Surgical-pathological predictors of disease-free survival and risk groupings for IB2 cervical cancer: do the traditional models still apply?

OBJECTIVE: To evaluate how the independent predictors of recurrence for stage IB2 cervical cancers treated with up-front radical hysterectomy apply to established risk models.

METHODS: Patients with IB2 cervical cancers diagnosed from 1990 to 2000 were identified from tumor registries of two institutions. Patients were classified into risk groups: high-risk (HR) (positive nodes, parametria, or margins), intermediate-risk (IR) (positive lymph vascular space involvement (LVSI) with any cervical stromal invasion (CSI), or (-) LVSI and > middle- CSI), or low-risk (LR) (absence of HR or IR characteristics). Disease-free survival (DFS) was estimated by Kaplan-Meier method and comparisons between subgroups were studied by log rank. A Cox proportional hazards model was used to determine independent predictors of recurrence.

RESULTS: We identified 86 patients with stage IB2 tumors treated by RH. We found 34% of patients to be HR, 60% IR, and 6% LR. Of the 52 IR patients, 28 had (+) LVSI with superficial, middle, and outer 1/3 CSI, and 24 had (-) LVSI with middle or outer 1/3 invasion. Overall, postoperative adjuvant radiation (PRT) was used in 52% of the 86 patients, including 0/5 LR, 16/52 IR, and 29/29 HR patients. Univariate predictors of recurrence were pelvic nodal disease, (+) LVSI, (+) parametria, outer 1/3 CSI, and tumor size > 6 cm. Age, grade, histology, and the use of postoperative radiation were not associated with recurrence. Multivariate analysis identified LVSI as the only independent predictor of recurrence (RR 5.2, P = 0.03). Two-year DFS for LR, IR, and HR patients was 100%, 83%, and 60%, respectively. Only 4/24 (17%) IR patients with (-) LVSI got PRT compared with 12/28 (43%) of IR patients with (+) LVSI. The 2-year DFS for IR patients with (-) LVSI was 96%. IR (+) patients recurred more frequently with a 2-year DFS of 71%.

CONCLUSIONS: Overall, 66% of patients with IB2 disease were classified as having low or intermediate-risk disease. IR patients with (-) LVSI and all LR patients did well with surgery alone. This study defines the independent importance of LVSI and questions the utility of published IR models when applied to stage IB2 cervical cancer.