Alexa McDonough, a former provincial and national NDP leader, has breast cancer, CBC News has learned.

McDonough said she received the news about four months ago after a routine mammogram.

The 68-year-old said she has been undergoing treatment ever since and is doing well.

"I'm feeling pretty good. Actually I'm feeling good for a lot of reasons. I feel very blessed. Early detection matters a lot and that's a shout-out to people who think annual mammograms for example are, you know, kind of a waste of time because that's the only reason I knew and got early intervention through a routine annual mammogram," said McDonough.

She was first elected to the House of Commons in 1997 after becoming leader of the federal NDP in 1995.

She led the NDP back to official party status in 1997 after it failed to hold on to enough seats in the 1993 election, and became the first NDP member elected to Parliament from the Nova Scotia mainland and the first NDP leader to win a majority of Nova Scotia seats in the House of Commons.

McDonough stepped down as leader in 2003 and was succeeded by Toronto politician Jack Layton.

In the 2006 federal election, McDonough became the first woman to win four consecutive terms representing Nova Scotia in Parliament and the second MP (since Gordon B. Isnor) to represent Halifax for four consecutive federal terms. That year, she was also the only woman elected among 32 MPs in Atlantic Canada.

Prior to entering federal politics, McDonough was the leader of the Nova Scotia NDP for 14 years. When she assumed the leadership of the provincial party in 1980, she became the first woman to lead a recognized political party in Canada.