Clinical-pathological features and treatment modalities associated with recurrence in DCIS and micro-invasive carcinoma: Who to treat more and who to treat less

- A register-based study of 865 DCIS and micro-invasive carcinomas has been performed.
- Age at diagnosis and biological features did not differ among ethnic groups.
- Treatment modalities significantly vary according to patient age and ethnicity.
- ER/PR negative DCIS are associated with significantly higher recurrence rate.
- Defining the molecular profile at worse prognosis may help to personalize treatment.

The primary aim in the management of DCIS is the prevention of recurrence and contralateral tumor. Risk factors for DCIS recurrence and appropriate treatments are still widely debated. Adjuvant therapies after surgical resection reduce recurrences and contralateral disease, but these treatments have significant financial costs, side effects and there is a group of low-risk patients who would not gain additional benefit. The aim of our analysis was to identify clinical-pathological features and treatment modalities associated with recurrence in DCIS and microinvasive carcinoma. In the Thomas Jefferson University Cancer Registry of Philadelphia, we identified 865 patients with DCIS or micro-invasive carcinoma treated between 2003 and 2013. Associations between recurrence and demographic factors (age at diagnosis, ethnicity), biological features (ER, PR and HER2) and treatment modalities (surgery, radiotherapy and endocrine treatment) were assessed. Our single institution register-based study showed that distribution of age at diagnosis and biological features did not significantly differ among ethnic groups. Younger women and micro-invasive carcinoma patients were more likely to undergo mastectomy, while African Americans were more likely to take endocrine therapy and undergo radiotherapy. In our sample only ER/PR negative DCIS were associated with significantly higher recurrence rate. Moreover, we reported a high rate of HER2 positive recurrences, suggesting that expression of this oncogene may represent a potential biomarker for DCIS at high risk of recurrence. To better define the molecular profile of the subgroup at worse prognosis might help to identify biomarkers predictive of recurrence or second tumors, identifying patients candidates for more appropriate treatments.