How would you treat a patient with urothelial cancer and 25% plasmacytoid variant who has a solitary recurrence in rectum 1 year after neoadjuvant chemotherapy and radical cystectomy?

Plasmacytoid urothelial carcinoma has a very high tendency to develop peritoneal carcinomatosis. And although on scan there could be solitary occurrence, on exploration, may be able to see more peritoneal involvement. Thus, systemic therapy would be a more appropriate strategy to treat.

Diamantopoul...

I have had 2 patients present with the rectum as the only site of recurrence of plasmacytoid bladder cancer after neoadjuvant chemotherapy and cystectomy. Both patients required colostomy diversions upon presentation due to bowel obstruction.

One patient relapsed more than 12 months after neoadjuvan...

Plasmacytoid urothelial carcinoma is a highly aggressive variant with a tendency for peritoneal dissemination and has been reported to be associated with CDH1 loss of function alterations, loss of E-cadherin, p-120 catenin expression, and mTOR pathway upregulation. FGFR3/2 activating alterations app...

Agree with @Dr. First Last. This typically represents, unfortunately, metastatic disease, often under-appreciated on imaging. Would treat with systemic therapy, which regimen depends on many factors, e.g. tolerance on neoadjuvant chemoTx, pathologic response, exact time interval between end of chemo...

I agree with all that has been mentioned above by Dr. @Dr. First Last and others. Plasmacytoid variant has a high predilection for under staging on cross sectional imaging and in the majority of cases, there is more extensive peritoneal involvement not captured on imaging. Based on performance statu...

Agree with the excellent comments from @Dr. First Last, @Dr. First Last, @Dr. First Last, @Dr. First Last, and @Dr. First Last. Cross-sectional imaging with CT scans and even PET/CT will often undercall the extent of disease for plasmacytoid variants. Anecdotally, I have found MRI a better tool to e...

Agree with the above comments. In our anecdotal experience of a couple of patients, local radiation therapy and immunotherapy have provided durable control, although the patients did progress after >1 year.

How would you manage, for instance, a patient with recent operative staging and ileal conduit...

I think in this case neoadjuvant chemo followed by surgery, if feasible, should be considered. I would consider staging by PET to evaluate for other areas of disease. My one case with plasmacytoid variant is in remission now 5 years plus. I treated him with chemotherapy with cis+gem for 1-2 cycles b...