Mucinous Carcinoma of the Breast: Clinicopathological Features and Long-term Prognosis in Comparison with Invasive Ductal Cancer; A Single Hospital's 30+-Year Experience

• Published in: Acta medica Okayama Vol. 74; no. 2; pp. 137 - 143
• Main Authors: Isozaki, Hiroshi, Yamamoto, Yasuhisa, Sakai, Kunihiko, Sho, Tatuo, Ishihara, Kiyohiro, Murakami, Shigeki, Matsumoto, Sasau, Takama, Takehiro
• Format: Journal Article
• Language: English
• Published: Japan 01.04.2020
• Subjects: Adenocarcinoma, Mucinous - mortality; Adenocarcinoma, Mucinous - pathology; Adenocarcinoma, Mucinous - therapy; Adult; Aged; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast Neoplasms - therapy; Carcinoma, Ductal, Breast - mortality; Carcinoma, Ductal, Breast - pathology; Carcinoma, Ductal, Breast - therapy; Disease-Free Survival; Female; Humans; Lymphatic Metastasis - diagnosis; Middle Aged; Progression-Free Survival; Proportional Hazards Models; clinicopathological features; breast cancer; long-term prognosis; mucinous carcinoma
• ISSN: 0386-300X
• DOI: 10.18926/amo/58272

Mucinous carcinoma (MC) of the breast is a rare and special type of malignancy, with a substantial amount of extracellular mucin. We compared the clinicopathological features and the long-term survival of MC patients with those of invasive ductal carcinoma-no special type (IDC-NST) patients, and we examined prognostic factors of MC. A total of 116 patients with mucinous carcinoma and 3,258 patients with IDC-NST who underwent surgery at our hospital (1977-2008) were enrolled. The 10-year overall survival rate and breast cancer-specific survival rate (BSS) of the MC patients (88.3%, 93.7%) were both significantly higher than those of IDC-NST patients (81.6%, 85.0%) (p=0.015, p=0.005, respectively). A Cox regression analysis demonstrated that MC tended to be an independent prognostic factor (hazard ratio 0.44, p=0.098). The BSS of the MC patients with positive lymph node (LN) metastasis was significantly poorer than that of the patients without it, by univariate analysis (p=0.002). The tumor size in the MC patients with positive LN metastasis (mean 3.2 cm) was significantly larger than that in the patients without it (mean 1.9 cm) (p=0.0004). Although a Cox regression analysis revealed no independent factor, MC patients with positive LN metastasis should be treated for advanced invasive ductal breast cancer.