The news of Jack Layton's passing early Monday morning dealt a particularly heavy blow to the millions of Canadians who have fought, or who continue to struggle, with their own battles with cancer.

The NDP released a statement to say Layton passed away at home, surrounded by family and loved ones, at about 4:45 a.m. He was 61.

While Layton had gone public with his prostate cancer diagnosis in early 2010, he announced in July that he was suffering from a different form of cancer that would require treatment. He did not reveal what new type of cancer he was battling.

His death serves as a grim reminder that cancer is the leading cause of death in Canada, having surpassed cardiovascular disease in 2007.

In 2011 alone, 75,000 people will die in Canada from cancer, according to the Canadian Cancer Society. More than 177,000 new cases of cancer will be diagnosed this year, and 40 per cent of women and 45 per cent of men in Canada are expected to develop cancer in their lifetimes.

Gerry Johnston, the associate dean of research at Halifax's Dalhousie University, said that we cannot become complacent, especially with the amount of Canadians facing this disease.

"Mr. Layton's passing reminds us how real and serious the war is," Johnston told CTV News on Monday.

While Layton used his public voice to raise awareness about prostate cancer, he revealed few details about his treatment regimen, and offered none about the new form of cancer he was diagnosed with this year.

In an interview with CTV's Lisa LaFlamme on the day the federal government unveiled its budget earlier this year, Layton would only say he did not want to reveal which medications he was taking.

"I haven't been going into the details of my treatment," Layton said. "I'm keeping that between my doctors and myself…and just making good progress."

According to the Canadian Cancer Society, prostate cancer is the most common cancer among males and accounts for more than a quarter of new cancer cases in men. In 2011, an estimated 25,500 men in Canada will be diagnosed with prostate cancer, while 4,100 will die from the disease.

On average, according to the society, 11 Canadian men will die from prostate cancer every day.

Dr. Neil Fleishner from Princess Margaret hospital in Toronto said that prostate cancer is the second most common cause of cancer death among Canadian men, but that the disease is highly treatable if caught in the early stages.

"Any time a high-profile Canadian comes forward we do see more men expressing an interest in being screened for prostate cancer," he told CTV News.

Prostate Cancer Canada released a statement Monday, saying members of the organization "are all saddened" to learn of Layton's passing and hailing his efforts to raise awareness of the disease.

"Jack was a great supporter of Prostate Cancer Canada," the statement said. "He recently participated in our It's Our Time education campaign. And, without Jack we would not have had access to Parliament last year when the entire House of Commons wore our tie in support of his fight."

The Canadian Cancer Society also released a statement mourning Layton's "untimely death."

"The Canadian Cancer Society will always be grateful for Jack Layton's passionate efforts to improve the health of Canadians and to raise awareness and funds for our organization to help us in our mission to eradicate cancer and assist those living with the disease," said president and CEO Peter Goodhand. "Our thoughts are with his family at this time of loss."

Goodhand told CTV News that Layton's passing shows how complex this disease is.

"It varies from person to person," he said. "The way Jack defied the disease -- that life is for living and not for cancer -- is the way he fought the battle. It's something that inspires us all."

He also said that the outcome of Layton's cancer should make us more determined than ever to find solutions.

"We need better screening, better diagnosis," Goodhand said.

In an open letter to Canadians released Monday and written days before his death, Layton thanked the well-wishers who had offered him their support.

"Tens of thousands of Canadians have written to me in recent weeks to wish me well. I want to thank each and every one of you for your thoughtful, inspiring and often beautiful notes, cards and gifts. Your spirit and love have lit up my home, my spirit, and my determination," Layton said.

After adding that treatment for the new form of cancer "had not worked out as I hoped," Layton had specific words for Canadians who are on their own "journeys to defeat cancer."

"Please don't be discouraged that my own journey hasn't gone as well as I had hoped. You must not lose your own hope. Treatments and therapies have never been better in the face of this disease," he said.

"You have every reason to be optimistic, determined, and focused on the future. My only other advice is to cherish every moment with those you love at every stage of your journey, as I have done this summer."