BS06 INDICATIONS FOR SENTINEL LYMPH NODE BIOPSY IN PATIENTS WITH A PRE‐OPERATIVE DIAGNOSIS OF DUCTAL CARCINOMA IN SITU

Abstract

Purpose: Ductal carcinoma in situ (DCIS) is non‐invasive so the use of sentinel lymph node biopsy (SLNB) in patients diagnosed with DCIS is questionable. DCIS has the potential to progress to invasive cancer, so SLNB would be useful in staging disease in patients at higher risk of invasion. This study aims to identify pre‐operative characteristics of DCIS that are predictors of invasive disease and thus provide a guide as to when to use SLNB.Methodology: This study is a consecutive series of 374 patients that underwent SLNB, of whom 37 patients had a preoperative diagnosis of DCIS, treated by one surgeon between July 2001 and February 2008. The association between pre‐ operative clinical and pathological factors and a post‐operative diagnosis of invasive disease were analysed. Associations between final pathological diagnosis of DCIS or invasive disease and treatment parameters were also analysed.Results: Of the 37 patients, 13 (35%) were found to have invasive disease post‐operatively. Analysis revealed that an initial suspicion of microinvasion, larger mammographic size, younger age, diagnosis with core biopsy, nipple discharge and presence of necrosis had statistically significant association with a post‐operative diagnosis of invasive cancer. Only patients with invasive disease had positive SLNs. Analysis of treatment with mastectomy or conservative surgery showed a link between mastectomy and a palpable lump.Conclusion: SLNB is recommended for staging disease in patients with a pre‐operative diagnosis of DCIS who also have characteristics suggestive of invasive disease