(NBC News) – By 2035, rectal cancer death rates could exceed deaths from colon cancer, new research suggests.

Deaths from rectal cancer are rising rapidly among younger adults, an alarming trend that is confounding scientists trying to understand why millennials are so hard-hit.

“The rate of rectal cancer seems to be increasing more than two to three times compared to colon cancer,” said Mythili Menon Pathiyil, lead author of a new study and a gastroenterology fellow at SUNY Upstate Medical University in Syracuse, New York.

If the trend continues, rectal cancer deaths will exceed the number of colon cancer deaths — already the nation’s No. 1 cause of cancer death in people under age 50 — by 2035. (Read More)