Medically inoperable stage I endometrial carcinoma: a few dilemmas in radiotherapeutic management

The aggressiveness of radiation therapy for patients with medically inoperable endometrial carcinoma is controversial. Patients may die of their underlining medical disease before succumbing to cancer. We try to identify certain subgroup of patients who might benefit most from an aggressive approach and also investigate the impact of residual tumor present in dilatation and curettage (D&C) specimen obtained in second intracavitary implant (ICI).

From 1965 to 1990, 101 patients were treated for clinical clinical Stage I endometrial carcinoma with RT alone due to medical problems. Ages ranged from 39 to 94 years (median 71 years). There were 18 patients with clinical Stage IA and 83 with clinical Stage IB disease. Histology included 44 well-differentiated, 37 moderately differentiated, and 20 poorly differentiated tumors. Radiation therapy consisted of external beam only in 3 patients, ICI alone in 26, whole pelvis plus ICI in 10, and whole pelvis plus split field plus ICI in 62. A second D&C was performed on 26 patients at the time of the second ICI. Minimum follow-up was 2 years (median, 6.3 years).

The 5-year actuarial disease-free survival (DFS) for the studied cohort is comparable to the expected survival of an age-matched population. Pelvic control was 100% for Stage IA and 88% for Stage IB with 5-year disease-free survivals of 80 and 84%, respectively. We also observed a greater disassociation of DFS and overall survial among patients older than 75 years (84 and 55%, respectively) than in younger patients (84 and 78%, respectively). This is mainly because older patients succumbed to their medical illness. Well-differentiated disease demonstrated the trend toward a better outcome than moderately or poorly differentiated lesions in Stage IB patients (p = 0.05), but not in Stage IA patients. Aggressive radiation therapy approach showed the trend toward a better result in Stage IB patients 75 years of age or younger. There were two failures among 19 patients with no tumor found in the D&C specimen at the time of second implant. In contrast, seven patients with residual tumor seen in the endometrial sample at the time of second implant remain disease free.

Radiation therapy alone is an effective treatment modality for medically inoperable Stage I endometrial carcinoma. Disease-free survival can be translated into longer overall survival in the younger age group, but not in older patients. The latter tend to die of their underlining medical illness. Tumor differentiation influenced the prognosis of Stage IB disease. No tumor seen in the endometrial sampling at the time of second implant did not correlate with a better disease control, and the treatment plan should not be modified on such information.