Veteran ABC radio presenter James Valentine announces cancer ...

ABC radio presenter James Valentine has been diagnosed with oesophageal cancer and will be off-air as he undergoes surgery to remove a four-centimetre tumour.

The Afternoons host announced the news today, about four months after receiving the diagnosis, in a story on the ABC website.

"Immediately it was meetings with oncologists, radiologists, and surgeons and, in early January, I started five weeks of chemotherapy and radiation," he said. 

Valentine will now undergo surgery, the main treatment for his cancer, in a few weeks.

"The surgery will remove my entire oesophagus and then stretch my stomach up and attach it to my throat," he said.

"After that, I'm very likely to feel like absolute crap for quite some time."

Valentine's radio show this afternoon will be his last for up to three months as he takes time off to recover from the surgery. 

"I'm going to make sure I'm fully recovered and my stomach is going to stay attached to my neck before I attempt broadcasting again," he said.

Valentine insisted he would be fine in the long term but admitted he wouldn't be the same again.

The veteran radio star has worked with the national broadcaster for more than 27 years, with the majority of that career spent on-air. 

He recently moved back to the later slot as Afternoons host this year after a short stint doing Breakfast. 

He was also a reporter on Sunrise and Good Morning Australia. 

Valentine also previously toured with bands as a saxophonist - which he still continues to play and perform at gigs.