Trends and issues in clinical research on satisfaction and quality of life after mastectomy and breast reconstruction: a 5-year scoping review

Breast reconstruction (BR) aims to improve the satisfaction and quality of life (QOL) of breast cancer survivors. Clinical studies using patient-reported outcomes (PROs) can therefore provide relevant information to the patients and support decision-making. This scoping review was conducted to analyze recent trends in world regions, methods used, and factors investigated. The literature search was conducted in August 2022. Databases of PubMed, MEDLINE, and CINAHL were searched for relevant English-language studies published from 2017 to 2022. Studies involving women with breast cancer who underwent BR after mastectomy and investigated PROs after BR using BR-specific scales were included. Data on the country, publication year, study design, PRO measures (PROMs) used, time points of surveys, and research themes were collected. In total, 147 articles met the inclusion criteria. BREAST-Q was the most widely used, contributing to the increase in the number and diversification of studies in this area. Such research has been conducted mainly in North America and Europe and is still developing in Asia and other regions. The research themes involved a wide range of clinical and patient factors in addition to surgery, which could be influenced by research methods, time since surgery, and even cultural differences. Recent BR-specific PROMs have led to a worldwide development of research on factors that affect satisfaction and QOL after BR. PRO after BR may be influenced by local cultural and social features, and it would be necessary to accumulate data in each region to draw clinically useful conclusion.


Introduction
Currently, surgical strategies for breast cancer are becoming increasingly diverse, including the development of breast reconstruction (BR) techniques and the widespread of prophylactic mastectomy. BR aims to improve the body image and quality of life (QOL) of breast cancer survivors; however, patients must choose the best treatment for themselves, considering implant-specific issues, donor-site sacrifice, psychological burden, costs, and physical and social rehabilitation. Thus, to help patients make a choice suitable for their situation and preferences, information on the advantages and disadvantages of each option in terms of QOL, complications, and aesthetic outcomes is necessary.
Outcome evaluation using patient-reported outcomes (PROs) is helpful for these areas. It enables scientifically quantify multidimensional outcomes that are only known to the patient, contributes to the consideration of patientcentered treatment strategies, supports decision making, and improves the quality of healthcare [1]. Only objective esthetic and symmetry evaluation has been used to assess BR outcomes in the past; however, with the advent of wellvalidated BR-specific PRO measures (PROMs) [2, 3], deep understanding of various aspects of patient's life, such as body image, pain, ease of bra wear, and psychological aspects, has become possible.
Although these BR-specific measures have been incorporated into clinical studies and have deepened research on QOL after BR, the influencing factors are diverse and 1 3 complex, and the evidence remains insufficient [4][5][6]. A scoping review of articles published in the last 5 years on this area was conducted to map and organize which world regions, which methods, and which factors were investigated. This review aimed to analyze the trend of studies, rather than study outcomes, to guide future research planning.

Methods
This scoping review was conducted according to the principles of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement [7]. The following question guided the mapping of this scoping review: What world regions, what research methods are being used, and what research questions are being investigated in recent clinical studies on satisfaction and QOL after mastectomy and BR?

Literature search
The literature search was conducted in August 2022. Pub-Med, MEDLINE, and CINAHL databases were searched for relevant English-language studies published from 2017 to 2022. The combination of search terms "breast reconstruction" and "breast cancer" with "patient-reported outcomes" or "satisfaction" or "quality of life" was used.

Selection of eligible studies
The inclusion and exclusion criteria were predetermined to select the relevant studies. The studies were included if it fulfilled all of following criteria: (1) studies involving women with breast cancer or with hereditary breast and ovarian cancer syndrome (HBOC) and underwent therapeutic or prophylactic mastectomy (PM), (2) studies involving women who underwent immediate BR (IBR) or delayed BR (DBR), (3) studies that assessed postoperative satisfaction and QOL using the BR-specific PROMs (namely, 9], Breast Reconstruction Satisfaction Questionnaire (BRECON-31) [10][11][12], and the European Organization for Research and Treatment of Cancer Quality of life Questionnaire BRR26 (EORTC QLQ-BRR26) [13,14], which were assessed as well-developed in a previous study), and examined factors that affect them [2], and (4) any type of BR including autologous and implant-based BR, and secondary procedures such as fat grafting, nipple reconstruction, contralateral symmetrization.
The exclusion criteria were as follows: (1) studies about BR following breast conserving surgery (BCS), (2) studies that compared BR with MT and BCS, and (3) opinion, review, letter, meta-analysis, case report, case series, prepost study, qualitative study.
Two reviewers (MS and RN) independently screened the title and abstracts to determine whether the studies met the criteria. Disagreements were resolved by further discussion between the two reviewers.

Data collection, analysis, and reporting of results
After determining studies eligible for inclusion in the final review, data were extracted by a reviewer (MS) to identify the following aspects: (a) region and country of the first author, (b) publication year, (c) study design, (d) PROM used, (e) time point of the PRO survey, and (f) research theme. Endnote and Excel were used for the management and analysis of studies.
The number of publications was described by country, year, and methodology of PRO investigation. The main themes of the study were divided into the following four categories: (i) factors related to reconstructive surgery, (ii) clinical factors related to indication and treatment, (iii) patient factors, and (iv) factors affecting QOL and satisfaction. After the categorization was reconfirmed by another reviewer (RN), the distribution of study themes by region was analyzed.

Results
In total, 1177 studies were retrieved from the literature search, 294 full texts were reviewed, and 147 articles were included in the final analysis (Fig. 1). Table 1 shows the countries of affiliation of the first author. Of the 147 studies, 69 (46.9%) were from North America, followed by 57 (38.8%) from Europe. Moreover, 17 (11.6%) papers were from Asia, of which more than half were from China. Very few papers were published from the rest of the world.

Region and publication year
As shown in the number of publications each year by region, the number consistently exceeds 10 in North America and is increasing in Europe and other regions (Fig. 2). Table 2 shows the characteristic regarding the methodology of the studies included, which were as follows: 76 (51.7%) cross-sectional studies, 23 (15.6%) retrospective cohort, 42 (28.6%) prospective studies, and 6 (4.1%) randomized controlled trials (RCT). Propensity-score matching analysis was used in three cross-sectional and two retrospective cohort studies.

Method to investigate PROs
The BREAST-Q was utilized in most of the studies. Preoperative baseline surveys were conducted in 51 (34.7%) studies. The timing of the postoperative survey was defined in 65 (44.2%) of the studies, whereas others were not clearly defined (36.7%), had only a lower limit such as "six months or more" (16.3%), or were broad to include years (2.7%).

Discussion
BR-specific PROMs developed in North America and Europe have been translated and disseminated in many countries, and the BREAST-Q is now the most used worldwide, contributing to the increase in the number and diversification of studies in satisfaction and QOL after BR.
As regards recent trends in research themes, in addition to the basic theme of autologous tissues in comparison with implants, optimization of the outcomes of each surgery by stratifying treatment factors and patient factors has been investigated. Studies have also discussed ATBR techniques based on abdominal flap BR to further improve the QOL of patients; however, the introduction of new surgical materials such as acellular dermal matrices (ADM) has led to changes in surgical techniques in IBBR, and many studies have evaluated new techniques from the perspective of patient satisfaction and QOL. Another major focus of the world is radiation therapy. Since BR is a part of breast cancer treatment, the timing of treatment and reconstruction is a major clinical issue. As patient factors, in addition to demographic factors such as race and age, obesity, preoperative psychiatric disorders, and postoperative psychological aspects are being considered, and these studies have been conducted mainly in North America. These patient factors should be considered potential confounders in future clinical studies. In clinical practice, patient education on these factors and patient support from the preoperative to the postoperative period were suggested to improve postoperative satisfaction and QOL.
Studies using BR-specific measures were expected to accumulate and be integrated into future meta-analyses with a higher level of evidence. However, potential barriers are the quality of each study [4,5,159] [138], race [144], and other factors. Such multicenter studies are a valuable reference for future clinical research. Gallo et al. stated that appropriate BREAST-Q administration, reporting of appropriate time horizon, and sample size calculations were important to ensure sufficient data quality [159]. In the present study, the time points of PRO surveys were clearly prespecified in 44.1% of the studies analyzed. Despite conflicting reports that satisfaction improves with time since surgery [115,160] and conversely declines [23, 31, 153], the short-term and long-term results likely vary because women's breast shape changes considerably with age, and implant-reconstructed breasts are deformed by capsular contracture. Therefore, the appropriate timing of evaluation should be determined in advance according to the purpose of the study.
Cultural backgrounds, women's body shapes, and values differ among countries, and the response patterns and average values differ even with the same scale. Thus, the extent to which the findings of other county's studies are applicable to Japanese populations is uncertain. They are more likely to be skinny than their Western counterparts, less likely to have large ptotic breasts, and have limited donor-site volume in the abdomen and thighs. Based on body shape, Asian studies may be more helpful for Japanese than for Westerners. For example, Cheng et al. analyzed 415 patients who underwent BR with abdominal free-flap BR in Taiwan, 76.8% were of normal weight (body mass index [BMI]; 18.5 < BMI < 24.9 kg/m 2 ) and 23.2% were overweight (25 < BMI < 29.9 kg/m 2 ) [137], whereas Srinivasa et al. reported that 24.3% of the 634 patients who underwent ATBR and enrolled in the MROC study were classified as normal weight, 34.5% as overweight, and 41.2% as class I or higher (29.9 kg/m 2 < BMI) obese [136]. Differences between countries can also be seen in healthcare resources. Specifically, biomaterials such as ADMs cannot be used under Japanese health insurance; however, many of the IBBR-related studies included in this study involved cases in which ADM was used. This suggests that while the results of studies conducted in other countries are very informative, country-specific surveys and data accumulation are needed. Studies have also reported low response rates and low average values for the sexual well-being of Japanese women based on BREAST-Q [158,161], and Japanese may have even lower scores than other Asian women [161]. A trend was found toward generating normative data for the interpretation of BREAST-Q [162][163][164]. Crittenden et al. reported that the Australian normative values were significantly lower than the US normative values on four of the five subscales [162], suggesting cultural and racial differences. Future work will require the creation of normative data in Japan to better understand the effect of BR.
This scoping review was conducted to map what studies on satisfaction and QOL after mastectomy and BR have been conducted, which demonstrated the increasing contribution of BR-specific PROMs worldwide and implied the need for further research in their respective culture using in appropriate methodology.
This study has several limitations. It dealt only with studies that measured postoperative satisfaction or QOL after mastectomy and BR. Therefore, important topics that may have influenced QOL after reconstructive surgery such as oncoplastic surgery [165], decision aids [166], and expectation management [167,168] were not included in the analysis. Similarly, studies that utilized other valuable PROMs to investigate perioperative pain management, decision regrets, overall health status, etc., were excluded. The authors also recognize the need to consider sample size calculations [159] and minimally important difference [169] estimation in planning future studies using PROs.
In conclusion, recent BR-specific PROMs have led to a worldwide development of research on factors that affect satisfaction and QOL after BR, including a wide range of surgical, clinical, and patient factors. PROs after BR may be influenced by local cultural and social features; thus, accumulating data in each region is necessary.
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