Incidental Breast Carcinoma in Reduction Mammoplasty: A Systematic Review

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Macromastia can negatively affect the health of women. Physically, macromastia causes neck, shoulder, and back pain, as well as dermatitis in the skin folds.^1,2 Functionally, macromastia can impair women’s confidence and quality of life.^2,3 As a solution, breast reduction is one of the most common plastic surgery procedures. Annually, more than 40000 breast reductions are performed in the United States, according to the American Society of Plastic Surgeons (ASPS).⁴ Because a portion of the breast is removed in breast reduction, plastic surgeons need to be mindful of the possibility of breast cancer.

Despite the high volume of breast reductions performed each year, breast cancer workup varies widely across plastic surgery practices. In general, the workup involves preoperative imaging and/or histopathologic evaluation of breast reduction specimens. Preoperative imaging before breast reduction aims to detect any abnormal radiological findings before the surgery and triage potential breast cancers for appropriate workups.⁵ National guidelines recommend breast cancer screening with mammography starting at 40 to 50 years of age for women with average risk.^6-8 A Continuing Medical Education article by the ASPS recommended obtaining preoperative mammography considering specific patient risk factors, such as age, past medical history, and family history.⁹ Preoperative imaging also lowers the odds of incidental breast cancer at the time of breast reduction.⁹

Histopathologic evaluation of breast reduction specimens aims to find occult pathologies that were not suggested in the preoperative imaging or clinical breast exams. Due to the benefits of detecting premalignant or malignant breast lesions and reducing patient anxiety, the 2022 ASPS practice guideline recommends that breast tissue from post-menarche women be sent to pathology.¹⁰ However, there is a wide range of incidental breast cancer rates reported at the time of breast reduction. Thus, in this study, we aimed to summarize the available literature on the incidence of occult breast cancer identified in patients undergoing reduction mammoplasties.

We queried the PubMed (National Institutes of Health) and Embase (Elsevier) databases on February 1, 2023, to identify research articles on breast cancer workup for patients undergoing breast reductions. Our search filter included any articles with titles or abstracts containing a term related to the surgery (breast reduction OR reduction mammoplasty) and a term related to the breast cancer workup (mammogram OR mammography OR breast cancer screening OR biopsy OR pathology OR path). Two independent reviewers, J.H.G. and R.K.A., screened the article titles and abstracts for relevance. The authors adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

From the initial query, our inclusion and exclusion criteria for titles and abstracts were as follows: (1) All full-length articles written in English evaluating breast cancer before or at the time of the procedure were included; (2) Only primary studies (eg, cohort studies, case series, and randomized controlled studies) were included; (3) Articles written in non-English language, conference abstracts, review articles, correspondences, articles with a primary focus on patients with breast cancer, duplicate articles, and research on unrelated topics were excluded; (4) The articles included after screening the titles and abstracts were screened at full length; (5) For multiple articles with the same cohort identified by the author list and study site, only the latest article was included in this study; (6) The references of the full-length articles were also screened to identify potentially relevant article.

From the included full-length articles, we extracted the manuscript title, author, publication year, journal, details in preoperative breast cancer screening, sample size, average (or median) age, imaging and/or histopathologic findings, and study recommendations. If the study included both patients with a history of breast cancer and those without breast cancer, we extracted data specific to the patients without breast cancer history, if possible. If not, we specified the percentage of patients with breast cancer history in each article.

The primary search included 328 articles (144 PubMed and 184 Embase articles, Figure). From the primary search, the titles and abstracts of 129 articles were screened for relevance. Among the 25 full-length articles that were screened, 20 full-length articles with unique study cohorts were included in this study. Three articles were added after reviewing the full-length articles’ references, resulting in a total of 23 articles included in this review. Most studies’ average/median patient age was around 40 years, and the youngest cohort had a median age of 28 years.

Figure. Study selection flowchart.

Among the included full-length articles, 2 (8.7%) studies discussed only preoperative imaging to screen for breast cancer prior to breast reduction (Table 1). The breast lesion biopsy rate after preoperative imaging was 3.7% to 5.1% (median, 4.4%), and the incidence of breast cancer confirmed with biopsy was 0.0% to 0.2% (median, 0.1%).^5,11 Derebaşınlıoğlu et al emphasized the importance of preoperative imaging for women 40 to 59 years old, as proliferative breast lesions were more frequently found in this age group.⁵ The authors also briefly mentioned that all breast reduction specimens at their institution are sent for histopathologic evaluation.⁵

HP, histopathologic evaluation; MMG, mammography; US, ultrasound.

Three (13.0%) studies discussed only the histopathologic evaluation of breast reduction specimens without requiring preoperative imaging in the inclusion criteria (Table 2). The rate of detecting occult malignancy was 0.0% to 1.0% (median, 0.5%).^12-14 All 3 studies recommended routine histopathologic evaluation of breast reduction specimens. Based on the study results, Hassan et al suggested that routine preoperative imaging for women 35 to 40 years and older would be logical before breast reductions.¹³ Of the included articles, 18 (78.3%) studies discussed both preoperative imaging and histopathologic evaluation of breast reduction specimens (Table 3). In this group of studies, 16 (88.9%) studies had specific indications for imaging,^15-30 and 9 (56.2%) studies had all radiologically benign preoperative imaging findings. Klement et al discussed preoperative imaging with 43.3% of breast reduction consults.³¹ Kuehlmann et al reported that 28.0% of patients completed preoperative imaging.³² The rate of incidental malignancy from histopathologic evaluation of breast reduction specimens was 0.0% to 2.0% (median, 0.4%).^15-32 The rate of significant breast pathologies was as high as 8.4%.¹⁶ All 18 studies universally recommended histopathologic evaluation of breast reduction specimens.

HP, histopathologic evaluation; MMG, mammography. US, ultrasound.

ACS, American Cancer Society; ASBS, American Society of Breast Surgeons; CBE, clinical breast exam; HP, histopathologic evaluation; MMG, mammography. US, ultrasound.

In this review of studies discussing breast cancer surveillance for patients undergoing breast reductions, we report 3 key findings. First, the preoperative biopsy rate based on imaging was 3.7% to 5.1% (median, 4.4%). However, malignancy was found only in 0.0% to 0.2% (median, 0.1%) of the patients. Second, most studies report low rates of incidental breast cancer at the time of breast reduction surgery, with a highest reported rate of 2.0%. Finally, despite the low rates of incidental breast cancer, the included studies unanimously recommend that plastic surgeons send breast reduction specimens for histopathologic evaluation.

National guidelines vary in the recommended age to start breast cancer screening and range from at age 40 to 50 years, and all recommend using mammography for women with average risk.^6-8 While there is strong evidence that the use of mammography can reduce breast cancer mortality,^33-35 false-positive imaging findings are quite common and have been reported to cause short-term anxiety for patients.³⁶ Based on a cohort of nearly 170000 patients who underwent breast cancer screening, Hubbard et al reported false-positive biopsy recommendation rates of 7.0% for women screened annually and 4.8% for those screened biennially.³⁷ In our review, the 2 studies on preoperative imaging reported similar or lower biopsy rates.^5,11 The lower biopsy rate of 3.7%, reported by Derebaşınlıoğlu et al may be due to having younger patients (mean age of 42 years) in the study cohort,⁵ while Hubbard et al analyzed women with a minimum age of 40 years.³⁷ Most studies in our review included various forms of preoperative imaging requirements, most commonly mammography for patients above an age cutoff and an ultrasound for those below the age cutoff. Some studies mentioned that the authors’ institutional policies require all patients undergoing breast reductions to have preoperative imaging. It is unclear whether these decisions on preoperative imaging are based on evidence or are defensive in nature. Regardless, women undergoing breast reductions should be compliant with breast cancer screening recommendations,^16,21 as the surgery could distort the breast anatomy postoperatively.⁵

The 2022 ASPS clinical practice guideline on reduction mammaplasty recommends that all breast reduction specimens be sent to pathology;¹⁰ this was a new addition to the 2012 ASPS clinical practice guideline.³⁸ The 2022 work group assigned “moderate” strength for both evidence quality and recommendation.¹⁰ Expected benefits of universal histopathologic evaluation of breast specimens include early detection of breast lesions and reducing patient anxiety.¹⁰ However, the authors also noted that benign pathological findings may have a higher associated cost and cause more patient anxiety.¹⁰ On a similar note, Srivastava et al reported a higher prevalence of anxiety and depression among women with benign breast diseases compared with their healthy counterparts.³⁹ The practice guideline work group recognized the importance of histopathologic evaluation for breast reductions on patients 40 years or older but did not find evidence suggesting against evaluation for those younger than 40 years, thus recommending it universally.¹⁰ Our review of a larger scope of literature found similar results, with studies highlighting the importance of histopathologic evaluation of breast specimens for women 40 years and older. Interestingly, Colwell et al reported that the mean age of patients indicated for macromastia who were diagnosed with breast cancer at the time of breast reduction was lower than the mean age of women with a history of breast cancer (38 vs 61 years old).²⁰ Although the authors report a 0.5% rate of incidental breast cancer in the macromastia group,²⁰ the benefits of sending breast reduction specimens to pathology, even for women younger than 40 years, seem to outweigh the harm. In a systemic review of 23 global guidelines for breast cancer screening by Ren et al, most guidelines recommended annual or biennial breast cancer screening for women aged 40 to 74 years with an average risk for breast cancer.⁴⁰ However, pre or intraoperative screening of breast cancer was not discussed in this systemic review.⁴⁰

Our study has several limitations. First, there were only 2 studies that primarily focused on preoperative imaging as the breast cancer screening modality prior to breast reductions. For the studies that designated specific preoperative imaging guidelines, evidence for the corresponding guidelines was often not cited. Also, several studies were conducted outside of the United States, resulting in various age cutoffs for using mammography vs ultrasound as the primary preoperative imaging modality. For the studies that recommended age-based imaging modality, ultrasound was recommended for younger patients The age cutoffs for using ultrasound to screen for breast cancer were most commonly 30, 35, or 40 years. Some studies recommended using both if either the mammography or ultrasound findings are equivocal. More studies evaluating the cost-effectiveness of different preoperative imaging requirements, especially for women younger than the age set by the national guidelines, are imperative. Perhaps the next iteration of the ASPS clinical practice guidelines could discuss a reasonable approach to screening for breast cancer before breast reduction. Lastly, a few studies included patients with a history of breast cancer on the contralateral side who were undergoing breast reductions. While we were able to extract data specific to patients without breast cancer in these studies, such data extraction was not entirely possible every time.

In this review of 23 studies on breast cancer workup for patients undergoing reduction mammoplasties, we found unanimous recommendations for performing histopathologic evaluation of breast reduction samples, which was consistent with a recommendation by the 2022 ASPS clinical practice guideline. Further research is still required to determine the optimal preoperative imaging approach for breast reduction, especially for women younger than 40 to 50 years.