Red cell distribution width really acted prognostic role in upper tract urothelial carcinoma?

By Da-xiong Zeng, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China

To the Editors:

In the article by Cheng et al [1], the authors estimated the prognostic role of blood markers in upper tract urothelial carcinoma. The results showed that high blood red cell distribution width (RDW) was independently associated with poor overall survival (OS), and white blood cells (WBC) count was a significant prognosticator for both OS and cancer-specific survival (CSS). It is a novel issue, but there are some points to be noticed.

As a marker of blood red cells heterogeneity, RDW was used as a parameter not only for anemia diagnosis but also in others, including heart failure and inflammatory diseases. [2-3] But, it should be noticed that RDW levels might be affected by numerous factors. Some factors have been adjusted in this study, such as age, gender, smoking, anemia, chemotherapy and radiation. But other abnormalities were not mentioned, including body mass index, hepatic or renal dysfunction, diabetes mellitus, hypertension, and autoimmune diseases.

Moreover, some drugs or therapy might also affect RDW levels, including antibiotics, erythropoietin and transfusion. [2-3] Details of these drugs might help to understand the prognostic role of RDW further. Additionally, the devices (anticoagulant, automated counter model) and elapsed time for blood collection and RDW measuring should be mentioned because RDW levels and reference range might changed with different detection methods. [4]

Our point is regarding RDW as an independent prognostic marker for upper tract urothelial carcinoma remained unclear. Details of above information might be beneficial to validate the role of RDW.

References

1. Cheng YC, Huang CN, Wu WJ, et. al. The Prognostic Significance of Inflammation-Associated Blood Cell Markers in Patients with Upper Tract Urothelial Carcinoma. Ann Surg Oncol.2016;23:343-51.

2. Lippi G, Plebani M. Red blood cell distribution width (RDW) and human pathology. One size fits all. Clin Chem Lab Med. 2014;52:1247-9.

3. Salvagno GL, Sanchis-Gomar F, Picanza A, Lippi G. Red blood cell distribution width: A simple parameter with multiple clinical applications. Crit Rev Clin Lab Sci. 2015;52:86-105.

4. Lippi G, Pavesi F, Bardi M, Pipitone S. Lack of harmonization of red blood cell distribution width (RDW). Evaluation of four hematological analyzers. Clin Biochem. 2014;47:1100-3.