Endometrial Cancer. Part 7
In the recent years, we have classified endometrial cancers into low risk, intermediate risk and high risk and this is to help us decide how we are going to treat endometrial cancer. Low risk is considered a grade I lesion that’s confined to the endometrium that has no extra uterine spread, you can do your hysterectomy and you’re done. Intermediate risk, this is the risk where everybody argues about this woman, needs adjunctive therapy, does not need adjunctive therapy and high risk, everybody can pretty much figure out, grade III deeply invasive or other factors that have high stage disease. If you look at the GOG data, when they broke it down into low risk, intermediate risk and high risk, and this is all on pathological specimens. We see that the low risk group, there were no incidences of pelvic and periaortic lymph, no metastases, and this is a grade I lesion with only endometrial involvement. The intermediate risk, if you had one factor was extremely low, but also we had two factors, your incidence of lymph node metastases was extremely low, so it was less than 10%, though it did exist, and then your high risk group, you were up to 20 to 60%, depending on how many risk factors you had as far as lymph node metastases. I bring the positive peritoneal cytology on this slide, it is an independent prognostic factor, in patient’s who have positive peritoneal cytology will have an apparent stage I, so you surgically stage these patient’s, the tumor is confined to the uterine cavity, there is no lymph node involvement but they have about 10 to 15% will have positive peritoneal cytology. It is unclear how to treat these patient’s. Piver has placed these patient’s who have positive peritoneal cytology with no other risk of lymph node metastases on Megace and restaged them in a year, and of the patient’s who restaged in a year, 80% did not have any further positive peritoneal cytology or positive nodes, 20% still had persistent either cytology or spread of disease and they were placed on Megace for another year and about half of those patient’s when they were restaged the second year had no persistent positive peritoneal cytology or evidence of endometrial cancer. So therefore, based on the Piver study, it is felt that patient’s who have positive peritoneal cytology, whether or not they receive adjunctive radiation therapy or need radiation therapy based on their surgical specimen should undergo Megace progesterone hormonal therapy postoperatively, and this brings us to the treatment of endometrial cancer which I briefly want to get into. If you have a well differentiated endometrial cancer, the obvious solution if the patient is a surgical candidate is to undergo a complete hysterectomy, send the uterus to the pathologist to see if there is deep myometrial invasion and of course always obtain peritoneal washings cause again, 10 to 15% will have positive cytology.
As GYN oncologists we do not send the specimen to pathology, you are asking your pathologist to do an awful lot on a frozen section. Sometimes it’s difficult, sometimes they will upgrade your tumor on the final histology and sometimes they will have foci of deep myometrial invasion or middle third myometrial invasion which cannot be picked up on the gross frozen section, so it’s very difficult to get a frozen section that sometimes 50% of the time can be changed. So in patient’s who undergo hysterectomies for endometrial cancers, I tend to sample their nodes. If, however, the patient has a well differentiated cancer or atypical hyperplasia, and there is not a GYN oncologist or somebody who can sample the nodes, a complete hysterectomy and peritoneal washings, it’s completely appropriate. Further adjunctive therapy would be based on the final hysterectomy specimen and the staging would then go to the old clinical systems.