Calling the day she learned about her breast cancer diagnosis in February a “personal 9/11,” tennis star Martina Navratilova discussed her treatment and prognosis with ABC's Good Morning America anchor Robin Roberts on Wednesday.

“In February, the tennis legend was diagnosed with an aggressive form of ductal carcinoma in situ (DCIS), considered the earliest form of breast cancer,” reports ABC News. “Navratilova had a lumpectomy in February, during which her doctors determined that the cancer had not spread to her lymph nodes.”

Navratilova said there is only a “very small chance of it coming back,” according to ABC News.