Surgical management of primary breast cancer has evolved from radical resections to less mutilating, oncologically safe approaches. Landmark randomized trials in the latter half of the 20th century initiated the paradigm shift showing that lumpectomy (BCS) plus adjuvant radiotherapy provides equivalent long-term survival to mastectomy for many early-stage cancers.Nevertheless, practice variation persists: mastectomy rates (including contralateral prophylactic procedures) have fluctuated across regions and time; imaging advances (notably MRI) have changed preoperative staging and surgical choices; and contemporary systemic therapy may alter relative benefits. This review synthesizes evidence on OS after mastectomy vs BCS+ radiotherapy, and highlights radiological considerations that influence surgical decision-making [1-3].

Breast cancer remains the most common malignancy among women worldwide and represents a leading cause of cancer-related mortality. Over the past several decades, surgical management of primary breast cancer has undergone profound evolution. Historically, radical mastectomy, as popularized by Halsted, was considered the gold standard for achieving local disease control and improving overall survival (OS). However, landmark clinical trials and long-term observational studies have challenged this paradigm, demonstrating that breast-conserving surgery (BCS) followed by adjuvant radiotherapy can achieve survival outcomes comparable to mastectomy in selected patients with early-stage disease. This shift has profoundly influenced surgical decision-making, patient counseling, and multidisciplinary cancer care [4].

Despite these advances, the optimal surgical approach remains a subject of ongoing investigation and debate, particularly in the context of contemporary imaging technologies, evolving systemic therapies, and patient-centered considerations. The present systematic review focuses on evaluating the effectiveness of mastectomy versus breast-conserving surgery on overall survival, with a particular emphasis on the role of radiological assessment in preoperative planning, intraoperative guidance, and postoperative evaluation [5].

Historical Perspective on Breast Cancer Surgery

Radical mastectomy, first described by William Halsted in the late 19th century, involved en bloc removal of the entire breast, underlying pectoral muscles, and axillary lymph nodes. This approach was based on the premise that breast cancer spread sequentially from the primary tumor to regional lymph nodes and then to distant sites. Although effective in achieving local control, radical mastectomy was associated with substantial morbidity, including loss of breast tissue, impaired upper limb function, and significant psychosocial impact [6].

The development of less extensive surgical techniques, such as modified radical mastectomy and, subsequently, breast-conserving surgery, was driven by an improved understanding of breast cancer biology and metastatic patterns, as well as growing attention to quality-of-life outcomes. Breast-conserving surgery involves removal of the primary tumor with a margin of surrounding healthy tissue, preserving the majority of the breast, and is typically combined with adjuvant radiotherapy to mitigate the risk of local recurrence. Early randomized controlled trials, including the landmark NSABP B-06 and Milan trials, demonstrated that BCS plus radiotherapy provided OS equivalent to that of mastectomy in patients with stage I–II disease, setting the stage for widespread adoption of breast conservation [7].

Evolution of Radiological Assessment

Radiology has played an increasingly pivotal role in the management of primary breast cancer. Mammography, ultrasound, magnetic resonance imaging (MRI), and, more recently, digital breast tomosynthesis, have enabled precise tumor localization, characterization, and assessment of multifocal or metacentric disease. Accurate imaging is critical for selecting candidates for BCS, planning the extent of resection, and reducing the likelihood of positive surgical margins [8].

Preoperative MRI, in particular, has emerged as a highly sensitive modality for detecting additional foci of disease within the ipsilateral breast or contralateral breast that may not be apparent on conventional mammography or ultrasound. Although MRI has improved detection rates, evidence indicates that its routine use can increase the likelihood of mastectomy without a corresponding improvement in overall survival in average-risk patients. Therefore, careful patient selection for preoperative MRI is essential, particularly in individuals with dense breast tissue, lobular histology, or discordance between clinical and conventional imaging findings [9].

Intraoperative imaging and margin assessment have also advanced significantly. Techniques such as specimen radiography, intraoperative ultrasound, and emerging technologies like optical coherence tomography and hyperspectral imaging facilitate real-time evaluation of surgical margins, reducing the need for re-excision and supporting successful breast conservation. These radiological innovations are integral to optimizing oncologic outcomes while minimizing overtreatment and preserving cosmetic results.

Comparative Effectiveness of Mastectomy and Breast-Conserving Surgery

Multiple lines of evidence support the oncologic equivalence of mastectomy and BCS plus radiotherapy in terms of OS for early-stage breast cancer. The NSABP B-06 trial, with over 20 years of follow-up, reported no significant difference in survival between patients undergoing total mastectomy and those receiving lumpectomy with adjuvant radiotherapy. Similarly, the Milan trial, a long-term randomized study, demonstrated equivalent long-term survival between radical mastectomy and breast-conserving approaches for appropriately selected small tumors. Pooled analyses by the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) further confirmed that adjuvant radiotherapy after BCS significantly reduces local recurrence and contributes to mortality reduction without compromising overall survival.

Contemporary population-based studies and meta-analyses have generally corroborated these findings, although some have observed modest survival advantages favoring BCS plus radiotherapy. These differences are often attributed to patient selection bias, more favorable tumor biology among BCS candidates, and improvements in systemic therapy that enhance outcomes. Conversely, routine bilateral or prophylactic mastectomy in average-risk patients has not been associated with improved OS, highlighting the need for individualized surgical decision-making [10].

Factors Influencing Surgical Choice

Surgical decision-making in primary breast cancer is multifactorial, incorporating tumor characteristics, patient preferences, genetic risk, comorbidities, and anticipated quality-of-life outcomes. Tumor-specific factors such as size, grade, receptor status, lymph node involvement, and multimodality influence eligibility for BCS and the likelihood of requiring adjuvant radiotherapy. Patient-specific factors, including age, breast size, personal values, and genetic predisposition (e.g., BRCA1/2 mutations), also significantly affect surgical choice. Multidisciplinary consultation integrating surgical oncology, radiation oncology, radiology, and medical oncology is essential to optimize outcomes and align treatment with patient goals [11].

Radiological Considerations in Modern Surgical Planning

Advances in radiological assessment have shifted the paradigm of surgical planning for breast cancer. Preoperative imaging allows accurate mapping of tumor extent, identification of satellite lesions, and planning for resection that achieves negative margins while preserving healthy tissue. Intraoperative imaging and margin evaluation reduce positive margins, minimize re-excisions, and support the feasibility of breast conservation even in complex cases. Post-neoadjuvant therapy imaging further refines patient selection, as MRI has shown superior accuracy in detecting residual disease compared to mammography or ultrasound alone, thereby expanding the population eligible for BCS.

However, radiological advances also carry potential risks. Over-reliance on high-sensitivity imaging modalities, particularly MRI, can result in overtreatment, including unnecessary mastectomies, without improving overall survival. Therefore, integration of imaging findings with clinical judgment, tumor biology, and patient preference is critical to balance oncologic safety with quality-of-life considerations.

Clinical Implications and Unresolved Questions

Despite the substantial evidence supporting equivalence of OS between mastectomy and BCS plus radiotherapy, several questions remain. Optimal patient selection for BCS, the role of preoperative MRI in various risk populations, strategies to minimize re-excision, and the impact of systemic therapy on surgical outcomes continue to be investigated. Additionally, understanding the psychosocial and functional consequences of different surgical approaches remains an essential component of patient-centered care.

Emerging studies suggest that, for carefully selected patients, BCS not only preserves breast tissue but may also confer modest advantages in psychosocial outcomes, body image, and quality of life without compromising survival. The integration of advanced imaging, intraoperative assessment, and precision radiotherapy enhances the safety and feasibility of breast conservation, underscoring the importance of a multidisciplinary, individualized approach.

The introduction of breast-conserving surgery combined with adjuvant radiotherapy has revolutionized the surgical management of primary breast cancer, offering oncologic outcomes comparable to mastectomy while preserving breast tissue and quality of life. Radiological advancements, including preoperative MRI, intraoperative imaging, and post-neoadjuvant therapy evaluation, play a critical role in guiding surgical decisions, optimizing margin clearance, and expanding eligibility for breast conservation. Nevertheless, the judicious application of these technologies is required to prevent overtreatment. Multidisciplinary collaboration, individualized patient assessment, and integration of tumor biology, imaging, and patient preference remain central to achieving optimal survival outcomes and holistic care in breast cancer management.

In this context, a systematic review of comparative effectiveness, integrating radiological considerations, is essential to inform evidence-based guidelines, support shared decision-making, and improve patient outcomes in contemporary breast cancer care [12].

Methods

This review used a targeted systematic approach (not a new meta-analysis): searches of PubMed/Medline, Cochrane Library, and key journals (NEJM, Lancet, JAMA, JCO) were conducted for randomized trials, pooled meta-analyses, and large observational cohorts comparing mastectomy and BCS+RT, and for systematic reviews on preoperative/intraoperative imaging and margin assessment up to September 2025. Priority was given to: (1) randomized controlled trials with long-term follow-up (e.g., NSABP B-06, Milan trial), (2) EBCTCG pooled analyses of radiotherapy/BCS outcomes, (3) large population-based registry analyses (SEER, national cohort studies), (4) high-quality meta-analyses, and (5) contemporary radiology systematic reviews. Studies addressing OS, breast cancer-specific survival (BCSS), local recurrence, and imaging-driven surgical conversion were included. Narrative synthesis was performed and key findings cited. (Representative high-impact sources are cited in Results/Discussion).

Figure 1: PRISMA 2020 flow diagram for new systematic reviews which included searches of databases and registers only

 Results

Surgical outcome: Randomized trials and pooled analyses

Two large randomized trials with long follow-up established equivalence of BCS+RT and mastectomy in OS:

ü  NSABP B-06 (Fisher et al.): randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus RT; 20-year follow-up showed no significant difference in overall survival between mastectomy and lumpectomy+RT.

ü  Milan randomized trial (Veronesi et al.): 20-year follow-up similarly demonstrated equivalent long-term survival between radical mastectomy and breast-conserving approaches for appropriately selected small tumors.

ü  EBCTCG meta-analysis (2011): individual-patient data meta-analysis confirmed that adjuvant radiotherapy after BCS significantly reduces local recurrence and reduces breast cancer mortality, supporting that BCS+RT yields survival outcomes comparable to mastectomy when radiotherapy is applied appropriately.

These high-level randomized data underpin modern recommendations that BCS+RT is an oncologically safe alternative to mastectomy for many early-stage tumors (Table 1).

 Table 1. Comprehensive results table for the section: “Surgical Outcome: Randomized Trials and Pooled Analyses” focusing on mastectomy vs breast-conserving surgery (BCS) with radiotherapy.

Notes / Analysis

1. Across all major randomized trials and pooled analyses, overall survival is statistically equivalent between mastectomy and breast-conserving surgery with adjuvant radiotherapy for early-stage breast cancer [11].
2. Local recurrence is consistently higher in BCS without radiotherapy, highlighting the critical role of adjuvant radiotherapy in breast conservation.
3. BCS+RT provides similar OS with better cosmetic and quality-of-life outcomes compared to mastectomy, supporting it as the preferred option for eligible patients.
4. The EBCTCG meta-analysis reinforces that the survival benefit is independent of age, nodal status, and tumor size, provided adjuvant RT is delivered [12].

Contemporary population studies and meta-analyses

Large registry and retrospective cohort studies in the modern era show complex results. Some analyses have reported similar OS across modalities; others have found modest survival advantages favoring BCS+RT in specific cohorts attributed to differences in tumor biology, stage, use of adjuvant therapy, and selection bias. For example, several recent population-based studies and meta-analyses show either non-inferiority or small OS benefits associated with BCS+RT versus mastectomy without radiation; however, these results are subject to confounding by indication and treatment selection (Table 2).

Table 2. Results table summarizing key contemporary population studies and meta-analyses comparing mastectomy versus breast-conserving surgery (BCS) with radiotherapy, focusing on overall survival (OS), local recurrence, and radiological considerations.

Analysis / Key Points:

1. Overall Survival: Across contemporary population studies and meta-analyses, OS remains equivalent between mastectomy and BCS+RT when modern radiotherapy is applied. Minor survival advantages in some cohorts are often due to selection bias or more favorable tumor biology among BCS candidates.
2. Local Recurrence: Local recurrence rates are slightly higher for BCS without RT, reinforcing the critical role of adjuvant radiotherapy. Modern imaging and margin assessment have reduced recurrence rates in BCS patients.
3. Radiological Influence: Preoperative imaging (MRI, mammography, tomosynthesis) and intraoperative margin assessment improve eligibility for BCS, reduce positive margins, and support comparable oncologic outcomes to mastectomy.
4. Clinical Implications: Population-level data validate randomized trial findings in real-world settings and emphasize the importance of multidisciplinary care, radiological evaluation, and guideline-based radiotherapy in optimizing surgical outcomes [11-13].

 Bilateral/double mastectomy

Recent large cohort analyses (e.g., JAMA Oncology 2024 large registry analysis) report no OS advantage from contralateral prophylactic (double) mastectomy for most women with unilateral disease (non-BRCA), despite reductions in subsequent contralateral breast cancer incidence. These findings argue against routine bilateral mastectomy for survival benefit in average-risk patients (Table 3).

Table 3. Results table summarizing key studies on bilateral or contralateral prophylactic mastectomy (CPM) for patients with unilateral breast cancer, focusing on overall survival (OS), recurrence, and radiological considerations

Analysis / Key Points:

1. Overall Survival: Most studies demonstrate no OS advantage for bilateral mastectomy in average-risk patients with unilateral breast cancer. The exception is for BRCA1/2 mutation carriers or other high-risk genetic profiles [14].
2. Contralateral Breast Cancer Risk: CPM effectively reduces the incidence of contralateral breast cancer (by ~50–75%), but absolute risk reduction is small for average-risk patients.
3. Patient Drivers: Rising CPM rates are often influenced by patient anxiety, desire for symmetry, imaging findings, or overestimation of contralateral risk rather than evidence-based survival benefit.
4. Radiological Considerations: Advanced imaging (MRI, tomosynthesis) can detect contralateral lesions preoperatively, sometimes prompting bilateral surgery; however, survival outcomes are not improved solely by imaging-guided CPM in average-risk populations.
5. Clinical Implication: CPM should be considered primarily for high-risk patients, while average-risk patients should receive counseling about limited survival benefit and potential surgical morbidity. Multidisciplinary decision-making including genetic counseling is recommended [15-17].

Radiological considerations

Preoperative MRI

Breast MRI is the most sensitive modality for detecting metacentric/multifocal disease and contralateral lesions, and it alters surgical planning (increasing mastectomy rates in many cohorts). However, randomized and pooled analyses do not consistently demonstrate that routine preoperative MRI improves local control or OS; MRI may increase mastectomy rates without clear survival benefit in average-risk populations. Use of MRI is most appropriate selectively (lobular histology, discrepancy between imaging and clinical exam, dense breasts, neoadjuvant therapy planning) [18].

Intraoperative and specimen imaging/margin assessment

Inadequate margins after BCS increase re-excisions and local recurrence risk. Advances in intraoperative specimen radiography, specimen mammography, tomosynthesis and emerging technologies (hyperspectral imaging, optical coherence tomography, intraoperative ultrasound, margin probes) help reduce positive margins and re-operation rates. Meta-analyses show specimen radiography to be a useful tool for immediate margin assessment and can support successful BCS. Real-time technologies remain investigational but promising (Table 4).

 Table 4. Results table summarizing key studies on intraoperative and specimen imaging / margin assessment in breast-conserving surgery (BCS), highlighting their impact on re-excision rates, margin status, local recurrence, and surgical outcomes

Analysis / Key Points:

1. Positive Margin Reduction: Intraoperative imaging and margin assessment tools consistently reduce positive margin rates from ~10–15% to 5–8%, which is critical for preventing local recurrence [19].
2. Re-excision Rates: Use of intraoperative imaging (US, specimen radiography, tomosynthesis, Margin Probe, frozen section) decreases the need for second surgeries, improving patient outcomes and cost-effectiveness.
3. Local Recurrence: Accurate intraoperative margin assessment correlates with lower local recurrence rates (3–7%), supporting oncologic safety of BCS.
4. Technology Integration: Combining multiple imaging modalities (e.g., ultrasound+specimen radiography) further enhances margin clearance and surgical precision.
5. Clinical Implication: Intraoperative and specimen imaging are essential adjuncts in modern BCS, ensuring oncologic safety, minimizing reoperations, and supporting optimal cosmetic outcomes. Radiology-guided margin assessment is particularly important when preoperative MRI identifies multifocal disease [20-22].

Imaging after neoadjuvant therapy

MRI is valuable to assess treatment response and residual disease after neoadjuvant chemotherapy; accurate radiologic assessment can expand BCS eligibility in responders. Meta-analyses indicate MRI has superior accuracy to mammography/US for residual disease detection, although it is not perfect and should be correlated with clinical and pathologic data (Table 5).

Table 5. Results table summarizing key studies on imaging after neoadjuvant therapy (NAT) in breast cancer, focusing on tumor response assessment, eligibility for breast-conserving surgery (BCS), margin status, and surgical outcomes