Aims: Traditional management of advanced ovarian carcinoma is surgical debulking followed by chemotherapy; however, there is an increasing tendency for neoadjuvant chemotherapy followed by surgery. The morphology of ovarian carcinoma following chemotherapy often differs markedly from native tumour. This study aimed to compare the immunophenotype of post-chemotherapy ovarian carcinomas with that of untreated tumour.
Methods: Post-chemotherapy ovarian carcinomas (n = 16) were stained with a range of antibodies. In six cases, pre-chemotherapy core biopsies were also stained; all were high-grade serous carcinomas. Antibodies used in the study were CK7, CA125, WT1, ER, PR, p53, p16, p63 and MIB1.
Results: In eight post-treatment cases, there was minimal or no morphological response to chemotherapy, and in eight there was a significant response (in two additional cases, no residual tumour was identified). All pre-chemotherapy biopsies showed diffuse positivity of the tumour cells with CK7, CA125 and WT1. ER, p53 and p16 were diffusely positive in five, four and three cases respectively. One case was focally PR positive, and all were p63 negative. MIB1 staining was high; all but one case exhibited a proliferation index of >60%. Post-chemotherapy tumours exhibited a similar immunophenotype: diffuse positivity with CK7 in all cases and with CA125, WT1, ER, p53 and p16 in the majority, an immunophenotype in keeping with a serous carcinoma. All were negative with p63, and all but two with PR. The MIB1 proliferation index was lower in those cases exhibiting a significant morphological response, and p53 was less likely to be positive in cases with minimal or no response.
Conclusions: The immunophenotype of post-chemotherapy ovarian carcinomas is very similar to that of native untreated tumours, illustrating that CK7, CA125, WT1, ER, p53 and p16 may be of value in identifying residual tumour cells and in subtyping the neoplasm if a pre-chemotherapy biopsy has not been obtained.