Cameron just completed the final year of his four-year rookie contract. Over 10 games this season, he caught 24 passes for 424 yards and two touchdowns.
In 2013, Cameron caught 80 passes for 917 yards and seven touchdowns and earned a Pro Bowl nod.
The 26-year-old has suffered three concussions over the past two years.
The Browns went 7-9 and finished in last place in the AFC North this season. Last month, Cleveland hired John DeFilippo as offensive coordinator and Kevin O'Connell as quarterbacks coach.