shutterstock_278020754-1A new systematic review finds inconclusive evidence about any association between silicone gel breast implants and long-term health outcomes.

The review appears online in the Annals of Internal Medicine.

After all these years of research on silicone-gel filled breast implants and long-term diseases, is the absence of evidence the evidence of absence?

“The current systematic review finds that to date, the body of comparative study evidence on breast implants still does not provide conclusive evidence regarding whether silicone gel implants affect the risk for cancer, [connective tissue diseases], or other health outcomes,” the researchers concluded

Researchers conducted a systematic review of Medline, Embase, and Ovid Healthstar from inception through June 30, 2015, and the Cochrane Central Register of Controlled trials and Cochrane Database of Systematic Review through the first quarter of 2015. The researchers culled data longitudinal studies that compared women with and without breast implants and long-term health outcomes, and then extracted data on participant and implant characteristics, analytic methods, and result. In all, 32 studies in 58 publications were included in the new analysis.

Primary breast cancer in women who had breast implants for augmentation was evaluated in 11 studies. Other types of cancers included cervix, endometrium, uterus, vulva, brain, lung, non-Hodgkin lymphoma, leukemia, Hodgkin lymphoma, and multiple myeloma. There was a possible decreased risk for primary breast and endometrial cancers associated with the implants, the study found. In addition, there was a possible increased risk for lung cancer, rheumatoid arthritis, Sjögren syndrome, and Raynaud syndrome seen in the studies. The relationship between breast implants and other outcomes showed limited evidence or no association.

In an editorial accompanying the new study, researchers from VU University Medical Center, Amsterdam, the Netherlands, point out that it’s time to refocus research efforts to understand the symptoms that some women with implants report. “It is unfortunate that we still lack definitive knowledge about silicone implants and long-term health outcomes after decades of research, “ they write.