Is endometrial carcinoma intrinsically more aggressive in elderly patients? Kaled M. Alektiar, M.D. Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 The current study was conducted to determine the influence of old age (age 70 years) on outcome in a group of patients with endometrial carcinoma who were treated with simple hysterectomy followed by adjuvant radiation therapy (RT). Between November 1987 and May 2000, 405 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB-II endometrial carcinoma were treated with postoperative RT. Intravaginal RT alone was given to 77% of patients (median dose, 21grays [Gy] given in 3 fractions). Additional postoperative external beam radiation therapy (EBRT) was given to 23% of patients (median dose, 45 Gy). Eighty-four patients were age 70 years and 321 patients were age < 70 years. The two groups were well balanced with regard to race, comprehensive surgical staging, aggressive histology, lymphovascular invasion, lower uterine segment involvement, cervical involvement, and the use of postoperative EBRT. Significantly more patients in the age 70 years group had other comorbidities such as obesity, diabetes mellitus, or hypertension (P = 0.02) and were found to have deep (> 50%) myometrial invasion (P = 0.008). With a median follow-up time of 48 months, the 5-year locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) rates were 95%, 91%, and 90% respectively. On multivariate analysis, poor LRC was found to be correlated with age 70 years (P = 0.019) and lymphovascular invasion (P = 0.001). Poor DFS was found to be correlated with age 70 years (P = 0.03), lymphovascular invasion (P = 0.01), and aggressive histology (P = 0.001). Similarly, poor OS was found to correlate with age 70 years (P = 0.001), lymphovascular invasion (P = 0.01), aggressive histology (P = 0.01), and cervical involvement (P = 0.02). The same factors that were found to correlate with OS (age 70 years, lymphovascular involvement, aggressive histology, and cervical involvement) also appeared to correlate with disease-specific survival (P = 0.03, P = 0.008, P = 0.001, and P = 0.04, respectively). The 5-year actuarial rates of Radiation Therapy Oncology Group late complications that were Grade 3 (gastrointestinal tract, genitourinary tract, or vagina) were 3% in both groups. CONCLUSIONS Even when treated in a similar fashion, endometrial carcinoma patients age 70 years appear to fare worse than younger patients independent of other poor prognostic factors. The rate of complications from adjuvant RT, despite a higher rate of comorbidity in elderly patients, was found to be similar in both age groups. Endometrial carcinoma appears to be intrinsically more aggressive in older patients, thus mandating further improvement in their treatment strategies.       Cancer 2003;98:2368