Early Rectal CancerGina Brown

Royal Marsden Hospital and Imperial College, London

Overstaging of ERC is a problem

Data published by the NBOCAP shows 45% of the 9,433 rectal cancers treated by radical resection in the UK annually were either T1 or T2 and 66% were node negative. Despite this 77% those operated on underwent major resection whilst only 11% were locally excised

Understaging is also a problem

• MDTs do not always refer eligible patients for TEM/Local excision procedure

• Local resection may be unfeasible for local technical rather than oncological reasons.

Current practice

• UK TEM database, 44% of pT1 and 31% of pT2 cancers were incorrectly presumed to be benign preoperatively

• Less than full thickness excision by flexible endoscopic excision or transanal endoscopic surgery.

Role of imaging in early lesions

• Confirm that muscularis propria thickness is preserved

• Identify sites of disease within the mesorectum

• Final decision regarding appropriateness of local excision is driven by Histopathology assessment of risk factors of the excised lesion

Assessment of ERC

• Is it malignant or not?• What is the depth of invasion?• Are lymph nodes involved?• How should lesion be removed:

– EMR/ESD– TEM– TME– APE

Depth of invasion is relevant

Kikuchi R, Dis Colon Rectum. 1995 (12):1286-95

Kikuchi levels classification: distance of SM invasion

nodal metsSM1 superficial 1/3 2%SM2 superficial 2/3 8%SM3 deep 1/3 23%

• 1994• Endorectal coil tested for staging of 12 rectal

cancers• High resolution T2• T2-weighted FSE Sequence (4,000/100, 256 x

256 matrix, echo train length of 16). All images were obtained with an 80-120-mm field of view and 3-mm-thick sections with no gap.

• Pixel size =120/256 = 0.46mm x 0.46mm

No endorectal coilPixel size 0.6 x 0.6mm

Technique Essential Checklist• Scan duration = quality• 4-6 NSA/NEX and T2- FSE / TSE• 0.6mm x 0.6mm x 3mm = 1.1mm3 voxel• Adequate coverage – 5cm above top of tumour• Perpendicular to the rectal wall• Low rectal cancer – parallel to anal canal• Ensure discontinuous deposits are covered on high res• Buscopan givrn as an i.m. injection• Saturation Bands• firm coil placement with secure strapping

The submucosal fold pattern

T staging• Location of tumour – anterior, posterior, r or l lateral• Morphology: annular, semi annular, polypoidal,

ulcerating, mucinous, villous• For annular/ulcerating – location of central invasive

portion vs raised edges• For polypoidal/villous lesions – site of stalk • Invasive margin: nodular infiltrating, broad based

pushing margin

T staging

• Submucosa visible at invasive edge? – T1• Submucosa not visible at invasive edge but good

thickness of muscularis propria visible? T1 (sm3)/early T2

• Part of muscularis propria visible? = T2• No muscularis propria visible but intermediate

signal intensity does not project beyond contour of bowel = T2 full thickness/T3a

• Tumour projecting beyond muscularis propria = T3

Early stage disease

Assessing depth of tumour invasion

ERC subclassification

• T0/early T1sm1 – no evident disruption of the submucosa – entire thickness of SM appears preserved

• T1sm2 – at least 1mm of submucosa is preserved• T1sm3/early T2: full thickness of muscularis propria is

preserved but <1mm submucosa is visible• T2 early >1mm muscularis is preserved• T2/T3a – 0mm of muscularis preserved microscopic invasion

beyond muscularis <1mm – prognosis identical for this subgroup

• T3b 1-5mm – good prognosis

MRI confirmation that full thickness of muscularis propria and subumucosa is

visible at deep margin of tumour

What is the T stage of this tumour

1. T1 : preservation of >3mm of muscularis and visible submucosal layer

2. T2 muscularis propria visible and intermediate signal tumour does not project beyond low signal

3. T3 : muscularis has been replaced and breached by intermediate signal intensity tumour at invasive border

What is the T stage of this tumour

1. T1 : preservation of >3mm of muscularis and visible submucosal layer

2. T2 muscularis propria visible and intermediate signal tumour does not project beyond low signal

3. T3 : muscularis has been replaced and breached by intermediate signal intensity tumour at invasive border

What is the T stage of this tumour

1. T1 : preservation of >3mm of muscularis and visible submucosal layer

2. T2 muscularis propria visible and intermediate signal tumour does not project beyond low signal

3. T3 : muscularis has been replaced and breached by intermediate signal intensity tumour at invasive border

Nodal staging – high resolution MRI must be used

• Criteria for predicting malignancy = mixed signal intensity and/or irregular border (Radiology 2003)

• Size of nodes not a useful predictor (Radiology 2003)

• Accuracy = 85%, sensitivity 83%, specificity 86% (BJS 2003)

Discontinuous vascular invasion

Where are the nodes?

EUS coverage MRI coverage

MRI coverage

EUS

Performance of MRI on nodal status (not using size criteria in 62 patients with mrT3b or less)

Count of hospital N pN stage mrN stage N0 N1 N2 LE/TEM missing unfit Grand TotalN0 25 2 2 18 1 48N1 4 8 1 13N2 1 1Grand Total 29 11 2 18 1 1 62

Count of hospital N pN stage mrN stage N0 N1 N2 Grand TotalN0 25 2 1 28N1 4 8 12N2 1 1Grand Total 29 11 1 41

Size and volume of metastatic disease in early rectal cancer

Post TEMS and local excision for T1 lesions

• What are the documented patterns of recurrence?

• Time to relapse, ideal follow up schedule and MRI appearances of early relapse

• What is the long term prognostic importance of nodal micrometastatic disease?

• What is the role of adjuvant chemoradiotherapy and chemotherapy in high risk T1 disease following local excision?

Recommended reporting structure for staging early rectal cancer using MRI

• State morphology – flat, polypoidal, mucin containing• Measure diameter and thickness of lesion• If polypoidal –state site and diameter of fibromuscular stalk• If flat – quadrant or clockface location of central depression versus raised rolled edges• Measure extent/diameter of invasive border• Assess degree of preservation of the mucosa, submucosa, muscularis propria layers at

the stalk• Assess lymph nodes for malignant characteristics based on nodal capsule breach or

heterogeneity of signal• Assess height of lesion in relation to anal verge and puborectalis sling• Evaluate extramural veins for discontinuous spread

Morphology – flat semiannularDiameter 16mmThickness of lesion : 7mmClockface location of central depression =4 oclockInvasive edge = 5mm diameterMuscularis fully preservedSubmucosa/muscle interface lost over 3mm distance on single slice at 4 oclockLymph nodes show smooth nodal capsule and no heterogeneity - benignAssess height of 6.5 cm above anal verge and 12mm above puborectalis slingNo extramural venous invasionT1sm3/ with potential focal early T2 invasion on a single slice section

Final pathology• CLINICAL SUMMARY

TEMS-anorectal polypoid lesion

• HISTOLOGY

The referred sections are of colonic mucosa with a tubulovillous adenoma having both highly and low-grade dysplasia, with an area of moderately to poorly differentiated adenocarcinoma with desmoplasia, tumour budding and focal mucinous differentiation. Invasive tumour area measures 13 x 5.5 mm and just involve the innermost fibres of the muscularis propria. There is lymphatic vascular invasion and focal submucosal venous angioinvasion. In therefore constitutes a higher risk lesion, although the nearest deep excisional or marginal clearance is 3.5 mm. Further deeper sections do not reveal any deeper invasion.

• pT2 NX MX LVI+ R0

I/12 after TEM 3/12 after TEM

Surveillance• She has been extremely well since her last review in the clinic. She is able

to manage a normal diet and her weight is stable. • She refers to mild incontinence for gas and stool but denies any blood or

mucous in the stool.• On examination today, the abdomen was soft, non tender. There was no

palpable lymphadenopathy. On PR examination, the sphincter tone was mild. There was no palpable mass in the rectum.

• There was no blood or stool on the gloved examination finger. The CEA on the 11th February was 3 and the CA19-9 was 3. The last MRI showed no evidence of recurrent disease.

• We will review in clinic in three months' time with a repeat of her blood tests including tumour markers and MRI of the pelvis.

Post TEM surveillance of mesorectum

Local excision scar

Nodal recurrence

Breach of the node capsule border by tumor signal

Lymph node capsule smooth border and homogenous signal 4 months earlier

Post TEM MRI surveillance

• 30 patients – 20 T1 (8 , Sm3), 8 T2 and 1 T3. – Median follow 3 years (1014 days, range 243 to

2989days). – 6 of the 12 <T1SM3 and all of the 17 with ≥T1Sm3

had adjuvant chemo/radiotherapy.– 1 local relapse identified on MRI – APER undertaken– 3% relapse rate (95% CI –0.6 -17%). S Balyasnikova, J Read et al ESCP 2014

Discontinuous extramural venous spread – a poor prognostic factor

MRI indications in ERC

• To assess bulky polyps >5mm thick • Initial assessment of disease remote from the lumen within

entire mesorectum• Identification of pelvic sidewall disease• Road-mapping for surgical planning – identify site location of

stalk or invasive border and relationship to puborectalis sling, peritoneal reflection, mesorectal or intersphincteric border

• Identification of high risk patients with extramural venous invasion

• Ongoing surveillance of high risk cancer patients opting for conservative approach

Minstrel Trialwww.minstrelstudy.co.uk

MINSTREL trial

MINSTREL trial

MINSTREL eligibility• Radiologists at recruting sites will be trained and hold delegated

responsibility • Eligible patients will be identified on colonoscopy if they are

found to have a 20mm to 50mm rectal tumour within 150mm of the anal verge (consent and completion of endoscopy CRF)

• All patients who enter the trial will be sent for an MRI. The MRI will be reported using the novel staging proforma (radiology CRF)

• The patients will proceed to excision or resection of the tumour as per clinician / MDT discussion. (MDT CRF)

• The appropriateness of preoperative stage will be compared against histopathology gold standaed (Pathology CRF)

Primary Endpoint

• To determine if there is a difference between the percentage correct allocation of clinical and MRI assessment of rectal lesions.

• Trial to open in 2015: 55 patients needed to show a 30% improvement compared with conventional assessment in staging for correct excision plane using MRI reporting system

Recommendations: staging accuracy is dependent on technique

Low ResolutionField of view 22 x24cmVoxel size: 1.6mm3

MERCURY protocol scan – same patient 1 week later

High ResolutionField of view 16 x 16cmVoxel size: 1.1mm3

75 yr old male

• PS1• Colonoscopic detected polyp• Endoscopic assessment

Treatment plan: scenario 1

• EUS reports: at least T1• MRI report : T1/T2 N0

– Options:• TME• Repeat biopsy• Preoperative RT/CRT• TEM

MRI Report

Histopathology report

MDT discussion of Imaging and pathology

Patient decision

Conclusions

• Early stage tumours can be usefully evaluated using high resolution MRI and high frequency ultrasound for superficial lesions– Technique important– Options to consider especially for low lying early

stage tumours: results from current trials awaited– Follow up if less radical therapy is given: MRI

surveillance is important to enable early detection of salvageable regrowth/recurrence

2 Day Rectal MRI Workshop –for further dates Workshop dates 2017

contact: gina.brown@rmh.nhs.uk

RECTAL MRI INTENSIVE TWO DAY WORKSHOP

WITH HANDS ON WORKSTATION PRACTICE FOR RADIOLOGISTS, SURGEONS AND ONCOLOGISTS

Euston House

24 Eversholt Street London NW1 1AD

Aims: This course enable will equip you to ensure high quality MRI in your institution and to be able to evaluate baseline and post treatment MRI assessment of rectal cancer and pelvic anatomy with confidence for your daily practice.

Day One with multidisciplinay faculty Will provide you with essential knowledge for MDT working and MRI assessment in different clinical scenarios with details revision of anatomy and interpretation criteria as a preparation for Day Two.

Day Two Will give you hands on workstation practice for assessing rectal cancer cases and pelvic anatomy and how this is applied to treatment planning. For teams participating in MINSTREL, TRIGGER AND STARTREC trials, you will be certified as having sufficient training to take delegated responsibility for trial participation.

PROFESSOR GINA BROWN

Registration Form Name: Position: Institution:

The information above will appear on your badge for the course email: Tel: Address:

I wish to register for:

Course Code M0916 26th 27th September 2016

Full 2 day course, 26th 27th September £550 early bird Booking after 26th August: £650

Day One only, 26th September £300

Day Two only, 27th September £350 Please return registration form to Gina.Brown@rmh.nhs.uk or Fax: + 44 (0) 208 915 6721 You will receive confirmation of your registration within 2 working days together with an invoice and instructions for payment.

Please contact +44 (0) 20 8661 3964 if you have any queries

REVISE TIPS AND TRICKS FOR:

Pelvic applied anatomy assessment skills

MDT based working

MRI rectal cancer interpretation skills

Case discussions and controversies

Rectal cancer scanning standards

Hands on workstation cases with live feedback and

course booklet

Registration

Two day workshop combined cost (early bird)) £550 Day One only MDT working and revising the MRI interpretation £300

Day Two only Workstation practice, self-testing with answer booklet and notes £350 Price includes lunch and refreshments for each delegate on both days. There is an optional evening course dinner on day one. Capacity is limited so to guarantee your place, please complete the registration section of this flyer and return as soon as possible

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