A Food & Drug Administration review found that women with breast implants have a greater chance of contracting a rare form of cancer than other women.

The federal watchdog agency warned doctors and patients of a possible link between saline- and silicone gel-filled breast implants and anaplastic large-cell lymphoma, a very rare type of cancer.

Patients who received the implants may have a "very small but significant risk of ALCL in the scar capsule adjacent to the implant," according to the FDA. Thirty-four cases were reported in women with breast implants in the U.S. with about 60 reported globally since 1997, according to the FDA.

Doctors diagnose ALCL in roughly 1 out of 500,000 women a year in the U.S.; ALCL in breast tissue is found in only about 3 out of every 100 million women without breast implants nationwide, according to the FDA.

"We need more data and are asking that healthcare professionals tell us about any confirmed cases they identify,” Center for Devices and Radiological Health chief scientist Dr. William Maisel said in prepared remarks.

The FDA is not recommending that women with implants seek medical care outside their routine, but physicians should consider the possibility of ALCL in patients with late-onset cancer symptoms, the agency said. The FDA is working with the American Society of Plastic Surgeons to build a breast implant registry to help track ALCL in women with implants.

Breast implant manufacturers include Johnson & Johnson (NYSE:JNJ) unit Mentor Corp. and Allergan Inc. (NYSE:AGN).

The FDA cleared breast implants for cosmetic surgery in 2006, after 14 years of limiting them to reconstructive purposes. The devices were introduced into the U.S. in 1962.