Gov. Phil Murphy disclosed Saturday he has a tumor on his kidney that is 90 percent likely to be cancerous and he will soon undergo surgery.

Murphy, 62, told NJ Advance Media that doctors caught it at an early stage and have “complete confidence” they’ll be able to fully remove the tumor. He said he does not expect he’ll have to undergo chemotherapy or radiation treatment.

“The expectation is that overwhelmingly, assuming nothing happens on the operating table or you don’t get an infection or something, you’re back on your feet and back in the game without any impairment going forward,” Murphy said during an interview at his Middletown home alongside First Lady Tammy Murphy.

While 90 percent of such tumors are malignant, doctors won’t know if it is renal cell carcinoma until after the surgery, Murphy’s office said. They said it is stage T1A, which according to the medical website Cancer.Net, is “where the tumor is found only in the kidney" and is 4 centimeters or smaller "at its largest area.”

The governor said he has been handling the news in stride and that his doctors are “optimistic” the tumor will not return in the future.

“It’s not something you look forward to doing,” Murphy said. “But we feel like we’re in really good hands. We caught it early. ... We consider ourselves incredibly fortunate.”

Murphy said he will undergo surgery in early March, will be hospitalized for two or three days, and then spend a few weeks recovering at home. Murphy’s office did not disclose the hospital where the surgery will take place but said it is in New York City.

Lt. Gov. Sheila Oliver will serve as acting governor while Murphy is incapacitated.

“You’re working by phone for a week, you’re then sort of another week kind of half in the game, and then by the third or fourth week, you’re fully in the game," Murphy said.

“I’ve got a 5K — knock on wood — scheduled for April that I fully expect to be running in," he added.

Murphy took to Twitter on Saturday night to confirm the news to his followers, saying “the prognosis is very good” and he’s profoundly grateful" to his doctors.

Friends – I’ve got a tumor on my left kidney and will undergo a partial nephrectomy in early March to remove it. The prognosis is very good and I’m profoundly grateful to my doctors for detecting the tumor early. — Governor Phil Murphy (@GovMurphy) February 23, 2020

Tammy Murphy, meanwhile, tweeted support, saying her husband is “a fighter.”

I know Phil and he’s a fighter. We’re grateful to his amazing team of doctors who detected this tumor early. Let’s keep fighting to make high-quality health care accessible and affordable for all! https://t.co/uEMtzVC9BW — Tammy Murphy (@FirstLadyNJ) February 23, 2020

The governor said he and his wife are “exceedingly fortunate” because there are no symptoms. An avid runner, Murphy noted that he was able to run a 5K last Sunday.

The 3-centimeter tumor is located on Murphy’s left kidney.

Murphy will undergo a partial nephrectomy, which means doctors will remove part of the kidney but not the whole organ. It’s an invasive surgery that will take a few hours, and it involves doctors freezing the kidney to extract the tumor, he said.

The governor said he will do a CAT scan in six months, another six months after that, and then in five years to monitor his recovery.

Murphy said his family has no history of cancer that he knows of, though there is a history of heart and coronary problems. His brother died unexpectedly of a heart attack at age 49.

That, Murphy said, is why he gets regular medical checkups. He said a gastrointestinal test during a recent doctor’s visit revealed the tumor “out of the blue.”

The governor said his doctors don’t know why it grew, though they said he could have a family history of which he’s not aware. They recommended he encourage his surviving siblings to get an abdominal CAT scan.

“Neither of us were expecting this,” Tammy Murphy said. “This was not even on our radar screen.”

“Because of the network of doctors Phil has and has had for decades now, I think he’s in great hands, and we believe what they’re telling us," she added. “So we’re going to keep living our lives as we do.”

The Murphys said they told their four children, whose ages range from 16 to 22, about the diagnosis Friday.

“They took it well, I think," the governor said.

Murphy noted that Tammy Murphy’s father and mother both died of cancer within the past three years.

“And they had miserable ends,” the governor said. “(The children) wanted to know: Are you telling us that’s what we’re looking at? The good news is: Assuming the operation goes well and you don’t get an infection or something, this is completely not that, thank God.”

The revelation comes days before Murphy is set to deliver his third state budget address on Tuesday. He said he plans to deliver his speech and then hold events this week to discuss his budget proposal.

He also plans to deliver the keynote speech Thursday night in Washington, D.C., to the New Jersey Chamber of Commerce following the organization’s annual train ride from New Jersey.

Murphy, a progressive Democrat, is in the third year of his term and is expected to run for re-election next year. He is also chairman of the Democratic Governors Association, where he is leading the effort to elect Democratic governors in more than a dozen states this year.

Murphy noted Saturday that about 50,000 New Jerseyans will be diagnosed with cancer this year.

He said a “big chunk” of the proposed budget he will deliver on Tuesday will focus on making health care more affordable for New Jerseyans. And his diagnosis, he said, has reinforced how important that is.

“It’s never abstract, because you can see the lives you impact,” the governor said. “But boy, this is real. This reminds you that having access to health care, having access to things like preventative services, regardless of what that might be, is a big deal."

Murphy tweeted a similar message Saturday night, saying “health care is a right, not a privilege for a select few.”

Health care is a right, not a privilege for a select few, and skyrocketing medical costs are a national emergency. If there’s anything my diagnosis reminds me of, it’s that preventative services are lifesaving and we need to continue fighting for affordable health care for all. — Governor Phil Murphy (@GovMurphy) February 23, 2020

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01.

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