Heart singer Ann Wilson has been diagnosed with cancer. The 74-year-old star – who shot to fame as the lead singer of the ‘Barracuda’ group alongside her younger sister, Nancy Wilson, 70, in the mid-70s – has cancelled the band’s upcoming ‘Royal Flush’ tour alongside Cheap Trick, which was scheduled to begin on 30 July and run until December while she can undergo chemotherapy to tackle the disease. Ann announced on Instagram on Tuesday (02.07.24): “Dear friends, I recently underwent an operation to remove something that, as it turns out, was cancerous. The operation was successful + I’m feelin…