Editing Upper Urinary Tract Urothelial Cancer (section)

===== Biopsy =====
*'''Approaches (2):'''
**'''Ureteroscopic biopsy with forceps'''
**'''Fluoroscopically guided retrograde brush biopsy'''
*'''Mucosal abnormalities may be difficult to biopsy effectively'''
**'''Attempted tissue confirmation may be facilitated with the use of brush biopsies or percutaneous image-guided biopsy.'''
*'''Diagnostic accuracy'''
**'''<span style="color:#ff00ff">Systematic review and meta-analysis evaluating diagnostic accuracy of URS biopsy (2020)</span>'''
*** Included studies comparing URS biopsy to pathology on surgical specimen (radical nephroureterectomy or segmental ureterectomy)
*** Results:
**** Included 23 studies comprising 2232 patients
**** Moderate to high risk of bias accross studies
**** Stage-to-stage match
***** Positive predictive value for cT1+/muscle-invasive: 94%
***** Negative predictive value for cTa-Tis/non-muscle-invasive disease of 60%
**** Grade-to-grade match
***** High-grade (cHG/pHG): 97%
***** Low-grade (cLG/pLG): 66%
**** Grade-to-stage match
***** Positive predictive value for cHG/muscle-invasive disease: 60%
***** Negative predictive value for cLG/non-muscle-invasive disease: 77%
**** '''<span style="color:#ff0000">Overall</span>'''
***** '''<span style="color:#ff0000">32% undergrading</span>'''
***** '''<span style="color:#ff0000">46% understaging</span>'''
****** '''<span style="color:#ff0000">A precise correlation with eventual tumor stage is difficult</span>''' mainly because of technical limitations of use of small biopsy instruments through the narrow channel of the flexible ureteroscope, resulting in the small size and shallow depth of ureteroscopic biopsy specimens. Brush biopsy may be used if cup biopsy forceps fail to obtain adequate tissue.
**** [https://pubmed.ncbi.nlm.nih.gov/32674841/ Subiela, José Daniel, et al.]"Diagnostic accuracy of ureteroscopic biopsy in predicting stage and grade at final pathology in upper tract urothelial carcinoma: Systematic review and meta-analysis." ''European Journal of Surgical Oncology'' (2020).
***'''<span style="color:#ff0000">Reasonable histologic correlation</span>''' (78-92%)
**'''Preoperative determination of the stage of UTUC tumors remains difficult. <span style="color:#ff0000">Therefore, in predicting the tumor stage, a combination of the radiographic studies, the visualized appearance of the tumor, and the tumor grade provides the surgeon with the best estimation for risk stratification.</span>'''