Answer based on context:

Coming off their bye week, the Patriots flew to Heinz Field for a Week 8 duel with the Pittsburgh Steelers.  New England trailed early in the first quarter, as Steelers quarterback Ben Roethlisberger completed a 5-yard touchdown pass to running back Mewelde Moore. Pittsburgh would add to their lead in the second quarter, as placekicker Shaun Suisham nailed a 33-yard field goal. The Patriots answered, with quarterback Tom Brady finding wide receiver Deion Branch on a 2-yard touchdown pass, but the Steelers came right back, with Roethlisberger completing a 7-yard touchdown pass to wide receiver Antonio Brown. New England would close out the half with a 46-yard field goal from placekicker Stephen Gostkowski. Pittsburgh began the third quarter with Suisham making a 21-yard field goal, followed by a 23-yard field goal in the fourth. The Patriots tried to rally, as Brady connected with tight end Aaron Hernandez on a 1-yard touchdown pass, but the Steelers' defense would prevail, with safety Troy Polamalu forcing a New England fumble out of the back of the end zone for a safety. With the loss, the Patriots fell to 5-2, being the first defeat by Steelers with Tom Brady starting at quarterback in the previous seven seasons.

How many seasons has it been since Tom Brady led Patriots have lost to the Steelers?
7