Improved outcome in patients treated with postoperative radiation therapy for pathologic stage I/II endometrial cancer

: To evaluate prognostic factors and treatment outcome for high risk pathological Stage I and II endometrial cancer patients treated with consistent postoperative radiation therapy (RT) in a single institution and to compare these results to series where RT was variably applied.

: Between 1986 and 1993, 98 pathologic Stage I and II endometrial cancer patients received postoperative RT at the Fox Chase Cancer Center. Papillary serous and clear cell histologies were excluded. Fifty-five patients underwent lymph node evaluation. In 17 patients, RT consisted of intracavitary brachytherapy alone to a median dose of 21 Gy, and in 81 patients, RT consisted od external beam RT to a median dose of 45 Gy followed by intracavitary brachytherapy to a median dose of 12 Gy. Intracavitary brachytherapy generally consisted of three high dose rate implants with the dose prescribed to a depth of 0.5 cm. Median follow up was 47 months.

: The 5-year overall survival (OS), disease free survival (DFS), and freedon from pelvic recurrence (FPR) rates were 83, 85, and 89%, respectively. Pelvic recurrence either as the sole pattern of failure or combined with distant metastases was seen in 2 and 7% of patients, respectively. Distant metastases alone occurred in 4% of the patients. Univariate analysis of prognostic factors including age, grade, capillary lymphatic space invasion, depth of myometrial invasion, type of lymph node evaluation, pathologic stage, the use of brachytherapy and the number of risk factors was perfomed for OS, DFS, FPR, and FDM. Capillary kymphatic space invasion was the only statistically significant predictor for reduced DFS. Absence of lymph node dissection as well as a higher number of risk factors showed a trend toward poorer DFS (p = 0.06 for both). Multivariate analysis revealed older age to be the only factor significant for reduced DFS, with the presence of capillary lymphatic space invasion and the absence of a lymph node dissection showing a trend toward poorer outcome (p = 0.07).

: The results of this study suggest a continued role for the use of postoperative RT in the treatment of patients with high risk endometrial cancer and eill be compared tp other series with similar high-risk factors.