Bestselling author Colleen Hoover is sharing a health update with her many readers and fans.

The "It Ends with Us" author revealed she was diagnosed with cancer and underwent treatment in an Instagram story photo post Monday, writing, "Second to last day of radiation! I wish I could blame my hair and facial expressions on @texas.oncology but they've been great. Hope you never need them, but highly recommend them."

In an earlier Facebook post on Friday, Hoover wrote that she had received test results back from a geneticist that explained her cancer did not stem from "family genes" and was not tied to HPV or hormonal factors.

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She added that she was "happy and grateful to be alive."

Hoover has not revealed the type of cancer with which she was diagnosed.

The author was noticeably absent from the October 2025 premiere for the movie "Regretting You," which was adapted from her 2019 book of the same name.

"I'm super bummed, but am having an unavoidable surgery and can't travel for a while," Hoover wrote in an Instagram post at the time.

Hoover's latest book, "Woman Down," is out Jan. 13.