She made the announcement in a Philadelphia Inquirer op-ed to raise awareness of the importance of regular screenings.
Quiñones- Sánchez, who is 52, said she put off having a mammogram for 7 years.
"I am waging my own fight against breast cancer, one that began this summer after I had my first mammogram in seven years," wrote the councilwoman.
She says after her diagnosis, she had a mastectomy. She is now cancer-free after undergoing aggressive treatment.
Quiñones-Sánchez is still undergoing chemotherapy and is set for another round of preventative care radiation. She hopes her story will convince other women to schedule a mammogram.