Identifying candidates for super-extended staging pelvic lymph node dissection among patients with high-risk prostate cancer.

OBJECTIVES

To assess if the preoperative lymph node invasion (LNI) risk could be used to tailor the extent of pelvic lymph node dissection (PLND) according to individual profile in patients with prostate cancer (PCa) undergoing radical prostatectomy (RP), and to identify those who would benefit from the removal of the common iliac and pre-sacral nodes.

PATIENTS AND METHODS

A total of 471 patients with high-risk PCa treated with RP and a super-extended PLND that included the removal of the pre-sacral and common iliac nodes between 2006 and 2016 were identified. The risk of LNI was calculated according to the Briganti nomogram. Multivariable logistic regression analyses assessed the association between LNI risk and involvement of the common iliac and pre-sacral regions. The risk of positive common iliac and pre-sacral nodes was plotted over the LNI risk using the LOWESS-smoothed fit curve.

RESULTS

The median preoperative LNI risk was 25.5%. The median number of nodes removed was 23, and 171 (36.3%) patients had LNI. Overall, 61 (13.0%) and 28 patients (5.9%), respectively, had positive common iliac and pre-sacral nodes alone or in combination with other sites. The LNI risk was associated with the involvement of the common iliac and pre-sacral regions (all P < 0.001). The proportion of patients with positive common iliac and pre-sacral nodes progressively increased according to the LNI risk. The adoption of a 30% threshold would result in avoiding the removal of the common iliac and pre-sacral nodes in >60% cases, with a risk of missing LNI in these regions of <5%.

CONCLUSIONS

Fewer than 5% of patients with an LNI risk of <30% harbour positive common iliac and pre-sacral nodes. A super-extended PLND that includes the dissection of these regions should be considered exclusively in patients with an LNI risk ≥30%.