Tumour necrosis is an indicator of aggressive biology in patients with urothelial carcinoma of the upper urinary tract.

BACKGROUND

Prognostic factors after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) are inconclusive, because most data in the literature have been obtained from small series.

OBJECTIVE

To assess the association of tumour necrosis with cancer recurrence and survival in a large international series of patients treated with RNU.

DESIGN, SETTING, AND PARTICIPANTS: Data were collected from 1425 patients treated with RNU at 13 centres and combined into a relational database. Pathologic slides were re-reviewed by genitourinary pathologists according to strict criteria. Extensive tumour necrosis was scored as >10% of the tumour area.

INTERVENTION

Patients underwent either open or laparoscopic RNU. Lymph node dissection was performed in the presence of enlarged nodes.

MEASUREMENTS

Recurrence was defined as tumour relapse in the operative field, lymph node (LN) metastasis, and/or distant metastases. Bladder recurrences were not considered. Associations of extensive tumour necrosis with recurrence-free survival and cancer-specific survival were evaluated by univariate and multivariate analyses.

RESULTS AND LIMITATIONS

Extensive tumour necrosis was observed in 364 patients (25.5%) and was associated with advanced tumour stage, high tumour grade, sessile architecture, lymphovascular invasion (LVI), concomitant carcinoma in situ, and LN metastasis (p<0.0001 each). Extensive tumour necrosis was independently associated with disease recurrence and survival (p=0.037 and p=0.046, respectively) after adjusting for the effects of pathologic stage, grade, LVI, and LN status. The addition of extensive tumour necrosis to a base model comprising standard pathologic predictors marginally improved its predictive accuracy for both cancer-specific recurrence (1.5%) and survival (1.4%).

CONCLUSIONS

Extensive tumour necrosis is an independent predictor of clinical outcomes in patients who undergo RNU for UTUC. Assessment of tumour necrosis may help to identify patients who could benefit from multimodal therapy after RNU in the future. Evaluation of extensive tumour necrosis should be part of standard pathologic reporting.