114 Radiation Oncology, Biology, Physics October 1987, Volume 13, Supplement 1

by hysterectony and radiothera~py - 60% (26 of 43). When postoperative radiation was given the -pattern of failure did not diEEer from that aEter preoperative radiotherapy. However, &en the dose to pint A was raised to over 70 grays local failures were reduced te 30% as ccanpared to 61% -when the dose was less than 60 grays. In addition, the tie to failure was 38 nronths and 19 mnths reqpectively.

The effect of cell grade on pattern of failures is noticeable where poor grade tunrxs failed locally m3re often than grade 1 tusors - 67% versus 30% indicating that poorly differentiated tuners may be less radiosensitive. In addition, t&a to failure is significantly different, 14 mnth average versus 33 months W=O.O3).

*Salvage therapy seined to be mre successful for patients failing in the pelvis or extra-abdominally, resulting in sow long tenn survival (18% and 22% 8 year survival) while all patients witn akdcnnnal disease succumbed at the 6 year naark. patients .who died with disease after failure shcwed a s-hat si;nilar -pattern with an average survivaL aEter failure of 17 months, 31 months and 10 months respectively. The impact of these findings on treabnent ,oolicy and techniques will be discuss&.

56

PERITONEAL FLUID CYTOLOGY IN ENDOMETRIAL CANCER: ITS SIGNIFICANCE AND THE ROLE OF CHROMIC PHOSPHATE THERAPY.

Robert Heath M.D., Julian Rosenman, Ph.D., M.D., Mahesh Varia M.D., Leslie Walton, M.D.

Departments of Radiation Oncology and Gynecologic Oncology, University of North Carolina, Chapel Hill Positive peritoneal cytology is seen in lo-15% of patients with clinical stage I endometrial carcinoma.

The significance and therapeutic management of these patients remains controversial. Creasman et al have found positive cytology to be the most important prognostic factor for recurrence in clinical stage I patients. They also found intraperitoneal chromic phosphate (P-32) significantly improved intra-abdominal tumor control and disease-free survival. However, Konski et al have recently reported no significant difference in disease-free survival or sites of relapse between positive and negative cytology patients. They were also unable to confirm the value of whole abdominal treatment for positive cytology patients.

At our institution 242 endometrial carcinoma patients (all stages) had peritoneal fluid cytologies performed while undergoing total abdominal hysterectomy and were followed for a median of 30 months. 39 patients (16%) were found to have positive peritoneal cytologies. Of clinical stage I patients, 16% had positive cytologies. At 36 months the disease-free survival for the 165 negative cytology stage I patients was 91%, and significantly worse (p<.OOl) for the 25 positive cytology patients at 56%. The 14 stage I positive cytology patients with greater than one-third myometrial invasion (deep) and/or histologic grade 2 or 3 had a significantly worse disease-free survival than the negative cytology patients with comparable depth of invasion and/or histologic grade. However, there was no difference between the negative and positive cytology clinical stage I patients who had one-third or less myometrial invasion or grade 1 histology.

Of 25 clinical stage I positive cytology patients 14 received 15 mCi of intraperitoneal P-32. At 36 months there was a 68% disease-free survival as compared to 27% for those not receiving P-32 (p=O.Ol). Since 9 of 11 patients with superficical myometrial invaasion or grade 1 histology received P-32 the value of P-32 in this group is unknown. However, the 36 month disease-free survival for patients with deep myometrial invasion was 75% for those who received P-32 (5 patients) and 0% for those not receiving P-32(p=.O2). For histologic grade 2 or 3 patients, there was a 64% 36 month disease-free survival in the P-32 treated group and 16% for those not receiving P-32 (p=O.O2). Twelve recurrences (7%) were found in negative cytology stage I patients with 5 patients having at least a component of locoregional failure. In the 11 positive cytology stage I patients not receiving P-32 there were 7 recurrences with 5 occurring in the abdomen. In the 14 patients receiving P-32 there were 3 recurrences with only one in the abdomen. Nine of the 14 clinical stage I patients receiving P-32 also received pelvic irradiation. Five of 9 experienced bowel obstruction requiring surgery. None of the positive cytology patients treated with radiation only had complications.

Seven of 40 clinical stage II patients had a positive peritoneal cytology. At 36 months the disease-free survival was 59% for the negative cytology group versus 21% for the positive cytology group (p=.OOl). Two of the 7 positive cytology patients received P-32 and both have recurred and died.

In summary, peritoneal cytology is an important prognostic factor for clinical stage I endometrial carcinoma patients with deep myometrial invasion and/or grade 2 or 3 cancers. Furthermore, intraperitoneal P-32 significantly improves disease-free survival and decreases abdominal recurrences. For stage II patients the impact of P-32 was not discernable. Finally, although P-32 appears to significantly improve disease-free survival, when it is combined with pelvic irradiation there is a significant risk of bowel obstruction that must be weighed against the risk of recurrence.