Led by the Minnesota Chamber of Commerce, business groups — including oncologists, the Minnesota Vikings football team and tobacco companies — accounted for nearly half of the $56.5 million spent lobbying state legislators last year.

The chamber spent $2 million in 2012, according to a new report from the Campaign Finance and Public Disclosure Board. The next largest single spender was Education Minnesota, the state’s teachers union, which spent just more than $1 million, including about $700,000 for television ads urging voters to make education issues an election year priority.

The spending by business groups produced some recent triumphs — the Vikings will soon have a new stadium and lawmakers did not raise taxes — and some disappointments — the GOP Legislature did not produce a health insurance marketplace bill and Dayton put a stop to some education overhaul proposals.

“We certainly had our share of frustrations last session but also had some successes,” said Laura Bordelon, the chamber’s senior vice president of advocacy.

Despite lobbying efforts that appear unabated, business groups may see less satisfaction this year. The governor and DFL legislators have already created a new health marketplace law that big business groups and health insurance companies opposed. Dayton and lawmakers also are eyeing higher income, tobacco and transit taxes.

“Every year is offense and defense. … This is a year when we are playing more defense. We’ve had some trouble moving some of our priorities,” said Bordelon.

Labor groups, which spent about $3 million on lobbying last year, may see more success. As voters replaced a Republican Legislature with a Democratic one, labor’s issues have taken on new prominence.

“The people that got elected, we believe, are pro-education, pro-labor people,” said Tom Dooher, Education Minnesota president. “The governor, the House and the Senate all agree that education is a priority.”

The lobbying figures also show heavy spending to influence public officials making health care decisions.

According to a Star Tribune analysis of last year’s lobbying reports, health care interests — from dueling oncology groups to the big health insurance companies — spent almost $5 million to sway official actions.

Just one health care interest, Minneapolis Radiation Oncology Physicians spent more than any other group that has health as its primary focus.

The oncology group, which wants to preserve a ban preventing new Minnesota radiation centers from being built, spent $640,000 last year on lobbying. A rival oncology group, Minnesota Oncology Hematology, spent about $260,000. Last year, the Legislature kept the ban in place.

The 2012 spending by Minneapolis Radiation Oncology Physicians was actually down by almost a third from the year before. In 2011, the group spent $900,000. All told, it has spent $4.6 million since 2006.

The Minnesota Vikings also decreased its lobbying a bit last year, spending $610,000, down from $840,000 in 2011 and $4.3 million in lobbying spending since 2006.

Lawmakers and the governor finally approved a new state-subsidized stadium for the football team last year.

“I certainly expect our lobbying figure to drop dramatically,” said Minnesota Vikings spokesman Jeff Anderson.

“Our goal is to not have a presence at the Capitol this year.”