Abstract 5747
Background
The use of sentinel lymph node biopsy (SLNB) during breast surgery for ductal carcinoma in situ (DCIS) is controversial. It is accepted in high risk lesions (high histological grade, palpable, large >25 mm, and multifocal lesions) since it avoids a second operation if the definitive diagnosis reveals infiltrating ductal carcinoma (IDC) and its recommended due to some technical obligations in patients with planned total mastectomy or with tumor localization to the upper outer quadrant.. We aimed to evaluate the use of SLNB in patients with preoperative diagnosis of high risk DCIS lesions.
Methods
A monocentric retrospective study was conducted on 467 patients with primary diagnosed DCIS operated for partial or total mastectomy with or without SLNB. The frequency of each risk factor, and the incidence of IDC were calculated in the overall series. The predictive value of each risk factor is calculated by comparing these factors in the groups depending to the definitive pathology (IDC vs DCIS) using the chi square test. A value of p < 0.05 was considered significant.
Results
Breast surgery was done within a median of 42 ± 23 days of DCIS diagnosis. Median age was 57± 10 years. High risk DCIS lesions accounted for 73.1% of all cases (342/468). Grade III lesion, multifocal, palpable and larger than 25 mm lesions were present in 263 (56.3%), 61 (13.1%), 86 (18.4%) and 99 (21.2%) respectively. IDC was diagnosed in 95/468 patients (20.3%) in the global series and in 75patients/342 (22%) in the patients with high risk lesions. A palpable lesions and a tumor diameter >25 mm were associated with higher risk of invasive carcinoma (p = 0.007 and p = 0.017 respectively).Overall SLNB was done in 383 patients (82%), of which 318 patients (83%) had high risk lesions. A Positive SLN was detected in overall 5 patients (1.3%), all of which had high risk lesions (5/318: 1.6%).
Conclusions
In our study, the preoperative classification of high risk lesion showed a 79% sensitivity (75/95) and a 22% specificity (75/342) of detecting IDC. A positive SLN was found in only 1.6% of patients with high risk CDIS lesions operated for SLNB. The use of SLNB in patients with high risk DCIS avoids reoperation in 22% of cases. Nevertheless the low risk of positive SLN finding in this setting cannot justify its routine use.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Jean Marie Nogaret.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2104 - Clinical implications of regorafenib-induced hypothyroidism in metastatic colorectal cancer refractory to standard therapies: A prospective evaluation
Presenter: Jwa Hoon Kim
Session: Poster Display session 2
Resources:
Abstract
2143 - Clinical impact of BRAF V600E mutations in patients (pts) with resectable solitary colorectal liver metastases (CRLM)
Presenter: Shin Kobayashi
Session: Poster Display session 2
Resources:
Abstract
3136 - Trifluridine/tipiracil in metastatic colorectal cancer: an updated multicentre real-world analysis on efficacy, safety and predictive factors.
Presenter: Chara Stavraka
Session: Poster Display session 2
Resources:
Abstract
4234 - Correlation between p53 expression and clinical outcome in RAS/BRAF wild type metastatic colorectal cancer patients receiving later-line irinotecan-cetuximab
Presenter: Eleonora Lai
Session: Poster Display session 2
Resources:
Abstract
4287 - Safety and effectiveness of aflibercept + FOLFIRI for the treatment of patients with metastatic colorectal cancer (mCRC): OZONE secondary analyses
Presenter: Ian Chau
Session: Poster Display session 2
Resources:
Abstract
1820 - A Phase Ib study of the safety and efficacy of atezolizumab (atezo) + bevacizumab (bev) + cobimetinib (cobi) in patients (pts) with metastatic colorectal cancer (mCRC)
Presenter: Johanna Bendell
Session: Poster Display session 2
Resources:
Abstract
5644 - Development and validation of a metastasis-associated immune prognostic model for concurrent metastatic colorectal cancer
Presenter: Zhiwen Luo
Session: Poster Display session 2
Resources:
Abstract
5697 - Prognostic role of blood cell count-based immuno-inflammatory parameters in the Valentino trial
Presenter: Giovanni Fuca
Session: Poster Display session 2
Resources:
Abstract
4704 - Evaluation of safety, immunogenicity and preliminary efficacy of PolyPEPI1018 vaccine in subjects with metastatic colorectal cancer (mCRC) with a predictive biomarker
Presenter: Joleen Hubbard
Session: Poster Display session 2
Resources:
Abstract
3266 - Morphology of tumor-associated macrophages dictates the prognosis of patients with colorectal liver metastases.
Presenter: Matteo Donadon
Session: Poster Display session 2
Resources:
Abstract