Outcomes of clinically node-negative breast cancer without axillary dissection: can preserved axilla be safely treated with radiation after a positive sentinel node biopsy?

PURPOSE: We analyzed whether axillary nodal irradiation could control clinically node-negative disease, including those patients with a positive sentinel lymph node biopsy (SLNB), most of whom received regional nodal irradiation. We also evaluated toxicity profiles that resulted from nodal irradiation. PATIENTS AND METHODS: From 1988 to 2011, 2107 patients with cT1-T2N0M0 breast cancer underwent breast conservation therapy in the absence of axillary dissection: nx group (n = 1548), without any axillary surgery; the sn(-) group (n = 518), with a negative SLNB; and sn(+) group (n = 104), with a positive SLNB. RESULTS: The median follow-up times were 88, 56, and 55 months for the nx, sn(-), and sn(+) groups, respectively. The nx group had more risk factors than did the other 2 groups in terms of age, grade, or T stage. Ninety-eight percent of the sn(-)group received only tangent irradiation, and 100% and 83% of the sn(+) and nx group, respectively, received additional regional nodal irradiation. The 5-year cumulative incidences of axillary failure and regional nodal failure were 34, 3, and 0 (2.7%, 0.7%, and 0%; P = .02, log-rank test) and 57, 4, and 0 (4.4, 1%, and 0; P = .04), respectively. Overall survival rates in 5 years were 96.4%, 98.9%, and 97.6% (P = .03), respectively. Symptomatic but transient radiation pneumonitis developed in 31, 16, and 6 (2.0%, 3.1%, and 5.7%). Mild arm edema was observed in 1, 4, and 0 (0.06%, 0.8%, and 0%) in the nx, sn(-), sn(+) groups, respectively. CONCLUSIONS: Treatment without axillary dissection showed excellent outcomes with negligible toxicity for patients with clinically node negative, including those with a positive SLNB. Regional nodal irradiation after a positive SLNB is a reasonable alternative to axillary dissection.

Axillary Irradiation with High Tangent Fields for Clinically Node-Negative Breast Cancer: Can 3-D Conformal Radiotherapy with a Field-in-Field Technique Better Control the Axilla?

BACKGROUND: The target volume for postoperative breast irradiation is the remaining breast tissue, and the axillary region is not an intentional target volume. PATIENTS AND METHODS: Between 2001 and 2009, eligible women with pT1-2cN0/pN0(sn) breast cancer underwent breast-conserving therapy without axillary dissection. Treatment outcomes between 2 radiotherapy planning groups, high tangent fields with 2-dimensional (2-D) simulation-based planning and 3-dimensional (3-D) computed tomography-based planning with a field-in-field technique, were compared. The correlating factors for axillary failure were also calculated. RESULTS: In total, 678 patients were eligible. As of May 2009, the median follow-up times for the 2-D (n = 346) and 3-D (n = 332) groups were 94 and 52 months, respectively. Patient characteristics were balanced, except for a younger population in the 2-D group and more lymphovascular invasion in the 3-D group. On multivariate analysis, 2-D planning was the only risk factor for axillary failure. In the 2-D and 3-D groups, the 5-year cumulative incidences of axillary failure were 8 (3.1%) and 1 (0.3%) (log-rank p = 0.009), respectively. The respective 5-year overall survival rates were 97.4 and 98.4% (p = 0.4). CONCLUSION: High tangent irradiation with 3-D planning improved axillary control compared to that with 2-D planning, suggesting that optimizing axillary dose distribution may impact outcomes.

Dose distribution analysis of axillary lymph nodes for three-dimensional conformal radiotherapy with a field-in-field technique for breast cancer.

PURPOSE: We previously reported that most of axillary regions could be irradiated by the modified tangential irradiation technique (MTIT). The purpose of this study was to determine whether the three-dimensional conformal radiotherapy (3D-CRT) with a field-in-field technique improves dosimetry for the breast and axillary nodes. METHODS AND MATERIALS: Fifty patients with left-sided breast cancer were enrolled. With MTIT, we planned the radiation field to be wider in the cranial direction than the standard tangential fields to include the axillary regions. With 3D-CRT, a field-in-field technique was used to spare the heart and contralateral breast to the extent possible by applying the multileaf collimator manually. Dose-volume histograms were compared for the breast, axillary region, heart, lung, and other normal tissues. RESULTS: There were no significant differences in the percent volume of the breast receiving >90% of the prescribed dose (V90) between MTIT and 3D-CRT. The mean V90 of the level I to III axillary regions were increased from 93.7%, 48.2%, and 41.3% with MTIT to 97.6%, 85.8%, and 82.8% with 3D-CRT. 3D-CRT significantly reduced the volume of the heart receiving >30 Gy (mean, 7.6 vs. 15.9 mL), the percent volume of the bilateral lung receiving >20 Gy (7.4% vs. 8.9%), and the volume of other normal tissues receiving >107% of the prescribed dose (0.1 vs. 2.9 mL). CONCLUSION: The use of 3D-CRT with a field-in-field technique improves axillary node coverage, while decreasing doses to the heart, lungs, and the other normal tissues, compared with MTIT.

Pattern of tumor recurrence in initially nonmetastatic breast cancer patients: distribution and frequency of metastases at unusual sites.

BACKGROUND: Breast cancer is likely to have systemic involvement. However, to the authors' knowledge there are few reports to date regarding clinically detected patterns of metastasis, meticulously studied in regard to the natural history of breast cancer, including unusual sites of metastasis. METHODS: Patients treated for invasive breast cancer from April 1983 to May 2007 were retrospectively analyzed. Patterns of clinically apparent tumor recurrence, focusing especially on unusual metastases, were studied as well as possible risk factors for unusual metastases and their influence on survival. RESULTS: Overall, 3783 patients were eligible for the current analysis. The median duration of follow-up was 5.0 years (range, 0.6 years-20.4 years). Cumulative 5-year and 10-year survival rates were 89.7% and 81.5%, respectively. "Unusual metastasis" was defined as systemic failure with a frequency of < or =1%; in the current series; it was observed in 85 (2.2%) patients %. Of those, 70 (82%) had preceding metastasis in the usual sites. The median duration until the development of usual and unusual metastasis was 2.3 years and 3.6 years, respectively (P < .0001). Among 764 patients with distant metastasis, the 5-year cumulative overall survival rate in those with or without unusual metastasis was 53.5% and 53.4 years, respectively (P = .33). No risk factors for unusual metastasis were identified. CONCLUSIONS: This retrospective study examined the frequency of unusual metastases in a large number of Japanese patients with initially nonmetastatic breast cancer. The prognosis of patients with unusual metastases was found to be similar to that of patients with metastasis only at more usual sites.

Treatment of breast carcinoma in patients with clinically negative axillary lymph nodes using radiotherapy versus axillary dissection.

BACKGROUND: The role of axillary lymph node dissection (AxD) for patients with breast carcinoma who have clinically negative lymph nodes (cN0) and undergo breast-conserving therapy has been controversial. If patients do not undergo AxD, then it is uncertain whether specific lymph node irradiation should be given. The authors compared the results obtained from patients w ho underwent AxD with the results from patients who received axillary irradiation (AxR) using one of two radiotherapy techniques. METHODS: Patients with T1-T2cN0 breast carcinoma were treated from 1983 to 2002 with either AxD (80 patients) or AxR (1134 patients received tangential-field [2-field] irradiation, and 303 patients received 3-field irradiation). The median follow-up was 161 months for the AxD group and 66 months for the AxR group (55 months for patients who received tangential-field irradiation, and 122 months for patients who received 3-field irradiation). RESULTS: One patient in the AxD group and 35 patients in the AxR group had axillary recurrences. The 10-year cumulative axillary recurrence rates were 1.3% and 4.6% for the AxD group and the AxR group, respectively (P = 0.21). For patients with T1 tumors, the 10-year overall survival rates for the two groups were 94.7% and 92.7%, respectively (P = 0.34); and, for patients with T2 tumors, the 10-year overall survival rates were 92.5% and 89.1%, respectively (P = 0.34). In the AxR group, the 5-year axillary recurrence rates were 2.5% for patients who received tangential-field irradiation and 1.7% for patients who received 3-field irradiation (P = 0.18), and the 5-year regional recurrence rates for the two groups were 4.8% and 2.4%, respectively (P = 0.048). On multivariate analysis, positive lymphovascular invasion, outer tumor location, and larger tumor size were significant risk factors for regional failure. CONCLUSIONS: For patients with cN0 breast carcinoma, AxD and AxR yielded the same overall survival rates. Most patients can be treated safely with tangential-field irradiation alone. Patients who are at increased risk of regional failure may benefit from three-field irradiation.