Node-positive cervical cancer: Impact of pelvic irradiation and patterns of failure

Purpose: The roles of postoperative pelvic and prophylactic paraaortic irradiation in pelvic node positive cervical cancer are currently controversial. A retrospective study was undertaken to examine the effect of pelvic irradiation on pelvic control and survival and to analyze the patterns of recurrence to determine whether indications exist for prophylactic paraaortic irradiation. Methods and Materials: From 1964 to 1991, 143 cases of FIGO Stage I and II cervical cancer undergoing explanatory laparotomy, pelvic lymph node dissection, and radical hysterectomy had positive pelvic lymph nodes. Postoperatively, 108 cases were treated with whole pelvic irradiation while 35 patients were observed. Prophylactic paraaortic irradiation was not given. Results: Patients who received postoperative whole pelvic irradiation compared with those treated with radical hysterectomy alone had a significantly improved pelvic control rate, disease-free survival (DFS), and overall survival. The 5-year actuarial pelvic control rate was 78% vs. 45% (p = <0.0001), respectively. The 5-year actuarial DFS was 65% vs. 41% (p = 0.0004). The 5-year actuarial overall survival was 58% vs 46% (p = 0.02). In multivariate analysis, pelvic irradiation continued to show a positive effect on DFS (p = 0.0001) and overall survival (p = 0.0035). Lymphatic invasion and the total number of positive lymph nodes were the only other independent predictors of overall survival and DFS. The actuarial 5-year pelvic, paraaortic, and distant failure rates were 30%, 10%, and 28%, respectively. An isolated first recurrence in the paraaortic nodes occurred in only three cases. Conclusion: Postoperative pelvic irradiation significantly improves pelvic control, DFS, and overall survival, and should be used in patients with early stage cervical cancer and pathologically proven pelvic nodal metastases. The low incidence of isolated paraaortic nodal failure calls into question the value of routine porphylactic paraaortic irradiation in these patients.