Are women being sold a "bill of goods" about prophylactic mastectomy? Although it may decrease the risk of cancer somewhat, it should not be touted as a panacea, says Dr. Susan Love.
The two kinds of preventive mastectomy, its role in decreasing the risk of breast cancer, and its associated risks were discussed by Dr. Susan M. Love of the UCLA Medical Center at the 11th Annual International Breast Cancer Meeting in San Antonio this past May.
With subcutaneous mastectomy, all the breast tissue is removed while the nipple and areola are left intact. However, in a number of series, a lot of breast tissue--in the tail of the breast, beneath the nipple, and in the skin flaps--routinely has been left with this approach. Therefore, its prophylactic use has been seriously questioned.
With total mastectomy, the goal is to remove all the breast tissue. Again, however, it is difficult to be certain that this has been accomplished. In terms of the anatomy of the breast, the glandular and ductal tissue certainly extends well beyond the protuberant part of the breast, and the extent may not be obvious to the surgeon. The actual ducts extend as far as the clavicle down below the costal margin, around past the latissimus, up into the axilla, and down even a little bit into the arm. In actuality, a very wide excision, not complete removal of all breast tissue, is performed. According to Dr. Love, this is a key distinction with preventive mastectomy.
Dr. Love questioned whether removing 95% of the tissue removes 95% of the risk of cancer; in studies evaluating the risk of breast cancer in relation to the size of the breast, there has been no correlation. The findings of two animal studies--one using a carcinogen and the other hereditary breast cancer--indicated that the mean number of tumors that developed was exactly the same regardless of whether they had removed 25%, 50%, 75%, or allegedly 100%. In essence, "removing a proportion of the breast tissue did not remove a proportion of the cancer risk," Dr. Love stated. Furthermore, in the study with hereditary breast cancer, the tumors occurred with equal frequency on the operative side and the nonoperative side. Dr. Love emphasized that these findings were in animals, not women. There have been no randomized controlled studies of prophylactic mastectomy in women.
It is Dr. Love's contention that prophylactic mastectomy in women may decrease the risk somewhat. In certain cases, when breast tissue is removed, undetected occult cancers may actually be removed as well. However, there are many anecdotal cases in the literature of women who have undergone prophylactic mastectomy, both total as well as subcutaneous, and still subsequently developed breast cancer.
Dr. Love explored the risks involved in performing preventive mastectomy--physical, psychological, and carcinogenic. One physical risk is necrosis of the flaps. In order to remove all the breast tissue, very thin flaps are needed. There are a lot of problems with the implants placed under thin flaps, including the complications that accompany saline and silicone implants.
The psychological risks were the real crux of Dr. Love's discussion. The main problem is that there are no guarantees to offer women with hereditary breast cancer who are considering preventive mastectomy. In the absence of any other type of cancer prevention, prophylactic mastectomy may be a reasonable approach provided that the patient understands it will not be a guarantee against the development of breast cancer. With mastectomy, there are obvious alterations in body image and sensation. Patients should be made to understand that there are benefits as well as risks associated with this procedure.
Might Surgery Increase the Risk?
There is also the question of whether the operation itself promotes breast cancer in high-risk women. In certain animal studies, an increased incidence of cancer was demonstrated in the group that underwent surgery versus the group that did not undergo surgery. Dr. Love added, "I think that we have to be very careful about what we are suggesting and the supposed advantages and disadvantages of what we are suggesting, because we don't know what all the implications are. Surgery may or may not be benign."
Dr. Love concluded that, for high-risk women in particular, the option of preventive mastectomy should be discussed; however, in other settings, Dr. Love rarely uses it. Most important, patients should obtain a complete understanding of the risks and benefits of the procedure, as well as the fact that a guarantee against cancer development cannot be made. "The ultimate betrayal," she said, "is to have both your breasts removed and then show up with breast cancer down the road."