A new study published Thursday confirms what oncologists have noticed for some time: that breast implants are associated with a small increased risk of cancer.

Health Canada insists the risk is very small, and that only five cases have been confirmed in the last 10 years. But CTV News has learned there have actually been many more women affected — nearly two dozen and possibly more — and that doctors may be missing some of the signs.

The new study in the journal JAMA Oncology found that approximately one in 7,000 women who get breast implants will develop a rare form of cancer called breast implant-associated anaplastic large cell lymphoma, or BIA-ALCL.