title: Long-term survival of patients with mismatch repair protein-deficient, high-stage ovarian clear cell carcinoma.
abstract: OBJECTIVE
  Gynaecological cancer patients with germline mutations appear to have a better prognosis than those with sporadic malignancies. Following the observation of long-term survival in a patient with stage III ovarian clear cell carcinoma (CCC) and possible Lynch syndrome (LS), DNA mismatch repair (MMR) protein immunohistochemistry was performed in a series of high-stage CCC and correlated with patient outcomes.
  
  
  RESULTS
  Thirty-two consecutive cases of stage III/IV ovarian CCCs accessioned between 1992 and 2015 were examined. The tumours from two patients (6%), including the index case, showed loss of MSH2/MSH6 expression while MLH1/PMS2 staining was retained. The index patient subsequently developed colonic and rectal carcinomas that were also MSH2/MSH6-deficient, while the second patient had a genetically confirmed germline MSH2 mutation. All other tumours showed retained expression of the four MMR proteins. The two patients with MMR protein-deficient tumours were alive 160 months and 124 months following surgery, whereas the median survival of patients with MMR protein-intact CCCs was 11.8 months (75th and 25th percentiles of 8.1 months and 39.3 months, respectively), with 21 patients deceased due to tumour.
  
  
  CONCLUSIONS
  Larger studies are required but high-stage, MMR protein-deficient CCCs may have a relatively favourable prognosis.
authors.affiliation: Department of Pathology, King Edward Memorial Hospital, Perth, Western Australia, Australia.|School for Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Colin J R
authors.initials: CJ
authors.lastname: Stewart
authors.affiliation: Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.|Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: David D L
authors.initials: DD
authors.lastname: Bowtell
authors.affiliation: School for Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Dorota A
authors.initials: DA
authors.lastname: Doherty
authors.affiliation: School for Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.|Department of Gynaecological Oncology, King Edward Memorial Hospital, Perth, Western Australia, Australia.
authors.forename: Yee C
authors.initials: YC
authors.lastname: Leung
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000235:genetics* / Q000401:mortality; D000328:Adult; D000368:Aged; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000150:complications*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000401:mortality*
keywords: clear cell carcinoma; lynch syndrome; ovary; prognosis; stage