Melissa Etheridge was supposed to play 11 dates this month in support of her recent album Lucky. Instead, she's lucky she had a cancer screening. The rocker has been diagnosed with breast cancer and is canceling her upcoming shows, her publicist announced Thursday. The 43-year-old, who last week signed a deal to star in an ABC sitcom, has already been receiving treatment, she said in a statement. ''I am fortunate to be under a wonderful doctor's care and thankful that this was caught early,'' said Etheridge, who will undergo surgery soon. ''I am looking forward to a quick and full recovery.''