Evidence map›Paper›PMID 42149434›Full record

ArticleBreast cancer (Tokyo, Japan)2026

Clinical outcomes of postoperative radiotherapy with regional nodal irradiation excluding internal mammary lymph nodes in breast cancer: a multi-institutional retrospective analysis.

Kanako Nakatsu, Yuka Ono, Michio Yoshimura, Kimiko Hirata, Chikako Yamauchi, Masakazu Ogura, Takahiro Kishi, Kota Fujii, Shuji Ohtsu, Takashi Sakamoto and 7 more

Abstract readMulticenter Study
In one paragraph

Article in Breast cancer (Tokyo, Japan), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

17 authors.

Kanako NakatsuDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.ORCID http://orcid.org/0000-0002-0161-1693
Yuka OnoDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. yukat@kuhp.kyoto-u.ac.jp.ORCID http://orcid.org/0000-0002-3010-7031
Michio YoshimuraDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.ORCID http://orcid.org/0000-0001-6665-2245
Kimiko HirataDepartment of Radiation Oncology, Kyoto City Hospital, 1-2 Mibu Higashitakada-cho, Nakagyo-ku, Kyoto, 604-8845, Japan.ORCID http://orcid.org/0009-0000-0349-9239
Chikako YamauchiDepartment of Radiation Oncology, Shiga General Hospital, 5-4-30, Moriyama, Shiga, 524-0022, Japan.
Masakazu OguraDepartment of Radiation Oncology, Kishiwada City Hospital, 1001 Gakuhara-cho, Kishiwada, Osaka, 596-8501, Japan.
Takahiro KishiDepartment of Radiation Oncology, Osaka Red Cross Hospital, 5-30 Fudegasaki-cho, Tennoji-ku, Osaka, 543-8555, Japan.
Kota FujiiDepartment of Radiation Oncology, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama, 710-8602, Japan.ORCID http://orcid.org/0000-0003-4656-2511
Shuji OhtsuDepartment of Radiation Oncology, Kyoto City Hospital, 1-2 Mibu Higashitakada-cho, Nakagyo-ku, Kyoto, 604-8845, Japan.
Takashi SakamotoDepartment of Radiation Oncology, Kyoto Katsura Hospital, 17 Yamada-Hirao-cho, Nishikyo-ku, Kyoto, 615-8256, Japan.ORCID http://orcid.org/0000-0003-0811-3926
Kazuhito UekiDepartment of Radiation Oncology, National Hospital Organization Kyoto Medical Center, 1-1 Fukakusa Mukaihata-cho, Fushimi-ku, Kyoto, 612-0861, Japan.
Kengo OguraDepartment of Radiation Oncology, Japanese Red Cross Wakayama Medical Center, 4- 20 Komatsubara-dori, Wakayama, 640-8558, Japan.
Setsuko OkumuraDepartment of Radiation Oncology, Hyogo Prefectural Amagasaki General Medical Center, 2-17-77 Higashi-Naniwa-cho, Amagasaki, 660-8550, Hyogo, Japan.
Itaru IkedaDepartment of Radiation Oncology, Kobe City Medical Center General Hospital, 2-1-1 Minatojimaminamimachi, Chuo-ku, Kobe, 650-0047, Hyogo, Japan.ORCID http://orcid.org/0000-0003-4839-1461
Takamasa MitsuyoshiDepartment of Radiation Oncology, Kobe City Medical Center General Hospital, 2-1-1 Minatojimaminamimachi, Chuo-ku, Kobe, 650-0047, Hyogo, Japan.
Masaki KokuboDepartment of Radiation Oncology, Kobe City Medical Center General Hospital, 2-1-1 Minatojimaminamimachi, Chuo-ku, Kobe, 650-0047, Hyogo, Japan.
Takashi MizowakiDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.ORCID http://orcid.org/0000-0002-8135-8746

Funding

Japan Society for the Promotion of Science 24K18763
6 · The paper itself

Abstract

backgroundPostoperative regional nodal irradiation (RNI) is a standard treatment for breast cancer at high risk of regional recurrence; however, the necessity of including the internal mammary node (IMN) region in the radiation field remains unclear. This study aimed to evaluate treatment outcomes in a large cohort of patients who received postoperative radiotherapy with RNI excluding the IMN region.

methodsThis study included patients with breast cancer who underwent surgery followed by RNI without IMN irradiation between 2007 and 2018. The primary endpoint was disease-free survival (DFS), and the secondary endpoints were overall survival (OS), breast cancer-specific mortality (BCM), distant metastasis-free survival (DMFS), recurrence patterns, and treatment-related adverse events.

resultsIn total, 799 patients were included. The 5-year DFS, OS, BCM, and DMFS rates were 75.9, 88.3, 9.7, and 77.1%, respectively. Worse outcomes were associated with a higher number of positive lymph nodes and estrogen receptor (ER)-negative disease. Medial/central tumor location and younger age were each significantly associated with poorer outcomes, being associated with worse DFS and DMFS. Bone was the most common recurrence site. ER-negative disease, a higher number of positive lymph nodes, medial/central location, and younger age were significant risk factors for recurrence, particularly distant metastasis. IMN recurrence was rare.

conclusionsIn this cohort, medial/central tumor location, ER-negative disease, and extensive nodal involvement were associated with poorer outcomes, suggesting that these factors may identify patients who can benefit from IMN irradiation. These findings may serve as important reference data when determining the indication for IMN irradiation on an individual patient basis.

Indexed as

Breast NeoplasmsLymphatic IrradiationLymph NodesNeoplasm Recurrence, LocalAdultAgedDisease-Free SurvivalFemaleHumansLymphatic MetastasisMastectomyMiddle AgedRadiotherapy, AdjuvantRetrospective StudiesTreatment OutcomeBreast cancerDisease-free survivalInternal mammary node regionPostoperative radiation therapyRegional nodal irradiation

Identifiers

PMID42149434
PMCPMC13283185

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