'DWTS' Pro Witney Carson Reveals Her Father-in-Law Is Battling Pancreatic Cancer, Leaves Tour

"The doctors have explained there is nothing that they can do and have told us that we only have a few weeks with him before the cancer takes his life," Witney Carson wrote in an emotional Instagram post Wednesday

Witney Carson‘s father-in-law is battling pancreatic cancer and has been told by doctors that he only has weeks to live.

The Dancing with the Stars pro announced on Instagram Wednesday that she would not be participating in the upcoming DWTS Live! winter tour because her father-in-law’s battle with cancer has worsened.

“My sweet father-in-law has been dealing with pancreatic cancer for the last year and a half. A few days ago he was having stomach issues & was unable to keep anything down. His doctors decided to do an exploratory surgery to find the problem, which we thought was just a minor issue. Unfortunately, we were completely wrong,” Witney, 24, wrote about her husband Carson McAllister’s father, Kevin McAllister.

“The cancer has spread throughout his entire abdomen. We are so blindsided and still in shock… The doctors have explained there is nothing that they can do and have told us that we only have a few weeks with him before the cancer takes his life,” she shared. “After much heartache and discussion, Kevin has decided to fight it and try another aggressive chemotherapy treatment.”

Witney continued: “My heart hurts to tell you all that I will not be able to do the DWTS tour this winter. This is an extraordinarily difficult time for us, I hope all of you can understand that my place is here with my family.”

She added that, “Right now, my focus needs to be on my family & especially on my husband,” and wished her season 25 DWTS partner, Frankie Muniz, “and the whole tour an amazing run. I love my fans & I feel so devastated that I can’t be there, but know that my heart is there with you ❤️.”

The DWTS Mirrorball champion wed her high school sweetheart during a three-part celebration in the Salt Lake City area on New Year’s Day in 2016.

The couple started dating during their senior year of high school, but their love story actually starts years before that.

“She was my dream girl since 7th grade. But she didn’t know I existed until senior year,” Carson told PEOPLE. “We became really close friends and kinda started dating. From the second I got to know her, I could tell she was the most loving and understanding girl I’d ever met.”

WATCH: ‘Dancing With the Stars’ Pro Witney Carson Ties the Knot on New Years Day

After graduating high school, he spent two years in Romania on a mission with the Church of Jesus Christ of Latter-day Saints, while she went on to compete on the Fox reality dance competition So You Think You Can Dance.

The two wrote e-mails and sent packages to each other, but “we had to make a lot of sacrifices,” she said of making things work while thousands of miles apart. The long-distance relationship continued while she joined the cast of DWTS and he enrolled in college and went into business with his father.

In June, Witney gushed about her hubby in a loving birthday tribute.

“Don’t even know where to begin with this one, so I I’ll start w/ IM SO HAPPY YOU WERE BORN 24 years ago today @carson.mcallister!!” she wrote.

“I really don’t know how or what I did to deserve such a caring, kind-hearted, hilarious, loving husband but I’m so grateful everyday that you’re mine!” she continued. “You are the light & love of my life!! ✨✨”