title: Sentinel lymph node biopsy can be omitted in DCIS patients treated with breast conserving therapy.
abstract: Breast cancer guidelines advise sentinel lymph node biopsy (SLNB) in patients with ductal carcinoma in situ (DCIS) on core biopsy at high risk of invasive cancer or in case of mastectomy. This study investigates the incidence of SLNB and SLN metastases and the relevance of indications in guidelines and literature to perform SLNB in order to validate whether SLNB is justified in patients with DCIS on core biopsy in current era. Clinically node negative patients diagnosed from 2004 to 2013 with only DCIS on core needle biopsy were selected from a national database. Incidence of SLN biopsy and metastases was calculated. With Fisher exact tests correlation between SLNB indications and actual presence of SLN metastases was studied. Further, underestimation rate for invasive cancer and correlation with SLN metastases was analysed. 910 patients were included. SLNB was performed in 471 patients (51.8 %): 94.5 % had pN0, 3.0 % pN1mi and 2.5 % pN1. Patients undergoing mastectomy had 7 % SLN metastases versus 3.5 % for breast conserving surgery (BCS) (p = 0.107). The only factors correlating to SLN metastases were smaller core needle size (p = 0.01) and invasive cancer (p < 0.001). Invasive cancer was detected in 16.7 % by histopathology with 15.6 % SLN metastases versus only 2 % in pure DCIS. SLNB showed metastases in 5.5 % of patients; 3.5 % in case of BCS (any histopathology) and 2 % when pure DCIS was found at definitive histopathology (BCS and mastectomy). Consequently, SLNB should no longer be performed in patients diagnosed with DCIS on core biopsy undergoing BCS. If definitive histopathology shows invasive cancer, SLNB can still be considered after initial surgery.
authors.affiliation: Department of Surgical Oncology, Maastricht University Medical Centre, P.O. Box 5800, 6202, Maastricht, The Netherlands.|Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands.|GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Amsterdam, The Netherlands.
authors.forename: L M
authors.initials: LM
authors.lastname: van Roozendaal
authors.affiliation: Department of Surgical Oncology, Maastricht University Medical Centre, P.O. Box 5800, 6202, Maastricht, The Netherlands. briete.goorts@mumc.nl.|Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands. briete.goorts@mumc.nl.|GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Amsterdam, The Netherlands. briete.goorts@mumc.nl.
authors.forename: B
authors.initials: B
authors.lastname: Goorts
authors.affiliation: Department of Surgical Oncology, Maastricht University Medical Centre, P.O. Box 5800, 6202, Maastricht, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Klinkert
authors.affiliation: Department of Surgical Oncology, Maastricht University Medical Centre, P.O. Box 5800, 6202, Maastricht, The Netherlands.
authors.forename: K B M I
authors.initials: KBMI
authors.lastname: Keymeulen
authors.affiliation: Department of Pathology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: De Vries
authors.affiliation: Department of Surgical Oncology, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
authors.forename: L J A
authors.initials: LJA
authors.lastname: Strobbe
authors.affiliation: Department of Pathology, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
authors.forename: C A P
authors.initials: CAP
authors.lastname: Wauters
authors.affiliation: Department of Surgical Oncology, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: Y E
authors.initials: YE
authors.lastname: van Riet
authors.affiliation: Department of Pathology, Laboratory for Pathology and Medical Microbiology (PAMM), Eindhoven, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Degreef
authors.affiliation: Department of Surgical Oncology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: E J T
authors.initials: EJT
authors.lastname: Rutgers
authors.affiliation: Department of Pathology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Wesseling
authors.affiliation: Department of Surgical Oncology, Maastricht University Medical Centre, P.O. Box 5800, 6202, Maastricht, The Netherlands.|GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Amsterdam, The Netherlands.
authors.forename: M L
authors.initials: ML
authors.lastname: Smidt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D017410:Practice Guidelines as Topic; D012307:Risk Factors; D000071036:Sentinel Lymph Node / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy / Q000706:statistics & numerical data*
keywords: DCIS; Incidence; Sentinel lymph node biopsy; Treatment