Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy

Background/Purpose: The optimal management of residual micrometastases and isolated tumor cells (ITC) in patients with invasive breast cancer who undergo neoadjuvant chemotherapy (NAC) followed by definitive surgery is not well-studied. We evaluated the role of regional nodal irradiation (RNI) in cl...

Full description

Bibliographic Details
Main Authors: Joseph K. Kim, Jerome M. Karp, Naamit K. Gerber
Format: Article
Language:English
Published: Elsevier 2023-01-01
Series:Clinical and Translational Radiation Oncology
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2405630822001136
_version_ 1811178928182657024
author Joseph K. Kim
Jerome M. Karp
Naamit K. Gerber
author_facet Joseph K. Kim
Jerome M. Karp
Naamit K. Gerber
author_sort Joseph K. Kim
collection DOAJ
description Background/Purpose: The optimal management of residual micrometastases and isolated tumor cells (ITC) in patients with invasive breast cancer who undergo neoadjuvant chemotherapy (NAC) followed by definitive surgery is not well-studied. We evaluated the role of regional nodal irradiation (RNI) in clinically node-positive (cN1) breast cancer patients with residual low-volume nodal disease following NAC. Methods/Materials: We queried the National Cancer Database (NCDB) and included patients with cN1 invasive breast cancer diagnosed from 2004 to 2016 who were treated with NAC and definitive surgery and had residual micrometastases (ypN1mi) or ITC (ypN0i+). We used univariable (UVA) and multivariable (MVA) Cox regression analyses to determine prognostic factors and Kaplan-Meier (KM) methods to evaluate overall survival (OS). We used inverse probability treatment weighting (IPTW) to reweight data to account for confounding factors. Results: Our final cohort included 1980 patients, including 527 patients with ypN0i + disease and 1453 patients with ypN1mi disease. 1101 patients (45.0%) received RNI in the overall cohort with a higher proportion of ypN1mi patients receiving RNI (56.5%) compared to 53.1% of ypN0i + patients. There was no significant difference in OS between ypN0i + and ypN1mi patients. RNI had no significant effect on OS in the overall cohort using Cox MVA and KM methods. With separate subset analysis of ypN0i + and ypN1mi patients, there was no significant effect of RNI on OS. This was confirmed with IPTW. Conclusions: In a national hospital-based study of cN1 invasive breast cancer patients with residual ITC or micrometastases after NAC, RNI did not have a significant effect on OS.
first_indexed 2024-04-11T06:26:14Z
format Article
id doaj.art-5a0a56ff7b73453fafee48e3d415c884
institution Directory Open Access Journal
issn 2405-6308
language English
last_indexed 2024-04-11T06:26:14Z
publishDate 2023-01-01
publisher Elsevier
record_format Article
series Clinical and Translational Radiation Oncology
spelling doaj.art-5a0a56ff7b73453fafee48e3d415c8842022-12-22T04:40:21ZengElsevierClinical and Translational Radiation Oncology2405-63082023-01-0138195201Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapyJoseph K. Kim0Jerome M. Karp1Naamit K. Gerber2Department of Radiation Oncology, NYU Langone Medical Center and School of Medicine, New York, NY, United StatesDepartment of Radiation Oncology, NYU Langone Medical Center and School of Medicine, New York, NY, United StatesCorresponding author at: NYU Perlmutter Cancer Center, Department of Radiation Oncology, 160 E. 34th Street, New York, NY 10016, United States.; Department of Radiation Oncology, NYU Langone Medical Center and School of Medicine, New York, NY, United StatesBackground/Purpose: The optimal management of residual micrometastases and isolated tumor cells (ITC) in patients with invasive breast cancer who undergo neoadjuvant chemotherapy (NAC) followed by definitive surgery is not well-studied. We evaluated the role of regional nodal irradiation (RNI) in clinically node-positive (cN1) breast cancer patients with residual low-volume nodal disease following NAC. Methods/Materials: We queried the National Cancer Database (NCDB) and included patients with cN1 invasive breast cancer diagnosed from 2004 to 2016 who were treated with NAC and definitive surgery and had residual micrometastases (ypN1mi) or ITC (ypN0i+). We used univariable (UVA) and multivariable (MVA) Cox regression analyses to determine prognostic factors and Kaplan-Meier (KM) methods to evaluate overall survival (OS). We used inverse probability treatment weighting (IPTW) to reweight data to account for confounding factors. Results: Our final cohort included 1980 patients, including 527 patients with ypN0i + disease and 1453 patients with ypN1mi disease. 1101 patients (45.0%) received RNI in the overall cohort with a higher proportion of ypN1mi patients receiving RNI (56.5%) compared to 53.1% of ypN0i + patients. There was no significant difference in OS between ypN0i + and ypN1mi patients. RNI had no significant effect on OS in the overall cohort using Cox MVA and KM methods. With separate subset analysis of ypN0i + and ypN1mi patients, there was no significant effect of RNI on OS. This was confirmed with IPTW. Conclusions: In a national hospital-based study of cN1 invasive breast cancer patients with residual ITC or micrometastases after NAC, RNI did not have a significant effect on OS.http://www.sciencedirect.com/science/article/pii/S2405630822001136Breast cancerRegional nodal irradiationRadiation therapyMicrometastasesIsolated tumor cellsNeoadjuvant chemotherapy
spellingShingle Joseph K. Kim
Jerome M. Karp
Naamit K. Gerber
Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
Clinical and Translational Radiation Oncology
Breast cancer
Regional nodal irradiation
Radiation therapy
Micrometastases
Isolated tumor cells
Neoadjuvant chemotherapy
title Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
title_full Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
title_fullStr Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
title_full_unstemmed Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
title_short Regional nodal irradiation (RNI) in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
title_sort regional nodal irradiation rni in breast cancer patients with residual isolated tumor cells or micrometastatic nodal disease after neoadjuvant chemotherapy
topic Breast cancer
Regional nodal irradiation
Radiation therapy
Micrometastases
Isolated tumor cells
Neoadjuvant chemotherapy
url http://www.sciencedirect.com/science/article/pii/S2405630822001136
work_keys_str_mv AT josephkkim regionalnodalirradiationrniinbreastcancerpatientswithresidualisolatedtumorcellsormicrometastaticnodaldiseaseafterneoadjuvantchemotherapy
AT jeromemkarp regionalnodalirradiationrniinbreastcancerpatientswithresidualisolatedtumorcellsormicrometastaticnodaldiseaseafterneoadjuvantchemotherapy
AT naamitkgerber regionalnodalirradiationrniinbreastcancerpatientswithresidualisolatedtumorcellsormicrometastaticnodaldiseaseafterneoadjuvantchemotherapy