Christina Choy

Predictors of positive margins after local excision of ductal carcinoma in situ

BACKGROUND This study aimed to examine the association between clinicopathologic parameters and positive margins in women with ductal carcinoma in situ (DCIS) treated by breast-conserving surgery (BCS). METHODS We retrospectively reviewed the clinical, radiologic, and pathologic data of 100 women who had undergone BCS for DCIS in our center. RESULTS Sixty-seven percent of patients presented via breast screening and 55% of all cases were diagnosed preoperatively on fine needle aspiration cytology ([FNAC] ie, C5). Overall, 45% of patients had clear margins after initial local excision. Positive margins showed a nonsignificant trend of association with distribution of microcalcifications (MCC), nonconsultant operating surgeon, inconclusive preoperative FNAC, presence of necrosis, and low specimen weight. There was a highly significant association between low grade DCIS (P = 0.003) and incomplete excision. There was no significant association with age, associated invasive focus, morphology of MCC, or with mode of presentation. CONCLUSION Positive margins after local excision of DCIS are significantly associated with low nuclear grade, and preoperative determination of nuclear grade by core biopsy may have surgical implications.

Towards optimal treatment of ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer with a variable biological behavior which is difficult to accurately predict using the current clinico-pathological parameters. Randomized controlled trials have demonstrated that adjuvant radiotherapy (RT) reduces the risk of local recurrence after adequate local excision of DCIS. Tamoxifen may be considered as an adjuvant endocrine treatment in patients with high risk estrogen receptor positive disease. There is however a growing consensus that RT can be safely omitted in a subgroup of patients with favorable biological features in order to avoid overtreatment. The sentinel node biopsy is not routinely indicated but should be considered in women undergoing mastectomy for DCIS. The discovery of molecular signatures that accurately predict the biological behavior of this common malignancy will facilitate a personalized treatment approach in the future.

Abstract P4-13-13: The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction

Introduction: The concept of “conservative” mastectomy with breast reconstruction has led to a huge positive impact on the quality of life of breast cancer survivors. In 2015, 106,338 breast reconstructions were performed with implant-based reconstruction (IBR) constituting 86,013 (80.9%) of those procedures. Technically speaking, there is still no consensus on the most accurate method of assessing the size of implant used to achieve the desirable aesthetic results and symmetry. Some surgeons use the volume of the mastectomy specimen, believing that the volume of the implant replacing the volume of breast tissue removed is a logical way of thinking. Others prefer to depend on the weight of the specimen owing to the presumption that a mixture of fat and fibroglandular tissue will give an approximate overall density of 1.0g/cm3. To the authors9 knowledge, the correlation between the mastectomy specimen volume and weight has been scarcely reported in the literature. Materials and Methods: Patients undergoing nipple or skin-sparing mastectomy with immediate IBR at the London Breast Institute between January 2014 and December 2016 were included in this study. They were under the care of two senior Oncoplastic breast surgeons. Data on breast weight and volume as well as the size of implants used were prospectively collected. The volume of the breast tissue was assessed by volume displacement method while the weight was measured on a scale in grams. The exclusion criteria included patients with mastectomy specimen weighing more than 2000 grams. Further subgroups were divided into patients younger and those older than 50 years old. The presence or absence of cancer was also reviewed to assess whether the tumor tissue would have heavier weight when compared with volume. Results: Between January 2014 and December 2016, a total of 236 mastectomies were performed, of which 144 were accompanied with IBR. The mean age of the patients was 45 years (range= 25-74). There were 79 right and 65 left breast specimens. Among these cases, 36 were bilateral. Tissue volume and weight had a strong direct correlation (N=144, R=0.99, P Conclusions: Our study has shown that mastectomy specimen weight and volume have close enough correlation. The volume measurement was best estimated to the nearest 25 to 50 mls. On the other hand, the weight assessment was more accurate, objective, easier, and more reproducible with minimal inter-observer error. Hence, we believe that the breast weight can be reliably used to estimate the size of the implant. However, there are many other factors that should be taken into consideration when choosing an implant. For instance, the woman9s wish for smaller or larger size, the width and height of the breast base, and the availability of a wide range of implants. Citation Format: Wazir U, El Hage Chehade H, Choy C, Kasem A, Mokbel K. The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-13.