Apple Inc. co-founder Steve Jobs downplayed the seriousness of his battle with cancer for years even as he received secret treatments, biographer Walter Isaacson told CBS Corp.'s '60 Minutes' in a segment scheduled to air Sunday evening.

According to a transcript of the taped interview, Mr. Isaacson said Mr. Jobs resisted having surgery after being diagnosed with cancer in 2004, choosing to treat his disease through diet. After having the surgery, Mr. Jobs had people believing he was cured even as his cancer spread to his liver.

'He's trying to deny it to himself, and to the public, and this is a problem of course,' said Mr. Isaacson, who said the matter created tension between the guarded CEO's desire for privacy and the rights of Apple's shareholders.

(This story and relatedbackground material will be available on The Wall Street Journal website, WSJ.com.)

The news magazine program says Mr. Isaacson interviewed Mr. Jobs more than 40 times for his highly anticipated biography of the legendary and controversial chief executive. 'Steve Jobs'--set to be released by CBS Corp.'s Simon & Schuster on Monday--was rushed after Mr. Jobs died after a long battle with pancreatic cancer on Oct. 5 at age 56. Preorders have topped best-seller lists for weeks.

Mr. Isaacson, who is a former editor of Time magazine, brushed through Mr. Jobs's bumpy biography during the interview. Mr. Isaacson covered how Mr. Jobs's adoption convinced him he was 'chosen' and his quest to meet his biological parents.

Mr. Jobs justified his callous management style to Mr. Isaacson in a taped interview, saying being brutally honest was 'the ante for being in the room,' according to the transcript.

After being ousted by the Apple board as a young man, Mr. Jobs returned to the company in 1997, launching a string of hits--including the iPhone a decade later. Those products have turned Apple into the world's most valuable technology concern.

In the interview, Mr. Isaacson also said Mr. Jobs spoke of his desire to make an easy-to-use television set, a project analysts widely expect the company to be working on.

An Apple spokesman didn't have an immediate comment.

Mr. Isaacson, who met with Mr. Jobs for a final time in mid-August, said that Mr. Jobs held out hope that he would be cured and ruminated about spirituality, saying he believed in God about half the time.