Postmastectomy radiation in patients with one to three positive axillary nodes receiving adjuvant chemotherapy: An unresolved issue

Dosimetric evaluation of left ventricle and left anterior descending artery in left breast radiotherapy

INTRODUCTION

We evaluated the dosimetric results of the identification of the left ventricle (LV) and left anterior descending artery (LAD) as organs at risk (OARs) in adjuvant radiotherapy (RT) after breast-conserving surgery (BCS).

MATERIALS AND METHODS

Twenty-two patients who had previously received RT in our center were evaluated retrospectively. All patients had undergone BCS operation for left breast cancer. LV and LAD were contoured as OARs on the same simulation CTs for these patients whose treatment was previously completed in which LV and LAD were not defined as OARs. Complying with the initial plans, intensity-modulated RT plans with 7-9 fields were made on the computer. Planning target volume (PTV), homogeneity index (HI), conformity index (CI), monitor unit (MU) values, and doses of OARs were compared using the Wilcoxon signed-rank test (p < 0.05).

RESULTS

There were no significant differences in PTV 50 (D 50% and D 98%), PTV 60 (D 2% and D 50%), HI, CI, and MU values when treatment plans and control plans were compared (p > 0.05). While it was possible to protect the heart, LAD, and LV better, LAD and LV were not contoured in the treatment plans, and they received higher doses compared to the control plans (p < 0.05). There was no significant difference in the other OARs.

CONCLUSION

In conclusion, it is essential to define the lower anatomical regions of the heart as OARs. Otherwise, the doses taken by these regions are ignored and may be maintained less than possible. In our study, it was shown that LV and LAD doses were significantly reduced even in the same center and planning by the same team.

Which patients might benefit from postmastectomy radiotherapy in breast cancer patients with t1-2 tumor and 1-3 axillary lymph nodes metastasis?

Purpose

This study compared the clinical outcomes of T1-2N1 breast cancer patients with and without postmastectomy radiotherapy (PMRT). Risk factors for loco-regional recurrence (LRR) were identified in order to define a subgroup of patients who might benefit from PMRT.

Materials and Methods

Of 110 T1-2N1 breast cancer patients who underwent mastectomy from January 1994 through December 2009, 32 patients underwent PMRT and 78 patients did not. Treatment outcomes and risk factors for LRR were analyzed.

Results

The 5- and 10-year LRR rates were both 6.2% in the PMRT group, and 10.4% and 14.6% in the no-PMRT group (p=0.336). In addition, no significant differences in distant metastasis-free survival (DMFS) or overall survival (OS) were observed between patients receiving and not receiving PMRT. In multivariate analysis, factors associated with higher LRR rates included grade 3 disease, extracapsular extension (ECE), and triple negative subtype. Patients who had one or more risk factors for LRR were defined as a high-risk patient group. In the high-risk group, both 5- and 10-year LRR rates for patients who underwent PMRT was 18.2%, and LRR rates of 21.4% at five years and 36.6% at 10 years were observed for patients who did not undergo PMRT (p=0.069).

Conclusion

PMRT in T1-2N1 breast cancer patients should be considered according to several prognostic factors in addition to T and N stage. Findings of our study indicated that PMRT did not improve LRR, DMFS, or OS in T1-2N1 breast cancer patients. However, in a subgroup of patients with grade 3 disease, ECE, or triple negative subtype, PMRT might be beneficial.

Comparison of clinical outcome of breast cancer patients with T1-2 tumor and one to three positive nodes with or without postmastectomy radiation therapy

OBJECTIVE

The value of postmastectomy radiation therapy for breast cancer patients with T1-2 tumor and one to three positive nodes remains controversial. The purpose of this retrospective study was to compare the clinical outcomes of breast cancer patients with T1-2 and one to three positive nodes with and without postmastectomy radiation therapy.

METHODS

Between May 1990 and June 2008, of 318 breast cancer patients with T1-2 and one to three positive nodes who had undergone modified radical mastectomy, 163 received postmastectomy radiation therapy and 155 did not. The clinico-pathologic characteristics were analyzed for clinical outcomes including loco-regional recurrence, distant metastasis, disease-free survival and overall survival.

RESULTS

During the median follow-up period of 102 months, the clinical outcomes in postmastectomy radiation therapy versus no-postmastectomy radiation therapy groups were as follows: loco-regional recurrence rate (3.1 versus 11.0%, P= 0.006); distant metastasis rate (20.9 versus 27.7%, P= 0.152); 10-year disease-free survival rate (73.8 versus 61.3%, P= 0.001); and 10-year overall survival rate (82.1 versus 76.1%, P= 0.239). Through a multivariate analysis, a positive nodal ratio of ≥25% (hazard ratio= 4.571, P= 0.003) and positive lymphovascular invasion (hazard ratio= 2.738, P= 0.028) were found to be independent poor prognostic predictors of loco-regional recurrence. The reduction in loco-regional recurrence (hazard ratio= 0.208, P= 0.004) by postmastectomy radiation therapy was found to be significant.

CONCLUSIONS

On the basis of our results, postmastectomy radiation therapy is highly recommended for breast cancer patients with T1-2 and one to three positive nodes, especially for high-risk subgroups with a positive nodal ratio of ≥25% and positive lymphovascular invasion, not only for reducing loco-regional recurrence but also for improving disease-free survival.

The prognostic value of the nodal ratio in N1 breast cancer

BACKGROUND

Although the nodal ratio (NR) has been recognized as a prognostic factor in breast cancer, its clinical implication in patients with 1-3 positive nodes (N1) remains unclear. Here, we evaluated the prognostic value of the NR and identified other clinico-pathologic variables associated with poor prognosis in these patients.

METHODS

We analyzed 130 patients with N1 invasive breast cancer who were treated at Seoul National University Bundang Hospital from March 2003 to December 2007. Disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) were compared according to the NR with a cut-off value of 0.15.

RESULTS

We followed patients' recovery for a median duration of 59 months. An NR > 0.15 was found in 23.1% of patients, and a median of 18 nodes were dissected per patient (range 1-59). The NR was statistically independent from other prognostic variables, such as patient age, T stage, extent of surgery, pathologic factors in the chi square test. On univariate analysis, patients with a NR > 0.15 had significantly lower 5-year LRRFS (88.7% vs. 97.9%, p = 0.033) and 5-year DMFS (81.3% vs. 96.4%, p = 0.029) and marginally lower 5-year DFS (81.3% vs. 94.0%, p = 0.069) than those with a NR ≤0.15, respectively. Since the predictive power of the NR was found to differ with diverse clinical and pathologic variables, we performed adjusted analysis stratified by age, pathologic characteristics, and adjuvant treatments. Only young patients with a NR > 0.15 showed significantly lower DFS (p = 0.027) as well as those presenting an unfavorable pathologic profile such as advanced T stage (p = 0.034), histologic grade 3 (p = 0.034), positive lymphovascular invasion (p = 0.037), involved resection margin (p = 0.007), and no chemotherapy (p = 0.014) or regional radiotherapy treatment (p = 0.039). On multivariate analysis, a NR > 0.15 was significantly associated with lower DFS (p = 0.043) and DMFS (p = 0.012), but not LRRFS (p = 0.064).

CONCLUSIONS

A NR > 0.15 was associated with an increased risk of recurrence, especially in young patients with unfavorable pathologic profiles.

Percent positive axillary lymph node metastasis predicts survival in patients with non-metastatic breast cancer

PURPOSE

We retrospectively evaluated the impact of percent positive axillary nodal involvement on the therapeutic outcomes in patients with non-metastatic breast cancer receiving postmastectomy radiotherapy and chemotherapy.

MATERIALS AND METHODS

Between January 1994 and December 2002, the medical records of 939 eligible non metastatic breast carcinoma patients were analyzed. Chest wall radiotherapy was indicated in case of positive surgical margin, tumor size equal or more than 4 cm, skin-fascia invasion. Lymphatic irradiation was applied for more than three metastatic axillary lymph nodes, incomplete axillary dissection (<10 lymph nodes), extracapsular extension or perinodal fat tissue invasion. A total dose of 50 Gy was given to chest wall and lymph node regions with 2 Gy daily fractions. Statistical analyses were performed by Kaplan-Meier method, Log-rank test and Cox's regression analysis.

RESULTS

The median follow-up for all patients alive was 62 months. The 5-year overall survival (OS) and disease-free survival (DFS) for entire cohort were 81%, and 65%, respectively. Univariate analysis for OS revealed significance for tumour size (< or =5 cm vs. >5 cm, p<0.001), metastatic nodal involvement (0 vs. 1-3 vs. >4 LN, p<0.001), percent positive nodal involvement ([metastatic nodes/total nodes removed] x 100; 0 vs. < or =25% vs. 26-50% vs. >50%, p<0.001), surgical margin status (negative vs. positive, p=0.05), and hormonal treatment (present vs. absent, p=0.03). DFS had similarly significance for age (< or =40 years vs. >40 years, p=0.006), tumour size (0.02), metastatic nodal involvement (p<0.001), percent positive nodal involvement (p<0.001), and perinodal invasion (present vs. absent, p=0.01). Multivariate analysis revealed significance for tumour size, percent positive nodal involvement, hormonal treatment, and surgical margin status for OS. Age and percent positive nodal involvement were found to be significant for DFS.

CONCLUSION

Percent positive nodal involvement was found to be a significant prognostic factor for survival in all end-points.

Nodal Ratios in Node-Positive Breast Cancer—Long-Term Study to Clarify Discrepancy of Role of Supraclavicular and Axillary Regional Radiotherapy

PURPOSE

To study the absolute number of involved nodes/the number of nodes examined or the nodal ratio (NR) in breast cancer. The primary study endpoint was to evaluate the role of supraclavicular and axillary radiotherapy (SART) according to the NR.

METHODS AND MATERIALS

From the Saskatchewan provincial registry of 1981-1995, the charts of 5,996 consecutive patients were retrieved to collect detailed prognostic factors. Among these patients, 1,985 were node positive. Because the NRs are more reliable the greater the number of nodes examined, we analyzed 1,255 patients with > or =10 nodes examined. Of these 1,255 patients, 667, 389, and 199 were categorized into three NR groups--low (< or =25%), medium (>25% to < or =75%), and high (>75%) nodal involvement, respectively.

RESULTS

The NR correlated significantly with the primary tumor size (< or =2 cm, >2 to < or =5 cm, and >5 cm; p = 2.2 x 10(-16)), clinical stage group (p = 5.5 x 10(-16)), pathologic stage group (p < 2.2 x 10(-16)), and the risk of any first recurrence (p = 5.0 x 10(-15)) using chi-square tests. For a low NR, the 10-year overall survival rate with and without SART was 57% and 58% (p = 0.18), and the cause-specific survival rate was 68% and 71% (p = 0.32), respectively. For a medium NR, the 10-year overall survival rate with and without SART was 48% and 34% (p = 0.007), and the cause-specific survival rate was 57% and 43% (p = 0.002), respectively. For a high NR, the 10-year overall survival rate with and without SART was 19% and 10% (p = 0.005), and the cause-specific survival rate was 26% and 14% (p = 0.005), respectively.

CONCLUSION

This is the first study demonstrating that for patients with > or =10 nodes examined, SART significantly improved the survival for the median and high NR groups but not for the low NR group.

The impact of the number of excised axillary nodes and of the percentage of involved nodes on regional nodal failure in patients treated by breast-conserving surgery with or without regional irradiation

PURPOSE

After breast-conserving surgery, recommendations for regional nodal radiotherapy are usually based on the number of positive nodes. This number is dependent on the number of nodes removed during the axillary dissection. This study examines whether the percentage of positive nodes may help to select patients for regional radiotherapy.

METHODS AND MATERIALS

A retrospective study was conducted on 1,372 T1-T2 node-positive breast cancer patients treated at L'Hôtel-Dieu de Québec Hospital between 1972 and 1997.

RESULTS

Among the patients who did not receive regional radiotherapy, the percentage of involved nodes was significantly associated with axillary failure. Ten-year axillary control rates were 97% and 91% when the percentage of involved nodes was <50% and > or =50%, respectively (p = 0.007). In addition, regional radiotherapy is always significantly associated with a decrease in overall regional failure (axillary and/or supraclavicular), regardless of the percentage of involved nodes. However, regional radiotherapy reduced the axillary failure rate (2% vs. 9%, p = 0.007) only when more than a specific percentage of nodes was involved (> or =40% if N1-3 and > or =50% if N>3 nodes).

CONCLUSIONS

The percentage of involved nodes should be taken into consideration in selecting patients for regional radiotherapy. Irradiation of the axilla should be reserved for patients with a specific ratio: >40% involved nodes if N1-3 and > or =50% involved nodes if N>3 nodes.

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.

Impact of locoregional radiotherapy in node-positive patients treated by breast-conservative treatment

PURPOSE

The aim of this study is to evaluate the impact of locoregional radiation in node-positive patients treated by tumorectomy and radiation therapy.

METHODS

A retrospective study including all our 1368 T1-2 node-positive patients was conducted. Conservative surgery was followed by breast irradiation. Axillary and supraclavicular irradiation was left to the discretion of the treating radiation oncologist.

RESULTS

In the group receiving locoregional radiation (472 patients), the 10-year regional control was 97% vs. 91% for the group receiving radiation to the breast only (896 patients) (p = 0.004). In a Cox model analysis, locoregional radiation is associated with a better regional control rate (hazard ratio: 0.27; 95% confidence interval: 0.13-0.54, p = 0.0001). Locoregional radiotherapy is associated with a better rate of locoregional control (hazard ratio: 0.56; 95% confidence interval: 0.38-0.8, p = 0.002). In particular, for the N>3 group, the substantial 10-year locoregional failure rate (26% with breast irradiation only) is cut by 50%. Locoregional radiotherapy, however, is not associated with a lower rate of distant metastases.

CONCLUSION

Locoregional radiation decreases the rate of locoregional failure by nearly 50%. Locoregional radiotherapy should be considered for node-positive patients, especially if they have more than 3 positive nodes.

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.

Accuracy of the extent of axillary nodal positivity related to primary tumor size, number of involved nodes, and number of nodes examined

PURPOSE

While a number of studies have evaluated the minimum number of axillary nodes that need to be examined to accurately determine nodal positivity or negativity, there is little information on the number of nodes which must be examined to determine the extent of nodal positivity. This study attempts to determine for patients with 1-3 positive nodes the probability that the number of positive nodes reported is the true number of positive nodes as well as the probability that 4 or more nodes could be positive based on primary tumor size and number of nodes examined.

MATERIALS AND METHODS

From 1979 to 1998, 1652 women with Stages I-II invasive breast cancer underwent an axillary dissection as part of their breast conservation therapy and had more than 10 lymph nodes examined. The mean and median number of nodes identified in the dissection was 19 and 17 (range, 11-75). The median age was 55 years. A total of 1155 women had T1 tumors and 497 had T2 tumors. Of the 459 node-positive women, 72% had 1-3 positive nodes, 18% had 4-9 positive nodes, and 10% had 10 or more positive nodes. A mathematical model based on tumor size and number of nodes examined was created using the hypergeometric distribution and Bayes Theorem. The resulting model was used to estimate the accuracy of the reported number of positive nodes and the probability of 4 or more positive nodes based on various observed sampling combinations.

RESULTS

For patients with T1 tumors and 1, 2, or 3 positive nodes, the minimum number of nodes examined needed for a 90% probability of accuracy is 19, 20, and 20. For T2 tumors and 1, 2, or 3 positive nodes, a minimum of 20 nodes is required. The probability of 4 or more positive nodes increases as tumor size and the number of reported positive nodes increase and as the number of examined nodes decreases. For a 10% or less probability of 4 or more positive nodes, a patient with a T1 tumor and 1, 2, or 3 observed positive nodes would require a minimum of 8, 15, and 20 nodes removed. For a T2 tumor and 1, 2, or 3 observed positive nodes, the corresponding numbers are 10, 16, and 20.

CONCLUSION

The accuracy of the extent of axillary nodal positivity is influenced by the number of observed positive nodes, tumor size, and the number of nodes examined. Underestimation of the number of positive nodes will result in errors in the assessment of an individual's risk for locoregional recurrence, distant disease, and breast cancer death and will adversely impact on treatment recommendations. This model provides the clinician with a means for assessing the accuracy of the number of positive nodes reported in patients with 1-3 positive nodes.