By Jennifer Newton Sarah Ferguson has broken her silence on her skin cancer diagnosis – which comes six months after she learned she had breast cancer. Taking to Instagram, she said: “I have been taking some time to myself as I have been diagnosed with malignant melanoma, a form of skin cancer, my second cancer diagnosis within a year after I was diagnosed with breast cancer this summer and underwent a mastectomy and reconstructive surgery. It was thanks to the great vigilance of my dermatologist that the melanoma was detected when it was. “Naturally another cancer diagnosis has been a shock b…