A nomogram for staging of exclusive nonobturator lymph node metastases in men with localized prostate cancer.
OBJECTIVE
Some patients with localized prostate cancer are at risk of nonobturator lymph node invasion (NOLNI) and may require an extended pelvic lymph node dissection (ePLND). We explored the rate of exclusive NOLNI and developed a nomogram to predict it.


METHODS
We mapped all ePLND specimens according to their anatomic location (obturator, external iliac, internal iliac lymph nodes) and assessed the location-specific rate of LNI in 565 patients. A multivariate logistic regression-based nomogram predicting NOLNI was then internally validated with 200 bootstrap resamples.


RESULTS
Overall, 11.1% (63 of 565) had LNI and 21 (3.7%) had exclusive NOLNI. The nomogram predicting exclusive NOLNI was 80.2% accurate. The nomogram's negative predictive value was 99%, when it predicted 0-10% probability of NOLNI. This approach could allow the omission of an ePLND in 350 of 565 (61.9%) patients and still correctly stage 85.8% of NOLNI cases.


CONCLUSIONS
Our nomogram-based approach offers the possibility of identifying men who are at virtually zero risk of exclusive NOLNI. In these men, an ePLND may be safely avoided.
Briganti
Alberto
A
Department of Urology, Vita-Salute University, Milan, Italy.
Chun
Felix K-H
FK
Salonia
Andrea
A
Zanni
Giuseppe
G
Gallina
Andrea
A
Dehò
Federico
F
Suardi
Nazareno
N
Da Pozzo
Luigi Filippo
LF
Valiquette
Luc
L
Rigatti
Patrizio
P
Montorsi
Francesco
F
Karakiewicz
Pierre I
PI
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010388:Pelvis; D011471:Prostatic Neoplasms / Q000473:pathology*; D012307:Risk Factors