The Potential Benefit of Preemptive Leukotriene Inhibitor Treatment to Breast Augmentation/Mastopexy Surgery

Capsular inflammation after immediate breast reconstruction - Gene expression patterns and inflammatory cell infiltration in irradiated and non-irradiated breasts

BACKGROUND

Capsular contracture following post-mastectomy radiotherapy (PMRT) is commonly seen in patients undergoing implant-based immediate breast reconstruction (IBR). Further understanding of the underlying biology is needed for the development of preventive or therapeutic strategies. Therefore, we conducted a comparative study of gene expression patterns in capsular tissue from breast cancer patients who had received versus those who had not received PMRT after implant-based IBR.

METHODS

Biopsies from irradiated and healthy non-irradiated capsular tissue were harvested during implant exchange following IBR. Biopsies from irradiated (n = 13) and non-irradiated (n = 12) capsules were compared using Affymetrix microarrays to identify the most differentially regulated genes. Further analysis using immunohistochemistry was performed in a subset of materials to compare the presence of T cells, B cells, and macrophages.

RESULTS

Enrichment testing using Gene Ontology (GO) analysis revealed that the 227 most differentially expressed genes were mainly involved in an inflammatory response. Twenty-one GO biological processes were identified [p < 0.05, false discovery rate (FDR) < 5%], several with B-cell-associated inflammation. Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) analysis identified macrophages as the most common inflammatory cell type in both groups, further supported by immunostaining of CD68. Radiation remarkably increased B-cell infiltration in the capsular region of biopsies, as quantified by immunostaining of CD20 (p = 0.016).

CONCLUSIONS

Transcript analysis and immunohistochemistry revealed inflammatory responses in capsular biopsies regardless of radiotherapy. However, the radiation response specifically involved B-cell-associated inflammatory responses.

Effect of Carboxymethyl Chitin on Capsule Formation around Silicone Implants: An In Vivo and In Vitro Study

BACKGROUND

Capsular contracture is a serious complication that occurs after augmentation mammaplasty. The authors previously identified that carboxymethyl chitin had an inhibitory effect on capsule formation. This study was performed to elucidate the possible molecular mechanisms through which carboxymethyl chitin inhibits the formation of a capsule around silicone implants.

METHODS

In this study, the authors cultured human dermal fibroblasts and treated them with carboxymethyl chitin in vitro. The difference in proliferation between treated and untreated cells was analyzed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Protein levels of transforming growth factor beta-1 and alpha smooth muscle actin (α-SMA) were examined by Western blot analysis. Expression levels of type I and type III collagen were checked by enzyme-linked immunosorbent assay. In vivo, silicone implants were placed under the pectoralis muscle in 12 female rabbits. The thickness of the capsule was measured by histologic analysis, and the effect of carboxymethyl chitin on α-SMA, collagen type I and III expression levels was evaluated by real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence analysis.

RESULTS

In the in vitro study, we confirmed that carboxymethyl chitin inhibited the proliferation of fibroblasts. The protein expression levels of collagen type I, transforming growth factor beta-1, and α-SMA were inhibited by carboxymethyl chitin treatment. In vivo, carboxymethyl chitin treatment reduced capsular thickness and the expression of α-SMA and collagen types I and III in capsules around silicone implants.

CONCLUSION

The authors' results showed that carboxymethyl chitin could influence capsule formation around silicone implants by inhibiting the fibroblast activity, interrupting fibroblast-to-myofibroblast differentiation, and decreasing collagen synthesis.

CLINICAL RELEVANCE STATEMENT

Carboxymethyl chitin influence capsule formation around silicone implants. Although more clinical studies are needed to verify the effect of carboxymethyl chitin on capsular contracture, the authors believe that it will play an effective role in the clinical application of reducing the occurrence of capsular contracture.

Treatment and Prevention of Periprosthetic Capsular Contracture in Breast Surgery With Prosthesis Using Leukotriene Receptor Antagonists: A Meta-Analysis

BACKGROUND

Capsular contracture (CC) is the most common long-term complication of breast surgery with prosthesis. Leukotriene receptor antagonists (LRAs) have been tested as a potential treatment; however, mixed results have been observed.

OBJECTIVES

The aim of this study was to undertake a meta-analysis to clarify the treatment and prophylactic capabilities of LRAs in the management of CC.

METHODS

A systematic literature search of the most popular English-language databases was performed to identify relevant primary publications. We included all studies that used the Baker scale to evaluate the treatment and preventive capabilities of LRAs.

RESULTS

Six eligible studies were included based on predefined inclusion and exclusion criteria, totalling 2276 breasts, of which 775 did not receive LRAs and 1501 did. Final pooled results showed that LRAs could help manage CC with a risk difference (RD) of -0.38 with a corresponding 95% CI of -0.69 to -0.08, showing statistical significance at a Z value of 2.48, P = 0.01. Subgroup analysis based on the type of drug showed that only montelukast yielded statistical significance (RD = -0.27, 95% CI = -0.51 to -0.03, Z = 2.20, P = 0.03). Zafirlukast did not seem to influence CC. Further subgroup analysis based on treatment timing showed that prophylaxis was ineffective and only treatment for ongoing CC yielded statistically significant improvements.

CONCLUSIONS

The current meta-analysis proved that LRAs could be used in the management of CC. Only treatment for ongoing CC showed statistically significant improvements. Montelukast seemed to be more efficient with a safer profile for adverse effects, whereas zafirlukast yielded no statistically significant results.

LEVEL OF EVIDENCE: 4

A Comparison of 28 Published Augmentation/Mastopexy Techniques Using Photographic Measurements

Background

Numerous augmentation/mastopexy methods have been described in the literature, including those reported in 16 publications in 2019. However, objective measurements of breast dimensions are lacking, leaving little information on which to base treatment selection. The goal is to increase upper pole projection using an implant and correct ptosis by elevating the lower pole with the mastopexy.

Methods

A PubMed search was conducted to identify published augmentation/mastopexy methods. Lateral photographs were matched for size and orientation and then compared using a 2-dimensional measurement system. Measurements were compared for 5 common approaches-vertical; periareolar; inverted-T, central mound; inverted-T, superior pedicle; and inverted-T, inferior pedicle. Four publications not fitting these 5 groups were also evaluated. Measurement parameters included breast projection, upper pole projection, lower pole level, breast mound elevation, nipple level, area, and breast parenchymal ratio.

Results

A total of 106 publications were identified; 32 publications included lateral photographs suitable for comparison. Twenty-eight publications fitting 1 of the 5 groups were compared. All published augmentation/mastopexy methods increased breast projection and upper pole projection, although not significantly for inverted-T methods. Vertical augmentation/mastopexy was the only method that significantly raised the lower pole level (P < 0.05). The vertical technique also significantly (P < 0.01) increased the breast parenchymal ratio. Periareolar; inverted-T, central mound; and inverted-T, inferior pedicle methods produced nonsignificant increments in the breast parenchymal ratio.

Conclusions

Breast implants increase breast projection and upper pole projection. Only vertical augmentation/mastopexy significantly elevates the lower pole. This method also significantly increases the breast parenchymal ratio, achieving the surgical objectives.

Pro-Fibrotic CD26-Positive Fibroblasts Are Present in Greater Abundance in Breast Capsule Tissue of Irradiated Breasts

BACKGROUND

Breast capsular contracture is a major problem following implant-based breast reconstruction, particularly in the setting of radiation therapy. Recent work has identified a fibrogenic fibroblast subpopulation characterized by CD26 surface marker expression.

OBJECTIVES

This work aimed to investigate the role of CD26-positive fibroblasts in the formation of breast implant capsules following radiation therapy.

METHODS

Breast capsule specimens were obtained from irradiated and nonirradiated breasts of 10 patients following bilateral mastectomy and unilateral irradiation at the time of expander-implant exchange, under institutional review board approval. Specimens were processed for hematoxylin and eosin staining as well as for immunohistochemistry and fluorescence activated cell sorting for CD26-positive fibroblasts. Expression of fibrotic genes and production of collagen were compared between CD26-positive, CD26-negative, and unsorted fibroblasts.

RESULTS

Capsule specimens from irradiated breast tissue were thicker and had greater CD26-postive cells on immunofluorescence imaging and on fluorescence activated cell sorting analysis than did capsule specimens from the nonirradiated breast. Compared with CD26-negative fibroblasts, CD26-positive fibroblasts produced more collagen and had increased expression of the profibrotic genes IL8, TGF-β1, COL1A1, and TIMP4.

CONCLUSIONS

CD26-positive fibroblasts were found in a significantly greater abundance in capsules of irradiated compared with nonirradiated breasts and demonstrated greater fibrotic potential. This fibrogenic fibroblast subpopulation may play an important role in the development of capsular contracture following irradiation, and its targeted depletion or moderation may represent a potential therapeutic option.

LEVEL OF EVIDENCE: 2