Risk of Recurrence and Patterns of Failure in Estrogen Receptor-Negative Ductal Carcinoma In Situ Patients

Abstract

Ductal carcinoma in situ (DCIS) constitutes 15%-25% of newly diagnosed breast cancers. Similar to invasive breast cancer, DCIS tumors vary in terms of immunohistochemistry markers and pathological variables. For invasive carcinoma, treatment options and prognosis depend on these factors, including the expression of estrogen receptors (ER). ER negative (ER-) invasive breast cancers are known to be more aggressive. Treatment guidelines and prognosis for DCIS, however, are less well defined. Compared to ER+ DCIS, ER- DCIS is a far less common diagnosis, with 75% of DCIS expressing ER receptors. Data specific for ER- DCIS patients are thus lacking. The objective of this study was to investigate recurrence rates and patterns of failure of ER- DCIS in a single institution, and compare these statistics to the historic predominantly ER+ data in attempt to enhance risk stratification methods for DCIS patients in the future.We performed a retrospective review of medical records of DCIS patients diagnosed between 2004 and 2018, identifying 138 patients with ER negative tumors. 22 patients were lost to follow up immediately after diagnosis and were excluded from further analysis. Median follow up time for the remaining 116 patients was 46.5 months. Data on recurrence were collected. Statistical analysis included descriptive statistics, chi-square test, T-test for independent samples, and logistic regression.11 (9.5%) patients were found to have breast cancer recurrence. Median time to recurrence was 37 months. 8 (72.7%) patients developed a non-invasive recurrence (DCIS), with the remaining patients diagnosed with invasive ductal carcinoma (IDC). The recurrence was ipsilateral in 7 (63.6%) patients, and contralateral in the remaining 4 (36.4%). All DCIS recurrences were ER- as opposed to IDC recurrences, all of which expressed ER receptors. Patients who developed a recurrence underwent a lumpectomy 90.9% of the time for their initial resection, compared with 56.2% of patients with non-recurrent DCIS. We next evaluated the use of adjuvant RT, RT dose, tumor grade, size, presence of necrosis, and width of surgical margins as predictors of recurrence. Neither rates of RT administration, nor the RT dose were significantly different between the patients who developed recurrent disease versus those who did not. There was a trend toward higher recurrence for patients with high grade DCIS (grade 3) and presence of necrosis. Other factors (tumor size, presence of necrosis, and width of excision margins) did not predict for recurrence risk in our sample.Contrary to expectations, ER- DCIS recurrence rates were similar to previously reported DCIS recurrence rates. This is in contrast to the well described findings for ER- invasive carcinomas. Future prospective studies are needed to further evaluate the outcomes for this patient population.