CBS News Correspondent Byron Pitts reports McCain will remain at the hospital overnight. McCain has said he plans to be back on the campaign trail for George W. Bush and other Republican candidates by Labor Day.
"We are pleased to let you know the preliminary report on the lymph nodes was clear, without any evidence of melanoma cells," Dr. John Eckstein, the senator's personal doctor, told a news conference.
He was referring to the lymph nodes related to a melanoma excised from McCain's temple. Tissue from the nodes was studied to ascertain if the cancer had spread.
"However it will take several days to fully evaluate the tissue At this time we are very optimistic and are very pleased," the doctor said.
This is the former GOP presidential hopeful's second battle with the disease.
"I'm very confident. The doctors are very confident," McCain said during a news conference at his central Phoenix home before the surgery.
McCain arrived at the hospital in Phoenix about 5:15 a.m. Saturday to undergo surgery to remove more skin and lymph nodes around the spots of melanoma, which is the most serious form of skin cancer.
"I've been in a number of fights in my life and this is just another one and I'm sure I will prevail," said McCain, who was wearing an Arizona Diamondbacks hat and handed out sunscreen with his wife, Cindy.
McCain had a similar lesion removed from his shoulder in 1993.
That's according to Dr. John Glaspy, a researcher at UCLA's Jonsson Cancer Center, who says "having an inch divot missing from your skin is not nothing, but you can hurt yourself worse falling off a bicycle."
"It's not like you're removing organs. It's not a major surgery," says Glaspy.
CBS News Chief Washington Correspondent Bob Schieffer reports McCain's cancer was discovered during a physical that he underwent at Bethesda Naval Hospital the day after he addressed the Republican National Convention in Philadelphia on Aug. 2.
McCain knew about the melanoma recurrence last week as he campaigned with George W. Bush, the GOP presidential nominee. When reporters noticed a bandage on temple, the senator reminded them to use sunscreen.
"Every few months, I have to go and get these basal cell things cut out from having a lot of exposure to the sun when I was very young," he said.
During his presidential bid earlier thi year, McCain released hundreds of pages of medical records that detailed the lingering effects of injuries suffered in a Vietnam POW camp. Those records also showed that in December 1993, McCain had a cancerous mole removed from his shoulder that proved to be melanoma.
John Eckstein, McCain's longtime personal physician in Arizona, said at the time that the senator was cured of the cancer.
The records said McCain regularly has suspicious skin lesions or moles removedoften basal cell carcinoma, the least aggressive and most common type of skin cancer.