Systematic Review
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 26, 2020; 8(4): 771-781
Published online Feb 26, 2020. doi: 10.12998/wjcc.v8.i4.771
Lymphoepithelioma-like carcinoma of the upper urinary tract: A systematic review of case reports
Shi-Cong Lai, Samuel Seery, Wei Zhang, Ming Liu, Guan Zhang, Jian-Ye Wang
Shi-Cong Lai, Ming Liu, Jian-Ye Wang, Department of Urology, Beijing Hospital, National Center of Gerontology, Beijing 100730, China
Shi-Cong Lai, Ming Liu, Jian-Ye Wang, Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
Samuel Seery, School of Humanities and Social Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
Wei Zhang, Department of Pathology, Beijing Hospital, National Center of Gerontology, Beijing 100730, China
Guan Zhang, Department of Urology, China-Japan Friendship Hospital, Beijing 100029, China
Author contributions: Lai SC and Seery S designed the study, conducted the systematic literature search to identify all pertinent studies, assessed eligibility and quality of each selected study, as well as performed data extraction and statistical analysis; Zhang W and Liu M coordinated the study and performed data acquisition; Lai SC, Seery S and Zhang G participated in collecting and interpreting the data, drafted and revised the paper; Zhang G and Wang JY participated in critical reviewing the paper; All authors read and approved the final manuscript.
Conflict-of-interest statement: The authors declare that they have no competing interests.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Jian-Ye Wang, MD, Professor, Surgeon, Surgical Oncologist, Department of Urology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dong Dan, Beijing 100730, China. wangjy@bjhmoh.cn
Received: October 20, 2019
Peer-review started: October 20, 2019
First decision: December 4, 2019
Revised: December 11, 2019
Accepted: December 22, 2019
Article in press: December 22, 2019
Published online: February 26, 2020
Processing time: 129 Days and 3.6 Hours
ARTICLE HIGHLIGHTS
Research background

Lymphoepithelioma-like carcinomas (LELC) are rare, malignant epithelial tumors that are generally considered a subtype of squamous cell carcinoma. LELCs are undifferentiated, with histological features bearing a striking morphological resemblance to non-keratinizing nasopharyngeal carcinomas. LELCs occur in multiple tissues across the body, including the salivary glands, thymus, lung, stomach, ovary, uterine cervix and breast. However, LELCs in the urinary tract are extremely rare, and to the best of our knowledge, most previously described urinary LELCs have been reported to occur in the bladder. Rationally speaking, there are likely to be distinctions between subtypes, related to the exact location, as well as specific risk factors associated with these carcinomas. This systematic review is an attempt to expand and synthesize findings to provide clinicians with guidelines for the best practices.

Research motivation

The limited current evidence is not sufficient to provide clinicians with clear guidelines, due to the relative rareness of these carcinomas. Even within the most common LELC locations, there remains some controversy. Several studies have identified an association between Epstein-Barr virus (EBV) and nasopharyngeal, stomach, and lung LELCs, although this association is not apparent in other locations. A previous systematic review of 142 patients diagnosed with bladder LELC, as well as several case reports focusing on renal LELCs, suggests that these types are not associated with the presence of EBV. There are several other controversies that should be investigated using meta-analytical techniques. Therefore, the general motivation was to differentiate all LELC types, and to identify risk factors for early identification, since little is known about upper urinary tract LELC (UUT-LELC).

Research objectives

The fundamental research objective of this study was to develop the evidence base for clinical diagnoses, and to engage patients in shared-decision making for the treatment of primary UUT-LELC.

Research methods

A systematic search of PubMed, Embase, and other databases was conducted for all reports on UUT-LELC up until October, 2019, according to PRISMA guidelines. A database was then developed by extracting data from previously published reports in order to analyze interactions between clinical characteristics, pathological features, interventions and outcomes. Survival was analyzed using Kaplan–Meier estimates, which were compared using log rank tests.

Research results

A total of 28 previously published cases were identified for inclusion. The median age was 72 years with a male to female ratio of 4:3. Pure type LELCs were most common with 48.3% (n = 14), followed by 37.9% (n = 11) predominant LELCs and 3.4% (n = 1) focal LELCs. EBV testing was negative in all cases. Fourteen patients received radical nephroureterectomy (RNU)-based intervention. Twenty-three patients survived with no evidence of further metastasis. Six died before the median 18 mo follow-up point. Survival analysis suggests pure histological subtypes, and patients who receive complete tumor resection have more favorable prognoses. As always in cancer care, early identification generally increases the probability of interventional success.

Research conclusions

Findings suggest that the treatment associated with the highest disease-free survival is an RNU-based intervention. However, this can only be a tentative recommendation given the limitations of this evidence base. We would encourage clinicians to actively communicate their findings and publish case reports. UUT-LELC cases may be rare, but there is an opportunity to save and prolong lives by sharing knowledge, enhancing the depth and breadth of data recording, and reporting and discussing clinical experiences.

Research perspectives

Case reports are not generally high priority for publication houses, although a lot of very valuable information can be extracted and synthesized. This is an incredibly meaningful approach that we would encourage others to conduct, especially for rare conditions such as UUT-LELC. Clinicians must be guided by the best available evidence to reduce anxiety that may manifest through unnecessary testing and unclear guidelines. Systematic reviews of case reports and case series such as this one can also be used to support best practices, which will reduce the possibility of unnecessary harm.