Significance Of CK7,PAX8,SATB2,CK20,CDX2,Tumor Size,and Laterality In Distinguishing Mucinous Ovarian Cancer From Gastrointestinal Metastases

Objective:Due to the similarity of biological behavior between primary mucinous ovarian carcinoma(PMOC)and gastrointestinal metastatic ovarian mucinous carcinoma,it is usually difficult to determine the source of mucinous carcinoma in clinic.This article mainly discusses the application of immunohistochemical indexes CK7,PAX8,SATB2,CK20,CDX2 combined with clinical characteristics of tumor size and laterality in the differentiation of primary mucinous ovarian tumors and metastatic ovarian mucinous carcinoma of the gastrointestinal tract,aiming to improve the accuracy of clinical diagnosis provides new ideas for differential diagnosis.Method:A total of 142 cases of primary and gastrointestinal metastatic ovarian mucinous tumors that were surgically removed from the Affiliated Hospital of Qingdao University from February 2013 to July 2020 were collected.61 cases of primary ovarian mucinous carcinoma,225 cases of primary borderline ovarian mucinous tumors.57 cases of large intestine metastatic ovarian mucinous carcinoma,including 22 cases of appendix metastatic ovarian mucinous carcinoma,35 cases of colorectal metastatic ovarian mucinous carcinoma and 26 cases of gastric metastatic ovarian mucinous carcinoma.Each specimen was reviewed and confirmed by two experienced pathologists in accordance with the 2014 WHO classification standards.Collect all patients’ age,tumor size,laterality and other clinical characteristics.The immunohistochemical method was used to detect the expression of CK7,PAX8,SATB2,CK20,and CDX2 in primary and gastrointestinal metastatic ovarian mucinous tumors.Analyze the application of immunohistochemical indexes,tumor size and laterality in the identification of mucinous carcinoma of ovarian and gastrointestinal origin.Results:(1)82.4%(117/142)of primary ovarian mucinous carcinoma had a tumor diameter of >10cm,57.9%(33/57)of colorectal metastatic carcinoma had a tumor diameter of≤10cm,and 73.1%(19/26)of gastric metastatic carcinoma had a tumor diameter of≤10cm.PMOC was mostly unilateral(132/142,91.9%),colorectal metastases were mostly bilateral ovarian metastases(39/57,68.4%),and gastric metastases were also bilateral(21/26,80.8%).(2)The positive expression rate of CK7 in PMOC and gastric metastases was significantly higher than that in colorectal metastases,with statistical differences(P<0.05).There was no statistical difference in the expression rate of CK7 in PMOC and gastric metastases(P>0.05).The positive expression rate of SATB2 in colorectal metastatic cancer was as high as 91.2%(52/47),which was significantly higher than PMOC(7.0%)and gastric metastatic cancer(3.8%),and the difference was statistically significant(P<0.05).The positive expression rate of PAX8 in PMOC was higher than that in colorectal and gastric metastatic cancers,with statistical differences(P<0.05).Only 1(1.8%)of 57 cases of colorectal cancer expressed PAX8,and gastric metastatic cancers did not express PAX8.The positive expressions of CK20 and CDX2 in PMOC and colorectal metastases,gastric and colorectal metastases were statistically different(P<0.05).(3)Simple combination of immunohistochemical indexes,CK7/PAX8/SATB2 has the highest accuracy rate(83.4%).Among all immunohistochemical indexes,tumor size,and laterality combined comparison,CK7/PAX8/SATB2/size/laterality The diagnostic sensitivity is 97.2%,the accuracy is 96.5%,the Youden index is 91.9%,the specificity is94.7%,the positive predictive value and the negative predictive value are both above 90%,except for the specificity and negative predictive value,all indicators are It is the highest among all combinations and individual immunohistochemical indexes.Conclusion:The positive expression of CK7 is very likely to be primary ovarian or gastric metastases,but metastatic colorectal cancer cannot be ruled out.The positive expression of PAX8 should be highly suspected of primary mucinous carcinoma of the ovary rather than metastatic carcinoma of the gastrointestinal tract.The positive expression of SATB2 should be highly suspected of metastatic colorectal cancer rather than ovarian and stomach origin.Because CK20 and CDX2 have more overlapping expressions in primary and metastatic tumors,the clinical application is limited.Even if CK20 and CDX2 are positively expressed,the possibility of ovarian origin cannot be ruled out.The combination of CK7/PAX8/SATB2/tumor size/laterality has the highest accuracy and Youden index,and the combined diagnostic performance is significantly better than the combination of single or multiple immunohistochemical indicators and clinical features.