Preoperative prediction of malignant involvement of resected ureters in patients undergoing radical cystectomy for bladder cancer

Achieving disease free distal ureteral margin at the time of radical cystectomy: Why and for whom? (an overview of literature)

OBJECTIVE

Achieving negative status of distal ureteral margin at the time of radical cystectomy (RC), and its therapeutic benefit, remains controversial. The aim of this review was to evaluate frequency, reliability and impact of positive distal ureteral margin after radical cystectomy for bladder cancer on upper tract recurrence, cancer specific and overall survival, and to identify best candidates for intraoperative frozen section analyses.

MATERIAL AND METHODS

A systemic review was performed following the PRISMA guideline. PubMed/Medline (with following terms; bladder cancer or cystectomy and frozen section or ureteral margin), and Cochrane Library were searched up to April 2020, to identify all papers evaluating distal ureteral margin and discussing clinical interest. Previous reviews and single case reports were excluded.

RESULTS

In total, thirty-two relevant studies were identified. Mean rate of positive ureteral frozen section after RC was close to 10% [1.1-25.4%]. Frozen section (FS) achieved a very good specificity [83-100%] and reserved sensibility [45-100%]. In many cases, an initial positive margin on FS can be converted to negative. Positive FS and/or PS (permanent section) were associated with upper urinary tract recurrence (UUTR). Conversion from positive FS to negative PS was associated with low UUTR frequency and better cancer survival in large retrospective studies. The relevant prognostic factor associated with positive FS and/or PS was CIS within the bladder.

CONCLUSION

FS should be recommended for patients with CIS within the bladder. Achieving negative FS/PS might be associated with lower rates of UUTR and better survival, for patients with higher life expectancy. Prospective randomized controlled studies need to be performed to provide definitive recommendations in this area.

The Immune Microenvironment and Cancer Metastasis

The dynamic interplay between neoplastic cells and the immune microenvironment regulates every step of the metastatic process. Immune cells contribute to invasion by secreting a cornucopia of inflammatory factors that promote epithelial-to-mesenchymal transition and remodeling of the stroma. Cancer cells then intravasate to the circulatory system assisted by macrophages and use several pathways to avoid recognition by cytotoxtic lymphocytes and phagocytes. Circulating tumor cells that manage to adhere to the vasculature and encounter premetastic niches are able to use the associated myeloid cells to extravasate into ectopic organs and establish a dormant microscopic colony. If successful at avoiding repetitive immune attack, dormant cells can subsequently grow into overt, clinically detectable metastatic lesions, which ultimately account to most cancer-related deaths. Understanding how disseminated tumor cells evade and corrupt the immune system during the final stages of metastasis will be pivotal in developing new therapeutic modalities that combat metastasis.