The use of radiotherapy after mastectomy: a review of the literature

The Relationship Between Radiation History and Outcomes of Immediate Implant-Based Breast Reconstruction

BACKGROUND

Postmastectomy Radiotherapy (PMRT) has become standard of care for patients with breast cancer. However, local recurrence following breast conserving therapy is increasing in incidence due to increased survivorship. The relationship between prior radiation therapy, PMRT and immediate breast reconstruction (IBR) outcomes has not been widely studied. We aim to assess factors that correlate with post-IBR complications in the face of radiation therapy.

METHODS

An IRB approved retrospective cohort review of 262 patients was completed using our tumor registry to identify female patients age ≥ 18 with and without history of radiation who underwent mastectomy with IBR. Operative, clinical, and pathological data was collected, and univariate and multiple logistic regression analyses were conducted to evaluate the relationship between receipt of radiation and major and minor complications. Kaplan-Meier analysis was also conducted to assess the differences between the time to receipt of radiation and cancer recurrence amongst the 3 treatment groups.

RESULTS

There was no correlation between major or minor complications and a history of prior radiation. Patients with PMRT demonstrated a higher incidence of "other" minor complications (OR 2.8, CI 1.27-6.28, P = .01), such as erythema and edema. There was a higher incidence of implant exposure requiring reoperation (OR 5.7, CI 1.36-23.78, P = .01) and "other'' minor complications (OR 3.1, CI 1.32-7.35, P < .001) in patients with PMRT. Receipt of PMRT was associated with lower survival in compared to patients with no history of radiation treatment.

CONCLUSION

Our study found no significant associations between history of prior radiation and surgical complications after mastectomy and IBR. However, patients with PMRT were at increased risk of developing minor complications requiring reoperation. This suggests that we should discuss radiation concerns preoperatively and manage expectations regarding its effect on outcome.

Machine Learning to Predict the Need for Postmastectomy Radiotherapy after Immediate Breast Reconstruction

Background

Post mastectomy radiotherapy (PMRT) is an independent predictor of reconstructive complications. PMRT may alter the timing and type of reconstruction recommended. This study aimed to create a machine learning model to predict the probability of requiring PMRT after immediate breast reconstruction (IBR).

Methods

In this retrospective study, breast cancer patients who underwent IBR from January 2017 to December 2020 were reviewed and data were collected on 81 preoperative characteristics. Primary outcome was recommendation for PMRT. Four algorithms were compared to maximize performance and clinical utility: logistic regression, elastic net (EN), logistic lasso, and random forest (RF). The cohort was split into a development dataset (75% of cohort for training-validation) and 25% used for the test set. Model performance was evaluated using area under the receiver operating characteristic curve (AUC), precision-recall curves, and calibration plots.

Results

In a total of 800 patients, 325 (40.6%) patients were recommended to undergo PMRT. With the training-validation dataset (n = 600), model performance was logistic regression 0.73 AUC [95% confidence interval (CI) 0.65-0.80]; RF 0.77 AUC (95% CI, 0.74-0.81); EN 0.77 AUC (95% CI, 0.73-0.81); logistic lasso 0.76 AUC (95% CI, 0.72-0.80). Without significantly sacrificing performance, 81 predictive factors were reduced to 12 for prediction with the EN method. With the test dataset (n = 200), performance of the EN prediction model was confirmed [0.794 AUC (95% CI, 0.730-0.858)].

Conclusion

A parsimonious accurate machine learning model for predicting PMRT after IBR was developed, tested, and translated into a clinically applicable online calculator for providers and patients.

Breast Cancer Tumor Board: A Radiologist's Guide to Postmastectomy Radiation Therapy

Radiation therapy represents a pillar in the current management of breast cancer. Historically, postmastectomy radiation therapy (PMRT) has been administered only in patients with locally advanced disease and a poor prognosis. These included patients with large primary tumors at diagnosis and/or more than three metastatic axillary lymph nodes. However, during the past few decades, several factors have prompted a shift in perspective, and recommendations for PMRT have become more fluid. Guidelines for PMRT in the United States are outlined by the National Comprehensive Cancer Network and the American Society for Radiation Oncology. Because evidence to support performing PMRT is frequently discordant, the decision to offer radiation therapy often requires team discussion. These discussions are usually held in multidisciplinary tumor board meetings in which radiologists play a pivotal role by providing critical information such as the location and extent of disease. Breast reconstruction after mastectomy is optional and is safe in cases in which the patient's clinical status allows it. The preferred method in the setting of PMRT is autologous reconstruction. If this is not possible, then a two-step implant-based reconstruction is recommended. Radiation therapy does involve a risk of toxicity. Complications can be seen in acute and chronic settings and range from fluid collections and fractures to radiation-induced sarcomas. Radiologists have a key role in detecting these and other clinically relevant findings and should be prepared to recognize, interpret, and address them. ^© RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Innovative nanotheranostics: Smart nanoparticles based approach to overcome breast cancer stem cells mediated chemo- and radioresistances

The alarming increase in the number of breast cancer patients worldwide and the increasing death rate indicate that the traditional and current medicines are insufficient to fight against it. The onset of chemo- and radioresistances and cancer stem cell-based recurrence make this problem harder, and this hour needs a novel treatment approach. Competent nanoparticle-based accurate drug delivery and cancer nanotheranostics like photothermal therapy, photodynamic therapy, chemodynamic therapy, and sonodynamic therapy can be the key to solving this problem due to their unique characteristics. These innovative formulations can be a better cargo with fewer side effects than the standard chemotherapy and can eliminate the stability problems associated with cancer immunotherapy. The nanotheranostic systems can kill the tumor cells and the resistant breast cancer stem cells by novel mechanisms like local hyperthermia and reactive oxygen species and prevent tumor recurrence. These theranostic systems can also combine with chemotherapy or immunotherapy approaches. These combining approaches can be the future of anticancer therapy, especially to overcome the breast cancer stem cells mediated chemo- and radioresistances. This review paper discusses several novel theranostic systems and smart nanoparticles, their mechanism of action, and their modifications with time. It explains their relevance and market scope in the current era. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Prognosis and Prophylactic Regional Nodal Irradiation in Breast Cancer Patients With the First Isolated Chest Wall Recurrence After Mastectomy

Background and Purpose

Optimal radiation target volumes for breast cancer patients with their first isolated chest wall recurrence (ICWR) after mastectomy are controversial. We aimed to analyze the regional failure patterns and to investigate the role of prophylactic regional nodal irradiation (RNI) for ICWR.

Materials and Methods

Altogether 205 patients with ICWR after mastectomy were retrospectively analyzed. Post-recurrence progression-free survival (PFS) and overall survival (OS) rates were calculated by Kaplan-Meier method and the differences were compared with Log-rank test. Competing risk model was used to estimate the subsequent regional recurrence (sRR) and locoregional recurrence (sLRR) rates, and the differences were compared with Gray test.

Results

The 5-year sRR rate was 25.2% with median follow-up of 88.6 months. Of the 52 patients with sRR, 30 (57.7%) recurred in the axilla, 29 (55.8%) in supraclavicular fossa (SC), and five (9.6%) in internal mammary nodes. Surgery plus radiotherapy was independently associated with better sLRR and PFS rates (p<0.001). The ICWR interval of ≤ 4 years was associated with unfavorable sRR (p=0.062), sLRR (p=0.014), PFS (p=0.001), and OS (p=0.005). Among the 157 patients who received radiotherapy after ICWR, chest wall plus RNI significantly improved PFS (p=0.004) and OS (p=0.021) compared with chest wall irradiation alone. In the 166 patients whose ICWR interval was ≤ 4 years, chest wall plus RNI provided the best PFS (p<0.001) and OS (p=0.022) compared with chest wall irradiation alone or no radiotherapy.

Conclusion

Patients with ICWR have a high-risk of sRR in SC and axilla. Chest wall plus RNI is recommended.

Postmastectomy radiotherapy reduces locoregional and disease recurrence in patients with stage II-III triple-negative breast cancer treated with neoadjuvant chemotherapy and mastectomy

Background

This study investigated the effect of postmastectomy radiotherapy (PMRT) in patients with stage II–III triple-negative breast cancer (TNBC) after neoadjuvant chemotherapy (NAC) and modified radical mastectomy (MRM).

Patients and methods

A total of 104 women with stage II–III TNBC who received NAC and MRM at our institution between January 2000 and July 2007 were identified. Patients were divided into 2 groups (PMRT and non-PMRT) for statistical analysis.

Results

The median follow-up time was 64 months (range 12–123 months). The 5 year cumulative locoregional recurrence (LRR) and disease recurrence (DR) rates were 26.5% and 49.6%, respectively. Despite their more adverse prognostic features, patients with PMRT had lower 5 year cumulative LRR and DR rates than those without PMRT (LRR: 18.3% vs 52.2%, respectively, p=0.0005; DR: 45% vs 69.1%, p=0.0334, respectively). On multivariate analysis of the entire study cohort, forgoing PMRT was significantly associated with developing LRR and DR. Subset analysis revealed that PMRT significantly reduced the 5 year LRR rate in patients with pre-chemotherapy clinical stages IIA (8.3% vs 46.2%, p=0.019) and IIIA (16% vs 66.7%, p=0.003). PMRT also significantly reduced the 5 year DR rate in patients with pre-chemotherapy clinical stage IIA (24.5% vs 69.3%, p=0.0151) and ≥IIIB (70.8% vs 100%, p=0.0481).

Conclusion

In our cohort of patients with TNBC treated with NAC and MRM, PMRT significantly improved locoregional control and disease-free survival in the entire cohort as well as in patients with stage IIA disease. Our results may help in tailoring adjuvant treatment decisions for these particular patient populations.

Dosimetric Evaluation of Critical Organs at Risk in Mastectomized Left-Sided Breast Cancer Radiotherapy Using Breath-Hold Technique

Aims and background

The aim of the study was to evaluate the dosimetric impact of the active breathing control-moderate deep inspiration breath-hold (ABC-mDIBH) technique on normal tissue sparing in locally advanced left-sided breast cancer radiotherapy.

Methods and study design

Twenty-seven consecutive patients with left-sided locally advanced breast cancer referred to our department for adjuvant radiotherapy were enrolled in the study. Each patient was scanned at free breathing and ABC-mDIBH for radiation treatment planning. Two separate radiotherapy treatment plans were generated with and without ABC-mDIBH to investigate the dosimetric impact of ABC-mDIBH in breast cancer radiotherapy.

Results

Between June 2011 and February 2012, 27 consecutive patients with left-sided locally advanced breast cancer referred to our department for adjuvant radiotherapy were enrolled in the study. Dose-volume parameters of left anterior descending coronary artery, lungs, heart, contralateral breast, esophagus and spinal cord were significantly reduced with the use of ABC-mDIBH ( P <0.001).

Conclusions

Our study revealed that the use of ABC-mDIBH in the practice of locally advanced mastectomized left-sided breast cancer radiotherapy improves normal tissue sparing with the expected potential of decreasing treatment-related morbidity and mortality. Moreover, the resultant reduction achieved with ABC in doses to the left anterior descending coronary artery, which plays a central role in cardiac perfusion, may have implications for decreasing the potential of radiation-induced cardiac morbidity and mortality.

Establishment of a risk scoring system for predicting locoregional recurrence in T1 to T2 node-negative breast cancer patients treated with mastectomy: Implications for postoperative radiotherapy

To establish a risk scoring system for predicting locoregional recurrence (LRR) and explore the potential value of radiotherapy in T1 to T2 node-negative breast cancer patients treated with mastectomy. From January 2001 to February 2008, a total of 353 node-negative T1 to T2 breast cancer cases treated with mastectomy without adjuvant radiotherapy were retrospectively analyzed. Preliminary screening of the prognostic factors was accomplished by Kaplan-Meier univariate analysis, and survival curves between different groups were compared by log-rank test. Risk factors were determined using Cox proportional hazards model. A categorical risk scoring system was generated according to the Cox model, weighing the relative importance of each risk variable. Median follow-up was 115.7 months (range, 1.2-238.4 months). The overall 5-year locoregional recurrence-free survival (LRFS) was 89.8% (95% confidence interval [CI] = 86.7%-92.9%). Chest wall (53.8%) was found to be the most common site of LRR, followed by supraclavicular nodes (48.7%). Age ≤40 years, primary tumor size ≥4.5 cm and number of nodes resected ≤10 were found to be independent factors for poor prognosis of LRR. Two risk stratifications based on the scoring system were subsequently obtained. The 5-year LRFS was 91.6% (95% CI = 88.5%-94.7%) with low risk (score <2) and 75.7% (95% CI = 61.8%-89.6%) with high risk (score ≥2), respectively (χ = 7.544, P = .006). In addition, significant differences in overall survival (P = .045) and disease-free survival (P = .019) were presented between them. Patients with T1-2N0M0 breast cancer achieved favorable prognosis in general. Those with risk factors, including age ≤40 years, primary tumor size ≥4.5 cm and number of nodes resected ≤10, were at higher risk of LRR. The established scoring system could help to distinguish the subgroups that might potentially benefit from postoperative radiotherapy.

Postmastectomy radiation for N2/N3 breast cancer: factors associated with low compliance rate

BACKGROUND

The National Comprehensive Cancer Network and American Society of Clinical Oncology guidelines recommend postmastectomy radiation therapy (PMRT) for women with N2/N3 breast cancer. We examined the compliance rate of PMRT using the National Cancer Data Base and determined what factors are associated with low compliance rate with PMRT.

STUDY DESIGN

The National Cancer Data Base, comprising 2,720,368 breast cancer cases diagnosed between 1998 and 2011, was evaluated. From this database, 56,990 women with N2/N3 diseases were evaluated. Statistics used include chi-square test, 2-sample t-test or Wilcoxon rank-sum test, and multivariate analysis.

RESULTS

Mean age of the patients was 58 years and median follow-up was 61 months. The majority of patients were from a comprehensive community cancer programs (59%), were Caucasian (81%), had health insurance (96%), resided in urban communities (98%), and had no comorbidities (83%). Approximately 82% received chemotherapy, but only 65% had PMRT. Factors associated with PMRT are tumor grade (p = 0.03), regional lymph node surgery (p = 0.03), readmission within 30 days of surgical discharge (p = 0.03), receipt of chemotherapy (p < 0.01) and hormonal therapy (p < 0.01), and 30-day mortality (p < 0.01). Socioeconomic variables, such as facility type (p = 0.85), facility geographic location (p = 0.27), race/ethnicity (p = 0.12), insurance status (p = 0.10), income level (p = 0.43), education level (p = 0.86), residential location (p = 0.83), and comorbidities (p = 0.83) were not contributory factors. Independent variables predicting compliance with PMRT include receipt of chemotherapy (odds ratio = 4.55; p < 0.01), readmission within 30 days after surgery (odds ratio = 1.14; p = 0.01), and alive within 30 days after surgery (odds ratio = 1.55; p = 0.04).

CONCLUSIONS

One third of patients with N2/N3 disease did not receive PMRT. Socioeconomic variables were not contributory factors. Noncompliance with PMRT is related to lack of receipt of chemotherapy, nonreadmission, or death within 30 days after surgery.

Tissue expander capsule for abdominal wall in autologous breast reconstruction

Summary:

Adjuvant treatment planning can change after breast cancer resection and definitive pathological examination. Radiation therapy is often chosen as a supplementary treatment. Rectus abdominis–based muscle flaps are one of the main choices when breast reconstruction plans must be changed from implant-based to autologous methods. We herein report a case in which the patient’s own tissue expander capsule was used to repair an abdominal wall defect after muscle-sparing transverse rectus abdominis myocutaneous flap reconstruction.

DEGRO practical guidelines for radiotherapy of breast cancer IV: radiotherapy following mastectomy for invasive breast cancer

BACKGROUND AND PURPOSE

Since the last recommendations from the Breast Cancer Expert Panel of the German Society for Radiation Oncology (DEGRO) in 2008, evidence for the effectiveness of postmastectomy radiotherapy (PMRT) has grown. This growth is based on updates of the national S3 and international guidelines, as well as on new data and meta-analyses. New aspects were considered when updating the DEGRO recommendations.

METHODS

The authors performed a comprehensive survey of the literature. Data from recently published (meta-)analyses, randomized clinical trials and international cancer societies' guidelines yielding new aspects compared to 2008 were reviewed and discussed. New aspects were included in the current guidelines. Specific issues relating to particular PMRT constellations, such as the presence of risk factors (lymphovascular invasion, blood vessel invasion, positive lymph node ratio >20 %, resection margins <3 mm, G3 grading, young age/premenopausal status, extracapsular invasion, negative hormone receptor status, invasive lobular cancer, size >2 cm or a combination of ≥ 2 risk factors) and 1-3 positive lymph nodes are emphasized.

RESULTS

The evidence for improved overall survival and local control following PMRT for T4 tumors, positive resection margins, >3 positive lymph nodes and in T3 N0 patients with risk factors such as lymphovascular invasion, G3 grading, close margins, and young age has increased. Recently identified risk factors such as invasive lobular subtype and negative hormone receptor status were included. For patients with 1-3 positive lymph nodes, the recommendation for PMRT has reached the 1a level of evidence.

CONCLUSION

PMRT is mandatory in patients with T4 tumors and/or positive lymph nodes and/or positive resection margins. PMRT should be strongly considered in patients with T3 N0 tumors and risk factors, particularly when two or more risk factors are present.

Progress and controversies: radiation therapy for invasive breast cancer

Radiation therapy is a critical component of the multidisciplinary management of invasive breast cancer. In appropriately selected patients, radiation not only improves local control, sparing patients the morbidity and distress of local recurrence, but it also improves survival by preventing seeding and reseeding of distant metastases from persistent reservoirs of locoregional disease. In recent years, considerable progress has been made toward improving our ability to select patients most likely to benefit from radiotherapy and to administer treatment in ways that maximize clinical benefit while minimizing toxicity and burden. This article reviews the role of radiation therapy in invasive breast cancer management, both after breast-conserving surgery and after mastectomy. It focuses particularly on emerging evidence that helps to define the clinical situations in which radiotherapy is indicated, the appropriate targets of treatment, and optimal approaches for minimizing both the toxicity and the burden of treatment, all in the context of the evolving surgical and systemic management of this common disease. It includes a discussion of new approaches in breast cancer radiotherapy, including hypofractionation and intensity modulation, as well as a discussion of promising avenues for future research.

Effect of local therapy on locoregional recurrence in postmenopausal women with breast cancer in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial

BACKGROUND AND PURPOSE

The TEAM trial investigated the efficacy and safety of adjuvant endocrine therapy consisting of either exemestane or the sequence of tamoxifen followed by exemestane in postmenopausal hormone-sensitive breast cancer. The present analyses explored the association between locoregional therapy and recurrence (LRR) in this population.

MATERIAL AND METHODS

Between 2001 and 2006, 9779 patients were randomized. Local treatment was breast conserving surgery plus radiotherapy (BCS+RT), mastectomy without radiotherapy (MST-only), or mastectomy plus radiotherapy (MST+RT). Patients with unknown data on surgery, radiotherapy, tumor or nodal stage (n=199), and patients treated by lumpectomy without radiotherapy (n=349) were excluded.

RESULTS

After a median follow-up of 5.2 years, 270 LRRs occurred (2.9%) among 9231 patients. The 5-years actuarial incidence of LRR was 4.2% (95% CI 3.3-4.9%) for MST-only, 3.4% (95% CI 2.4-4.2%) for MST+RT and 1.9% (95% CI 1.5-2.3%) for BCS+RT. After adjustment for prognostic factors, the hazard ratio (HR, reference BCS+RT) for LRR remained significantly higher for MST-only (HR 1.53; 95% CI 1.10-2.11), not for MST+RT (HR 0.78; 95% CI 0.50-1.22).

CONCLUSION

This explorative analysis showed a higher LRR risk after MST-only than after BCS+RT, even after adjustment for prognostic factors. As this effect was not seen for MST+RT versus BCS+RT, it might be explained by the beneficial effects of radiation treatment.

Postmastectomy radiation therapy: an overview for the practicing surgeon

Locoregional control of breast cancer is the shared domain and responsibility of surgeons and radiation oncologists. Because surgeons are often the first providers to discuss locoregional control and recurrence risks with patients and because they serve in a key gatekeeping role as referring providers for radiation therapy, a sophisticated understanding of the evidence regarding radiotherapy in breast cancer management is essential for the practicing surgeon. This paper synthesizes the complex and evolving evidence regarding the role of radiation therapy after mastectomy. Although substantial evidence indicates that radiation therapy can reduce the risk of locoregional failure after mastectomy (with a relative reduction of risk of approximately two-thirds), debate persists regarding the specific subgroups who have sufficient risks of residual microscopic locoregional disease after mastectomy to warrant treatment with radiation. This paper reviews the evidence available to guide appropriate referral and patient decision making, with special attention to areas of controversy, including patients with limited nodal disease, those with large tumors but negative nodes, node-negative patients with high risk features, patients who have received systemic chemotherapy in the neoadjuvant setting, and patients who may wish to integrate radiation therapy with breast reconstruction surgery.

Pre-mastectomy sentinel lymph node biopsy: a strategy to enhance outcomes in immediate breast reconstruction

The pre-mastectomy sentinel lymph node biopsy (PM-SLNB) is a technique that provides knowledge regarding nodal status prior to mastectomy. Because radiation exposure is associated with poor outcomes in breast reconstruction and reconstructed breasts can interfere with the planning and delivery of radiation therapy (RT), information regarding nodal status has important implications for patients who desire immediate breast reconstruction. This study explores the safety and utility of PM-SLNB as part of the treatment strategy for breast cancer patients desiring immediate reconstruction. We reviewed the charts of adult patients (≥18 years old) who underwent PM-SLNB from January 2004 to January 2011 at our institution. PM-SLNB was offered to patients with stage I or IIa, clinically and/or radiographically node-negative breast cancer who desired immediate breast reconstruction following mastectomy. PM-SLNB was also offered to patients with ductal carcinoma in situ if features concerning for invasive carcinoma were present. Ninety-one patients underwent PM-SLNB of 94 axillae. PM-SLNB was positive in 25.5% of breasts (n = 24). Nineteen node-positive patients (79.2%) have undergone or planning to undergo delayed reconstruction at our institution. Seventeen of these 19 node-positive patients (89.5%) have received adjuvant RT. Two patients (10.5%) elected against RT despite our recommendation for it. No biopsy-positive patient underwent immediate reconstruction or suffered a radiation-induced complication with their breast reconstruction. There were two minor complications associated with PM-SLNB, both in node-negative patients. This study demonstrates the utility of PM-SLNB in providing information regarding nodal status, and therefore the need for adjuvant RT, prior to mastectomy. This knowledge can be used to appropriately counsel patients regarding optimal timing of breast reconstruction.

Validating a prognostic scoring system for postmastectomy locoregional recurrence in breast cancer

PURPOSE

This study is designed to validate a previously developed locoregional recurrence risk (LRR) scoring system and further define which groups of patients with breast cancer would benefit from postmastectomy radiation therapy (PMRT).

METHODS AND MATERIALS

An LRR risk scoring system was developed previously at our institution using breast cancer patients initially treated with modified radical mastectomy between 1990 and 2001. The LRR score comprised 4 factors: patient age, lymphovascular invasion, estrogen receptor negativity, and number of involved lymph nodes. We sought to validate the original study by examining a new dataset of 1545 patients treated between 2002 and 2007.

RESULTS

The 1545 patients were scored according to the previously developed criteria: 920 (59.6%) were low risk (score 0-1), 493 (31.9%) intermediate risk (score 2-3), and 132 (8.5%) were high risk (score ≥4). The 5-year locoregional control rates with and without PMRT in low-risk, intermediate-risk, and high-risk groups were 98% versus 97% (P=.41), 97% versus 91% (P=.0005), and 89% versus 50% (P=.0002) respectively.

CONCLUSIONS

This analysis of an additional 1545 patients treated between 2002 and 2007 validates our previously reported LRR scoring system and suggests appropriate patients for whom PMRT will be beneficial. Independent validation of this scoring system by other institutions is recommended.

[Radiotherapy for breast cancer: which strategy in 2012?]

Postoperative radiotherapy remains essential in breast cancer in 2012. After conserving surgery, it reduces local recurrence risks from 50 to 70%, both for ductal carcinoma in situ and invasive cancers. This was confirmed in several randomized trials and three meta-analyses. The boost increases local control in invasive cancers, but its role should be better defined in ductal carcinoma in situ. Among the latter, there is no clearly identified subgroup for which radiotherapy could be avoided. Local recurrence risk factors are now well-identified both for ductal carcinoma in situ and invasive cancers, with an inclusion, for the latter, of new molecular subgroups. After mastectomy, radiotherapy reduces local recurrence rates from 60 to 70%, especially among patients with axillary nodal involvement, with, in parallel, a 7 to 9% increased survival rate. In order to reduce the waiting list and to avoid under treatment, especially in the elderly, several hypofractionated radiotherapy schemes have been developed for several years. Three randomized trials confirmed similar results to classical radiotherapy. For ten years, several techniques of partial breast irradiation have been developed, with various doses and treated volumes. The optimal indications should be defined according to the new international guidelines.

Locoregional recurrence risk factors and the impact of postmastectomy radiotherapy on patients with tumors 5 cm or larger

BACKGROUND

Locoregional recurrence (LRR) after mastectomy reduces the patient's quality of life and survival. There is a consensus that postmastectomy radiotherapy (PMRT) helps achieve locoregional control and reduces LRR. However, in patients with large tumors, the question of which variables affect the likelihood of LRR and the role of PMRT have been subjects of substantial controversy. This study investigated what the risk factors are for LRR and the efficacy of PMRT in this patient population.

METHODS

This retrospective study examined 589 cases of invasive breast carcinoma with tumors 5 cm or larger from 1998 to 2008. We divided the study population into 3 groups: patients with negative nodes, 1-3 positive nodes, and ≥4 positive nodes. The relationship between various clinicopathological variables and LRR was examined, and the relationship between LRR and PMRT was estimated.

RESULTS

During the median follow-up of 44.2 months, 38 (6.5 %) patients experienced LRR. In the multivariate analysis, independent risk factors for LRR included pectoral invasion in patients with 1-3 positive nodes, severity of lymphatic invasion, estrogen receptor-negative status, and a nodal ratio of positive/excised nodes >0.50 in patients with ≥4 positive nodes. In patients without positive nodes, none of the examined variables were significantly associated with LRR. Although patients treated with PMRT had good outcomes, there was no significant difference.

CONCLUSIONS

With systemic therapy and adequate lymph node dissection, PMRT by itself was of limited value in establishing locoregional control. Due to the very low incidence of LRR observed, PMRT was not necessary for patients with large tumors without lymph node metastasis. Further examination and consensus about the indications for PMRT in patients with 1-3 metastatic nodes are needed.

Mastectomy without radiotherapy: outcome analysis after 10 years of follow-up in a single institution

The aim of this study was to identify the prognostic factors associated with the risk of loco-regional recurrence (LRR) of women undergoing mastectomy and complete axillary dissection without radiotherapy. We analyzed data from 650 women operated between 1997 and 2001 in a single institution. Median follow-up was 10 years. Overall survival was 89.8 % at 5 years and 76.6 % at 10 years. The 10-year cumulative incidence of LRRs was 10.0 % (5.0, 10.5, 15.8, and 18.5 % in patients with 0, 1-3, 4-9, and ≥10 positive lymph nodes (LNs), respectively). Sixty-two (9.5 %) LRRs were observed, 5 (0.8 %) of which occurred in the axillary LNs. Supraclavicular LNs recurrences (n = 16, 2.5 %) occurred more frequently in patients with four or more positive LNs, Ki-67 ≥ 20 % or extensive peritumoral vascular invasion (PVI). At multivariable analysis, nodal status was the only prognostic factor for local events, while nodal status, Ki-67 and PVI were significant prognostic factors for recurrences in the regional LNs. Moreover, within each category of positive LNs, high values of Ki-67 and extensive PVI were associated with the highest risk of LRR while low values of Ki-67 and absence of extensive PVI were associated with the lowest risk of LRR. Women with node-negative tumors have the lowest risk of LRR and represent the group of patients that might benefit the least from radiotherapy. PVI and Ki-67 might help tailoring PMRT indications among patients with positive LNs. Finally, the very low incidence of recurrences in the axillary LNs raises questions about the inclusion of the axilla in the radiation field.

Influence of lymphatic invasion on locoregional recurrence following mastectomy: indication for postmastectomy radiotherapy for breast cancer patients with one to three positive nodes

PURPOSE

The indication for postmastectomy radiotherapy (PMRT) in breast cancer patients with one to three positive lymph nodes has been in discussion. The purpose of this study was to identify patient groups for whom PMRT may be indicated, focusing on varied locoregional recurrence rates depending on lymphatic invasion (ly) status.

METHODS AND MATERIALS

Retrospective analysis of 1,994 node-positive patients who had undergone mastectomy without postoperative radiotherapy between January 1990 and December 2000 at our hospital was performed. Patient groups for whom PMRT should be indicated were assessed using statistical tests based on the relationship between locoregional recurrence rate and ly status.

RESULTS

Multivariate analysis showed that the ly status affected the locoregional recurrence rate to as great a degree as the number of positive lymph nodes (p < 0.001). Especially for patients with one to three positive nodes, extensive ly was a more significant factor than stage T3 in the TNM staging system for locoregional recurrence (p < 0.001 vs. p = 0.295).

CONCLUSION

Among postmastectomy patients with one to three positive lymph nodes, patients with extensive ly seem to require local therapy regimens similar to those used for patients with four or more positive nodes and also seem to require consideration of the use of PMRT.

Locoregional recurrence risk factors in breast cancer patients with positive axillary lymph nodes and the impact of postmastectomy radiotherapy

BACKGROUND

Locoregional recurrence (LRR) after mastectomy reduces the patient's quality of life and survival. There is a consensus that postmastectomy radiotherapy (PMRT) helps establish locoregional control and reduces LRR in patients with ≥4 metastatic nodes. However, in patients with 1-3 metastatic nodes, the incidence of LRR and the role of PMRT have been the subject of substantial controversy. This study assessed the risk factors for LRR and the efficacy of PMRT in Japanese breast cancer patients with metastatic nodes.

METHODS

This study analyzed 789 cases of invasive breast carcinoma with metastatic nodes from 1998 to 2008. We divided the study population into 4 groups: 1-3 positive nodes with/without chemotherapy and ≥4 positive nodes with/without chemotherapy. Risk factors for LRR were identified and the relationship between LRR and PMRT was analyzed.

RESULTS

During the median follow-up of 59.6 months, 61 (7.7%) patients experienced LRR. In patients who received chemotherapy, independent LRR risk factors were high nuclear grade, severe lymphatic invasion, vascular invasion, and progesterone receptor-negative status in patients with 1-3 positive nodes, and severe lymphatic invasion and estrogen receptor-negative status in patients with ≥4 nodes. Although patients treated with PMRT had good outcomes, there was no significant difference, and PMRT did not significantly improve the outcome of the patients with all risk factors.

CONCLUSIONS

With systemic therapy and adequate dissection, PMRT by itself was of limited value in establishing locoregional control. The indication for PMRT in patients with 1-3 positive nodes remains controversial.

Role of systemic therapy in the development of lung sequelae after conformal radiotherapy in breast cancer patients

PURPOSE

To analyze the risk of radiogenic lung damage in breast cancer patients after conformal radiotherapy and different forms of systemic treatment.

METHODS AND MATERIALS

In 328 patients receiving sequential taxane-based chemotherapy, concomitant hormone therapy (tamoxifen or aromatase inhibitors), or no adjuvant systemic therapy, symptomatic and asymptomatic lung sequelae were prospectively evaluated via the detection of visible CT abnormalities, 3 months or 1 year after the completion of the radiotherapy.

RESULTS

Significant positive associations were detected between the development of both pneumonitis and fibrosis of Grade 1 and patient age, ipsilateral mean lung dose, volume of the ipsilateral lung receiving 20 Gy, and irradiation of the regional lymph nodes. In multivariate analysis, age and mean lung dose proved to be independent predictors of early (odds ratio [OR] = 1.035, 95% confidence interval [CI] 1.011-1.061 and OR = 1.113, 95% CI 1.049-1.181, respectively) and late (OR = 1.074, 95% CI 1.042-1.107 and OR = 1.207, 95% CI 1.124-1.295, respectively) radiogenic lung damage, whereas the role of systemic therapy was significant in the development of Grade 1 lung fibrosis (p = 0.01). Among the various forms of systemic therapy, tamoxifen increased the risk of late lung sequelae (OR = 2.442, 95% CI 1.120-5.326, p = 0.025). No interaction was demonstrated between the administration of systemic therapy and the other above-mentioned parameters as regards the risk of radiogenic lung damage.

CONCLUSIONS

Our analyses demonstrate the independent role of concomitant tamoxifen therapy in the development of radiogenic lung fibrosis but do not suggest such an effect for the other modes of systemic treatment.

Patterns and risk factors of locoregional recurrence in T1-T2 node negative breast cancer patients treated with mastectomy: implications for postmastectomy radiotherapy

PURPOSE

Postmastectomy radiation therapy (PMRT) can reduce locoregional recurrences (LRR) in high-risk patients, but its role in the treatment of lymph node negative (LN-) breast cancer remains unclear. The aim of this study was to identify a subgroup of T1-T2 breast cancer patients with LN- who might benefit from PMRT.

METHODS AND MATERIALS

We retrospectively reviewed 1,136 node-negative T1-T2 breast cancer cases treated with mastectomy without PMRT at the Massachusetts General Hospital between 1980 and 2004. We estimated cumulative incidence rates for LRR overall and in specific subgroups, and used Cox proportional hazards models to identify potential risk factors.

RESULTS

Median follow-up was 9 years. The 10-year cumulative incidence of LRR was 5.2% (95% CI: 3.9-6.7%). Chest wall was the most common (73%) site of LRR. Tumor size, margin, patient age, systemic therapy, and lymphovascular invasion (LVI) were significantly associated with LRR on multivariate analysis. These five variables were subsequently used as risk factors for stratified analysis. The 10-year cumulative incidence of LRR for patients with no risk factors was 2.0% (95% CI: 0.5-5.2%), whereas the incidence for patients with three or more risk factors was 19.7% (95% CI: 12.2-28.6%).

CONCLUSION

It has been suggested that patients with T1-T2N0 breast cancer who undergo mastectomy represent a favorable group for which PMRT renders little benefit. However, this study suggests that select patients with multiple risk factors including LVI, tumor size ≥2 cm, close or positive margin, age ≤50, and no systemic therapy are at higher risk of LRR and may benefit from PMRT.

Controversies in loco-regional treatment: post-mastectomy radiation for pT2-pT3N0 breast cancer arguments in favour

Post-mastectomy RT decreases the rate of locoregional recurrences of about 70% in all patients irrespective of age, tumor characteristics or systemic therapy. Post-mastectomy RT has to be proposed, moreover when locoregional lymph nodes are part of the PTV, if an optimal coverage of the PTV and a satisfactory sparing of the OAR could be obtained. Due to the results of meta-analysis, consensus conferences and randomized trials the long-term efficacy of RT in decreasing the risk of LRF is well established and the vast majority of women, treated with mastectomy, will benefit from it.

Recent advances in breast cancer radiotherapy: Evolution or revolution, or how to decrease cardiac toxicity?

Radiation therapy has a major role in the management of breast cancers. However, there is no consensus on how to irradiate and on volume definitions, and there are strong differences in strategies according to different centers and physicians. New treatment protocols and techniques have been used with the principal purpose of decreasing lung and heart toxicity and adapting radiation treatment to patients’ anatomy. There is evidence that indicates internal mammary chain radiotherapy should be used carefully and that high quality techniques should be used for decreasing the dose delivered to the heart. This review of the literature presents the state of the art on breast cancer radiotherapy, with special focus on the indications, techniques, and potential toxicity.

[Local control in breast cancer: constant importance, changing radiotherapy practice]

Local control is of primary importance when treating operable breast cancer. Local relapse serves as a secondary source of distant metastases, and compromises survival. Postoperative radiotherapy improves local control after mastectomy or breast conserving surgery, however, sometimes it leads to overtreatment. The risk of local relapse may be estimated based on different correlated factors, such as the type of the surgery, the size and stage of the tumor, the nodal status, the histological type, multifocality and biological features of the cancer, the margin status, the age and the mammographic appearance of the lesion. Late radiogenic sequelae appearing 5-10 years after radiotherapy are sometimes fatal, but may be prevented if radiotherapy is delivered at a high standard. Systemic therapies contribute to local control, and in some cases may substitute radiotherapy. In other low risk cases, radiotherapy may be either omitted or lessened. Local therapies in breast cancer should be tailored individually.

Adjuvant chest wall radiotherapy for breast cancer: black, white and shades of grey

BACKGROUND

Adjuvant chest wall irradiation after mastectomy remains a core and highly effective element in the loco-regional management of early breast cancer. While the evidence base for postmastectomy radiotherapy (PMRT) in patients with 4 or more involved axillary nodes is robust, its role in 'intermediate' risk patients with 1-3 involved nodes is unclear and practice varies. Traditionally patients have been selected for PMRT on the basis of clinic-pathological factors such tumour size, nodal status, tumour grade and presence of lymphovascular invasion. However these factors alone may not predict the response of individual patients to radiotherapy. There is recent evidence that biological factors such as oestrogen and progesterone receptor and HER-2 status may also influence survival as well as loco-regional control.

METHODS

A literature review was undertaken, searching Pubmed using the mesh heading of 'breast cancer' and 'adjuvant chest wall irradiation/radiotherapy'. Priority was given to reports of meta-analyses and randomised trials of postmastectomy radiotherapy.

OBSERVATIONS

The 2005 Oxford Overview of randomised trials of postoperative radiotherapy established a clear biological link between loco-regional control and survival. Paradoxically the largest survival benefits do not occur in patients at the highest risk of recurrence. Molecular markers to identify exactly which patients are likely to benefit from PMRT are being actively investigated. Surgeons are encouraged to enter patients with 1-3 involved nodes into a clinical trial of postmastectomy radiotherapy.

Are mastectomy resection margins of clinical relevance? A systematic review

Although some guidelines support the use of post-mastectomy radiotherapy where the resection margin is involved or close, the scientific basis of this practice is not established. This systematic review explores the relationship between margin status and subsequent relapse. Pooled data from 22 studies (18,863 women) identified an involved post-mastectomy margin in 2.5%, a close margin in 8.0% and muscle or fascia invasion in 7.2% of patients. In a meta-analysis of five studies of non-inflammatory breast cancer without radiotherapy, local recurrence was increased by an involved or close margin (relative risk 2.6; P<0.00001). The effect of muscle or fascia invasion was of borderline significance (relative risk 1.7; P=0.04). In two separate meta-analyses, risk of relapse was related to margin status in women with inflammatory breast cancer (relative risk 3.1; P<0.0001) but not in those undergoing skin-sparing mastectomy (relative risk 2.1; P=0.16).

Tumor dormancy and metastasis

Metastasis--the spread of cancer to distant organs--is responsible for most cancer deaths. Current adjuvant therapy is based on prognostic indicators that stratify patients into defined risk groups. However, some patients believed to have a good prognosis nonetheless develop metastases, in some cases many years after apparently successful treatment of their primary cancer. This period of clinical dormancy leads to many questions about how best to manage patients, including how to better assign risk of late recurrence, how long to monitor patients, and whether some patients will benefit from extended therapy to prevent late recurrences. The development of targeted therapies with fewer side effects is leading to clinical trials aimed at determining the effectiveness of such long-term therapy. However, much remains to be learned about tumor dormancy. Experimental studies are shedding light on biological and molecular mechanisms potentially responsible for tumor dormancy. Emerging research into tumor initiating cells, immunotherapy, and metastasis suppressor genes, may lead to new approaches for targeted antimetastatic therapy to prolong tumor dormancy. An improved understanding of tumor dormancy is needed for better management of patients at risk for late-developing metastases.

Multidisciplinary care for patients with breast cancer

The care of patients with breast cancer has become increasingly complex with advancements in diagnostic modalities, surgical approaches, and adjuvant treatments. A multidisciplinary approach to breast cancer care is essential to the successful integration of available therapies. This article addresses the key components of multidisciplinary breast cancer care, with a special emphasis on new and emerging approaches over the past 10 years in the fields of diagnostics, surgery, radiation, medical oncology, and plastic surgery.

Chest wall radiotherapy: middle ground for treatment of patients with one to three positive lymph nodes after mastectomy

PURPOSE

To evaluate the outcomes for patients with Stage II breast cancer and one to three positive lymph nodes after mastectomy who were treated with observation or adjuvant radiotherapy to the chest wall (CW) with or without the regional lymphatics.

METHODS AND MATERIALS

We retrospectively analyzed 238 patients with Stage II breast cancer (one to three positive lymph nodes) treated with mastectomy at the Massachusetts General Hospital between 1990 and 2004. The estimates of locoregional recurrence (LRR), disease-free survival (DFS), and overall survival were analyzed according to the delivery of radiotherapy and multiple prognostic factors.

RESULTS

LRR and DFS were significantly improved by postmastectomy radiotherapy (PMRT), with a 5- and 10-year LRR rate without PMRT of 6% and 11%, respectively and, with PMRT, of 0% at both 5 and 10 years (p = .02). The 5- and 10-year DFS rate without PMRT was 85% and 75%, respectively, and, with PMRT, was 93% at both 5 and 10 years (p = .03). A similar benefit was found for patients treated with RT to the CW alone. The LRR, DFS, and overall survival rate for patients treated to the CW only was 0%, 96%, and 95% at 10 years, respectively.

CONCLUSION

Our data suggest that adjuvant PMRT to the CW alone provides excellent disease control for patients with breast cancer <5 cm with one to three positive lymph nodes.

Disruption of estrogen receptor alpha-p53 interaction in breast tumors: a novel mechanism underlying the anti-tumor effect of radiation therapy

Inactivation of tumor suppressor p53 is one of the most frequent events in cancer. Unlike many other cancers, however, p53 gene mutations are infrequent in breast cancers, as about 80% of breast tumors contain wild type p53. The mechanisms underlying functional inactivation of wild type p53 in breast cancer have remained elusive. Besides, how p53 gets activated in breast tumors subjected to radiation therapy remains unknown. We recently reported that in MCF-7 breast cancer cells, estrogen receptor alpha (ERalpha) directly binds to p53 and represses its function. Furthermore, the ERalpha-p53 interaction was disrupted by ionizing radiation. These observations have important translational implications especially as there are no reliable cellular or molecular criteria for rational radiotherapy for breast cancer. Here we report our studies towards addressing this important issue, using an MCF-7 breast cancer xenograft model in mice. Radiation effectively inhibits growth of these tumors and stabilizes p53, but has no observable effect on ERalpha protein level. Importantly, chromatin immunoprecipitation (ChIP) assays demonstrated that ERalpha interacts with p53 bound to endogenous target gene promoters in tumors in vivo, and this interaction is considerably reduced in response to radiotherapy although p53 level is increased. Concomitant with its effect on ERalpha-p53 interaction, radiation increases p53-mediated transcriptional activation of several target genes and increases p53-mediated transcriptional repression of survivin. Our studies show that disruption of ERalpha-p53 interaction in vivo resulting in restoration of functional p53 is a cellular response to radiation. Radiation could be affecting ERalpha and/or p53 directly or it could be influencing other proteins associated with the ERalpha-p53 complex. To the best of our knowledge, this is the first report on analysis of DNA-protein-protein interaction occurring on endogenous gene promoters in vivo in breast tumor tissues. These findings suggest that alleviating the inhibitory effect of ERalpha on p53 could be one of the molecular mechanisms underlying activation of p53 by radiation in breast tumors, and therefore, could be exploited to develop more effective ways of combining radiation therapy with systemic therapies such as hormonal therapy and chemotherapy.

Using microarray analysis as a prognostic and predictive tool in oncology: focus on breast cancer and normal tissue toxicity

Microarray analysis makes it possible to study the expression levels of tens of thousands of genes in one single experiment and is widely available for research purposes. Gene expression profiling is currently being used in many research projects aimed at identifying gene expression signatures in malignant tumors associated with prognosis and response to therapy. An important goal of such research is to develop gene expression-based diagnostic tests that can be used to guide therapy in cancer patients. Here we provide examples of studies using microarrays, especially focusing on breast cancer, in a wide range of fields including prediction of prognosis, distant metastasis and local recurrence, therapy response to radio- and chemotherapy, and normal tissue response.

Postmastectomy Electron Beam Chest Wall Irradiation in Women With Breast Cancer: A Clinical Step Toward Conformal Electron Therapy

PURPOSE

Electron beam radiotherapy of the chest wall with or without lymph node irradiation has been used at the Institut Curie for >20 years. The purpose of this report was to show the latest improvements of our technique developed to avoid hot spots and improve the homogeneity.

METHODS AND MATERIALS

The study was split into two parts. A new electron irradiation technique was designed and compared with the standard one (dosimetric study). The dose distributions were calculated using our treatment planning software ISIS (Technologie Diffusion). The dose calculation was performed using the same calculation parameters for the new and standard techniques. Next, the early skin toxicity of our new technique was evaluated prospectively in the first 25 patients using Radiation Therapy Oncology Group criteria (clinical study).

RESULTS

The maximal dose found on the five slices was 53.4 +/- 1.1 Gy for the new technique and 59.1 +/- 2.3 Gy for the standard technique. The hot spots of the standard technique plans were situated at the overlap between the internal mammary chain and chest wall fields. The use of one unique field that included both chest wall and internal mammary chain volumes solved the problem of junction. To date, 25 patients have been treated with the new technique. Of these patients, 12% developed Grade 0, 48% Grade 1, 32% Grade 2, and 8% Grade 3 toxicity.

CONCLUSIONS

This report describes an improvement in the standard postmastectomy electron beam technique of the chest wall. This new technique provides improved target homogeneity and conformality compared with the standard technique. This treatment was well tolerated, with a low rate of early toxicity events.

Local recurrence after mastectomy in patients with T3pN0 breast carcinoma treated without postoperative radiation therapy

OBJECTIVE

The need for comprehensive adjuvant radiotherapy in patients with T3pN0 breast cancer is controversial. This retrospective analysis was performed to assess the frequency of local and distant recurrence in patients treated with mastectomy without postoperative radiation.

MATERIALS AND METHODS

A single institution database of 2362 patients with breast carcinoma treated from 1974 to 1994 yielded 101 patients who had T3pN0 disease and did not receive chest wall or nodal irradiation. The median follow-up time was 93 months (range, 10-256 months). Sites of first failure were categorized as isolated chest wall (CWF), regional lymph nodes (RNF, which in this case were considered to be either axillary or supraclavicular), or distant sites (DF). CWF and/or RNF were considered local recurrences. Patients with simultaneous CWF and DF or RNF and DF were scored as DF. A comparison was made to 286 T2pN0 patients, also treated between 1974 and 1994.

RESULTS

Twenty-two T3N0 patients developed recurrent disease. Site of first recurrence was isolated local recurrence in 11 patients and distant in 11 patients. Four patients had simultaneous local and distant recurrences. Site of isolated local recurrence was CWF in 5 patients and RNF in 6 patients. Median tumor size was 6 cm (range, 5-10.5 cm). There was no difference in local recurrence for tumor sizes < or =7 cm versus >7 cm (P = 0.07). The crude recurrence rate for T3pN0 patients treated by mastectomy was similar to T2pN0 patients treated in similar fashion (P = 0.3).

CONCLUSION

The risk of isolated local recurrence in patients with T3pN0 breast cancer and negative margins is moderately low and similar to T2pN0 patients. These results suggest that routine use of postoperative chest wall and nodal irradiation in all T3pN0 patients may not be required.

Rehabilitation in Women with Breast Cancer

The diagnosis and treatment of breast cancer in women has undergone profound changes in the past century. Although much research and clinical attention has been focused on saving the lives of women with this condition, less focus has been on rehabilitation aspects. This postacute care should be a distinct phase of treatment. The field of physical medicine and rehabilitation has much to offer women who undergo extremely toxic although life-prolonging therapies for breast cancer. The focus of rehabilitation should include improving strength and cardiovascular conditioning, alleviating pain and improving fatigue. With respect to exercise, this can help women to physically recover from treatment and potentially prevent cancer recurrence. Many exciting opportunities will be available for rehabilitation specialists to improve the care of women with breast cancer and to participate in research in the field of oncology rehabilitation.

Postmastectomy radiation therapy: indications and controversies

The indications and benefits of postmastectomy radiation therapy (PMRT) continue to evolve. Advances in systemic adjuvant therapy and targeted therapy for breast cancer are likely to play an increasingly important role in control of locoregional as well as distant disease. Ongoing scrutiny of patterns of chest wall failure will be required to define the net benefit derived from PMRT. This article discusses the 2001 American Society of Clinical Oncology guidelines for PMRT and current practices using PMRT in selected groups of patients who have breast cancer.

[Approaches to individual radiotherapy in breast cancer: individual risk estimation and individualized techniques]

INTRODUCTION

Radiotherapy comprises an integral part of the curative therapy of breast cancer by improving the locoregional control and survival when given on an individualized basis. Conformal radiotherapy and three-dimensional radiation treatment planning enhance the safety of radiotherapy by adjusting the irradiated volume to the shape of the target volume, and providing control of the radiation dose to the organs at risk (OARs).

PATIENTS AND METHODS

The methods introduced at the authors' institute in 2002 are demonstrated. The breast/chest wall and lymph node areas were irradiated provided that there was a minimum risk of local or locoregional relapse of 10%. CT-based 3D radiotherapy treatment planning and individual patient-positioning were applied, with thermoplastic mask-fixation in the second part of the study. The dose constraints of the OARs were given in accordance with the literature recommendations. In the first group of patients, individually shaped blocks, in the second group, multileaf collimator, and in the third group, with the aim of a more homogenous dose-distribution in the target volume, intensity-modulated beams were applied.

RESULTS

During the study, 737 breast cancer patients received conformal radiotherapy based on individual risk estimation. In 372 cases only local, while in 365 cases locoregional radiotherapy was delivered. The dose-homogeneity in the target volume was significantly improved in the second period of the study, when segments were superposed on the radiotherapy fields. The proportions of the target volumes irradiated with +/-10% of the planned dose in the breast/chest wall, axillary and supraclavicular lymph nodes and internal mammary lymph nodes varied between 90.5-94.2%, 84.1-93.8% and 86.7-91.6%, respectively, depending on the radiation technique used. The parameters indicating the dose to the ipsilateral lung or to the heart were significantly higher when locoregional radiotherapy was applied compared to that in case of local radiotherapy. Radiation dose to the ipsilateral lung and the heart was significantly reduced in the second part of the study when locoregional, but not when local radiotherapy was delivered. The introduction of individual immobilization by means of thermoplastic mask-fixation resulted in a relevant decrease in the uncertainty due to breathing motion and daily positioning errors, and also in a significant reduction of the dose to the contralateral breast.

CONCLUSIONS

Adjuvant radiotherapy should be based on individual risk-benefit features. The need of the introduction of special techniques may be decided after the dose-volume analysis of the conformal radiotherapy plan based on 3D radiation treatment planning.

Can a subgroup of node-negative breast carcinoma patients with T1-2 tumor who may benefit from postmastectomy radiotherapy be identified?

PURPOSE

To determine a subgroup of T1-2N0 breast carcinoma patients at high risk for local recurrence.

METHODS AND MATERIALS

In this retrospective study, univariate and multivariate prognostic factor analyses for local recurrence and distant recurrence were carried out in 502 patients.

RESULTS

During the median observation time of 77 months (range, 24-191 months), 14 patients (2.8%) had local recurrence and 55 (11.0%) had distant recurrence. Tumor size (continuous, p = 0.03; hazard ratio [HR] 1.2; 95% confidence interval [CI], 1.1-1.7), grade (p = 0.01; HR, 2.4; 95% CI, 1.2-5.0), lymphatic vascular invasion (LVI) (p = 0.01; HR, 10.0; 95% CI, 2.4-17.3), estrogen receptor status (p = 0.01; HR, 6.3; 95% CI, 2.0-23.0) and cErbB2 status (p = 0.01; HR, 10.0; 95% CI 1.8-87.5) were strongly associated with distant recurrence. Tumor size (< or =2 cm vs. >2 cm; p = 0.05; HR, 5.4; 95% CI, 1.2-28.0) and LVI (p = 0.004; HR, 9.0; 95% CI, 2.0-41.0) in patients aged < or =40 years, and tumor size (< or =3 cm vs. >3 cm; p = 0.05; HR 8.6; 95% CI 1.3-75.0), LVI (p = 0.007; HR, 18.0; 95% CI, 2.1-153.0), and grade (p = 0.05; HR, 7.0; 95% CI, 1.2-63.0) in patients aged >40 years were the most important predictive factors for local recurrence.

CONCLUSIONS

Among breast carcinoma patients, young patients with tumor size >2 cm and LVI and older patients with tumor size >3 cm, LVI, and high-grade tumor had a high risk of local recurrence.