Differences in clinicopathologic features and subtype distribution of invasive breast cancer between elderly and non-elderly women

• Main Authors: Toshiaki Utsumi, Naomi Kobayashi, Kaori Ushimado, Makoto Kuroda
• Format: Article
• Language: English
• Published: Fujita Medical Society 2021-05-01
• Series: Fujita Medical Journal
• Subjects: breast cancer; elderly woman; clinicopathologic characteristics; subtype
• Online Access: https://www.jstage.jst.go.jp/article/fmj/7/2/7_2020-019/_article/-char/en
• ISSN: 2189-7247; 2189-7255

Objectives: This study aimed to investigate the clinicopathologic features and subtype distribution of invasive breast cancer in elderly women (≥70 years of age). Methods: This retrospective study of 1,130 women compared the clinicopathologic characteristics and subtype distribution of invasive breast cancer in elderly (≥70 years) versus non-elderly (<70 years) women. Tumors were classified into five distinct subtypes based on the immunohistochemistry status of estrogen receptor (ER), progesterone receptor (PR), Ki67, and human epidermal growth factor receptor 2 (HER2). Results: The two patient groups did not differ significantly regarding ER and HER2 status. Breast cancers in elderly women were more likely to have negative PR status (40.4% vs. 32.6%, P=0.033) and low Ki67 expression (62.0% vs. 54.4%, P=0.047) than those in non-elderly women. Elderly women were less likely to undergo axillary lymph node dissection and axillary surgery (P<0.001). Consequently, unknown node status was more common in elderly women than non-elderly women (11.1% vs. 1.4%, respectively, P<0.001), while node involvement was less common in elderly women than non-elderly women (26.9% vs. 37.7%, respectively, P<0.001). There was no significant difference in the distribution of subtypes between the two groups. Conclusions: Breast cancers in elderly women were less frequently node positive and more frequently PR negative and with low Ki67 expression than those in non-elderly women. Moreover, there was no difference in subtype distribution between the two age groups.