Does breast fat transfer increase the risk of breast cancer?

Thanks for your excellent questions. There is no evidence to date that fat transfer increases the risk of breast cancer. However, it can increase the risk of causing changes on mammograms which may lead to unnecessary investigation, so it is important that you let your breast team know if you are having breast cancer surveillance.
If fat is injected directly into a major vessel, then you can get a 'fat embolus' and this can be life threatening. This has been reported following fat injection for buttock augmentation, but is not associated with fat transfer to the breasts.
It would be possible to increase size from A-C cup if you have enough donor fat available and are willing to undergo multiple procedures in order to achieve your desired volume. If you have had your implants removed, another option may be to combine an uplift procedure with some fat transfer.

In general, 200 cc per breast is typically the upper limit of fat injection recommended by most plastic surgeons.  It is not that more cannot be injected; but on average, this has been determined to be the most that can be expected to live during one transfer.  The fat must be injected through multiple planes in small amounts to the tissue through one tiny incision under each breast.  If you want more than a one cup size increase, this may require multiple treatments to reach the size you desire.
Fat transfer to the breast could improve the fullness of the breast, particularly at the top of the breast.   About 50% of the fat obtains permanence.  Calcification can occur after any fat transfer procedure.  I am not sure that the data has been collected on rate of calcification, and then the issue becomes whether that is clinically significant. The calcifications can be delineated from those for malignancy.
Kenneth Hughes, MD, Board Certified Plastic Surgeon

There was a concern previously that fat grafting may result in calcification that could be confused with breast cancer on mammography. This has subsequently been shown to be a minimal risk. There is no concern that the fat grafting actually causes cancer however. The fat survives as a graft in the new location and it is a permanent transfer of the fat and should survive for your lifetime. It behaves like fat anywhere else however and if you put on weight it will get larger, and if you lose weight it will get smaller. The "take" of the graft varies somewhat, but with careful technique 70% or more of the graft should survive. The volume change depends on the space available for fat injection. If you have laxity of the skin following the implant removal a higher volume may be possible. In order to get a change from A to C cup size it may require more than one session of fat grafting. Accidental intravenous injection of fat is a higher risk for buttock augmentation. Careful use of blunt cannulae reduces this risk. I don't see any problem with moderate use of alcohol after fat grafting.

Dear Vikilou,fat transfer is a good option to increase breasts size in case you want to avoid implants. It can increase your breasts up to one bra cup size. If you are considering a surgery, I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations.Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Dear Vikilou,
The fat that is moved to your breasts will largely act like fat from the site it was taken - so i always use those persistent stubborn fat reserves (knee fat, banana roll, saddle bags, inner thighs) rather than abdominal fat that can come and go easily with fluctuations in weight.
Measuring breast cup size difference isn't always helpful since it depends on your starting breast cup size, breast skin and girth of your chest, 1 cup size difference in a large chested lady can require as much fat as a 2-3 cup size difference in a small breasted woman.
The fat will last a lifetime if it "takes" ie establishes a blood supply, but remember  fat cells can grow and shrink with weight and hormone fluctuations. Also breast size may vary due to changes in other components of the breast ie breast tissue reduces (involutes) after the menopause even though the fat stays. 
Fat necrosis where the fat does not 'take' can be manifest as microcalcification on a mammogram which can be mistaken for DCIS if the radiographer is inexperienced or not aware of the history of fat transfer.
Fat transfer is especially successful after silicone implant removal since there is a natural space for the fat and the skin envelope has already been expanded.
Essentially I would say if you are interested in fat transfer, do have a detailed discussion with an FRCS (Plast) surgeon who has experience and an interest in the subject. Fat is a living tissue and the outcome is dependent on more than just the techniques and technologies used. It's also useful to have well-managed expectations so you can be satisfied with the outcome.
Best of luck.

Hi,
Thanks for your question. Many surgeons had this concern originally but it has not been borne out by the medical evidence - see my video for my explanation of all this.
Good luck with your research!