Department of Pathology, University Medical Center of Princeton, Plainsboro, NJ, UK.
Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA.
Histopathology. 2017 Dec;71(6):874-886. doi: 10.1111/his.13328. Epub 2017 Sep 28.
Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are predominant and well-documented types of invasive breast cancer (IBC). We investigated the clinical outcomes of other types of IBC (i.e. uncommon IBC), which collectively account for Σ20% of all IBC cases, as these are largely unknown.
We identified all IBC cases diagnosed in 2004-2006 (n = 159 293) and 2010-2011 (n = 118 822) from the Surveillance, Epidemiology and End Results (SEER) database. Uncommon IBCs included mixed IDC and ILC (MDLC), IDC mixed with other types of carcinoma, ILC mixed with other types of carcinoma, and other-type breast cancers (OCs). We estimated overall survival (OS) and cancer-specific survival in multivariate regression models. As compared with IDC, MDLC was associated with an increased OS [adjusted hazard ratio (aHR) = 0.92, P < 0.001 at Σ10 years of follow-up; aHR = 0.88, P = 0.01 at Σ4 years of follow-up], whereas OCs were associated with a decreased OS (aHR = 1.06, P = 0.005 at Σ10 years of follow-up; aHR = 1.23, P < 0.001 at Σ4 years of follow-up). Women with other uncommon IBCs had an OS similar to those with IDC. Heterogeneity in survival was observed for some subtypes of OC, with better OS for women with MDLC and tubular carcinoma. Radiotherapy extended OS for all types of IBC in older women (≥50 years). For younger women (<50 years), radiotherapy improved OS in women with IDC, but not in those with ILC or uncommon IBC. Radiotherapy did not change cancer-specific survival of younger women with any IBC.
Uncommon IBCs have distinct patterns of prognosis and survival. The effectiveness of radiotherapy in women with uncommon IBC may differ by age. The underlying mechanisms warrant further studies.
浸润性导管癌（IDC）和浸润性小叶癌（ILC）是主要且有充分文献记录的浸润性乳腺癌（IBC）类型。我们研究了其他类型的 IBC（即罕见 IBC）的临床结果，这些罕见 IBC 约占所有 IBC 病例的 20%，但目前对此知之甚少。
我们从监测、流行病学和最终结果（SEER）数据库中确定了 2004-2006 年（n=159293）和 2010-2011 年（n=118822）诊断的所有 IBC 病例。罕见 IBC 包括混合性 IDC 和 ILC（MDLC）、IDC 与其他类型的癌混合、ILC 与其他类型的癌混合以及其他类型的乳腺癌（OC）。我们在多变量回归模型中估计了总生存率（OS）和癌症特异性生存率。与 IDC 相比，MDLC 与 OS 增加相关[调整后的危险比（aHR）=0.92，P<0.001，随访 10 年；aHR=0.88，P=0.01，随访 4 年]，而 OC 与 OS 降低相关[aHR=1.06，P=0.005，随访 10 年；aHR=1.23，P<0.001，随访 4 年]。其他罕见 IBC 患者的 OS 与 IDC 患者相似。一些 OC 亚型的生存存在异质性，MDLC 和管状癌患者的 OS 更好。对于年龄较大的女性（≥50 岁），放疗可延长所有 IBC 类型的 OS。对于年轻女性（<50 岁），放疗可改善 IDC 患者的 OS，但不能改善 ILC 或罕见 IBC 患者的 OS。放疗未改变任何 IBC 年轻女性的癌症特异性生存率。
罕见 IBC 具有不同的预后和生存模式。放疗对罕见 IBC 患者的有效性可能因年龄而异。其潜在机制需要进一步研究。
