Postmastectomy radiotherapy: questions for the twenty-first century

Risk-Adapted Postmastectomy Radiotherapy Decision Based on Prognostic Nomogram for pT1-2N1M0 Breast Cancer: A Multicenter Study

PURPOSE

The aim of this study was to develop a widely accepted prognostic nomogram and establish a risk-adapted PMRT strategy based on locoregional recurrence for pT1-2N1M0 breast cancer.

METHODS AND MATERIALS

A total of 3,033 patients with pT1-2N1M0 breast cancer treated at 6 participating institutions between 2000 and 2016 were retrospectively reviewed. A nomogram was developed to predicted locoregional recurrence-free survival (LRFS). A propensity score-matched (PSM) analyses was performed in risk-adapted model.

RESULTS

With the median follow-up of 65.0 months, the 5-year overall survival (OS), disease free survival (DFS) and LRFS were 93.0, 84.8, and 93.6%, respectively. There was no significant difference between patients who received PMRT or not for the entire group. A nomogram was developed and validated to estimate the probability of 5-year LRFS based on five independent factors including age, primary tumor site, positive lymph nodes number, pathological T stage, and molecular subtype that were selected by a multivariate analysis of patients who did not receive PMRT in the primary cohort. According to the total nomogram risk scores, the entire patients were classified into low- (40.0%), moderate- (42.4%), and high-risk group (17.6%). The 5-year outcomes were significantly different among these three groups (P<0.001). In low-risk group, patients who received PMRT or not both achieved a favorable OS, DFS, and LRFS. In moderate-risk group, no differences in OS, DFS, and LRFS were observed between PMRT and no PMRT patients. In high-risk group, compared with no PMRT, PMRT resulted in significantly different OS (86.8 vs 83.9%, P = 0.050), DFS (77.2 vs 70.9%, P = 0.049), and LRFS (90.8 vs. 81.6%, P = 0.003). After PSM adjustment, there were no significant differences in OS, DFS, and LRFS in low-risk and moderate-risk groups. However, in the high-risk group, PMRT still resulted in significantly better OS, DFS and improved LRFS.

CONCLUSIONS

The proposed nomogram provides an individualized risk estimate of LRFS in patients with pT1-2N1M0 breast cancer. Risk-adapted PMRT for high-risk patients is a viable effective strategy.

Nomogram to Predict Internal Mammary Lymph Nodes Metastasis in Patients With Breast Cancer

Background: Numerous studies have showed that internal mammary lymph node (IMLN) metastasis is an important adverse prognostic factor in patients with breast cancer (BC), however, there are no available prediction model for the preoperative diagnosis of IMLN metastasis.

Methods: Data from 102 breast cancer patients treated with IMLN operation were used to establish and calibrate a nomogram for IMLN status based on multivariate logistic regression. Prediction performance of this model was further validated with a second set of 50 patients with BC. Discrimination of the predict model was assessed by the C-index, and calibration assessed by calibration plots. Moreover, we conducted the decision curve analysis (DCA) to evaluate the clinical value of the nomogram. Finally, the survival status of patients in different risk groups based on nomogram were also compared.

Results: The final multivariate regression model included tumor location, lymph vascular invasion (LVI), and pathological axillary lymph node stage (pALN stage). A nomogram was developed as a graphical representation of the model and had good calibration and discrimination in both sets (with C-index of 0.86 and 0.83 for the training and validation set, respectively). Moreover, the DCA showed the clinical usefulness of our constructed nomogram. False negative (FN) in low risk group classified by nomogram (FN-LR-nomogram) did not significantly impact adjuvant treatment decision making, and more importantly, patients with FN-LR-nomogram had recurrence-free survival equivalent to patients with pathologically ture negative in low risk group classified by nomogram (TN-LR-nomogram).

Conclusions: As a non-invasive prediction tool, our nomogram shows favorable predictive accuracy for IMLN metastasis in patients with BC and can serve as a basis to integrate future molecular markers for its clinical application.

Clinical Significance of Lymph-Node Ratio in Determining Supraclavicular Lymph-Node Radiation Therapy in pN1 Breast Cancer Patients Who Received Breast-Conserving Treatment (KROG 14-18): A Multicenter Study

This study evaluated the clinical significance of the lymph-node ratio (LNR) and its usefulness as an indicator of supraclavicular lymph-node radiation therapy (SCNRT) in pN1 breast cancer patients with disease-free survival (DFS) outcomes. We retrospectively analyzed the clinical data of patients with pN1 breast cancer who underwent partial mastectomy and taxane-based sequential adjuvant chemotherapy with postoperative radiation therapy in 12 hospitals (n = 1121). We compared their DFS according to LNR, with a cut-off value of 0.10. The median follow-up period was 66 months (range, 3–112). Treatment failed in 73 patients (6.5%) and there was no significant difference in DFS between the SCNRT group and non-SCNRT group. High LNR (>0.10) showed significantly worse DFS in both univariate and multivariate analyses (0.010 and 0.033, respectively). In a subgroup analysis, the effect of SCNRT on DFS differed significantly among patients with LNR > 0.10 (p = 0.013). High LNR can be used as an independent prognostic factor for pN1 breast cancer patients treated with partial mastectomy and postoperative radiotherapy. It may also be useful in deciding whether to perform SCNRT to improve DFS.

Clinical significance of the lymph node ratio in N1 breast cancer

PURPOSE

The purpose of this study was to evaluate the prognostic value of the lymph node ratio (LNR), which was defined as the proportion of involved nodes of all dissected nodes, in pN1 breast cancer.

MATERIALS AND METHODS

We retrospectively analyzed the clinical data of patients with pN1 breast cancer (N = 144) treated at Keimyung University Dongsan Medical Center, Daegu, Korea between 2001 and 2010. The median age was 46 years (range, 27 to 66 years). The LNR was 0.01-0.15 (low LNR) in 130 patients and >0.15 (high LNR) in 14 patients. Sixty-five patients (45.1%) had T1 tumors, 74 (51.4%) had T2 tumors, and 5 (3.5%) had T3 tumors. Eighty-eight patients (61.1%) underwent total mastectomy and 56 (38.9%) underwent partial mastectomy. Fifty-nine patients (41.0%) underwent radiotherapy and 12 (8.3%) underwent regional radiotherapy. The median follow-up period was 65 months.

RESULTS

The 5- and 10-year disease-free survival (DFS) rates were 92.7% and 82.4%, respectively. Univariate analyses revealed that high LNR (p = 0.004), total mastectomy (p = 0.006), no local radiotherapy (p = 0.036), and stage T2 or T3 (p = 0.010) were associated with worse DFS. In multivariable analysis, only high LNR (p = 0.015) was associated with worse DFS.

CONCLUSION

High LNR is an independent prognostic factor in pN1 breast cancer and could be an indication for adjuvant radiotherapy in these patients.

The Effect of the Timing of Radiotherapy on Clinical and Patient-Reported Outcomes After Latissimus Dorsi Breast Reconstruction: A 10-Year Study

Background:

Breast reconstruction (BR) is considered to be adversely affected by radiotherapy (RT), particularly when an implant is used. The aim of this study was to compare clinical and patient-reported outcomes after expander-assisted latissimus dorsi breast reconstruction depending on the timing of RT.

Methods:

Patients undergoing BR over a 10-year period (follow-up mean, 56 [14–134] months) were divided into 3 groups. Group 1, RT after mastectomy and BR, Group 2, RT before mastectomy and BR, and Group 3, RT after mastectomy but before BR. The primary endpoints were early and late surgical interventions. Validated questionnaires were circulated to all study patients and matched controls.

Results:

Three hundred thirteen patients underwent 389 BRs. One hundred eighteen patients received RT, of which 65 had undergone expander-assisted latissimus dorsi breast reconstruction. Both use and timing of RT influenced clinical outcomes. Overall, use of RT resulted in a 3-fold increase in complications (P = 0.003). Postreconstruction RT resulted in more than double the number of complications compared with prereconstruction RT (P = 0.008) and delaying BR until after mastectomy and RT reduced complications to levels observed in control patients (P = nonsignificant). Complications were halved in patients undergoing autologous LD reconstruction (P = 0.0001). Patient-reported outcomes were similar for emotional well-being, satisfaction, and shoulder symptoms, although a nonsignificant increase in chronic breast symptoms was reported by the RT group.

Conclusion:

The timing and type of LD reconstruction chosen by patients receiving RT has a significant impact on the risk of subsequent complications and unplanned interventions but has little impact on longer term patient well-being or satisfaction.

Real-world outcomes of postmastectomy radiotherapy in breast cancer patients with 1-3 positive lymph nodes: a retrospective study

OBJECTIVE

To assess the treatment outcomes and to explore the determinants of clinical outcome in breast cancer patients with 1-3 positive nodes who did or did not receive postmastectomy radiotherapy (PMRT) in a tertiary care referral cancer center in Northern Thailand.

METHODS

We investigated a retrospective cohort of registered breast cancer patients at the Faculty of Medicine, Chiang Mai University, Thailand from 2001-2007. Analysis was performed using Cox regression models to identify factors affecting the overall survival (OS) and relapse-free survival (RFS) rates. Comparisons were made between two cohorts: women who received adjuvant PMRT (74 patients) and women who did not receive adjuvant PMRT (81 patients).

RESULTS

A total of 155 patients were included with a median follow-up period of 4.45 years. There was a statistically significant 4-year OS difference between the two groups of patients: 100% for the PMRT group and 93.1% for the non-PMRT group (P = 0.044). The 4-year RFS was 85.9% for patients receiving PMRT and 78.3% for patients who did not receive PMRT (P = 0.291). On multivariate analysis of OS, using hormonal treatment was the only significant independent factor associated with improved OS. On multivariate analysis of RFS, none of the variables were significantly associated with improved RFS. PMRT was notfound to be a prognostic variable related to the outcome of patients using a logistic regression model.

CONCLUSION

Our retrospective, hospital-based analysis demonstrated that PMRT improved the treatment outcome in terms of OS for women with 1-3 node positive early-stage breast cancer.

Postmastectomy irradiation in breast in breast cancer patients with T1-2 and 1-3 positive axillary lymph nodes: is there a role for radiation therapy?

Background

We aimed to evaluate retrospectively the correlation of loco-regional relapse (LRR) rate, distant metastasis (DM) rate, disease free survival (DFS) and overall survival (OS) in a group of breast cancer (BC) patients who are at intermediate risk for LRR (T1-2 tumor and 1-3 positive axillary nodes) treated with or without postmastectomy radiotherapy (PMRT) following modified radical mastectomy (MRM).

Methods

Ninety patients, with T1-T2 tumor, and 1-3 positive nodes who had undergone MRM received adjuvant systemic therapy with (n = 66) or without (n = 24) PMRT. Patient-related characteristics (age, menopausal status, pathological stage/tumor size, tumor location, histology, estrogen/progesterone receptor status, histological grade, nuclear grade, extracapsular extension, lymphatic, vascular and perineural invasion and ratio of involved nodes/dissected nodes) and treatment-related factors (PMRT, chemotherapy and hormonal therapy) were evaluated in terms of LRR and DM rate. The 5-year Kaplan-Meier DFS and OS rates were analysed.

Results

Differences between RT and no-RT groups were statistically significant for all comparisons in favor of RT group except OS: LRR rate (3%vs 17%, p = 0.038), DM rate (12% vs 42%, p = 0.004), 5 year DFS (82.4% vs 52.4%, p = 0.034), 5 year OS (90,2% vs 61,9%, p = 0.087). In multivariate analysis DM and lymphatic invasion were independent poor prognostic factors for OS.

Conclusion

PMRT for T1-2, N1-3 positive BC patients has to be reconsidered according to the prognostic factors and the decision has to be made individually with the consideration of long-term morbidity and with the patient approval.

Radiotherapy of the regional lymph nodes: shooting at the sheriff?

The role of immune surveillance in controlling the spread of breast cancer to the regional nodes is poorly understood. In theory regional nodal irradiation (RNI) might compromise this host function. However the clinical evidence suggests that the risk of regional recurrence is lower in patients with early breast cancer whose axilla has been irradiated compared to no axillary treatment. The role of RNI after breast conserving surgery has not been well studied. A policy of level III clearance and only irradiating the axilla for residual disease and a selective policy of axillary irradiation in node positive patients after sentinel node biopsy or lower axillary node sample is recommended. Irradiation of the medial supraclavicular fossa after axillary dissection is suggested where there are four or more nodes involved on axillary dissection. There is little data to inform selection of patients for RNI after neoadjuvant systemic therapy. The role of postmastectomy radiotherapy (PMRT) was largely established on the basis of comprehensive RNI. It is unclear whether irradiating less than the chest wall and peripheral lymphatics confers the same level of benefit. The role of PMRT in women with 1-3 involved nodes remains controversial and investigational. Biological factors such as oestrogen and progesterone receptor status and HER-2 protein expression may play a role in determining benefits from PMRT. The role of internal mammary nodal irradiation is unclear. The individualisation of RNI based on molecular and genetic factors should be a priority for research. The benefits of RNI need to be carefully balanced against the risks of cardiotoxicity, pneumonitis, lymphoedema, brachial plexopathy and secondary malignancy.

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.

Post-mastectomy radiation in large node-negative breast tumors: does size really matter?

Treatment decisions regarding local control can be particularly challenging for T3N0 breast tumors because of difficulty in estimating rates of local failure after mastectomy. Reports in the literature detailing the rates of local failure vary widely, likely owing to the uncommon incidence of this clinical situation. The literature regarding this clinical scenario is reviewed, including recent reports that specifically address the issue of local failure rates after mastectomy in the absence of radiation for large node-negative breast tumors.

WITHDRAWN: Radiotherapy for early breast cancer

BACKGROUND

The long-term effects of radiotherapy on mortality from breast cancer and other causes remain uncertain.

OBJECTIVES

In this report the Early Breast Cancer Trialists' Collaborative Group present their systematic overview of treatment with radiotherapy.

SEARCH STRATEGY

Trial identification procedures for the EBCTCG overviews have been described elsewhere. See under "EBCTCG" in the Breast Cancer Group module.

SELECTION CRITERIA

A meta-analysis was done of 10-year and 20-year results from 40 unconfounded randomised trials of radiotherapy for early breast cancer. Radiotherapy fields generally included not only chest wall (or breast) but also axillary, supraclavicular, and internal mammary nodes.

DATA COLLECTION AND ANALYSIS

Data collection involved central review of individual patient data on recurrence and cause-specific mortality from 20,000 women.

MAIN RESULTS

A reduction of approximately two-thirds in local recurrence was seen in all trials, largely independent of the type of patient or type of radiotherapy (8.8% vs 27.2% local recurrence by year 10). Hence, to assess effects on breast cancer mortality of substantially better local control, results from all trials were combined. Breast cancer mortality was reduced (2p=0.0001) but other, particularly vascular, mortality was increased (2p=0.0003), and overall 20-year survival was 37.1% with radiotherapy versus 35.9% control (2p=0.06). There was little effect on early deaths, but logrank analyses of later deaths indicate that, on average after year 2, radiotherapy reduced annual mortality rates from breast cancer by 13.2% (SE 2.5) but increased those from other causes by 21.2% (SE 5.4). Nodal status, age, and decade of follow-up strongly affected the ratio of breast cancer mortality to other mortality, and hence affected the ratio of absolute benefit to absolute hazard from these proportional changes in mortality.

AUTHORS' CONCLUSIONS

Radiotherapy regimens able to produce the two-thirds reduction in local recurrence seen in these trials, but without long-term hazard, would be expected to produce an absolute increase in 20-year survival of about 2-4% (except for women at particularly low risk of local recurrence). The average hazard seen in these trials would, however, reduce this 20-year survival benefit in young women and reverse it in older women.

Radiation therapy, cardiac risk factors, and cardiac toxicity in early-stage breast cancer patients

PURPOSE

The benefits of adjuvant radiation therapy (RT) for breast cancer may be counterbalanced by the risk of cardiac toxicity. We studied the cardiac effects of RT and the impact of pre-existing cardiac risk factors (CRFs) in a population-based sample of older patients with breast cancer.

METHODS AND MATERIALS

In the Surveillance, Epidemiology and End-Results (SEER)-Medicare database of women > or = 65 years diagnosed with Stages I to III breast cancer from January 1, 1992 to December 31, 2000, we used multivariable logistic regression to model the associations of demographic and clinical variables with postmastectomy and postlumpectomy RT. Using Cox proportional hazards regression, we then modeled the association between treatment and myocardial infarction (MI) and ischemia in the 10 or more years after diagnosis, taking the predictors of treatment into account.

RESULTS

Among 48,353 women with breast cancer; 19,897 (42%) were treated with lumpectomy and 26,534 (55%) with mastectomy; the remainder had unknown surgery type (3%). Receipt of RT was associated with later year of diagnosis, younger age, fewer comorbidities, nonrural residence, and chemotherapy. Postlumpectomy RT was also associated with white ethnicity and no prior history of heart disease (HD). The RT did not increase the risk of MI. Presence of MI was associated with age, African American ethnicity, advanced stage, nonrural residence, more than one comorbid condition, a hormone receptor-negative tumor, CRFs and HD. Among patients who received RT, tumor laterality was not associated with MI outcome. The effect of RT on the heart was not influenced by HD or CRFs.

CONCLUSION

It appears unlikely that RT would increase the risk of MI in elderly women with breast cancer, regardless of type of surgery, tumor laterality, or history of CRFs or HD, for at least 10 years.

Post-mastectomy radiation therapy: Translating local benefits into improved survival

Several randomized trials and the most recent meta-analysis from the Oxford Overview have confirmed the efficacy of post-mastectomy radiation therapy (PMRT) in improving local control and long-term survival. The survival advantage of PMRT has been established in patients with a 10% risk of local regional recurrence. Patients with four or more positive lymph nodes fall in this category, even with effective systemic therapy. However, it remains difficult to identify the subset of patients with 1-3 positive lymph nodes at highest risk of local recurrence, who would most likely demonstrate a survival benefit with PMRT. When PMRT is used, careful treatment planning, particularly with regard to cardiac dose, is critical to minimizing serious late effects of treatment. Further developments in pathologic stratification of these patients, guided by expression profiles or novel biologic markers, are required to enable individualized assessment of long-term therapeutic risks and benefits.

Radiation therapy for older cancer patients

Cancer is the leading cause of death among the elderly. With the dramatic increase in life expectancy, treatment approach of older cancer patients poses major challenges. There is no consensus on treatment guidelines for elderly cancer patients with significant variability among physicians due to concerns for toxicity. The issue is further complicated by a lack of quality data on age-related issues of cancer management. This review highlights important factors relevant to treatment decision making in older cancer patients with special emphasis on radiation therapy for lung, prostate and breast cancer. The potential benefits of recent innovations and emerging radiotherapeutic technologies and their application to elderly cancer patients is also presented.

Postmastectomy radiotherapy in intermediate-risk patients: the gray zone

Postmastectomy radiotherapy continues to be one of the most controversial issues in breast radiotherapy. At the crux of the controversy lies the lack of conclusive studies that specifically address the risk-benefit ratio of postmastectomy radiotherapy for patients at intermediate risk of developing locoregional recurrence. A well-designed phase III trial was initiated, but the trial failed to accrue and was closed prematurely, leaving the issue unresolved. Recent data confirm that postmastectomy radiotherapy yields a clear benefit in breast cancer-specific survival. Furthermore, the risk of cardiac morbidity that historically has offset the benefit of postmastectomy radiotherapy appears to be lessening with modern radiotherapy approaches. However, newer, more efficacious systemic therapy regimens may decrease the risk of locoregional recurrence and increase the risk of toxicity from combined-modality therapy. Recent studies attempt to better stratify patients into risk categories based on disease factors and to estimate the benefit of postmastectomy radiotherapy when traditional risk estimates, such as nodal status, are obscured by neoadjuvant systemic therapy. Nonetheless, a clear consensus on the role of postmastectomy radiotherapy remains elusive for patients who are at intermediate risk of locoregional recurrence after mastectomy.

When May Adjuvant Radiotherapy be Avoided in Operable Breast Cancer?

Randomised trials in which the omission of radiotherapy has been tested after breast-conserving surgery, with or without adjuvant systemic therapy, show a significant four- to five-fold reduction in local recurrence. As yet, no subgroup of women managed by breast-conserving surgery has been identified from whom radiotherapy can be withheld. Few randomised data have been published on the effect of omission of radiotherapy on local control, quality of life and costs, particularly in older women for whom the risk of local recurrence is generally lower. Ongoing trials are evaluating the role of radiotherapy in this population of low risk, older women. Adjuvant radiotherapy after breast-conserving surgery or mastectomy significantly reduces the incidence of local recurrence. In women who have had a mastectomy at high risk of recurrence (> 20% risk of recurrence at 10 years), adjuvant radiotherapy improves survival if combined with adjuvant systemic therapy. Among women with T3 tumours, and those with four or more involved axillary nodes treated by mastectomy, postoperative radiotherapy is the standard of care. For women at intermediate risk of recurrence (i.e. <15% 10-year risk of recurrence after surgery and systemic therapy alone), with one to three involved nodes or node negative with other risk factors, the role of radiotherapy is unclear. Clinical trials to assess the role of postmastectomy radiotherapy (PMRT) in this setting are needed. For pT1-2, pNO tumours without other risk factors, there is no evidence at present that PMRT is needed.

Quantitative molecular diagnosis of axillary drainage fluid for prediction of locoregional failure in patients with one to three positive axillary nodes after mastectomy without adjuvant radiotherapy

PURPOSE

A quantitative multiple-marker reverse transcriptase (RT)-polymerase chain reaction (PCR) assay for sensitive detection of cancer cells in axillary drainage fluid was developed to examine whether the presence of cancer cells in axillary drainage fluid can be used as a predictor of locoregional recurrence (LRR) in patients with breast cancer who had T1/2 primary tumors and one to three positive axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy.

METHODS AND MATERIALS

Axillary drainage fluid was collected from 126 patients with invasive ductal carcinoma of the breast who were treated with modified radical mastectomy and were found to have one to three positive axillary nodes. Cancer cells in axillary drainage fluid were detected by RT-PCR assay using primers specific for carcinoembryonic antigen (CEA) and cytokeratin-19 (CK-19) together with numerous clinicopathologic and treatment-related factors and were analyzed for their impact on LRR.

RESULTS

A total of 38 patients suffered LRR during follow-up and the multimarker RT-PCR assays for CEA and CK-19 in the axillary drainage fluid both were positive in 34 patients (27.0%), of which 29 patients had LRR. In univariate analysis, the 5-year LRR-free survival showed higher rates in patients with PCR-negative findings in axillary drainage fluid (p<0.0001), age>or=40 years old (p<0.0001), tumor size<2.5 cm (p<0.0001), negative lymph-vascular space invasion (p=0.026), and T1 status (<0.0001); in multivariate analysis, PCR-positive findings together with age and tumor size were found to be independent predictors of LRR (all p<0.05).

CONCLUSION

Multiplex RT-PCR assay for CEA and CK-19 was highly sensitive for detection and might be useful for prediction of LRR in such subgroup breast cancer patients.

Phase II study of dose-dense sequential doxorubicin and docetaxel for patients with advanced operable and inoperable breast cancer

Rapid sequential delivery of doxorubicin 75 mg/m2 q 2 weeksx3 cycles followed by docetaxel 100 mg/m2 q 2 weeksx3 cycles, with filgrastim support was evaluated in patients with inoperable and large operable breast cancers who were not initially candidates for breast conservation therapy. Postoperative CMF chemotherapy and/or radiation were administered based on surgical findings. Median age of the 39 enrolled patients was 47 (range 27-59), stage IIA (6 patients), IIB (14 patients), IIIA (10 patients), IIIB (9 patients), and 23 patients (59%) had clinical nodal involvement. The average bidimensional tumor size before treatment was 30 cm2. Clinical responses included 13 (33%) complete responses, 23 (59%) partial responses, 1 stable disease, and 2 progressive disease, for an overall response rate of 92%. Clinical response rate was 11/13(85%) in HER2/neu positive patients compared to 25/26 (96%) in tumors that did not express HER2/neu. Twenty patients (51%) underwent breast conservation surgery. Pathologic tumor response at the time of definitive surgery included 4 pathologic CR (pCR, 10%), 4 microscopic invasion (pINV), and 14 (36%) pathologically negative axillary nodes. pCR was not observed in any HER2/neu positive patients. 5/39 patients were unable to complete all cycles of docetaxel and 8 patients required dose reduction of docetaxel due to development of grade 3-4 mucositis and hand-foot syndrome. This observation prompted a protocol change requiring 3 weeks between doxorubicin and docetaxel. Primary chemotherapy with dose-dense doxorubicin and docetaxel given sequentially is well tolerated and allows a high rate of breast sparing in patients with large breast cancers.

The prognostic significance of the percentage of positive/dissected axillary lymph nodes in breast cancer recurrence and survival in patients with one to three positive axillary lymph nodes

BACKGROUND

Adjuvant therapy for women with T1-T2 breast carcinoma and 1-3 positive lymph nodes is controversial due to discrepancies in reported baseline locoregional recurrence (LRR) risks. This inconsistency has been attributed to variations in lymph node staging techniques, which have yielded different numbers of dissected lymph nodes. The current study evaluated the prognostic impact of the percentage of positive/dissected lymph nodes on recurrence and survival in women with one to three positive lymph nodes.

METHODS

The study cohort was comprised of 542 women with pathologic T1-T2 breast carcinoma who had 1-3 positive lymph nodes and who had undergone mastectomy and received adjuvant systemic therapy without radiotherapy. Ten-year Kaplan-Meier (KM) LRR, distant recurrence (DR), and overall survival (OS) rates stratified by the number of positive lymph nodes, the number of dissected lymph nodes, and the percentage of positive lymph nodes were examined using different cut-off levels. Multivariate analysis was performed to evaluate the prognostic significance of the percentage of positive lymph nodes in disease recurrence and survival.

RESULTS

The median follow-up was 7.5 years. LRR, DR, and OS rates correlated significantly with the number of positive lymph nodes and the percentage of positive lymph nodes, but not with the number of dissected lymph nodes. The cut-off level at which the most significant difference in LRR was observed was 25% positive lymph nodes (the 10-year KM LRR rates were 13.9% and 36.7% in women with < or = 25% and > 25% positive lymph nodes, respectively; P < 0.0001). Higher DR rates and lower OS rates were observed among patients who had > 25% positive lymph nodes compared with patients who had < or = 25% positive lymph nodes (DR: 53.0% vs. 30.3%, respectively; P < 0.0001; OS: 43.4% vs. 62.6%, respectively; P < 0.0001). In the multivariate analysis, the percentage of positive lymph nodes and the histologic grade were significant, independent factors associated with LRR, DR, and OS.

CONCLUSIONS

The presence of > 25% positive lymph nodes was an adverse prognostic factor in patients with 1-3 positive nodes and may be used to identify patients at high risks of postmastectomy locoregional and distant recurrence who may benefit with adjuvant radiotherapy and more aggressive systemic therapy regimens.

Patient subsets with T1-T2, node-negative breast cancer at high locoregional recurrence risk after mastectomy

PURPOSE

To identify patient subsets with T1-T2N0 breast cancer at high risk of locoregional recurrence (LRR) who may warrant consideration for postmastectomy radiotherapy.

METHODS AND MATERIALS

Data were analyzed for 1505 women referred between 1989 and 1999 with pathologic T1-T2N0M0 breast cancer treated with mastectomy with clear margins and no adjuvant radiotherapy. Logistic regression analysis was performed to identify statistically significant factors associated with LRR. Recursive partitioning was used to develop a classification tree model for LRR given the prognostic variables.

RESULTS

The median follow-up was 7.0 years. The 10-year Kaplan-Meier LRR rate was 7.8%. On logistic regression analysis, the statistically significant factors predicting LRR were histologic grade (p <0.0001), lymphovascular invasion (LVI) (p <0.0001), T stage (p = 0.05), and systemic therapy use (p = 0.01). In the recursive partitioning model, the first split in the classification tree was histologic grade. For 972 patients without high-grade histologic features, the 10-year Kaplan-Meier LRR rate was 5.5%. For 533 patients with Grade 3 disease (LRR rate 12.1%), the concomitant presence of LVI was associated with a LRR rate of 21.2% (n = 126). In patients with Grade 3 disease without LVI, T2 tumors conferred a LRR rate of 13.4% (n = 194), which increased to 23.2% for patients who did not receive systemic therapy (n = 63).

CONCLUSION

Women with pT1-T2N0 breast cancer experienced a LRR risk of approximately 20% in the presence of Grade 3 disease with LVI or Grade 3 disease, T2 tumors, and no systemic therapy. These subsets of node-negative patients warrant consideration of for postmastectomy radiotherapy.

Selecting breast cancer patients with T1-T2 tumors and one to three positive axillary nodes at high postmastectomy locoregional recurrence risk for adjuvant radiotherapy

PURPOSE

To define the individual factors and combinations of factors associated with increased risk of locoregional recurrence (LRR) that may justify postmastectomy radiotherapy (PMRT) in patients with T1-T2 breast cancer and one to three positive nodes.

METHODS AND MATERIALS

The study cohort comprised 821 women referred to the British Columbia Cancer Agency between 1989 and 1997 with pathologic T1-T2 breast cancer and one to three positive nodes treated with mastectomy without adjuvant RT. The 10-year Kaplan-Meier estimates of isolated LRR and LRR with or without simultaneous distant recurrence (LRR +/- SDR) were analyzed according to age, histologic findings, tumor location, size, and grade, lymphovascular invasion status, estrogen receptor (ER) status, margin status, number of positive nodes, number of nodes removed, percentage of positive nodes, and systemic therapy use. Multivariate analyses were performed using Cox proportional hazards modeling. A risk classification model was developed using combinations of the statistically significant factors identified on multivariate analysis.

RESULTS

The median follow-up was 7.7 years. Systemic therapy was used in 94% of patients. Overall, the 10-year Kaplan-Meier isolated LRR and LRR +/- SDR rate was 12.7% and 15.9%, respectively. Without PMRT, a 10-year LRR risk of >20% was identified in women with one to three positive nodes plus at least one of the following factors: age <45 years, Stage T2, histologic Grade 3, ER-negative disease, medial location, more than one positive node, or >25% of nodes positive (all p < 0.05 on univariate analysis). On multivariate analysis, age <45 years, >25% of nodes positive, medial tumor location, and ER-negative status were statistically significant predictors of isolated LRR and LRR +/- SDR. In the classification model, the first split was according to age (<45 years vs. >/=45 years), with 29.3% vs. 13.7% developing LRR +/- SDR (p < 0.0001). Of 123 women <45 years, the presence of >25% of nodes positive was associated with a risk of LRR +/- SDR of 58.0% compared with 23.8% for those with </=25% of nodes positive (p = 0.01). Of 698 women >45 years, the presence of >25% of nodes positive also conferred a greater LRR +/- SDR risk (26.7%) compared with women with </=25% of nodes positive (10.8%; p < 0.0001). In women >45 years with </=25% of nodes positive, tumor location and ER status were factors that could be used to further distinguish low-risk from higher risk subsets.

CONCLUSION

Clinical and pathologic factors can identify women with T1-T2 breast cancer and one to three positive nodes at high LRR risk after mastectomy. Age <45 years, >25% of nodes positive, a medial tumor location, and ER-negative status were statistically significant independent factors associated with greater LRR, meriting consideration and discussion of PMRT. Combinations of these factors further augmented the LRR risk, warranting recommendation of PMRT to optimize locoregional control and potentially improve survival. The absence of high-risk factors identifies women who may reasonably be spared the morbidity of PMRT.

Evaluation of set-up deviations during the irradiation of patients suffering from breast cancer treated with two different techniques

PURPOSE

To compare reproducibility of set-up for two different treatment techniques for external irradiation of the breast.

METHODS AND MATERIALS

In total, the analysis comprised 56 pairs of portal and simulator films for 14 consecutive patients treated following breast conserving therapy and 98 pairs of portal and simulator films for 20 consecutive patients treated after mastectomy. For the first group the tangential field technique (TF technique) was used, for the second the inverse hockey stick technique (IHS technique). Evaluation of the treatment reproducibility was performed in terms of systematic and random error calculated for the whole groups, comparison of set-up accuracy by means of comparison of cumulative distribution of the length of the displacement vector.

RESULTS

In the IHS and TF techniques for medial and lateral fields, displacement larger than 5 mm occurred in 28.3, 15.8 and 25.4%, respectively. For the IHS technique, the systematic errors for lateral and cranial-caudal direction were 1.9 and 1.7 mm, respectively (1 SD), the random errors for lateral and cranial-caudal direction were 2.0 and 2.5 mm. For the TF technique, the systematic errors for ventral-dorsal and cranial-caudal direction were 2.6 and 1.3 mm for medial field and 3.7 and 0.7 mm for lateral fields, respectively, the random errors for lateral and cranial-caudal direction were 2.2 and 1.0 mm for medial field and 2.9 and 1.1 for lateral field, respectively. Rotations were negligible in the IHS technique. For the TF technique the systematic and random components amounted to about 2.0 degrees (1 SD).

CONCLUSIONS

Both the inverse hockey stick and standard tangential techniques showed good reproducibility of patients' set-up with respect to cranial-caudal direction. For the TF technique, the accuracy should be improved for the medial field with respect to the ventral-dorsal direction.

Skin-sparing mastectomy and immediate reconstruction is an acceptable treatment option for patients with high-risk breast carcinoma

BACKGROUND

Skin-sparing mastectomy (SSM) followed by immediate reconstruction is an effective treatment option for patients with early-stage breast carcinoma, but its use in patients with more advanced disease is controversial.

METHODS

A retrospective review was performed that included 38 consecutive patients with high-risk breast carcinoma who underwent SSM and immediate reconstruction (between July 1996 and January 2002). Tumor characteristics, type of reconstruction, margin status, timing of adjuvant therapy, postoperative complications, and incidence of recurrence were evaluated.

RESULTS

High-risk patients (Stage IIA [n=4 patients] Stage IIB [n=23 patients] Stage IIIA [n=8 patients] and Stage IIIB [n=3 patients]) underwent immediate reconstruction after SSM with the use of a transverse rectus abdominis myocutaneous flap (n=31 patients), a latissimus dorsi myocutaneous flap plus an implant (n=3 patients), or tissue expanders with subsequent implant placement (n=4 patients). The median follow-up was 52.9 months (range, 27.5-92.0 months), and the median time to recurrence has not yet been reached at the time of last follow-up. The median interval from surgery to the initiation of postoperative adjuvant therapy was 38 days (range, 25-238 days). Local recurrence was seen in 1 patient (2.6%), systemic recurrence in was seen in 10 patients (26.3%), and both local and distant metastases in were seen in 2 other patients (5.3%).

CONCLUSIONS

SSM with immediate reconstruction appeared to be an oncologically safe treatment option for high-risk patients with advanced stages of breast carcinoma. In addition to the aesthetic and psychological benefits of performing SSM with immediate reconstruction, local recurrence rates and disease-free survival were favorable when combined with the use of radiation therapy and adjuvant chemotherapy, as indicated.

Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial

BACKGROUND

The British Columbia randomized radiation trial was designed to determine the survival impact of locoregional radiation therapy in premenopausal patients with lymph node-positive breast cancer treated by modified radical mastectomy and adjuvant chemotherapy. Three hundred eighteen patients were assigned to receive no further therapy or radiation therapy (37.5 Gy in 16 fractions). Previous analysis at the 15-year follow-up showed that radiation therapy was associated with a statistically significant improvement in breast cancer survival but that improvement in overall survival was of only borderline statistical significance. We report the analysis of data from the 20-year follow-up.

METHODS

Survival was analyzed by the Kaplan-Meier method. Relative risk estimates were calculated by the Wald test from the proportional hazards regression model. All statistical tests were two-sided.

RESULTS

At the 20 year follow up (median follow up for live patients: 249 months) chemotherapy and radiation therapy, compared with chemotherapy alone, were associated with a statistically significant improvement in all end points analyzed, including survival free of isolated locoregional recurrences (74% versus 90%, respectively; relative risk [RR] = 0.36, 95% confidence interval [CI] = 0.18 to 0.71; P = .002), systemic relapse-free survival (31% versus 48%; RR = 0.66, 95% CI = 0.49 to 0.88; P = .004), breast cancer-free survival (48% versus 30%; RR = 0.63, 95% CI = 0.47 to 0.83; P = .001), event-free survival (35% versus 25%; RR = 0.70, 95% CI = 0.54 to 0.92; P = .009), breast cancer-specific survival (53% versus 38%; RR = 0.67, 95% CI = 0.49 to 0.90; P = .008), and, in contrast to the 15-year follow-up results, overall survival (47% versus 37%; RR = 0.73, 95% CI = 0.55 to 0.98; P = .03). Long-term toxicities, including cardiac deaths (1.8% versus 0.6%), were minimal for both arms.

CONCLUSION

For patients with high-risk breast cancer treated with modified radical mastectomy, treatment with radiation therapy (schedule of 16 fractions) and adjuvant chemotherapy leads to better survival outcomes than chemotherapy alone, and it is well tolerated, with acceptable long-term toxicity.

Effect of Addition of Adjuvant Paclitaxel on Radiotherapy Delivery and Locoregional Control of Node-Positive Breast Cancer: Cancer and Leukemia Group B 9344

Purpose

We compared radiotherapy (RT) delivery and locoregional control in patients with node-positive breast cancer randomly assigned on Cancer and Leukemia Group B 9344 to receive adjuvant doxorubicin/cyclophosphamide (AC) with patients assigned to receive AC followed by paclitaxel (AC+T).

Methods

Eligible patients were randomly assigned to receive adjuvant AC versus AC+T chemotherapy. RT was required if breast-conserving surgery was performed but was elective after mastectomy. Information about RT delivery was retrospectively collected. Cumulative incidence of locoregional recurrence (LRR), use of elective RT, and RT delivery were compared between treatment arms.

Results

For patients treated with breast-conserving surgery and RT, the 5-year cumulative incidence of isolated LRR was 9.7% in the AC arm and 3.7% in the AC+T arm (P = .04) and of LRR as any component of failure was 12.9% versus 6.1%, respectively (P = .04). Although LRR rates in patients who did not receive postmastectomy RT were lower in the AC+T arm, the difference was not statistically significant. Despite the lack of protocol guidelines, RT use did not differ between arms, nor did RT dose, treatment interruption, or completion.

Conclusion

Despite the delay to RT during additional chemotherapy, adjuvant AC+T afforded better local control than AC alone in patients treated with breast-conserving therapy. Addition of paclitaxel did not adversely affect delivery or ability to tolerate RT, as indicated by similar rates of completion of timely, full-dose RT between arms.

Status of postmastectomy radiotherapy in the United States: A patterns of care study

PURPOSE

The Patterns of Care Study performed this first known practice survey to establish a national profile of the delivery of postmastectomy radiotherapy (RT) in operable breast cancer.

METHODS AND MATERIALS

A Patterns of Care Study research associate collected data from 55 randomly selected institutions. The survey data included 132 items describing the patient, pathologic features, and treatment course for patients with clinical Stage I, II, and IIIA breast cancer undergoing postmastectomy RT in 1998 and 1999. A multivariate analysis was performed to determine the impact of tumor factors and type of treatment facility on the radiation fields used.

RESULTS

A weighted sample size of 13,720 was obtained from a sampling of 405 patient records. The mean tumor size was 3.5 cm, and the mean number of axillary nodal metastases was 4.55. Lymphatic vascular invasion was noted in 34%, microscopic skin or dermal lymphatic invasion in 16%, positive or close margins in 36%, and extracapsular nodal extension in 23%. Radiotherapy included the chest wall in all cases and the regional nodes in 78%. When nodal RT was delivered, it included a supraclavicular field, supplemental axillary field, and/or an internal mammary field in 98%, 46%, and 23% of cases, respectively. Chest wall and supraclavicular RT was delivered in >90% of instances with 6-MV photons to doses between 45 and 50 Gy. More variation was seen in the delivery of the axillary and internal mammary RT. On multivariate analysis, the presence of four or more positive nodes and treatment at a large-volume facility were the factors most frequently associated with the use of regional radiation fields.

CONCLUSION

This Patterns of Care Study survey has demonstrated that breast cancer patients undergoing postmastectomy RT in 1998 and 1999 had a high proportion of factors associated with an increased risk of locoregional failure. The practice patterns established in this study provide a baseline for comparison with future survey results.

T1-T2 Breast Cancer with Four or More Positive Axillary Lymph Nodes: Adjuvant Locoregional Radiotherapy with High-Dose or Standard-Dose Chemotherapy. Results of an Observational Study

Aim and background

The aim of this study was to investigate the efficacy of postoperative locoregional radiotherapy in patients with T1-T2 breast cancer and four or more positive axillary lymph nodes submitted to mastectomy or breast-conserving surgery followed by standard-dose or high-dose adjuvant chemotherapy. The incidence of locoregional relapses and the survival correlated with the number of positive nodes were recorded for each treatment arm.

Patients and methods

From August 1992 to August 1999 86 breast cancer patients (median age, 54 years, T1-T2, N+ >4) submitted to surgery were treated. Sixty-three patients received standard-dose chemotherapy while 23 patients with 10 or more positive nodes received high-dose chemotherapy. After four courses of standard-dose anthracycline-based chemotherapy peripheral blood stem cells were mobilized with cyclophosphamide (7g/m2) and G-CSF (10-16 μg/kg/day/sc). High-dose chemotherapy consisted of etoposide 1000 mg/m2, thiotepa 500 mg/m2 and carboplatin 800 mg/m2. Hormone receptor-positive patients underwent hormone therapy. Following chemotherapy all 86 patients were given conventional radiotherapy to the breast or the chest wall and the supraclavicular fossa. The high-dose subgroup received radiotherapy to the internal mammary nodes ± axilla. Results: The median follow-up from the start of radiotherapy was 36.5 months. Locoregional relapses occurred in nine patients (10.4%); in four of them they were isolated (4.6%). Local relapses were four (4.6%) and regional relapses six (6.9%). Twenty-five patients (29%) had distant metastases. The five-year and eight-year overall actuarial survival rates were 82.6% ± 4.8 and 60.1% ± 8.8, respectively. No statistical differences were found when the number of positive nodes or the type of treatment of N+ 10 patients was included in the analysis.

Conclusions

Breast cancer patients with four or more positive axillary lymph nodes are at high risk of developing locoregional and distant relapses. The results reported here demonstrate the efficacy of radiotherapy in the reduction of locoregional failure; no differences in survival and locoregional control in relation to treatment arm and number of positive nodes were found.

Clinical practice guidelines for the care and treatment of breast cancer: 16. Locoregional post-mastectomy radiotherapy

OBJECTIVE

To provide information and recommendations to assist women with breast cancer and their physicians in making decisions regarding the use of locoregional post-mastectomy radiotherapy (PMRT).

OUTCOMES

Locoregional control, disease-free survival, overall survival and treatment-related toxicities.

EVIDENCE

This guideline is based on a review of all meta-analyses, consensus statements and other guidelines published between 1966 and November 2002. Searches of MEDLINE and CANCERLIT for English-language randomized controlled trials published between 1995 and November 2002 were also conducted to supplement the literature previously reviewed by the American Society of Clinical Oncology (ASCO) Health Services Research Committee panel in its published guideline. A nonsystematic review of the literature was continued through June 2003.

RECOMMENDATIONS

Locoregional PMRT is recommended for women with an advanced primary tumour (tumour size 5 cm or greater, or tumour invasion of the skin, pectoral muscle or chest wall). Locoregional PMRT is recommended for women with 4 or more positive axillary lymph nodes. The role of PMRT in women with 1 to 3 positive axillary lymph nodes is unclear. These women should be offered the opportunity to participate in clinical trials of PMRT. Locoregional PMRT is generally not recommended for women who have tumours that are less than 5 cm in diameter and who have negative axillary nodes. Other patient, tumour and treatment characteristics, including age, histologic grade, lymphovascular invasion, hormone receptor status, number of axillary nodes removed, axillary extracapsular extension and surgical margin status, may affect locoregional control, but their use in specifying additional indications for PMRT is currently unclear. PMRT should encompass the chest wall and the supraclavicular, infraclavicular and axillary apical lymph node areas. To reduce the risk of lymphedema, radiation of the entire axilla should not be used routinely after complete axillary dissection of level I and II lymph nodes. A definite recommendation regarding the inclusion of the internal mammary lymph nodes in PMRT cannot be made because of limited and inconsistent data. The use of modern techniques in radiotherapy planning is recommended to minimize excessive normal tissue exposure, particularly to the cardiac and pulmonary structures. Common short-term side effects of PMRT, including fatigue and skin erythema, are generally tolerable and not dose-limiting. Severe long-term side effects, including lymphedema, cardiac and pulmonary toxicities, brachial plexopathy, rib fractures and secondary neoplasms, are relatively rare. The optimal sequencing of PMRT and systemic therapy is currently unclear. Regimens containing anthracyclines or taxanes should not be administered concurrently with radiotherapy because of the potential for increased toxicity.

VALIDATION

The authors' original text was submitted for review, revision and approval by the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer. Subsequently, feedback was provided by 11 oncologists from across Canada. The final document was approved by the steering committee.

SPONSOR

The Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer was convened by Health Canada. COMPLETION DATE: November 2003.

Radiotherapy to the conserved breast, chest wall, and regional nodes: is there a standard?

BACKGROUND

The role of radiotherapy in the treatment of breast cancer has changed considerable during the last two decades. It has now become the standard part of the breast-conserving procedure, as well as in patients who underwent mastectomy with T3+tumor and/or 4 or more positive lymphnodes in axilla.

METHODS

Improvements are seen in the postmastectomy radiotherapy area by delivering better treatment techniques herewith avoiding treatment of the heart and lungs in order to optimize the improvement of local control and the significant improvement in survival. Indications exist that the largest impact of postmastectomy radiotherapy on survival is mostly seen in patients with minimal tumorload, i.e. small tumors and/or 1 or 2 positive lymphnodes.

RESULTS

In several clinical trials, it was shown that the relapse rate in the ipsilateral breast is reduced with a HR of 4 if whole breast irradiation is given after tumorectomy. The update of the Oxford meta-analysis demonstrated that this improvement in local control has also led to an improved survival in these patients. More information is recently gained on the required radiation dose in breast-conserving therapy. Especially patients less than 50 years of age have to be treated with a high radiation dose, 50 + 16 Gy boost, while a dose of 50 Gy in 5 weeks seems sufficient for patients older than 50 years, who have a microscopically complete excision. Further optimization of the radiotherapy technique is found in imaged guided approaches and intensity modulated radiotherapy. Combining these efforts allows for a more precise delivery of the radiation dose to a limited volume, so that the side effects like fibrosis will be reduced.

CONCLUSIONS

Partial breast irradiation, instead of whole breast irradiation, is now being tested in a few randomized trials. Although this approach may be useful in certain patients groups, it still cannot be accepted as standard treatment, as no proper selection criteria exist and no long-term follow-up data have been presented.

Evidence-based indications for postmastectomy irradiation

The ASCO guidelines panel found that PMRT reduces the risks of both local-regional recurrence and distant recurrence, and improves survival rates for patients with invasive breast cancer with involved axillary lymph nodes receiving systemic therapy. The benefits of PMRT, however, vary with regards to particular patient subsets (such as those defined by the number of involved axillary nodes). The panel agreed that PMRT is indicated routinely for patients with four or more positive axillary nodes, tumors larger than 5 cm in size, or locally advanced cancers. There was insufficient evidence for the panel to make recommendations or suggestions for the use of PMRT for patients with T1-2 tumors with one to three positive axillary nodes or for all patients receiving neoadjuvant systemic therapy. Physicians and patients are encouraged to participate in randomized trials exploring such issues, such as the ongoing intergroup study for patients with one to three positive axillary nodes.

Accuracy of internal mammary lymph node localization using lymphoscintigraphy, sonography and CT

BACKGROUND AND PURPOSE

An accurate internal mammary (IM) lymph node localization technique is required for proper irradiation of the IM lymph nodes in breast cancer patients. In this study the measurement accuracy of three techniques for direct or indirect localization of the IM nodes was estimated.

MATERIALS AND METHODS

In 40 patients the IM lymph node depth and lateral distance from the patient midline were measured with lymphoscintigraphy in intercostal spaces 2, 3 and 4. The corresponding position of an IM vessel was measured with sonography and CT in intercostal spaces 1-4. The sonography and CT vessel measurements in the four intercostal spaces were compared to determine the measurement accuracy of sonography. The node and vessel data in intercostal space 2 were inserted into a mathematical model to determine the measurement accuracy of lymphoscintigraphy and CT for node detection.

RESULTS

Vessel depths measured by sonography were systematically too shallow and the lateral vessel position could not be accurately determined. The mathematical model showed that the node depth and lateralization in one intercostal space can be measured directly by lymphoscintigraphy within an accuracy (1 SD) of 5 mm in depth and 6 mm in the lateral direction. The accuracy of CT for indirect node detection was 6 mm in depth and 7 mm in the lateral direction.

CONCLUSIONS

Sonography is not a suitable technique for measuring the IM vessel or node position. Lymphoscintigraphy and CT have measurement accuracies for node detection that are acceptable for radiotherapy.

Lung cancer risks in women with previous breast cancer

Evaluation of the adverse effects of breast cancer treatment is becoming increasingly important in light of the earlier detection and prolonged survival of the patients. The beneficial effect of post-surgical radiotherapy has lately been challenged. The Swedish Cancer Registry (SCR) was used to identify approximately 141000 women with breast cancer, diagnosed between 1958 and 1997, followed-up for the occurrence of lung cancer. Standardised incidence ratios and expected number of lung cancers were calculated using incidence rates from the SCR. There were 613 subsequent lung cancers and a statistically significant increased risk of lung cancer was seen >5 years after breast cancer diagnosis, in contrast to a significantly decreased risk the first five years after the breast cancer diagnosis. The latter finding was confined to those >60 years of age when diagnosed with breast cancer. When restricting the analyses to those cases with information on the laterality of breast and lung cancer, an increased risk of a lung cancer on the same side as the breast cancer was seen >10 years after the breast cancer diagnosis. Birth cohorts with a higher smoking prevalence, i.e. 1930-1949, revealed a higher risk of lung cancer, than previous birth cohorts. Women with breast cancer have a significantly increased risk of developing a subsequent lung cancer possibly related to an interaction between radiotherapy and smoking.

Locoregional failure of postmastectomy patients with 1-3 positive axillary lymph nodes without adjuvant radiotherapy

PURPOSE

To analyze the incidence and risk factors for locoregional recurrence (LRR) in patients with breast cancer who had T1 or T2 primary tumor and 1-3 histologically involved axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy (RT).

MATERIALS AND METHODS

Between April 1991 and December 1998, 125 patients with invasive breast cancer were treated with modified radical mastectomy and were found to have 1-3 positive axillary nodes. The median number of nodes examined was 17 (range 7-33). Of the 125 patients, 110, who had no adjuvant RT and had a minimum follow-up of 25 months, were included in this study. Sixty-nine patients received adjuvant chemotherapy and 84 received adjuvant hormonal therapy with tamoxifen. Patient-related characteristics (age, menopausal status, medial/lateral quadrant of tumor location, T stage, tumor size, estrogen/progesterone receptor protein status, nuclear grade, extracapsular extension, lymphovascular invasion, and number of involved axillary nodes) and treatment-related factors (chemotherapy and hormonal therapy) were analyzed for their impact on LRR. The median follow-up was 54 months.

RESULTS

Of 110 patients without RT, 17 had LRR during follow-up. The 4-year LRR rate was 16.1% (95% confidence interval [CI] 9.1-23.1%). All but one LRR were isolated LRR without preceding or simultaneous distant metastasis. According to univariate analysis, age <40 years (p = 0.006), T2 classification (p = 0.04), tumor size >==3 cm (p = 0.002), negative estrogen receptor protein status (p = 0.02), presence of lymphovascular invasion (p = 0.02), and no tamoxifen therapy (p = 0.0006) were associated with a significantly higher rate of LRR. Tumor size (p = 0.006) was the only risk factor for LRR with statistical significance in the multivariate analysis. On the basis of the 4 patient-related factors (age <40 years, tumor >==3 cm, negative estrogen receptor protein, and lymphovascular invasion), the high-risk group (with 3 or 4 factors) had a 4-year LRR rate of 66.7% (95% CI 42.8-90.5%) compared with 7.8% (95% CI 2.2-13.3%) for the low-risk group (with 0-2 factors; p = 0.0001). For the 110 patients who received no adjuvant RT, LRR was associated with a 4-year distant metastasis rate of 49.0% (9 of 17, 95% CI 24.6-73.4%). For patients without LRR, it was 13.3% (15 of 93, 95% CI 6.3-20.3%; p = 0.0001). The 4-year survival rate for patients with and without LRR was 75.1% (95% CI 53.8-96.4%) and 88.7% (95% CI 82.1-95.4%; p = 0.049), respectively. LRR was independently associated with a higher risk of distant metastasis and worse survival in multivariate analysis.

CONCLUSION

LRR after mastectomy is not only a substantial clinical problem, but has a significant impact on the outcome of patients with T1 or T2 primary tumor and 1-3 positive axillary nodes. Patients with risk factors for LRR may need adjuvant RT. Randomized trials are warranted to determine the potential benefit of postmastectomy RT on the survival of patients with a T1 or T2 primary tumor and 1-3 positive nodes.

Radiotherapy for early breast cancer

BACKGROUND

The long-term effects of radiotherapy on mortality from breast cancer and other causes remain uncertain.

OBJECTIVES

In this report the Early Breast Cancer Trialists' Collaborative Group present their systematic overview of treatment with radiotherapy.

SEARCH STRATEGY

Trial identification procedures for the EBCTCG overviews have been described elsewhere. See under "EBCTCG" in the Breast Cancer Group module.

SELECTION CRITERIA

A meta-analysis was done of 10-year and 20-year results from 40 unconfounded randomised trials of radiotherapy for early breast cancer. Radiotherapy fields generally included not only chest wall (or breast) but also axillary, supraclavicular, and internal mammary nodes.

DATA COLLECTION AND ANALYSIS

Data collection involved central review of individual patient data on recurrence and cause-specific mortality from 20,000 women.

MAIN RESULTS

A reduction of approximately two-thirds in local recurrence was seen in all trials, largely independent of the type of patient or type of radiotherapy (8.8% vs 27.2% local recurrence by year 10). Hence, to assess effects on breast cancer mortality of substantially better local control, results from all trials were combined. Breast cancer mortality was reduced (2p=0.0001) but other, particularly vascular, mortality was increased (2p=0.0003), and overall 20-year survival was 37.1% with radiotherapy versus 35.9% control (2p=0.06). There was little effect on early deaths, but logrank analyses of later deaths indicate that, on average after year 2, radiotherapy reduced annual mortality rates from breast cancer by 13.2% (SE 2.5) but increased those from other causes by 21.2% (SE 5.4). Nodal status, age, and decade of follow-up strongly affected the ratio of breast cancer mortality to other mortality, and hence affected the ratio of absolute benefit to absolute hazard from these proportional changes in mortality.

REVIEWER'S CONCLUSIONS

Radiotherapy regimens able to produce the two-thirds reduction in local recurrence seen in these trials, but without long-term hazard, would be expected to produce an absolute increase in 20-year survival of about 2-4% (except for women at particularly low risk of local recurrence). The average hazard seen in these trials would, however, reduce this 20-year survival benefit in young women and reverse it in older women.

Evaluation of level I and II axillary nodes included in the standard breast tangential fields and calculation of the administered dose: results of a prospective study

PURPOSE

To evaluate if Level I and II axillary nodes are included in the standard breast tangential fields, and to calculate the dose administered.

METHODS AND MATERIALS

In 35 patients treated with conservative surgery and axillary dissection, three clips were surgically positioned: one at the beginning of Level I, one between Level I and II, and another at the end of Level II. The breast was irradiated with two tangential fields. On simulation films, the volume between the clips was scored as "entirely included" or "not entirely included" in the treatment fields. Computed tomography (CT) scans were performed; CT data were imported into a treatment planning system, and three-dimensional plans were devised. Axillary Levels I and II were delineated on CT slices on the basis of anatomic landmarks. Fields and isodose curves previously obtained were superimposed to calculate the dose administered to the first two axillary node levels and to 90% of both volumes.

RESULTS

On X-rays, the volume between clips corresponding to Level I was completely included in the medial field in 66.7% of cases and in the lateral field in 63.7% of cases, whereas the volume of Level II was entirely included in the medial field in 54.5% of cases and in the lateral field in 45.4% of cases. The median dose administered to Level I and II was 38.58 Gy +/- 11.01 (range 3.46-47.14) and 20.65 Gy +/- 14.07 (range 0.95-38.94), respectively. The median dose to 90% of both volumes of Level I and II was 6.75 Gy +/- 14.01 (range 1.9-39) and 1.75 Gy +/- 9.72 (range 0.8-29), respectively.

CONCLUSION

The standard tangential fields do not entirely include Levels I and II axillary nodes.

Postmastectomy radiotherapy: clinical practice guidelines of the American Society of Clinical Oncology

OBJECTIVE

To determine indications for the use of postmastectomy radiotherapy (PMRT) for patients with invasive breast cancer with involved axillary lymph nodes or locally advanced disease who receive systemic therapy. These guidelines are intended for use in the care of patients outside of clinical trials.

POTENTIAL INTERVENTION

The benefits and risks of PMRT in such patients, as well as subgroups of these patients, were considered. The details of the PMRT technique were also evaluated.

OUTCOMES

The outcomes considered included freedom from local-regional recurrence, survival (disease-free and overall), and long-term toxicity.

EVIDENCE

An expert multidisciplinary panel reviewed pertinent information from the published literature through July 2000; certain investigators were contacted for more recent and, in some cases, unpublished information. A computerized search was performed of MEDLINE data; directed searches based on the bibliographies of primary articles were also performed.

VALUES

Levels of evidence and guideline grades were assigned by the Panel using standard criteria. A "recommendation" was made when level I or II evidence was available and there was consensus as to its meaning. A "suggestion" was made based on level III, IV, or V evidence and there was consensus as to its meaning. Areas of clinical importance were pointed out where guidelines could not be formulated due to insufficient evidence or lack of consensus.

RECOMMENDATIONS

The recommendations, suggestions, and expert opinions of the Panel are described in this article.

VALIDATION

Seven outside reviewers, the American Society of Clinical Oncology (ASCO) Health Services Research Committee members, and the ASCO Board of Directors reviewed this document.

Deep inspiration breath hold to reduce irradiated heart volume in breast cancer patients

PURPOSE

To evaluate the use of deep inspiration breath hold (DIBH) during tangential breast radiation therapy as a means of reducing irradiated cardiac volume.

METHODS AND MATERIALS

The Active Breathing Control (ABC) device designed at William Beaumont Hospital, Michigan was used to quantify the potential benefit of radiation delivery during DIBH for five left-sided breast cancer patients. This device initiates a breath hold at a predefined, reproducible lung volume. For each patient, two CT scans were acquired with and without breath hold, and virtual simulation was performed for regular tangent and wide-tangent techniques. The resulting dose-volume histograms were calculated, and the volume of heart irradiated to 25 Gy or more was assessed.

RESULTS

The influence of ABC on irradiated heart volumes varied considerably among the five patients. Three patients with substantial cardiac volume in the treatment field during normal respiration showed a significant dose-volume histogram reduction when deep inspiration was applied, with decreases in the heart volume receiving 25 Gy of more than 40 cc observed. For one patient, deep inspiration reduced irradiated cardiac volumes only with the wide-tangent technique, while one patient showed no substantial irradiated volume decrease.

CONCLUSION

A DIBH technique during tangential breast irradiation has the potential to significantly decrease irradiated cardiac volume for suitably selected patients. The magnitude of the impact of the breath hold application depends on patient anatomy, lung capacity, and pulmonary function.

The influence of patient geometry on the selection of chest wall irradiation techniques in post-mastectomy breast cancer patients

BACKGROUND AND PURPOSE

To evaluate three chest wall (CW) irradiation techniques: wide tangential photon beams, direct appositional electron field and electron arc therapy with regards to target coverage and normal tissue tolerance.

MATERIALS AND METHODS

Thirty-two post-mastectomy breast cancer patients were planned using three CW irradiation techniques. Computed tomography (CT) simulation was done on all patients and clinical target, heart and lung volumes were contoured. For each technique, dose distributions and dose-volume histograms (DVH) were calculated. Pass/fail criteria were applied based on volumetric target and critical structure dose coverage. Passing criteria for target was 95% of target receiving 95% of dose using a standard dose of 50 Gy/25 fractions, for heart </=10% volume receiving 50% dose (i.e. 25 Gy) and for lung </=25% volume ipsilateral lung receiving 50% dose (i.e. 25 Gy).

RESULTS

The number of patients optimally treated by each technique were as follows: wide tangential photon beams 23/32 (72%), direct appositional electron field 1/32 (3%), electron arc 4/32 (12.5%) and in 4/32 (12.5%) no technique was optimal. Geometric predictors for technique suitability include CW thickness, medial to lateral CW curvature, uniformity of superior to inferior CW curvature and length of mastectomy scar.

CONCLUSIONS

This study confirms the utility of CT planning and DVH analysis for treatment planning of breast cancer. Patient factors that predict for treatment technique suitability and aid in technique selection can be identified. In a small subset of patients, none of the currently studied techniques were optimal and more novel methods of chest wall irradiation are required.