Maryland Gov. Larry Hogan announced in a news conference that he is '100 percent cancer free' after announcing that he had cancer in June. (WUSA9)

Maryland Gov. Larry Hogan announced Monday that medical scans show no sign of the cancer he was diagnosed with five months ago, indicating that 18 weeks of intensive chemotherapy have put the disease into remission.

Doctors will continue to monitor Hogan (R) regularly for signs of a recurrence. But at this point, the test results are the best possible news for the first-term governor, whose battle with non-Hodgkin’s lymphoma has made him an advocate for cancer patients and caused him to juggle state responsibilities with treatments that compromised his immune system and left him weaker.

“Incredibly, as of today, I am 100 percent cancer-free,” Hogan said at an emotional news conference in the governor’s reception room of the Maryland State House in Annapolis, which was packed with family members, friends, aides and well-wishers.

The governor disclosed his diagnosis in June, after discovering a lump on his neck during a trade mission to Asia. He said doctors found that parts of his body were riddled with tumors, some the size of oranges and golf balls.

Maryland Gov. Larry Hogan speaks about the outpouring of support during his battle against cancer and how the disease has changed him. (Tom LeGro/The Washington Post)

The news prompted an outpouring of support from people around the world, including a handwritten note from President Obama, well-wishes from politicians and residents throughout the state, and a corn maze that a Frederick County farmer carved out with Hogan’s image and the phrase “Maryland is HoganStrong” — a reference to a nonprofit group established in the governor’s name to raise funds for cancer research and support organizations.

On Monday, many of the notes and cards he received were on display as he spoke.

“I am so in­cred­ibly thankful to so many people who have stood by me in the fight,” the governor said, his voice cracking.

Hogan said he will begin a monthly regimen of “preventive maintenance” and will undergo regular scans to monitor his condition. He said that he expects his hair to grow back and his physical appearance to return to normal in coming days and weeks, while his energy level increases to pre-chemo levels.

“God willing, I will be back to 110 percent before you know it,” he said.

As part of his treatment, Hogan underwent 30 days of 24-hour chemotherapy, three surgeries, four spinal taps and multiple drug therapies. He announced in August, after eight weeks of treatment, that scans showed that his tumors were “95 percent” gone.

But independent medical experts said at the time that Hogan’s prognosis would not be clear until after his chemotherapy had been finished for a while and additional scans were performed.

Hundreds of cards and e-mails have been sent to Gov. Larry Hogan since he announced his diagnosis in June. The handwritten letters have come from Hogan's first-grade teacher, President Obama, a couple in Illinois and many others. (Ovetta Wiggins/TWP)

If a scan is negative six to eight weeks after therapy has been completed, there is a 90 percent chance that the patient is cured, said Bruce D. Cheson, the head of hematology at Georgetown University Medical Center. The longer a patient is cancer-free after finishing chemo, the better the odds of a full recovery. Hogan completed his chemotherapy about 30 days ago.

The governor remained on the job during his treatment, with Lt. Gov. Boyd Rutherford (R) filling in for him occasionally at meetings and public appearances.

Hogan sometimes held meetings in a makeshift conference room at the hospital, and he made several major decisions after his diagnosis, including approving the Purple Line light-rail project for Maryland’s Washington suburbs, closing the scandal-plagued Baltimore City Detention Center and unveiling plans to overhaul Baltimore’s bus system.

Hogan remained upbeat throughout the ordeal, joking at times that he had a better chance of beating the disease than he’d had of triumphing over former Lt. Gov. Anthony Brown (D) in last year’s gubernatorial election. He also quipped that his staff probably wished the treatments had sapped more of his energy so they would not have quite so much work to do.

The governor became a prominent advocate, documenting his experiences on Facebook, wearing green lymphoma-awareness ribbons and bracelets, and spending considerable time with ­cancer-stricken children and their parents.

At Monday’s news conference, Hogan received a card and a hug from 5-year-old cancer patient Andrew Oberle, who became his pen pal after the governor invited him to be his guest at the Redskins’ home opener this year.

The governor said he plans to continue his advocacy work.

“It’s because of these fellow patients that I will remain committed to raising awareness, encouraging research that will one day lead to a cure for this terrible disease,” he said.

A Washington Post-University of Maryland poll released last month found that Hogan is deeply popular in his home state, despite Democrats holding a 2-to-1 advantage among registered voters.

His approval rating stood at 61 percent, compared with 42 percent in February.

Fifty-six percent of Marylanders have heard at least something about Hogan’s cancer diagnosis, the poll showed, and his approval ratings are significantly higher among those who are aware of the cancer.