Kathy Griffin Just Revealed She Has Lung Cancer—Even Though She's Never Smoked

Kathy Griffin shared shocking news on social media Monday: She has lung cancer.

"I've got to tell you guys something. I have cancer. I'm about to go into surgery to have half of my left lung removed. Yes, I have lung cancer even though I've never smoked!" the 60-year-old comedian wrote on Twitter and Instagram. "The doctors are very optimistic as it is stage one and contained to my left lung. Hopefully no chemo or radiation after this and I should have normal function with my breathing. I should be up and running around as usual in a month or less."

In an interview with Nightline, which is set to air on ABC Monday night, Griffin revealed she was diagnosed after a doctor noticed a mass on her lung that had doubled in size. "I've had it for a long time," she said, regarding the mass. "And it gets X-rayed every three years and hasn't grown. So she said, 'Well, this time, it grew."

Griffin said she was in shock after hearing the news—especially since she doesn't have a history of smoking. "I'm still a little bit in shock. Not denial, but ... once a day, I'll just turn to, like, nobody next to me and go, 'Can you believe this s--t? Is this a bitch or what,'" she told Nightline. "It's stage 1. It's nowhere else in my body. So I need to focus on that."

The comments of Griffin's Instagram and Twitter posts were flooded with well wishes, including from fellow stars. "We love you Kathy! Thank you for being so honest and strong. You are an example to us all," said Nikki Glaser. "Wow So brave❤️My heart is wide-open for you. Thank God you found it early and a safe recovery," said Andie MacDowell.

Here's what you need to know about lung cancer—stage 1 specifically—and how even non-smokers can be affected by the disease.

What is lung cancer?

Lung cancer is cancer that starts in the lungs. It happens when cells in the lung mutate, grow uncontrollably, and cluster together to form a tumor, according to the American Lung Association (ALA). As those cancer cells grow out of control, they destroy the healthy lung tissue around them.

There are two main types of lung cancer: small cell lung cancer and non-small cell lung cancer, the ALA says. Non-small cell lung cancer makes up about 80% of all lung cancer cases, and grows and spreads more slowly than small cell lung cancer, which is "almost always" associated with smoking, per the ALA. Griffith didn't share the type of lung cancer she has.

What is stage 1 lung cancer?

Lung cancer staging tells where the lung cancer cells are located, the size of the lung cancer tumor, and if (and where) the lung cancer has spread, the ALA says. It also can help doctors recommend that best type of treatment and give some information about prognosis.

Stage 1 lung cancer means that the cancer has not spread to the lymph nodes or other parts of the body.

What are the symptoms of lung cancer?

Lung cancer doesn't usually cause symptoms at its earliest stages, and symptoms usually show up when the cancer is advanced, the Mayo Clinic says. Those can include:

• A new cough that doesn't go away
• Coughing up blood
• Shortness of breath
• Chest pain
• Hoarseness
• Losing weight without trying
• Bone pain
• Headache

What causes lung cancer?

Smoking is one of the largest causes of lung cancer, but people who have never smoked can also develop the disease, the Mayo Clinic points out.

Up to 20% of people in the U.S. who die from lung cancer have never smoked or used any type of tobacco, the American Cancer Society (ACS) says. These are the other factors that can increase your risk of lung cancer, aside from smoking:

• Exposure to radon gas
• Exposure to secondhand smoke
• Being around cancer-causing agents, like asbestos, arsenic gas, and diesel exhaust
• Air pollution
• Genetic changes

How is lung cancer treated?

Treatment for lung cancer can include surgery to remove a portion of the impacted lung or removal of an entire lung, radiation therapy, chemotherapy, targeted drug therapy, and immunotherapy, the Mayo Clinic says. The best type of treatment often depends on the form of lung cancer a person has and the stage of their disease.

At the end of her Instagram and Twitter posts, Griffin reassured fans and followers that she will be "just fine." She also added that she's fully vaccinated against COVID-19—which, if she hadn't been, would have complicated her situation even more. She ended with some advice for readers: "Please stay up to date on your medical checkups. It'll save your life."