George Alagiah, 62, will undergo medical treatment fro cancer, after the disease returned, his agent confirmed.
The news presenter had been been diagnosed with bowel cancer in April 2014.
“George Alagiah, the presenter of BBC News at Six, is to undergo medical treatment after a recurrence of cancer,” said Alagiah’s agent.
“He was first diagnosed with bowel cancer in April 2014, and returned to the screen in November 2015 after extensive treatment. He is in discussions with his medical team about treatment options and the way forward.”
Alagiah said: “My brilliant doctors are determined to get me back to a disease-free state, and I know they have the skill to do just that.
“I learned last time around how important the support of family and friends is and I am blessed in that department.
“I genuinely feel positive as I prepare for this new challenge.”
Bowel cancer that returns after treatment is known as recurrent bowel cancer, according to Bowel Cancer UK.
During initial treatment for bowel cancer, doctors try to destroy all cancer cells with treatment.
But, the cancer can return if some of the cancer cells spread to other parts of the body, or if some were left behind at the original site, the charity said.
Those who survive bowel cancer have a higher risk of developing recurrent bowel cancer.
After treatment has finished, doctors will investigate whether all of the cancer has been destroyed.
Follow-up investigations aim to find any non-cancerous growths in the bowel, or any cancerous cells that have returned.
Treatments could help to keep symptoms under control. These include palliative care, supportive care, or symptoms managed, Bowel Cancer UK said.
Radiotherapy, chemotherapy and biological therapies could help to keep symptoms under control.
“A new or recurrent cancer can be difficult to cope with when you have already been through treatment for cancer,” said the charity.
“You may have thought that the cancer had gone and your life may have started to get back to normal.
“If you are having trouble coping, speak to your healthcare team. They may be able to refer you to a counsellor or psychologist. Family and friends can also be a great support.”