Ductal Carcinoma in situ after Core Needle Biopsy: In Which Cases Is a Sentinel Node Biopsy Necessary?

Oncological Safety of Skin-Sparing Mastectomy and Immediate Breast Reconstruction in Extensive Ductal Carcinoma In Situ

INTRODUCTION

Skin-sparing mastectomy (SSM) with immediate breast reconstruction is the ideal treatment for interested and suitable patients with extensive ductal carcinoma in situ (DCIS). There is no guideline to indicate on how large DCIS the procedure can be performed safely. The primary target of this study was to define the oncological safety of SSM in extensive pure DCIS. The secondary target was to find predictive factors for DCIS upstaging to invasive disease.

MATERIALS AND METHODS

A total of 71 consecutive patients with extensive pure DCIS and undergoing SSM with immediate latissimus dorsi (LD) breast reconstruction were retrospectively evaluated.

RESULTS

The median size of DCIS lesion in preoperative imaging was 60 mm, the median weight of mastectomy specimen was 350 g, and the median resection margin (RM) was 2.0 mm. A total of 20 patients (28%) had an RM less than 0.5 mm and nine patients (13%) had ink positive margins. Six patients having positive RM underwent reoperation. A total of 29 patients (41%) presented invasive cancer foci in final histopathological assessment and nine patients (13%) had an axillary metastasis. Adjuvant therapy was given to 23 patients presenting invasive cancer. There were no local recurrences or distant metastases (0%, 95% confidence interval 0-0.051) during the mean follow-up of 71 mo. None of the factors evaluated predicted upstaging to invasive disease.

CONCLUSIONS

SSM with immediate breast reconstruction in patients with extensive DCIS is oncologically safe even when the margins are close or positive. Additional invasive foci and solitary axillary lymph node metastases are frequent but do not worsen the outcome.

Necessity of sentinel lymph node biopsy in ductal carcinoma in situ patients: a retrospective analysis

BACKGROUND

Sentinel lymph node biopsy (SLNB) is unnecessarily performed too often, owing to the high upstaging rates of ductal carcinoma in situ (DCIS). This study aimed to evaluate the upstaging rates of DCIS to invasive cancer, determine the prevalence of axillary lymph node metastasis, and identify the clinicopathological factors associated with upstaging and lymph node metastasis. We also examined surgical patterns among DCIS patients and determined whether SLNB guidelines were followed.

METHODS

We retrospectively analysed 307 consecutive DCIS patients diagnosed by preoperative biopsy in a single centre between 2014 and 2018. Data from clinical records, including imaging studies, axillary and breast surgery types, and pathology results from preoperative and postoperative biopsies, were extracted. Univariate analyses using Chi-square tests and multiple logistic regression analyses were used to analyse the data.

RESULTS

The rate of upstaging to invasive cancer was 19.2% (59/307). DCIS diagnosed by core-needle biopsy (odds ratio [OR]: 6.861, 95% confidence interval [CI]: 2.429-19.379), the presence of ultrasonic mass-forming lesions (OR: 2.782, 95% CI: 1.224-6.320), and progesterone receptor-negative status (OR: 3.156, 95% CI: 1.197-8.323) were found to be associated with upstaging. The rate of sentinel lymph node metastasis was only 1.9% (4/202), and all were total mastectomy patients diagnosed by core-needle biopsy. SLNB was performed in 37.2% of 145 breast-conserving surgery patients and 91.4% of 162 total mastectomy patients. Among the 202 patients who underwent SLNB, 145 (71.7%) without invasive cancer on final pathology had redundant SLNB. Two of 59 patients (3.4%) with disease upstaged to invasive cancer had inadequate primary staging of the axilla, as the rate seemed sufficiently small.

CONCLUSIONS

In patients with a preoperative diagnosis of DCIS, although an unavoidable possibility of upstaging to invasive cancer exists, axillary metastasis is unlikely. Only 2.7% of patients with DCIS undergoing total mastectomy were found to have sentinel lymph node metastases. SLNB should not be performed in breast-conserving surgery patients and should be reserved only for total mastectomy patients diagnosed by core-needle biopsy.