How important is the number of pelvic lymph node retrieved to locorregional staging of cervix cancer?

OBJECTIVE To explore how important is the number of pelvic lymph nodes dissected for the nodal staging in FIGO IA2-IB2 cervical cancer, submitted to radical surgical treatment. METHODS A cross-sectional study was carried out on patients who underwent Piver class II radical hysterectomy and pelvic lymphadenectomy, in two centers in the state of Pernambuco, from January, 2001 to December, 2008. The analysis of the area under the ROC curve was adopted as a summary-measure of discriminatory power of the number of nodes dissected in predicting the pelvic nodal status. Additionally, we also confirm our findings using logistic regression and the Fisher's exact test. RESULTS The postoperative pathological study included 662 pelvic lymph nodes dissected (median per-patient=9, q25=6 - q75=13) from 69 patients. The ROC curve analysis revealed AUC=0.642, for the discriminatory value of the number of nodes dissected in predicting the pelvic nodal status. Similar findings were found after categorization using 10 and 15 lymph nodes as cut-offs (AUC=0.605 and 0.526, respectively). Logistic regression revealed odds ratio of 0.912 (95%CI=0.805-1.032; p=0.125) for the predictive value of the number of nodes dissected, and a number of nodes ≥10 or ≥15 lymph nodes was not significantly associated with the nodal status by the Fischer's exact test (p=0.224 and p=0.699, respectively). CONCLUSION The number of pelvic lymph nodes dissected did not correlate with pelvic lymph node metastatic involvement. This study suggests that dissection of a greater number of lymph nodes does not increase locoregional nodal staging in cervical cancer.