more prone to local recurrence than colon cancer because the pelvis is such a crowded area that it is difficult for surgeons to get clean margins.
"Nothing has been said as to the origin of the cancer. All we know is that this was a tumor in the pelvis. After that he had a number of cycles of chemotherapy, presumably around 6 cycles. We don't even know what drugs he was given in the way of chemotherapy," said Sunil Daryanani, an oncologist at the Hospital de Clínicas Caracas.
He said because Chavez' tumor was diagnosed with an infection, the fact that he has had a local recurrence is not a surprise, but the time between treatment and progression of the cancer has been pretty short.
"This could imply that the original chemotherapy wasn't effective enough, but this is just speculation," Daryanani said.
"Once they've opened him up (on Monday/Tuesday), they'll have an idea if this is a localized occurrence or something more advanced," he said.
With a local recurrence of cancer, doctors will likely remove the tumor and then use radiation to "sterilize" the area and potentially kill off any remaining local cells, said Dr. Michael Pishvaian, a gastrointestinal cancer specialist at Georgetown University's Lombardi Comprehensive Cancer Center.
Radiation typically starts about a month after surgery and involves daily treatment, Monday-Friday, for five to six weeks. The whole treatment process could last through mid-May.
Side effects tend to be mild and localized, and fatigue is usually the biggest problem, doctors said.
"Some can go back to work on the same day; some are severely laid up and need to rest the whole time," Pishvaian said.
He said he thinks Chavez will be able to carry on the activities of being president, but "in terms of the rigors of a campaign trail, that would be pretty hard for anyone undergoing radiation."
"I think it definitely could have an impact in the middle of re-elections."
Schilsky said three months from now, Chavez should be feeling pretty good. What is less clear is whether the cancer will spread to other parts of his body, like the liver or lungs.
"The highest risk of finding a metastasis would be some time in the next two years. That would be an important milestone," Schilsky said.
As for Chavez seeking treatments in Cuba, Pishvaian said he hears the medical education in Cuba is surprisingly good, and the treatment Chavez needs is widely available. "There is no fancy chemotherapy that he would need at this point."
Additional reporting by Girish Gupta in Caracas and Esteban Israel in Sao Paulo; editing by Todd Eastham