Health issues forced Jack Layton to miss a public event Saturday - his first scheduled appearance since announcing he has cancer.

The 59-year-old NDP leader was diagnosed in December with prostate cancer. He has vowed to beat the disease his father also overcame.

Layton said Friday he would stay on as leader of the New Democrats and MP for Toronto-Danforth, though he joked his treatments would give him more time to watch the Olympics on TV.

Fighting the disease may have already put a dent in the energetic politician's normally jam-packed schedule of community and cultural events.

He was to attend a celebration for a local publication in Brampton, Ont., at a Sikh place of worship early Saturday afternoon, but wasn't able to make it.

"I didn't speak to his doctors, but he was not in a condition to travel," said Layton's spokesman Karl Belanger.

"I do not know if it was related to his cancer or not."

Layton did call one of the speakers at the event, Jay Jagasia, who held his phone up to a microphone as Layton read his prepared remarks.

"First, I apologize for not being able to be there with you today," Layton said.

"I am however honoured to be able to join you by phone, celebrating the sixth anniversary of Road News being published and distributed in the community."

Jagasia extended his best wishes to Layton on behalf of the Sikh community gathered there.

"We wish him good luck and we pray for him here," he said.

Belanger said Layton still planned to attend a fundraiser event in Toronto in the early evening in celebration of the upcoming Chinese New Year with his wife, fellow NDP MP Olivia Chow.

Chow is also a cancer survivor, having won a battle with thyroid cancer.

Layton said Friday that his treatment plan is underway, but his staff said the details would remain between Layton and his doctor.

Layton has represented the riding of Toronto-Danforth since 2004. He just celebrated his seventh anniversary as leader.