Maryland Gov. Larry Hogan talks with Douglass Mayer, his deputy director of communications, while working in his office on Sept. 10 in Annapolis, Md. (Jonathan Newton/The Washington Post)

The letters poured in almost as soon as Maryland Gov. Larry Hogan gripped the podium at a news conference and announced that he had cancer. Hogan brought them with him when he checked into the hospital days later, for his first round of chemotherapy.

There was a note from a Baltimore woman battling Stage 4 breast cancer. Another from a New Jersey man who survived bladder cancer. And one from Vivian Krawitz of Towson, who was diagnosed with non-Hodgkin’s lymphoma — the same kind of cancer as Hogan — at age 62. She is now 84. “May you be well and know I send my very best wishes!” Krawitz wrote. “Thought this might help!”

The letters, and thousands like them, have pushed the first-term governor into what he refers to as his newest “calling” — advocating for cancer patients and their families. Since he was diagnosed in June, Hogan (R) has invited people with cancer to the State House, set up a #HoganStrong fundraising effort that has raised $35,000, and visited the pediatric oncology ward at the University of Maryland Medical Center.

On Sunday, the governor appeared at FedEx Field with fellow cancer patients during the Washington Redskins’ home opener to call attention to their battle against a “monster of a disease.”

“I never expected to be in this position. But having gone through this experience myself just opened up a whole new world,” said Hogan, 59, who has lost his hair and eyelashes and has two chemotherapy sessions to go. “I’m part of the club. I’m one of them. . . . They know when they see me, [they can say,] ‘He knows what chemo is like.’ ”

A poster hangs in the administrative office of Hogan showing support during his battle against cancer. (Jonathan Newton/The Washington Post)

The Redskins event is one of several planned for Hogan in September, which has been designated Blood Cancer Awareness Month and Childhood Cancer Awareness Month.

On Tuesday, the governor will host a blood drive outside the State House while wearing a green lymphoma awareness ribbon or bracelet, as he has done since announcing his cancer diagnosis in June. There also will be a bone marrow registry. He will join cancer-stricken children and their parents to promote Ronald McDonald House Charities at an Orioles game Wednesday, and he will participate in a program at M&T Bank Stadium with the Ravens on Sept. 27.

Hogan has joined a small cadre of politicians who have battled cancer while in office, including former New York mayor Rudolph W. Giuliani, former U.S. senator Arlen Specter and former U.S. senator Edward M. Kennedy. According to the Leukemia and Lymphoma Society, Hogan is one of 200,000 people who will be diagnosed with a blood cancer this year.

His high public profile means he is well positioned to reach out to others with cancer and call attention to the disease, advocates say. “There are so many negatives with any kind of tragic event in any of our lives, and it can be crushing,” said Laurie Strongin, who founded the D.C.-based Hope for Henry Foundation after her son died of Fanconi anemia, a rare blood disease. “But there is the positive side — when you ask yourself what you can do for other people around you.”

Officials with the Leukemia and Lymphoma Society said the governor’s efforts started the moment he held a June news conference to reveal and candidly discuss the diagnosis of late Stage 3 non-Hodgkin’s lymphoma.

“Your willingness to share your story has catapulted our cause to become extremely relevant and important to Marylanders,” Jonathan Wilson, the executive director of the group’s Maryland chapter, wrote in a letter to Hogan about a week after the news conference. “Thank you for being a hero to so many with your demonstration of transparency and courage.”

Hogan in his office. (Jonathan Newton/The Washington Post)

Hogan’s immune system is compromised, and he has developed dark circles around his eyes as a result of the chemotherapy. He routinely calls on Lt. Gov. Boyd K. Rutherford to stand in for him at public events. But he continues to play the lead role in governing the state, and he has maintained a heavy meeting schedule — sometimes in a makeshift conference room at the hospital during treatment.

He said some days he feels “like hell” but added: “I’m getting out of bed and I’m going to work, because we’re killing cancer cells. I don’t want to be laying around in the bed. And I kind of feel like if I keep moving, I’m doing more good. I don’t know.”

Hogan has used social media to chronicle much of his journey. His 20 cancer-related posts on Facebook have received more than 6 million page views, said spokesman Doug Mayer. The Kojak-like picture showing that Hogan had gone bald as a result of chemotherapy reached 1.5 million people and received 44,536 likes — the most of any of his posts during his time in office.

Hogan also posted several pictures of himself with patients he met while pacing both floors of the oncology ward at the University of Maryland Medical Center, a circuit he says equals a mile if he traverses it 17 times.

The governor has told reporters about the fatigue he experiences after getting medicine to help his bone marrow; fretted about his inability to shake hands because of his weakened immune system; and joked about his “chemo pie face,” the puffiness associated with his steroid medication.

Todd Eberly, a political science professor at St. Mary’s College of Maryland, said Hogan’s cancer and the near-celebrity status he has created could make it difficult for Democrats as they try to recapture the governor’s office in 2018 — especially if Hogan is well enough to run for a second term.

“I think their greatest concern is it has made him a much more human person,” Eberly said, noting that voters throughout the country are showing increasing disdain for career politicians. As an individual, he said, Hogan “is going to have a nice reserve of goodwill from the public.”

Hogan’s State House visitors since his diagnosis included John Carver and his daughter, Juliana, 13, who is battling cancer for the fifth time. Carver said he left feeling that the governor and first lady Yumi Hogan “get it.”

“They understand the pain and the struggle, because he is going through it,” the Carroll County resident said. “You could see the passion in their eyes.”

Hogan says he has gained more from his interactions with other patients and their families than they likely have received from him. He said he is inspired by those who are fighting cancer and those who have won the battle against the disease, including David Brinkley, his budget secretary.

Shortly after his diagnosis, Hogan said, Brinkley gave him advice: When he is feeling his worst, he should think about how bad the cancer must feel.

Scans show that the chemotherapy has greatly shrunk the dozens of tumors that doctors found when the cancer was diagnosed. But oncologists say Hogan’s doctors won’t have a clear sense of whether the chemotherapy has eradicated the cancer until at least several weeks after the treatment is finished. (Hogan began his fourth round of chemotherapy late last month.)

An emotional person to start with, Hogan says he has become even more so in the last three months, perhaps in part because of the drugs he is taking as part of his treatment. He has attended three funerals or memorial services this month — for former governor Marvin Mandel; Steven Kreseski, who was an aide to former governor Robert L. Ehrlich; and Keiffer Mitchell Sr., the father of one of Hogan’s staff members — and said they, too, may have taken a toll.

Discussing his outreach effort, Hogan fought back tears several times — then abruptly switched gears, joking that he hoped a reporter wouldn’t write “that the governor was crying like a baby.”

“I see people with much tougher fights than me,” Hogan said, his voice thick. “To watch their attitudes and the faith that they have and the positive attitude that they have. . . . It encourages me.”

Since his diagnosis, tens of thousands have left messages on his Facebook page offering prayers — an outpouring Hogan said leaves him deeply appreciative but also feeling almost guilty. The governor routinely posts comments asking those who are praying for him to pray for all cancer patients as well.

“I’m thinking, these guys down the hall, maybe they have their family there, or maybe they have a few friends checking in on them,” Hogan said. “But they don’t have thousands saying they are praying for them.”

The prayers and well wishes, he said, “makes me feel great. But I want that for the other people. They deserve it. That’s part of what the outreach is about.”