A Brooklyn resident who is not only alive but doing well after being diagnosed with stage four lung cancer is sharing his story this Lung Cancer Awareness Month.

Fifty-three-year-old Oswald Peterson had just lost his mother and his long-term partner and was finally starting to feel like himself again, until his life took another turn.

"January 1, 2017 I woke up with this pain in my back," Perterson recalls.

He was diagnosed with stage four lung cancer.

"Along with the fluid in my heart and the fluid in my lungs, I had cancer on my chest, blood cots in my back," Peterson says, who adds that he had lost hope.

"I had kind of accepted it was my time," Peterson says.

But then he met Dr. Catherine Shu, a lung cancer specialist at New York-Presbyterian and Columbia University Medical Center.

"Lung cancer is a scary diagnosis, but the treatment has improved dramatically over the last 10 years. We have a lot of new treatments," Shu says.

For Peterson, immunotherapy worked wonders.

"One month after I left the hospital, I gained back 40 pounds, I was doing the elliptical and stairmaster for an hour straight," Peterson says.

That's why during Lung Cancer Awareness Month, he's sharing his story with the hope to encourage more people who might have symptoms to get checked out.

"For anyone who is a heavy smoker, I would recommend discussing with their primary care doctor or their pulmonologist whether or not they might be a candidate for lung cancer screening," Shu says.

Because if caught and treated, more New Yorkers can get a whole new lease on life just like Peterson did.

"I have no sign of disease and cancer free, and I'm healthy. I get to still do all the things I want to do. I have a new partner, we travel, we just got back from Costa Rica, we were in Mexico a few weeks ago," Peterson says.