Say Goodbye to Cancer, One Layer at a Time: Mohs Surgery for Skin Cancer

Say Goodbye to Cancer, One Layer at a Time: Mohs Surgery for Skin Cancer

Jamie L. McGinness, MD

www.SpringfieldClinic.comwww.SpringfieldClinic.com

Meet my family…

Mohs Surgery

Objectives

• What is Mohs surgery?

• How is Mohs different from other surgical techniques?

• How effective is Mohs and for what tumors?

• What are the indications for Mohs?

• What are the limitations of Mohs?

• Who performs Mohs surgery?

Take home message….. • When properly performed, MMS is the gold standard

for skin cancer therapy– Complete margin control. – Superior Cure rate. – Tissue Sparing

• Mohs is not appropriate for every tumor• Mohs alone is not the cure-all for some tumors

• MMS success depends on a philosophy of one– Surgeon = Pathologist– Surgical expertise + Histologic interpretation

Who is Jamie McGinness?• Born and raised in Potosi, MO

• 1994-1998 Undergraduate School - BS, Biochemistry University of Missouri Columbia (Columbia, MO)

• 1998-2002 Medical School - MD, University of Missouri Columbia (Columbia, MO)

• 2002-2003 Internship - Internal Medicine, University of Missouri Columbia Hospital and Clinics (Columbia, MO)

• 2003-2006 Residency - Dermatology, University of Virginia (Charlottesville, VA)

• 2006-2007 Fellowship - Dermatology & Skin Cancer Center (Leawood, KS)

• 2010-2011 Advanced Mohs and Reconstructive surgery training in Houston, TX

What is Mohs Surgery?• Mohs Micrographic

Surgery is an advanced surgical treatment for skin cancers.

Mohs SurgeryMohs Surgery

• Dr Frederick Mohs

History

• Developed by Frederic E. Mohs, M.D. in the 1930s, Mohs Micrographic Surgery has been refined and perfected for more than half a century.

History• He developed a unique technique of

– color coding excised specimens – creating a mapping process to accurately

identify the location of remaining cancerous cells.

– Used zinc chloride paste.

History

• The technique evolved and was refined with fresh tissue frozen histology – Excise tumor – Examine tissue with frozen histology

immediately– Chemosurgical technique developed by Dr.

Mohs no longer used.

Mohs Surgery is the Gold Standard for Surgical Tumor Clearance

Why??

Copyright: Tri H Nguyen, MD, FACMS

Advantages of Mohs Surgery

1. Excellent tumor cure rates

2. Tissue sparing

3. Outpatient surgery

Principles of MMS

Complete margin controlHigher cure rates (100% margin evaluated)

Tissue sparingTissue conservation (out with the bad in with the good)

Philosophy of ONE (Mohs surgeon = surgeon & pathologist)

What is Mohs?

• Mohs is a precisely controlled process– ensures accuracy during tumor tissue

removal– accuracy and integrity during tissue

processing– precise and complete histologic evaluation

of margins

What is Mohs?

• Skin cancer roots can be accurately traced and removed while preserving healthy tissue

Mohs Surgery Procedure

• Tumor marked with margin


• Tumor debulked


• Incision with 1-2 mm margins

• Knicks made for orientation


• Tissue removed


• Tissue grossed and mapped


• Section color coded for orientation

Mohs Surgery Procedure• Tissue embedded for horizontal sections


• Sections cut and put on slides.


• Sections stained and read.


• Pathology read and mapped.

• Process repeated until margins clear.

Principles of MMS




Myth

As long as margins are negative, the method of

margin control is irrelevant

Why not?

Margin Control Techniques

Conventional Vertical Sections

Intraoperative Frozen Section Control

Mohs Micrographic Surgery

But how do these techniques differ?

Wide Local ExcisionParaffin Processing

(Conventional Vertical Sections)

• Wide excision• Wound closed • Patient discharged• Tissue vertically sectioned

(breadloaf)

• Paraffin sections & results about 1-2 weeks later

Intraoperative Frozen Sections

• Wide excision • Wound open• Tissue vertically sectioned

(breadloaf)

• Frozen sections read intraoperatively by pathology

• Wound closed if Negative• Paraffin sections to

confirm


In both forms of WLE (paraffin & IOFS), the resecting surgeon usually

does not ink the tissue, map the tissue, or read the pathology

Sections are processed vertically (breadloaf)

BA DC E

Conventional Sectioning

• Breadloaf sectionsExtension of tumor not represented in sections A-E.

BA

DC E FG

MARGINS NEGATIVERight?? WRONG

Why?<1% of tissue is examined in standard histologic sections

BA

DC E FG

C-1

Mohs Sectioning

• 100% of peripheral and deep margin examined

Extension of tumor would be seen with Mohs section.

Mohs Sectioning

Mohs Sectioning

• Tissue is layed down and cut horizontally– Peripheral margin and deep margin in 1 plane.

• How is this done?

Relaxing incisions made

Epidermis

Dermis

Fat

Peripheral and deep margin now in 1 plane

EpidermisEpidermis Dermis DermisFat

1 2

Mohs Sectioning

Mohs Sectioning

Mohs Sectioning

1 2

Mohs Sectioning

Mohs Sectioning

Myth

Mohs Surgery is just like Intraoperative Frozen Section

Control (IOFSC)

Both Mohs surgery & IOFSC are forms of margin control using frozen sections

But there are critical differences in But there are critical differences in tissue processing, mapping, & tissue processing, mapping, &

orientation.orientation.

Traditional Sections

SurgeonSurgeon TechnicianTechnician PathologistPathologist

Paraffin SectionParaffin Section

Processing


Intraoperative Frozen SectionIntraoperative Frozen Section

Mohs Processing




Principles of MMS




How is Mohs Different?• Ability to remove less since 100%

margin is evaluated• Meticulous mapping: tissue

– color coded mapping of excised specimens

• Margin examination– thorough microscopic examination

• This allows precise localization and removal of tumor if needed.– Saves normal skin

Principles of MMS





Mohs surgery: The philosophy of ONE (Mohs surgeon = surgeon & pathologist)

• When Surgeon & Pathologist are one:– tissue integrity and superior tumor clearance

are achieved.



• More integrity of tissue processing

• More effective tumor management– Ensure tissue integrity microscopically

• More accuracy in tissue orientation & mapping

• Accurate histologic tumor identification

• More tissue conservation

Mohs Processing











Ensuring tissue integrityMissing epidermis Tissue hole








Tissue Sparing• Precise margin control saves healthy

tissue.• If tumor is seen only tumor-involved tissue

is precisely removed to cure the skin cancer– Cancer roots are resected one layer at a time

until clear• Saves as much healthy tissue as possible• Smallest defect possible• Maximal cure rate

MMS: Tissue ConservationStandard Excision• Should be at least 4 mm

margins for low risk basal cell and squamous cell cancer

• More for high risk skin cancers– National comprehensive Cancer

Network (NCCN guidelines)

• 90% 5-year cure rate for primary BCC

• 83% 5-year cure rates for recurrent BCC

Mohs Surgery• 1-2 mm margins per layer

• 99% 5-year cure rates for primary BCC

• 94% 5-year cure rates for recurrent BCC

Traditional Excision

4-6 mm Margins4-6 mm Margins

4 mm margins (low 4 mm margins (low risk)risk)

6-10 mm margins (high 6-10 mm margins (high risk)risk)

Mohs Removal

1-2 mm Margins1-2 mm Margins

Sometimes smaller margins are taken…

• Margins of 1-3 mm are inadequate for– Small, well-demarcated

primary basal cell cancers on the face.

– These should be treated with standard 4 mm margins or Mohs.

• Higher chance of positive margins

• Higher risk of recurrence

What Tumors are Treated with Mohs?

• Most common skin cancer treated– Basal cell carcinoma– Squamous cell carcinoma – primary tumors

• (cancers that have not been treated before)

– Recurrent tumors • (cancers that have returned despite previous

treatment)

– Other non common tumors

How effective is Mohs surgery?

Myth

Mohs surgery has comparable cure rates with other therapies


5-yr Cure Rates Primary BCC

90

92

92.5

91.3

99

84 86 88 90 92 94 96 98 100

EDC

Excision

Cryosurgery

Radiation

Mohs

%

Rowe. Et al. J Dermatol Surg Oncol 1989;15:315-328


5-yr Cure Rates Recurrent BCC

60

82.6

83.6

94.4

0 10 20 30 40 50 60 70 80 90 100

EDC

Excision

Radiation

Mohs

%

Caccialanza M. Eur J Dermatol 2001 Jan-Feb;11(1):25-8

Rowe. Et al. J Dermatol Surg Oncol 1989;15:424-431


Excision: Primary BCC & Size

Excision: 5-yr Cure Rates primary BCC & size

9291

96.8

90

92

94

96

98

100

0-5mm

6-9mm

>10mm

Lesion Size

%

Silverman. Et al. J Dermatol Surg Oncol 1991;17:720-726

Excision & BCC Location

Excision: 5-yr Cure Rates & BCC Location

93.4

99.3

90919293949596979899

100

Head Othersites

per

cen

tag

e

Silverman. Et al. J Dermatol Surg Oncol 1991;17:720-726


SCC of the Lip

5-yr Cure Rates Primary SCC of Lip

9890

0102030405060708090

100

Non-MOHS Mohs Surgery

*

Rowe. Et al. J Am Acad Dermatol 1992;26:976-990

Recurrent SCC

5-yr Cure Rates

9277

0102030405060708090

100

Excision Mohs Surgery

Rowe. Et al. J Am Acad Dermatol 1992;26:976-990

The BEST chance to cure skin cancer, is your FIRST chance

Recurrent skin cancers have a lower cure rate than primary skin cancers

Disadvantages

• Time consuming– Tissue turnover time: at least 30-60 minutes per

layer (sometimes longer)• Dependent on tissue integrity and need for recuts of

tissue

– Immunostains add additional time

• Cost – more expensive than traditional standard excisions

(but higher cure rates)

• Labor intensive

Is it worth it?

Cost Comparison

Head/ Neck $

Trunk

$

Extremities

$

Office excision with Permanent sections

1201 905 1125

Mohs Micrographic surgery

1278 964 993

Office excision with Frozen sections

1438 1117 1136

Excision in ASC with Frozen sections

2012 1694 1620

(ASC: Ambulatory Surgical Center)

Cook J.et al. J American Acad Dermatol 98:39; 698-703

MMS is 7% more expensive than routine excisions but 11% less expensive than office excision with

frozen sections

Significantly less expensive than ASC based surgical excision

(Not calculating intrinsic value of superior cure rates and tissue conservation)


Outpatient Surgery

Mohs is an outpatient Mohs is an outpatient procedure, performed under procedure, performed under

local anesthesialocal anesthesia

Mohs patients continue all their Mohs patients continue all their medications, including medications, including

anticoagulation regimens. All are anticoagulation regimens. All are ambulatory home.ambulatory home.

Mohs surgery is very well tolerated Mohs surgery is very well tolerated under local anesthesia.under local anesthesia.

Outpatient Surgery

• Mohs is performed under local anesthesia, which allows patients to return home immediately

• Patients do not have to discontinue their medications.

• Patients recover more quickly, which is important since most skin cancers occur in the elderly

Cook J. Arch Dermatol 2003;139:143-52

• 1358 Mohs cases (1052 patients)– Prospective evaluation– 99% in-house reconstruction– Local anesthesia +/- anxiolysis

• Incidence of complications = 1.64%– No deaths, no hospitalizations, no

resuscitations– Majority of incidents related to Postop

bleeding

Indications for MMS

MMS: Indications

• Histologically aggressive tumors

• Large tumors (>2cm) in any location

• Incompletely excised tumors

Tumor Indications• Basal cell carcinoma• Squamous cell carcinoma• Lentigo maligna/melanoma• Dermatofibrosarcoma protuberans• Sebaceous carcinoma• Microcystic adnexal carcinoma• Atypical Fibroxanthoma• Extramammary Pagets disease

Special Patients• Organ transplant

patients• Basal cell nevus

syndrome patients

Not every tumor needs or qualifies for Mohs…When is Mohs Not Indicated?

• Small localized tumors

• Tissue conservation less of an issue– trunk

• Superficial BCC & SCC– unless recurrent

• Topical therapy• Photodynamic

therapy• Cryotherapy• Curettage &

electrodessication• Laser ablation• Excision with

margins

When is Mohs Not Indicated?

• Difficult tumor Locations

• Local anesthesia• When tumor is too

large for complete margin control

• When tumors become non-contiguous

Mohs surgeon: Training matters

Who may perform Mohs Surgery?

RequirementsSurgical expertise

and

Frozen section pathology

Training of a Mohs Surgeon

• Dermatology Residency– Medical & surgical

dermatology– Dermatopathology part of

Board Certification in dermatology

• Mohs Fellowship (1-2 years)– Frozen section

dermatopathology– Cutaneous oncology – Reconstruction

Not everyone who performs Mohs surgery is fellowship trained

Mohs College & Mohs Society

What is the difference?Mohs College

• 1-2 year fellowships after Dermatology

• Minimum 500 cases– Diversity– Complexity– Under supervision of

experienced ACMS approved Mohs surgeon

• Only approved ACMS programs allowed to train.

Mohs Society• Intense instructional

courses• No fellowship• Minimum 75 cases• Submit 2 cases for

review• Passed a written and

practical exam on Mohs

• Annual QA

After Mohs tumor clearance, defects are then reconstructed

The Magic after Mohs The Magic after Mohs SurgerySurgery

Non Mohs Defect

1 week follow-up

1 week follow-up

Take home message….. • When properly performed, MMS is the gold standard

for skin cancer therapy– Complete margin control. – Superior Cure rate. – Tissue Sparing

• Mohs is not appropriate for every tumor• Mohs alone is not the cure-all for some tumors

• MMS success depends on a philosophy of one– Surgeon = Pathologist– Surgical expertise + Histologic interpretation

More Resources

Find videos, handouts and more resources at

www.SpringfieldClinic.com/DoctorIsIn

http://www.springfieldclinic.com/DoctorIsIn

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Say Goodbye to Cancer, One Layer at a Time: Mohs Surgery for Skin Cancer