Advanced colonic cancer with clinically suspected bladder invasion: Outcomes and prognosis from a multicentric study of 117 patients from the FRENCH research group.

Background: Bladder invasion by colon cancer is rare; however, its management is still controversial. Our objective was to report outcomes and identify risk factors for local recurrence in colon cancer with clinically suspected bladder invasion.

Methods: We conducted a retrospective study in 23 centers in France. All patients who underwent colon surgery with bladder resection (2010-2017) were included. Metastatic and recurrent colon cancers were excluded.

Results: One hundred and seventeen patients (men = 73) were included. Partial cystectomy occurred in 108 patients (92.3%), with a total cystectomy occurring in 9 patients (7.7%). Neoadjuvant treatment was given to 31 patients (26.5%). Major morbidity was 20.5%. R0 resection rates were 87.2%. Histologically confirmed bladder invasion was present in 47%. Thirty-four patients were pN+, while 60 patients (51.3%) received adjuvant chemotherapy. Mean follow-up was 33.8 months. Three-year overall survival and disease-free survival were 82.9% and 59.5%. Rates of local recurrence and distant recurrence were 14.5% and 18.8%, respectively; the local recurrences (11/17; 65%) were in the bladder, while 4 of these patients had a bladder recurrence despite not having histologically confirmed bladder invasion at the index surgery. The rate of bladder recurrence after histologic bladder invasion was 13% (7/55), while the rate of bladder recurrence without primary bladder invasion was 7% (4/62) (P = .343). Neoadjuvant therapy, type of cystectomy, and adjuvant therapy did not influence local recurrence (P > .445 each). R1 bladder resections, when compared with a R0 bladder resections, were associated with an increased rate of local recurrence (63% vs 10%; P < .0001).

Conclusion: Clinically suspected bladder invasion increases local recurrence even in the absence of histologically confirmed bladder invasion. Only complete resections with R0 margins decrease local recurrence. Careful, detailed postoperative surveillance is required, even without pathologic bladder invasion.