Maryland Gov. Larry Hogan (R) has the most common form of cancer that affects the lymphatic system, which fights disease throughout the body.  But even when non-Hodgkin's lymphoma reaches its later stages and has spread, as it has in Hogan, it is often curable because of drugs that have been developed to fight it, experts say.

James Rubenstein, a hematologist-oncologist at the University of California San Francisco Medical Center, said that, conservatively, half the patients with the disease survive five years. Other experts put the figure somewhat higher.

"This still seems to be a curable condition with this type of presentation," Rubenstein said after hearing Hogan's description of his condition and symptoms.

[Maryland Gov. Larry Hogan says he has ‘advanced’ form of cancer]

The 59-year-old governor can expect a six-month course of therapy with both chemotherapy and immunotherapy drugs that most likely will leave him fatigued, cause hair loss and increase his risk of infection, Rubenstein said. Chemotherapeutic drugs target the cancer itself, while immunotherapy attempts to unleash a patient's immune system against the invading disease.

The governor might not be able to work full-time as he goes through treatment because of fatigue, Rubenstein said. But some people are able to keep up with their schedules, experts said.

Jason Westin, an assistant professor of lymphoma and myeloma at MD Anderson Cancer Center in Houston, said that an aggressive form of the cancer is actually more treatable than a slower growing form of the disease.

“Lymphomas are very responsive to treatment, to chemotherapy, more than say, lung cancer or pancreatic cancer,” he said. “The nature of these cells is that they grow faster but they die faster too. They can be killed off... The slow-growing ones come back more often.”

[On social media, Marylanders wish Gov. Larry Hogan a speedy recovery]

Westin also said the description of Hogan's cancer as late stage 3--which means  it’s on both sides of the diaphragm--is a bit misleading.

“Lymphoma stage is not as important as it is with other cancers because it’s a disease of the immune system,” he said, “so it’s already dispersed, unlike other types of cancer that then spread to other parts of your body.  Stages 2 to 4 are identical in terms of treatment.”

There are more than 60 different types of B-cell non-Hodgkin's lymphoma, the kind Hogan has, said Bruce Cheson, deputy chief of the hematology/oncology division in the Lombardi Comprehensive Cancer Center at MedStar Georgetown University Hospital. B cells produce antibodies that fight infection throughout the body. It is the sixth-most-common form of cancer in the United States and somewhat less curable than Hodgkin's lymphoma.

"We cure more than 80 percent of Hodgkin's lymphoma and the numbers are moderately lower with non-Hodgkin's aggressive lymphoma,” Cheson said.

The major risk in the treatment regimen is the patient becoming resistant to chemotherapy, which generally happens within two years, Rubenstein said. That may be caused by genetic factors in the tumor or inability to deliver adequate therapy, he said.

Critical factors in Hogan's prognosis are his age (the disease typically develops about age 60 or later, and Hogan is 59), how functional he is at the time treatment begins and the stage and metabolism of the tumor itself.

Westin also said the disease is often asymptomatic, discovered only when a lymph node is enlarged enough to be noticed, as it apparently was in Hogan’s case.

“It’s often a serendipitous finding, detected with a physical, because there are few if any symptoms,” he said. “It’s more common to have a painless mass.”

If the drug therapy fails, said Richard Fisher, president and CEO of the Fox Chase Cancer Center, part of the Temple University health system in Philadelphia, the standard treatment involves harvesting the patient's own blood cells and giving him or her a very high dose of chemotherapy. It works in about half of people eligible for the treatment.

There also are a number of promising clinical trials for this type of cancer, Fisher said.

“You don’t go into this treatment hoping to keep cancer at bay," said Eric Jacobsen, clinical director of the adult lymphoma program a the Dana-Farber Cancer Institute in Boston. "You are going into it to eradicate it.”

Ariana Eunjung Cha, Amy Ellis Nutt and Lena Sun contributed to this report.

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