Corynebacterium kroppenstedtii breast abscesses in context, a retrospective cohort study.

Corynebacterium kroppenstedtii breast abscesses and granulomatous mastitis have gained increased recognition in the 20 years since their association was first described. No studies to date have described this organism in the context of all breast abscess pathogens. We retrospectively reviewed 160 community-acquired breast abscess samples from 135 patients in a 3 year period, describing the organisms isolated along with risk factors, site of infection and outcomes. We compared patient subgroups with acute and chronic abscesses, the latter defined as having a requirement for repeat aspiration more than 1 month apart. The prevalence of C. kroppenstedtii breast abscesses was 8 % in all patients (11/135), rising to 32 % in chronic abscesses (10/31), but only 1 % in acute abscesses (1/104; P<0.01). Only 10 % (1/10) of patients with C. kroppenstedtii chronic abscesses were smokers, whereas 75 % of patients (15/20) with non-C. kroppenstedtii chronic abscesses were smokers (P=0.01). C. kroppenstedtii should be considered in recurrent and prolonged infections, especially in non-smokers, and diagnostic methods altered accordingly. Identifying C. kroppenstedtii provides diagnostic clarity and alters management with recommendations for longer courses of treatment using non-beta-lactam antibiotics.

Current margin practice and effect on re-excision rates following the publication of the SSO-ASTRO consensus and ABS consensus guidelines: a national prospective study of 2858 women undergoing breast-conserving therapy in the UK and Ireland.

INTRODUCTION: There is variation in margin policy for breast conserving therapy (BCT) in the UK and Ireland. In response to the Society of Surgical Oncology and American Society for Radiation Oncology (SSO-ASTRO) margin consensus ('no ink on tumour' for invasive and 2 mm for ductal carcinoma in situ [DCIS]) and the Association of Breast Surgery (ABS) consensus (1 mm for invasive and DCIS), we report on current margin practice and unit infrastructure in the UK and Ireland and describe how these factors impact on re-excision rates. METHODS: A trainee collaborative-led multicentre prospective study was conducted in the UK and Ireland between 1st February and 31st May 2016. Data were collected on consecutive BCT patients and on local infrastructure and policies. RESULTS: A total of 79 sites participated in the data collection (75% screening units; average 372 cancers annually, range 70-900). For DCIS, 53.2% of units accept 1 mm and 38% accept 2-mm margins. For invasive disease 77.2% accept 1 mm and 13.9% accept 'no ink on tumour'. A total of 2858 patients underwent BCT with a mean re-excision rate of 17.2% across units (range 0-41%). The re-excision rate would be reduced to 15% if all units applied SSO-ASTRO guidelines and to 14.8% if all units followed ABS guidelines. Of those who required re-operation, 65% had disease present at margin. CONCLUSION: There continues to be large variation in margin policy and re-excision rates across units. Altering margin policies to follow either SSO-ASTRO or ABS guidelines would result in a modest reduction in the national re-excision rate. Most re-excisions are for involved margins rather than close margins.