There is a recent article which asks this question (full reference below). I think it is a question which must be answered on an individual basis.
For someone like me, the answer would be no. I have no family history or personal history of breast cancer. I have small, more dense than fatty breast, but have always had normal mammograms. I have never had any lesions which needed biopsy.
For an individual woman with a strong family history of breast cancer (especially genetically proven, BRCA1 and BRCA2) and a person history of breast cancer (ie right mastectomy for lobular carcinoma), then it is easy to say “Yes, a prophylactic left mastectomy would be worth it for you.”
In between these two examples is the gray area, and this article doesn’t necessarily make the gray area any clearer.
There is plenty of evidence that prophylactic mastectomy lowers the risk of breast cancer in the high–risk population in at least 95%.
The authors of the June 2011 Aesthetic Plastic Surgery Journal article performed a retrospective study by reviewing the records of all their patients (n=52) who underwent prophylactic mastectomy within a 25-year period to look at the aesthetic and long-term oncologic outcomes, complications, and patient satisfaction.
Of the 52 patients, 40 had the surgery on one side only (contralateral prophylactic mastectomy) and 12 had bilateral (bilateral prophylactic mastectomy), giving a total of 64 prophylactic mastectomies.
Of the 52 patients/ 64 mastectomies, there was 1 (1.56%) case of unexpected breast cancer in the mastectomy specimens.
Two thirds (42/64) were subcutaneous prophylactic mastectomies and the other third (22/64) were simple total prophylactic mastectomies.
Most of their patients chose to have reconstruction with implants (58/64 = 90.62%) while the other 6 (9.37) chose to use autologous tissue -- 5 (7.81%) received latissimus dorsi flaps with implants and 1 (1.56%) had a TRAM flap.
The complications included 4 (6.25%) breasts that developed capsular contracture, 2 (3.12%) cases of hematoma, and 1 (1.56%) infection.
More than 90% of the patients reported being either highly (39/52) or partially satisfied (10/52). Only 3/52 reported being unsatisfied. The authors report an overall aesthetic index of 8.8.
There were no deaths among their patients, nor any new development of breast cancer during the time period.
Women Don’t Regret Prophylactic Mastectomy (May 5, 2011)
Prophylactic Mastectomy (January 28, 2009)
Advances in Nipple-Sparing Mastectomy – an article review (April 27, 2011)
Are Patients Making Good Decisions About Breast Reconstruction? (February 28, 2011)
Prophylactic Mastectomy: Is It Worth It?; Jose Abel de la Peña-Salcedo, Miguel Angel Soto-Miranda, Jose Fernando Lopez-Salguero; Aesthetic Plastic Surgery, Volume 35 (3), June 2011; DOI: 10.1007/s00266-011-9769-x
American Cancer Society: What are the risk factors for breast cancer?