Objective: Serous papillary carcinomas of
the endometrium are aggressive tumors that tend to
permeate, in a very extensive fashion, to uterine and
adnexal lymphatic and vascular channels at an early
stage in their evolution, and are associated with a
particularly gloomy prognosis. It is generally thought
that even tumors apparently limited to the endometrium
or confined to an endometrial polyp have a poor
outcome. Our study points towards the value of HLADR
antigen in the outcome of serous papillary
endometrial cancer. Our aim was to assess the HLA-DR
expression in inactive, endometrial intraepithelial
carcinoma (EIC), and invasive serous carcinoma
curretage specimens from the endometrial cavity,
suggesting a role inimmune response to keep tumor
proliferation in check. Study design: Thirty-one cases of
inactive endometrium, twelve cases of EIC, and thirtynine
cases of serous papillary invasive carcinoma
curettings were evaluated for the detection of HLA-DR
monoclonal antigen. T helper (TH) marker (CD4) in the
tumor stroma of the relevant cases was also studied,
given that it is now known that the dependence of
immune responsiveness on the class II antigens reflects the central role of these molecules in presenting antigen
to TH cells. Results: HLA-DR was expressed in 20 of 31
inactive endometrium (64.5%), 4 of 12 in EIC (33.3%),
and in 10 of 39 serous papillary invasive carcinomas
(25.6%). CD4 was expressed in 9 of 31 inactive
endometrium (29%), 5 of 12 in EIC (42%), and in 26 of
39 serous papillary invasive carcinomas (67%).
Conclusions: The results showed decreased expression
of HLA-DR and increased expression of CD4 as the
lesion progressed to malignancy. The aberrant
expression of HLA-DR by epithelial cells of inactive
endometrium, of EIC and of serous papillary invasive carcinomas agrees with the hypothesis of the inactive
endometrium - carcinoma in situ sequence as the usual
route for the development of serous papillary invasive
carcinoma. The immune attract mechanism by low
HLA-DR signaling seems to be of minor importance in
the malignant and metastatic potential of the serous
papillary endometrial tumours