Post on 24-Feb-2016
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DCIS – Are we cutting it?
Dr Alex Lemaigre
With thanks to:Mr Richard BoultonDr Elizabeth OsinibiMr Oladapo Fafemi
Introduction to DCIS
• Ductal carcinoma in situ• Non invasive neoplasm in the milk ducts of the
breast• Predisposes to invasive ductal carcinoma• 2900 cases of screen-detected DCIS per
annum (9)
DCIS - Treatment
• Usually wide local excision (lumpectomy) +- radiotherapy.
• Prognosis improved by greater resection margin, and the use of radiotherapy.(1,2,3)
• Sentinel node biopsy (SNLB) not recommended (incidence LN metastases <1%). (4,5)
Aims and Objectives
• To discover how many of DCIS cases on core biopsy will be found to have invasive cancer on excision histology.
• Can we predict which these will be?• Should we be doing SNLB on these patients?
• How successful are we at adequately excising the neoplasm with wide local excision?
Methods
• Analysed all new patients diagnosed with DCIS only on core biopsy in 2009, 2010 and 2011.– grade of initial DCIS– diagnosis on excision specimen
– closest resection margin– need for re-excision
• Inclusion criteria: all patients newly diagnosed with DCIS ONLY on core biopsy in 2009, 2010 or 2011, regardless of age, sex, or method of detection.
• Exclusion criteria: Recurrent breast cancer, DCIS + any other diagnosis on core biopsy.
• Where multiple grades of DCIS were present in a specimen, the highest grade was considered.
Results
• Total 36 patients with DCIS only in 3 years
High grade61% (22)
Interme-diate grade
22% (8)
Low grade17% (6)
Pie chart demonstrating the percentages of low, intermediate and high grade DCIS found on core biopsy for patients diagnosed with DCIS between 2009
and 2011
DCIS + microinvasion 19% (7)
DCIS + invasive cancer 19% (7)
DCIS - higher grade than on core biopsy
3% (1)
DCIS - same or lower grade than on core
biopsy 59% (21)
Pie chart demonstrating excision biopsy results for patients diagnosed with DCIS only on core biopsy between 2009 and 2011
High grade28% (2)
Intermediate grade43% (3)
Low grade29% (2)
Pie chart demonstrating the breakdown of DCIS grade on initial core biopsy for patients diagnosed with invasive cancer on excision histology
DCIS of same or lower grade59%
DCIS + microinvasion32%
DCIS + invasive cancer9%
Pie chart showing breakdown of excision histology for patients diagnosed with high grade DCIS on core biopsy
Conclusions
• 19% of patients with DCIS only on core biopsy were found to have invasive ductal carcinoma on excision histology.
• These patients cannot be predicted by the initial grade of the DCIS.
• High grade DCIS does not increase the risk of invasive cancer compared to lower grades.
Resection Margins
• Analysed the resection margins on excision specimens.
• 1 case was excluded as the patient had a mastectomy for multifocal DCIS
• 1 case was excluded as the biopsy appeared to have entirely excised the DCIS
• Total = 34 patients
• North Middlesex standard “safe” excision margin for DCIS = 5mm
• There is some variability between centres on this figure (1mm – 10mm).
involved <1mm <5mm > 5mm0
2
4
6
8
10
12
6
8
9
11
Bar Graph to show closest resection margins on excision histology
Size of excision margin
Tota
l num
ber o
f cas
es
Anterior Posterior Medial Lateral Superior Inferior0
2
4
6
8
10
12
14
9
12
8
6
2
8
Bar chart to show which margins are most commonly the closest on excision histology
Margin involved
Tota
l num
ber
NB – total number here = 45 as many specimens had >1 margin reported as close
Need for Re-excision?• According to these data 11 out of 34 cases had
wide enough resection margins.• Therefore 23/34 (67%) require re-excision to
improve margins. • However – improving the posterior margin
involves resecting the chest wall (including pectoralis major).
• There is no prognostic benefit to this, and it causes greater morbidity.
• Excluded those where the posterior margin was the only close margin <5mm (n=3)
Involved <1mm <5mm0
1
2
3
4
5
6
7
8
Bar chart to show distribution of close excision margin after exclusion of those cases with only the posterior margin deemed close
Size of excision margin
Tota
l num
ber
The Saga Continues...
• 20 cases still require re-excision• = 55% of our original population of 36 patients
• 2 had a mastectomy• 1 was referred to Royal Free• 2 lost to NMUH follow-up• 11 had successful re-excision• 4 had inadequate re-excision
Conclusions
• 55% of DCIS patients required more than one operation to adequately clear the DCIS
Discussion – Excision histology + SLNB
• SLNB used in invasive cancer to determine lymph node spread.
• SLNB cannot be performed after WLE due to disruption of lymphatic drainage.
• DCIS grade does not predict probability of invasive carcinoma.
• Therefore cannot guide us which patients to select for SLNB.
• No value in SLNB on DCIS patients as <1% will show LN involvement (4,5).
• Ductal carcinoma in situ • 1.4.5 Do not perform SLNB routinely in
patients with a preoperative diagnosis of DCIS who are having breast conserving surgery, unless they are considered to be at a high risk of invasive disease.
• 1.4.6 Offer SLNB to all patients who are having a mastectomy for DCIS.
Discussion – Excision Margins
• Surgery for DCIS aims to balance disease clearance (and risk of recurrence) and an acceptable cosmetic appearance.
• No prospective trials have assessed optimum excision width for in situ disease.
• Involved margins carry the worst prognosis (6)
• No consensus on standard acceptable margins• How do we decide?
• 1.3 Surgery to the breast • Ductal carcinoma in situ • 1.3.1 For all patients treated with breast conserving surgery
for DCIS a minimum of 2 mm radial margin of excision is recommended with pathological examination to NHSBSP reporting standards. Re-excision should be considered if the margin is less than 2 mm, after discussion of the risks and benefits with the patient.
• 1.3.2 Enter patients with screen-detected DCIS into the Sloane Project (UK DCIS audit)[5].
• 1.3.3 All breast units should audit their recurrence rates after treatment for DCIS.
Discussion – Re-excision rates
• 55% re-excision seems very high.• Wong et al stated a re-excision rate of 84% to
achieve margins of >10mm. (7)
• Holland et al stated a re-excision rate of 43% to achieve margins of >1mm. (8)
• Re-excision rates will depend on what distance the excision margin is considered safe.
Discussion - Radiotherapy• Post-operative radiotherapy significantly decreases risk of
disease recurrence (1,2,3).– Julien et al 2000: 4 year recurrence free = 84% vs 91% if
treated with radiotherapy (1)
– Chan et al 2001: Recurrence of 18.6% vs 11.1% if treated with radiotherapy (3)
– Wong et al 2006: abandoned trial of WLE only (10mm margin) due to high recurrence rate of 2.4% per patient year. (7)
• NMUH does not routinely offer radiotherapy to DCIS patients
• 1.11 Radiotherapy • Radiotherapy after breast conserving surgery • 1.11.1 Patients with early invasive breast cancer
who have had breast conserving surgery with clear margins should have breast radiotherapy.
• 1.11.2 Offer adjuvant radiotherapy to patients with DCIS following adequate breast conserving surgery and discuss with them the potential benefits and risks (see recommendation in section 1.3.1)
Further Work
• Audit recurrence rates in these patients.
• Compare our results with rates of re-excision data from other centres with similar choice of acceptable margins.
• Compare our data with previous data collected by Mr Fafemi some years ago.
Re-assess the treatment we offer for DCIS
References1. Julien J, Bijker et al. Radiotherapy in breast conserving treatment for ductal carcinoma in situ:
first results of EORTC randomized phase III trial 10853. Lancet 2000; 355:528-33.2. Fisher ER, Dignam J et al. Pathologic findings from the National Surgical Adjucant Breast Project
(NSABP) eight-year update of Protocol B-17 intraductal carcinoma. Cancer 1999;86:429-383. Chan KC, Knox WF et al. Extent of excision margin width required in breast conserving surgery for
ductal carcinoma in situ. Cancer 2001;91:9-164. Kitchen PR, Cawson JN et al. Axillary dissection and ductal carcinoma in situ of the breast: a
change in practice. Aust NZ J Surg 2000;70:419-225. Veronesi P, Intra M et al. Is sentinel node biopsy necessary in conservatively treated DCIS? Ann
Surg Oncol 2007;14(8):2202-86. Law, Tsz Ting MBBS; Kwong, Ava FRCS. Surgical Margins in Breast Conservation Therapy: How
Much Should We Excise? Southern Medical Journal: December 2009 - Volume 102 - Issue 12 - pp 1234-1237
7. Wong J, Kaelin CM et al. Prospective study of wide local excision alone for ductal carcinoma in situ of the breast. J clin oncol 2008;24(7):1031-1036
8. Holland PA, Gandi A, et al. The importance of complete excision in the prevention of local recurrence of ductal carcinoma in situ. Br J Cancer 1998; 77(1):110-114.
9. Dodwell D, Clements K, Lawrence G, Kearins O, Thomson C, Dewar J, Bishop H, on behalf of the Sloane Project Steering Group. Radiotherapy following breast-conserving surgery for screen-detected ductal carcinoma in situ: indications and utilisation in the UK. Interim findings from the Sloane Project. British Journal of Cancer 2007; 97: 725-729
10. NICE guidelines – Feb 2009 – Early and locally advanced breast cancer, diagnosis and treatement.
Any questions?