Pathology Unit, University Hospital OO.RR, Foggia, Italy,
Urology Unit, University of Foggia, Bonomo Teaching Hospital, Foggia, Italy.
Oncology. 2021;99(6):345-358. doi: 10.1159/000514759. Epub 2021 Mar 18.
The most common bladder cancer (BC) histotype is pure urothelial carcinoma (UC), which may undergo divergent differentiation in some cases. Variant histology (VH) presents along variable morphologies, either single or combined between them or with pure UC. From a clinical standpoint, the vast majority of BC is diagnosed at non-invasive or minimally invasive stages, namely as non-muscle invasive BC (NMIBC). There is a wide range of therapeutic options for patients with NMIBC, according to their clinical and pathological features. However, current risk stratification models do not show optimal effectiveness. Evidence from the literature suggests that VH has peculiar biological features, and may be associated with poorer survival outcomes compared to pure UC.
In order to describe the biological features and prognostic/predictive role of VH in NMIBC, and to discuss current treatment options, we performed a systematic literature search through multiple databases (PubMed/Medline, Google Scholar) for relevant articles according to the following terms, single and/or in combination: "non-muscle invasive bladder cancer," "variant histology," "micropapillary variant," "glandular differentiation," "squamous differentiation," "nested variant," "plasmacytoid variant," and "sarcomatoid variant." We extracted 99 studies including original articles, reviews, and systematic reviews, and subsequently analyzed data from 16 studies reporting on the outcome of NMIBC with VH. We found that the relative rarity of these forms as well as the heterogeneity in study populations and therapeutic protocols results in conflicting findings overall. Key Messages: The presence of VH should be taken into account when counseling a patient with NMIBC, since it may upgrade the disease to high-risk tumor and thus warrant a more aggressive treatment.
最常见的膀胱癌（BC）组织学类型是纯尿路上皮癌（UC），但在某些情况下可能会发生不同的分化。变异组织学（VH）以不同的形态出现，要么是单一的，要么是它们之间的组合，要么是与纯 UC 混合存在。从临床角度来看，绝大多数 BC 是在非浸润性或微浸润性阶段诊断出来的，即非肌肉浸润性 BC（NMIBC）。根据患者的临床和病理特征，NMIBC 患者有广泛的治疗选择。然而，目前的风险分层模型并不能显示出最佳的效果。文献中的证据表明，VH 具有独特的生物学特征，与纯 UC 相比，其生存结局可能更差。
为了描述 VH 在 NMIBC 中的生物学特征和预后/预测作用，并讨论当前的治疗选择，我们通过多个数据库（PubMed/Medline、Google Scholar）进行了系统的文献检索，使用了以下术语的单一和/或组合：“非肌肉浸润性膀胱癌”、“变异组织学”、“微乳头状变异”、“腺分化”、“鳞状分化”、“巢状变异”、“浆细胞样变异”和“肉瘤样变异”。我们提取了 99 篇包括原始文章、综述和系统综述在内的研究文章，并随后分析了 16 篇报道 VH 对 NMIBC 结局的研究的数据。我们发现，这些形式的相对罕见性以及研究人群和治疗方案的异质性导致总体上存在相互矛盾的发现。
在为 NMIBC 患者提供咨询时，应考虑到 VH 的存在，因为它可能将疾病升级为高危肿瘤，从而需要更积极的治疗。
