SP8.1.8 Factors influencing the post-operative upgrade of ductal carcinoma in situ (DCIS) to invasive cancer

Abstract Aims Ductal carcinoma in situ (DCIS) can be upgraded on pathological histology to invasive cancer and require a subsequent sentinel node biopsy (SNB). This second procedure increases the morbidity costs of treating DCIS. Our study aims establish proportion preoperatively diagnosed DCIS that is identify factors associated with this upgrading. Method A retrospective review was conducted 122 consecutive patients undergoing surgery following diagnosis percutaneous at our institution, from 1st January 2017 30th November 2019. Histological upgrade evaluated against clinical, radiological parameters. Results Of patients, 31 (25.4%) were upgraded, 11 (9.1%) having microinvasive disease (T1mi) only. third group (n = 11) did not have SNB during initial surgery. Upgraded younger (median 54yrs v 62yrs P 0.005), had higher BMI 28.9 26 0.02) more likely palpable lesion (41.9% 14.9% < 0.001). Multivariate logistic regression analysis showed mass detected ultrasound (OR 3.6 0.04), lump 5.2 0.03) finding high grade 11.9 0.001) independently final tumour upgrade. In contrast, vacuum assisted less after 0.23 Conclusion Patients BMI, lump, showing are increased risk harbouring should considered for