Comparative Study On Clinicopathological Characteristics And Prognosis Of Ductal Carcinoma In Situ With Or Without Concomitant Paget Disease

Background and Objective:Paget disease is a rare cutaneous adenocarcinoma that targets mainly the nipple‐areola complex of the breast as well as the genital and perianal skin.Most mammary Paget disease is associated with underlying in situ or invasive breast cancer.According to underlying malignancy,mammary Paget disease can be divided into three groups: Paget disease with invasive ductal carcinoma,Paget disease with ductal carcinoma in situ,and Paget disease of the nipple without concurrent breast cancer.A previous study suggested that compared with invasive ductal carcinoma without Paget disease,Paget disease with invasive ductal carcinoma has more aggressive pathology characteristics,which may lead to poor prognostic outcomes and reduced survival.Nevertheless,little is known about Paget disease with ductal carcinoma in situ clinicopathologic features,especially the differences in these characteristics compared with those of ductal carcinoma in situ alone.The objective of this study was to compare the clinicopathological characteristics and prognosis between Paget disease with ductal carcinoma in situ and ductal carcinoma in situ alone.Methods:The study retrospectively analyzed 92 patients with the diagnosis of Paget disease with ductal carcinoma in situ and 728 patients with the diagnosis of ductal carcinoma in situ alone,who underwent surgical treatment in Tianjin Medical University Cancer Hospital from January 2014 to October 2018.Independent demographic and clinicopathological variables of patients of Paget disease with ductal carcinoma in situ were compared to patients with ductal carcinoma in situ.Continuous variables such as age were compared using Student’s t test,and categorical variables were compared using Pearson’s chi‐square test.All the statistical analyses were performed using SPSS version 25.0 statistical software.Results:1、The median age of patients with Paget disease combined with ductal carcinoma in situ is 55.51 years old,and the median age of patients with pure ductalcarcinoma in situ is 50.63 years old(P = 0.000).2、The ER negative expression rate of patients with Paget disease complicated with ductal carcinoma in situ was 85.9%,and the ER negative expression rate of patients with pure ductal carcinoma in situ was 21.8%(P = 0.000).3、The PR negative expression rate of patients with Paget disease complicated with ductal carcinoma in situ was 91.3%,and the PR negative expression rate of patients with pure ductal carcinoma in situ was 30.2%(P = 0.000).4、The rate of HER2 positive expression in patients with Paget disease and ductal carcinoma in situ was 66.3%,and the rate of HER2 positive expression in patients with pure ductal carcinoma in situ was 26.1%(P = 0.000).5、59.8% of patients with Paget disease complicated with ductal carcinoma in situ showed high expression of Ki67,and 21.5% of patients with pure ductal carcinoma in situ showed high expression of Ki67(P=0.000).6、30.4% of patients with Paget disease complicated with ductal carcinoma in situ had histological grade III,and 15.2% of patients with pure ductal carcinoma in situ had histological grade III(P = 0.000).7、There is a difference in tumor size between patients with Paget disease complicated with ductal carcinoma in situ and patients with ductal carcinoma in situ alone(P=0.000).Conclusion:1 、 Compared with patients with pure ductal carcinoma in situ,patients with Paget disease complicated with ductal carcinoma in situ have a higher age at diagnosis.And there is a difference in tumor size.2 、 Paget disease with ductal carcinoma in situ had more aggressive tumor clinicopathological characteristics than ductal carcinoma in situ alone.such as a lower ER‐positive ratio,lower PR-positive ratio,higher HER2‐positive ratio,Ki67 high expression,and higher histologic grade.3、Compared with patients with pure ductal carcinoma in situ,most patients with Paget disease complicated with ductal carcinoma in situ have no effect on endocrine therapy.