Does internal mammary node irradiation affect treatment outcome in clinical stage II–III breast cancer patients receiving neoadjuv ant chemotherapy?
- 515 Downloads
The purpose of this study is to assess the value of internal mammary node irradiation (IMNI) in patients receiving postoperative radiotherapy after neoadjuvant chemotherapy (NAC) using modern systemic therapy. Between 2001 and 2009, 521 consecutive patients with clinical stage II–III breast cancer received NAC and postoperative radiotherapy. With a consistent policy, the treating radiation oncologist either included (N = 284) or excluded (N = 237) the internal mammary node in the treatment volume. Anthracycline- and taxane-based chemotherapy was provided to 482 (92.5 %) patients. To account for the unbalanced characteristics between the two groups, we performed propensity score matching and covariate adjustment using the propensity score. The median follow-up duration was 71 months (range 31–153 months). The 5-year disease-free survival (DFS) with and without IMNI was 81.8 and 72.7 %, respectively (p = 0.019). The benefit of IMNI varied according to patient characteristics such that it was more apparent in patients with N1–2 disease, inner/central location, and triple-negative subtype. After adjusting for all potential confounding variables, IMNI was independently associated with improved DFS (p = 0.049). The significant effect of IMNI on DFS was sustained after propensity score matching (p = 0.040) and covariate adjustment using the propensity score (p = 0.048). Symptomatic radiation pneumonitis developed in 9 (3.2 %) patients receiving IMNI. Our results indicated that IMNI was associated with a significant improvement in DFS with low toxicity rate for breast cancer patients receiving NAC. Further prospective studies are warranted to confirm the effect of IMNI in the NAC setting.
KeywordsInternal mammary node irradiation Neoadjuvant chemotherapy Breast cancer
This work was supported by a Grant from the National R&D Program for Cancer Control, Ministry for Health, Welfare, and Family Affairs, Republic of Korea (0820010).
Compliance with ethical standards
Conflict of interest statement
The authors declare that they have no conflict of interest.
Human and animal rights
This article does not contain any studies with human participants or animals performed by any of the authors.
For this type of study, formal consent is not required.
- 1.Danish Breast Cancer Cooperative Group, Nielsen HM, Overgaard M et al (2006) Study of failure pattern among high-risk breast cancer patients with or without postmastectomy radiotherapy in addition to adjuvant systemic therapy: long-term results from the Danish Breast Cancer Cooperative Group DBCG 82 b and c randomized studies. J Clin Oncol 24(15):2268–2275. doi: 10.1200/JCO.2005.02.8738 CrossRefGoogle Scholar
- 2.McGale P, Taylor C et al (2014) Effect of radiotherapy after mastectomy and axillary surgery on 10-year recurrence and 20-year breast cancer mortality: meta-analysis of individual patient data for 8135 women in 22 randomised trials. Lancet 383(9935):2127–2135. doi: 10.1016/S0140-6736(14)60488-8 CrossRefPubMedGoogle Scholar
- 3.Whelan T, Olivotto I, Ackerman I et al (2011) (suppl; abstr LBA1003)) NCIC-CTG MA. 20: an intergroup trial of regional nodal irradiation in early breast cancer. J Clin Oncol 29:80sGoogle Scholar
- 4.Poortmans P, Struikmans H, Kirkove C et al (2013) Irradiation of the internal mammary and medial supraclavicular (IM-MS) lymph node chain irradiation in stage I-III breast cancer: 10 year results of the EORTC Radiation Oncology and Breast Cancer Groups phase III trial 22922/10925. In Presented at the European cancer congress, Amsterdam, Accessed Sep 27–Oct 1 2013Google Scholar
- 5.Stemmer SM, Rizel S, Hardan I et al (2003) The role of irradiation of the internal mammary lymph nodes in high-risk stage II to IIIA breast cancer patients after high-dose chemotherapy: a prospective sequential nonrandomized study. J Clin Oncol 21(14):2713–2718. doi: 10.1200/JCO.2003.09.096 CrossRefPubMedGoogle Scholar
- 6.Chang JS, Park W, Kim YB et al (2013) Long-term survival outcomes following internal mammary node irradiation in stage II-III breast cancer: results of a large retrospective study with 12-year follow-up. Int J Radiat Oncol Biol Phys 86(5):867–872. doi: 10.1016/j.ijrobp.2013.02.037 CrossRefPubMedGoogle Scholar
- 7.Keum KC, Shim SJ, Lee IJ et al (1998) The 1998, 1999 patterns of care study for breast irradiation after mastectomy in Korea. J Korean Soc Ther Radiol Oncol 25(1):7–15Google Scholar
- 12.Kyndi M, Overgaard M, Nielsen HM et al (2009) High local recurrence risk is not associated with large survival reduction after postmastectomy radiotherapy in high-risk breast cancer: a subgroup analysis of DBCG 82 b&c. Radiother Oncol 90(1):74–79. doi: 10.1016/j.radonc.2008.04.014 CrossRefPubMedGoogle Scholar
- 13.Shim SJ, Park W, Huh SJ et al (2014) The role of postmastectomy radiation therapy after neoadjuvant chemotherapy in clinical stage II-III breast cancer patients with pN0: a multicenter, retrospective study (KROG 12-05). Int J Radiat Oncol Biol Phys 88(1):65–72. doi: 10.1016/j.ijrobp.2013.09.021 CrossRefPubMedGoogle Scholar
- 14.McGuire SE, Gonzalez-Angulo AM, Huang EH et al (2007) Postmastectomy radiation improves the outcome of patients with locally advanced breast cancer who achieve a pathologic complete response to neoadjuvant chemotherapy. Int J Radiat Oncol Biol Phys 68(4):1004–1009. doi: 10.1016/j.ijrobp.2007.01.023 PubMedCentralCrossRefPubMedGoogle Scholar
- 15.Noh JM, Park W, Suh CO et al (2014) Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II-III breast cancer? A multicentre retrospective study (KROG 12-05). Br J Cancer 110(6):1420–1426. doi: 10.1038/bjc.2014.26 PubMedCentralCrossRefPubMedGoogle Scholar
- 21.Cho JH, Cho KH, Keum KC et al (2003) The Benefit of individualized custom bolus in the postmastectomy radiation therapy: numerical analysis with 3-D treatment planning. J Korean Soc Ther Radiol Oncol 21(1):82–93Google Scholar
- 24.Darby SC, McGale P, Taylor CW et al (2005) Long-term mortality from heart disease and lung cancer after radiotherapy for early breast cancer: prospective cohort study of about 300,000 women in US SEER cancer registries. Lancet Oncol 6(8):557–565. doi: 10.1016/S1470-2045(05)70251-5 CrossRefPubMedGoogle Scholar