ADRB2 and cancer: Higher β2AR expression was associated with improved recurrence‐free, overall, and cancer‐specific survival, and the magnitude of associations were marginally strengthened (adjusted HR 0.53, 95% CI 0.29–0.96; HR 0.50, 95% CI 0.27–0.94; HR 0.45, 95% CI 0.23–0.87, respectively).