Updated findings of skin flap thickness and residual breast tissue after mastectomy for breast cancer: a systematic review of the literature

BACKGROUND

There is limited evidence on the ideal retention thickness of skin flap in mastectomy. Residual breast tissue (RBT) after mastectomy still represents an unknown risk for local recurrence or new breast cancer lesions. We made this systematic review to identify the optimal flap after mastectomy with minimal complications and better oncological safety.

METHODS

A systematic review was performed using MEDLINE search in PubMed, Embase, and Cochrane Library with the search terms relevant to skin flap thickness and residual breast tissue in breast cancer patients undergoing mastectomy.

RESULTS

Twenty-one studies were included of which fifteen studies enrolled 3814 patients who received mastectomy, and additional six studies were based on cadavers or breast specimens. Four studies confirmed the presence of the superficial fascial layer (Camper's fascia) which can theoretically be used as an anatomical marker for flap retention during mastectomy. Two other studies confirmed Camper's fascia deficiency to a greater or lesser extent. The flap thickness ranged from 3.8 mm to 23 mm in 2692 patients of 7 studies, which was related to BMI, breast size, and examination modalities. Two retrospective and one prospective studies confirmed flaps exceeding 5 mm could significantly increase postoperative complications. Nine studies including 1122 patients explored the association among flap thickness, RBT, and complications, 3 studies of which confirmed excessive flap thickness could cause a significant increase in RBT, which proved to be a potential risk factor for local recurrence in 3 studies. Flaps beyond 5 mm were also found to significantly increase the chance of local recurrence in 4 studies.

CONCLUSION

Camper's fascia can serve as an ideal demarcation between fat and breast tissue based on most current studies. 5 mm thickness of the flap retention in mastectomy is recommended if Camper's fascia is absent or obscure, through which better cosmetic outcomes and less RBT can be achieved.

Pregnancy induced hyperplasia of residual breast tissue following risk reducing contralateral mastectomy - simply interesting or a clinically important observation

After a diagnosis of breast cancer women with increased genetic risk often have a risk reducing contralateral mastectomy, and may opt for a nipple or skin sparing mastectomy with immediate reconstruction. A variable amount of residual breast tissue remains which may substantially increase in volume during pregnancy. Whether this increases later risk of breast cancer is unknown. We describe the clinical details of 3 patients with a history of unilateral breast cancer, including 2 with a BRCA mutation, who developed hyperplasia of residual breast tissue in the 3rd trimester of a later pregnancy. They all had a delayed contralateral risk reducing skin sparing mastectomy and immediate reconstruction. Pregnancy occurred some years later. We summarise their management, review the literature and raise questions for discussion. All developed prominent hyperplasia of breast tissue in the 3rd trimester that was clinically obvious asymmetrical breast swelling in the reconstructed contralateral breast. MRI demonstrated substantial breast tissue. The risk of breast cancer, particularly in those at high genetic risk developing in the residual breast tissue is unknown but in view of the volume, breast tissue was excised postpartum. This phenomenon of pregnancy induced hyperplasia of breast tissue after risk reducing mastectomy is not well described .There is residual breast tissue following a risk reducing subcutaneous mastectomy. The risk factors include age and skin flap thickness. MRI can demonstrate the residual breast tissue. Pregnancy induced hyperplasia of residual breast tissue may occur after risk reducing mastectomy with a hypothetical increased risk of subsequent breast cancer.

Location and Frequency of Residual Breast Tissue after Mastectomy

Introduction

Residual breast tissue after mastectomy is a problem since breast cancer can arise from it. The aim of this study was to investigate the incidence and location of residual breast tissue following modified radical mastectomy.

Methods

111 consecutive breast cancer patients who underwent mastectomy were enrolled in this study. During surgery, after removal of the breast tissue and before skin closure, a 1-cm² tissue sample was obtained from each quadrant under the skin flaps. These samples were evaluated histopathologically for the presence of any residual breast tissue.

Results

Residual breast tissue was detected in the tissue samples of 12/111 (10.8%) patients. 4 of these patients had residual breast tissue in all 4 quadrants. 6 patients had residual tissue in a single quadrant. With 9 positive biopsy results, the upper medial quadrant was the most frequently involved location. The other quadrants had 6 positive biopsy results each. At the end of a median of 20 months of follow-up, none of these patients developed breast cancer recurrences.

Conclusion

Mastectomy has a high probability of residual breast tissue being left behind. Physicians should be aware of this and act accordingly when planning surgical or follow-up treatment.