BackgroundComprehensive studies of somatosensory change following breast reconstruction are limited. We investigated altered sensation quantitatively and qualitatively in patients undergoing mastectomies for cancer treatment and unaffected individuals who had risk-reducing mastectomies (RRM) for cancer predisposing genes. MethodsWomen attending breast clinic review at Royal Marsden Hospital, London were invited to participate. Sensory testing was performed a minimum of 1 year after surgery. Quantitative assessment of light touch and temperature sensation was performed at six points on the breast mound using Semmes-Weinstein monofilaments and temperature regulated droplets. Subjective sensibility of pain, tingling and pleasurable sensation was assessed using a four-point Likert scale questionnaire. Results181 breast envelopes were examined, 77 following mastectomy for cancer, 68 after RRM and 36 controls. Partial sensation was maintained with normal light touch in at least 1 quadrant in 57% following surgery. Preserved sensation was highest in the medial breast mound (p = 0.001). On qualitative assessment 74% reported significant loss of pleasurable sensation and 9% reported chronic pain. No difference in light touch and temperature sensation was noted in cancer versus RRM groups but loss of pleasurable sensation was more frequent in the former. Radiotherapy did not affect sensory change post-mastectomy. Following nipple sparing mastectomies, 47% retained normal touch sensation in the preserved areola and nipple. ConclusionBreast sensibility is significantly impaired following mastectomy and reconstruction but sensory loss is partial in the majority of women. Patients should be informed of these adverse post-operative effects to facilitate an informed decision if there is a surgical choice other than mastectomy as a surgical option.