NASHVILLE, Tenn. (WKRN) — Country singer Toby Keith revealed Sunday that he was recently diagnosed with stomach cancer and has been privately receiving treatment.

“Last fall, I was diagnosed with stomach cancer,” Keith, 60, wrote on Twitter. “I’ve spent the last 6 months receiving chemo, radiation, and surgery. So far, so good. I need time to breathe, recover and relax. I am looking forward to spending this time with my family, but I will see the fans sooner than later. I can’t wait.”

Stomach cancer “begins when cells in the stomach start to grow out of control,” according to the American Cancer Society. Sometimes known as gastric cancer, stomach cancer accounts for about 1.5% of all new cancers diagnosed in the U.S. each year. Survival rates are based on how far the cancer has spread.

NewsNation’s “Rush Hour” spoke to Shikha Jain, a board-certified hematologist, Monday for more insight on Keith’s diagnosis. Jain said there are about 25,000-28,000 cases of stomach cancer per year, with it most commonly occurring in men.

“You can have weight loss, you can have pain with eating, you can have poor appetite, some abdominal pain, nausea, some swelling in the abdomen,” Jain said.

While Keith has been undergoing treatment since last fall, Jain says the type of procedure one would need depends on how far along the cancer has progressed.

“Depending on the stage of the cancer — whether it’s local or it’s become advanced — you can either require treatments like chemotherapy and radiation followed by surgery, followed, sometimes, by more chemotherapy if you’re being treated with a plan for curing you of the cancer or removing it altogether,” Jain said.

There are some patients who, unfortunately, are diagnosed at a later stage and if theyu’re not a candidate for curative surgery, they may just be a candidate for chemo and possibly radiation.

“In his [Keith’s] case, we don’t know the stage but it sounds like if he underwent chemotherapy, radiation and surgery. Hopefully, it was caught early and hopefully they were able to treat all of it and remove it,” Jain said.

The singer has long worked to support those facing cancer diagnoses. In 2006, Keith began the Toby Keith Foundation, an organization that streamlines its efforts around no-cost housing for children with cancer. In 2014, the foundation opened OK Kids Korral, a cost-free home for pediatric cancer patients who receive treatment at The Children’s Hospital at OU Medical Center in Oklahoma. 

Concerts scheduled for June, July, August and September are still listed on Keith’s website. It’s unclear how many, if any, will be canceled or postponed. Keith is also scheduled to perform at Coachella Crossroads in Coachella, California on November 11.