Risk stratification models for para-aortic lymph node metastasis and recurrence in stage IB–IIB cervical cancer

OBJECTIVE To examine the surgical-pathological predictors of para-aortic lymph node (PAN) metastasis at radical hysterectomy, and for PAN recurrence among women who did not undergo PAN dissection at radical hysterectomy. METHODS This is a retrospective analysis of a nation-wide cohort study of surgically-treated stage IB-IIB cervical cancer (n=5,620). Multivariate models were used to identify independent surgical-pathological predictors for PAN metastasis/recurrence. RESULTS There were 120 (2.1%) cases of PAN metastasis at surgery with parametrial involvement (adjusted odds ratio [aOR]=1.65), deep stromal invasion (aOR=2.61), ovarian metastasis (aOR=3.10), and pelvic nodal metastasis (single-node aOR=5.39 and multiple-node aOR=33.5, respectively) being independent risk factors (all, p<0.05). Without any risk factors, the incidence of PAN metastasis was 0.9%, while women exhibiting certain risk factor patterns (>20% of the study population) had PAN metastasis incidences of ≥4%. Among 4,663 clinically PAN-negative cases at surgery, PAN recurrence was seen in 195 (4.2%) cases that was significantly higher than histologically PAN-negative cases (2.5%, p=0.046). In clinically PAN-negative cases, parametrial involvement (adjusted hazard ratio [aHR]=1.67), lympho-vascular space invasion (aHR=1.95), ovarian metastasis (aHR=2.60), and pelvic lymph node metastasis (single-node aHR=2.49 and multiple-node aHR=8.11, respectively) were independently associated with increased risk of PAN recurrence (all, p<0.05). Without any risk factors, 5-year PAN recurrence risk was 0.8%; however, women demonstrating certain risk factor patterns (>15% of the clinically PAN-negative population) had 5-year PAN recurrence risks being ≥8%. CONCLUSION Surgical-pathological risk factors proposed in this study will be useful to identify women with increased risk of PAN metastasis/recurrence.