This is a response-adaptive (RAR) prospective randomized study with a long-term follow-up and the aim of this clinical study is to measure with qualitative and quantitative indicators the changes in cosmetic results, quality of life and patient satisfaction after breast reconstructive surgery with silicone implant (following SSM, ASM or NSM mastectomy) and symmetrization (mastopexy and/or silicone implant and/or Ultrapro mesh sling technique) over time. According to the hypothesis of the study, the results of implant-based breast reconstruction and symmetrization following advanced postmastectomy techniques significantly decrease over time and later results limited patient satisfaction rate. This is mainly due to the fact that over time, the natural breast differs from the reconstructed breast with silicone implant. Because of the different biological properties (gravity results ptosis on breast with mastopexy, significant volume increasement of the breast with mastopexy due to endocrine therapy, gradually progressive capsular contracture on the tumorous side, nipple flattening, nipple tattoo fading etc.) the two sides change differently resulting in significant asymmetry and consequently could lead to decreased patient satisfaction. The high degree of asymmetry over time (which can be similar to the difference between the result of a simple mastectomy and natural breast (control group)), may indicates additional surgeries or usage of medical devices, putting a financial burden on the patient and the health system. On the other hand, the symmetry can be achieved with bilateral skin-sparing mastectomies and implant-based immediate or delayed-immediate reconstructions is clearly better and change less with time. The mastectomy of the contralateral disease-free side is considered as an unreasonable burden for moderate risk patients. The information such as the need for multiple surgeries, change in symmetry over time etc., should be an important part of the professional decision-making mechanism and the surgeon should inform the patient during the primer surgery. Nowadays due to the lack of evidence-based knowledge, it is not part of the patient's information and surgical planning internationally. Planning breast units, attention, capacity and financial resources must also be provided to meet the long-term needs of patients who underwent postmastectomy breast reconstruction. Simple mastectomy with an external prosthesis can be an alternative for patients with intolerable degree of asymmetry or on the contrary, the results may justify the need for bilateral mastectomy and reconstruction even in the absence of high oncological risk and for purely symmetrical and cosmetic reasons.