The prognostic value of C-ERB B2(Her-2/neu) expression in patients with ductal carcinoma in situ of breast

Objective: Breast cancer is the most common cancer in women and the most common cause of mortality. Ductal carcinoma in situ (DCIS) is a precursor lesion of breast cancer. Her-2 is an important prognostic and predictive factor in invasive breast cancer. Studies are ongoing to determine the prognostic significance of Her-2 expression in DCIS. In our study, we aimed to evaluate the prognostic importance of her-2 overexpression in DCIS, the relationship of Her-2 with clinical and pathological factors, and factors associated with ipsilateral recurrence and disease-free survival. Material And Method: In our study, 179 patients who were diagnosed with pure DCIS and received breast-conserving treatment at Ondokuz Mayıs University Faculty of Medicine Hospital between January 2005 and December 2022 were evaluated. These patients were evaluated according to age, tumor size, nuclear grade, surgical margin, presence of comedo necrosis, hormone receptor status, Her-2 status, and Ki-67 index. Results: 53 of 179 patients were Her-2 positive and 129 Her-2 negative. Her-2 positivity was found to be associated with larger tumor size, high nuclear grade, presence of comedo-type necrosis, estrogen and progesterone receptor status negative, and high Ki-67 index. Ipsilateral recurrence was seen in 27 patients. Of these, 17 were Her-2 positive and 10 were Her-2 negative. Her-2 positive patients had more recurrences than Her-2 negative patients. Larger tumor size, high nuclear grade, presence of comedo necrosis, surgical margin less than 1 mm, Her-2 positivity, high Ki-67 index were found to be associated with ipsilateral recurrence and shorter disease-free survival. It was observed that the high Her-2 positive/Ki-67 index patient group was associated with more relapses and shorter survival than the Her-2 negative and low Ki-67 index patient group. Discussion and Conclusion: Although Her-2 positivity is associated with aggressive tumor features in DCIS, its relationship with ipsilateral recurrence and disease-free survival is controversial. In our study, Her-2 positivity was found to be associated with more aggressive tumor features, higher risk of ipsilateral recurrence, and shorter disease-free survival in patients with pure DCIS.