Indications for Mohs Surgery Chrys Schmults, MD, MSCE Christine Liang, MD

Brief review of Mohs technique and how it differs from standard excision Review of data comparing outcomes with Mohs vs. standard excision 2010 NCCN guidelines Cost-effectiveness of Mohs as compared to excision Indications for Mohs Too small Too big Just right Enough to share (multidisciplinary approach) Role of Mohs surgeon as cutaneous oncologist/care coordinator, especially for large and complex cases Overview

Technique for removing skin cancer Developed by Frederick Mohs, M.D. beginning in 1930s 2 key features: Nearly 100% of surgical margin is evaluated microscopically The surgeon is also the pathologist If another pathologist makes call on margin, its not Mohs and should not be billed as such What is Mohs surgery?

Mohs Surgery Advantage All of peripheral & deep margin examined microscopically Less than 1% is examined in standard vertical sections

Mohs Surgery Advantage

Mohs Surgery Procedure Debulk visible tumor Hatch marks made on skin for orientation

Mohs Surgery Procedure Tumor excised with small ( 1 mm - 2 mm ) border

Tissue is placed on map preserving orientation Tissue is inked Locations and colors of ink replicated on map Mohs surgery procedure Tissue inkedCorresponding Mohs map

Mohs Surgery Procedure Tissue is frozen so it can be cut in thin layers (frozen sections)

Mohs Surgery Procedure Tissue pieces stained with hematoxylin and eosin

Mohs Surgery Procedure Positive areas are recorded on the map

Mohs Surgery Procedure Additional tissue is taken from positive areas

Mohs Surgery Procedure Tissue is again inked, mapped, frozen, cut, and read by surgeon Process repeated until margins are clear

Mohs Surgery Procedure Wound is reconstructed so as to minimize scarring

Highest reported cure rates (97-99% overall) for many types of skin cancer due to complete margin evaluation Spares normal tissue so the wound is as small as possible while still fully removing cancer Why is Mohs surgery used?

No. Clear margins are the crucial factor. Used to look at debulk but stopped as almost never added information beyond the biopsy Only evaluate debulk if Diagnosis was in question Biopsy location is in question It is an unusual tumor (though looking at biopsy slides is usually sufficient to assess tumor appearance) Mohs high cure rates have been established by looking only at the margins Do we miss valuable information by not looking at entire tumor?

Data comparing Mohs vs. excision and NCCN treatment guidelines regarding Mohs

Recurrence Rates for the Treatment of Primary Basal Cell Carcinoma Rowe et al. J Dermatol Surg Oncol, 1989.

Summary of Recurrence Rates for Treatment of Recurrent BCC Rowe et al. J Dermatol Surg Oncol, 1989.

RCT Mohs vs Excision of facial BCC 5 year local recurrence rate LesionMohs surgeryExcision Primary BCC n=408 2.5%4.1% Recurrent BCC n=204 2.4%12.1% (p=0.01) Mosterd et al, Lancet Oncol 2008

Mohs vs non-Mohs treatments in SCC 5 year local recurrence rate LocationMohs surgeryNon-Mohs treatment Lip2.3% (952)10.5% (7022) Ear5.3% (337)18.7% (214) Recurrent SCC10.0% (151)23.3% (34) (surgical excision) From Rowe et al JAAD 1992

Overall cure rates for SCC: Mohs vs. non-Mohs treatments Tumor factorMohs surgeryNon-Mohs treatments Size > 2cm75% (652)58% (1205) Poorly differentiated67% (387)46% (222) From Rowe et al JAAD 1992

Treatment outcomes for perineural SCC (determinate cases) Mohs surgerySurgical excision Local recurrence rate0% (17)47% (72) Metastatic rate8% (24)47% (112) **Surgical clearance of tumor is critical and may require head and neck surgeon to pursue tumor into parotid or cranium From Rowe et al JAAD 1992

2010 NCCN treatment guidelines for BCC and SCC

2010 NCCN Guidelines Consensus category 2A based on lower level evidence/NCCN uniform consensus

2010 NCCN treatment guidelines High risk BCC and SCC can only be treated with standard excision (using 1cm clinical margin) if: its on trunk/extremities AND diameter 2cm is only risk factor AND it can be closed primarily Otherwise, Mohs or complete circumferential peripheral and deep margin assessment with frozen or permanent sections (CCPDMA) is indicated

Use of Mohs in other tumors Dermatofibroma sarcoma protuberans Microcystic adnexal carcinoma Extramammary pagets disease Atypical fibroxanthoma Merkel cell carcinoma Lentigo maligna, melanoma in situ

Dermatofibromasarcoma protuberans StudyStudy DesignResults Meguerditchian et al., 2010 Retrospective cohort 28 WLE (50 mo f/u) 20 Mohs (40 mo f/u) Recurrence rate -Wide local excision: 3.6% -Mohs: 0% (p = 1.0) Paradisi et al., 2008 Retrospective cohort 38 WLE (4.8 yr f/u) 41 Mohs (5.4 yr f/u) Recurrence rate -Wide local excision: 13% -Mohs: 0% (p = 0.015) Gloster et al., 1996 Retrospective cohort 39 WLE (36 mo f/u) 15 Mohs (40 mo f/u) Recurrence rate -Wide local excision: 12.8% -Mohs: 6.6%

Microcystic adnexal carcinoma StudyStudy DesignResults Chiller, et al, 2000Retrospective cohort 26 Excision 22 Mohs Recurrence rate (3 yr mean f/u) -Excision 1.5% pp/yr -Mohs: 2.4% pp/yr MMS exhibited a clear benefit over simple excision in that 30% of tumors treated with simple excision required at least another office visit Leibovitch et al 2005 Prospective cohort 20 Mohs Recurrence rate (5 yr f/u) -Mohs: 5% (Local recurrence rates of up to 30- 47% have been reported with standard surgical excision)

Extramammary Pagets Disease StudyStudy DesignResults Lee et al., 2008Retrospective cohort 22 wide excision 11 Mohs Recurrence rate (mean f/u 62 months) -Wide excision: 36.4% -Mohs: 18.2% OConnor et al,Retrospective cohort 38 WLE 41 Mohs Recurrence rate -Wide local excision: 22% -Mohs: 8% Recurrence with Mohs is still high and surgery can carry a very high morbidity in this disease Superficial (electron beam) radiation warrants further study and has been used with success in our experience

Atypical fibroxanthoma StudyStudy DesignResults Ang et al, 2009Retrospective cohort 23 wide excision 59 Mohs Recurrence rate -Wide excision: 8% (8.7 yr) -Mohs: 0% (4.5 yr f/u)

Merkel Cell Carcinoma StudyStudy DesignResults OConnor et al., 1997Retrospective cohort 41 wide local excision 13 Mohs Local recurrence rate -Wide local excision: 31.7% -Mohs: 8.3% Regional metastasis rate -Wide local excision: 48.8% -Mohs: 33.3% Boyer et al 2002Retrospective cohort 25 Mohs alone 20 Mohs +XRT Local recurrence rate Mohs alone: 16% (28 mo f/u) Mohs+XRT =0% (27 mo f/u)

Lentigo Maligna/MMIS StudyStudy DesignResults Walling et al., 2007Retrospective cohort 41 staged excision 16 Mohs Recurrence rate -Staged excision: 7.3% (mean f/u 95 months) -Mohs: 33% (p < 0.025) (mean f/u 117 months) Bene et al., 2008 Prospective study 167 MIS pts 116 LM pts Recurrence rate 1.8% Frozen sections accurate 95.1% compared to paraffin sections

Cost Considerations

When something is more effective and cheaper/equivalent in price, it is superior When something is both less effective and more expensive, it is inferior If something is more effective but also more expensive, when is it cost-effective? Available data indicate Mohs is more effective in curing non-melanoma skin cancer Is it cost-effective? Is Mohs cost-effective?

Cost of Mohs vs. excision for 1cm tumor on cheek (2010 BWH Medicare professional + technical) Excision: 11643 (2-3cm excision) $249 + $664 13132 (Complex repair >2.5cm) $513 +$366 88305 (path) $154 +$311 (plus $176 + $310 for each immunostain if needed) Total for excision: $2,257 Mohs: 99214 (Level 4 established) $82 (+ ? technical) 17311 (stage 1) $417 (+ ?$644 technical) 13132 (Complex repair >2.5cm) $513 +$366 Total for Mohs: $2,022

When something is both more effective and cheaper/equivalent in price, it is superior Mohs is in this category since reimbursement was cut 2 years ago Is Mohs cost-effective? YES!

Too small (or too superficial) Used to be lesions less than 2cm on trunk and proximal extremities Now this is more case by case with cost equivalency But the tumor should require surgery Avoid biopsy of AK/SCCIS Usually lie on a field of histologically similar damage Hard to locate biopsy site When is it clear? Try cryotherapy (with light curettage) or topical 5FU Biopsy and refer for surgery only if fails to clear with non-invasive treatment Indications for Mohs

Too big? Extremely large tumors may require large excisions, bone removal, and reconstructions difficult to perform under local anesthesia Still, we prefer to evaluate as we have experience in managing difficult tumors assessing need for nodal staging, pre-op imaging, adjuvant therapy coordination of multidisciplinary care via DFCI relationships and tumor board Indications for Mohs

Team Approach for Extensive Tumors Recurrence after multiple standard excisions Involvement of bone on CT Mohs established peripheral margin to level of periosteum Complete excision including bone performed by Head and Neck and Neurosurgery

Team Approach for Extensive Tumors Recurrent SCC s/p excision and adjuvant XRT MRI w/ bone involvement Mohs for peripheral margin including periosteum Neurosurgery removed bone Head and neck reconstructed with free flap

Team Approach for Extensive Tumors Mohs for peripheral margin including periosteum Head and neck excised deep margin including bone Patient opted for prosthesis

In summary, no case is too big but some are too small Please send us all invasive non-melanoma skin cancer (BCC, SCC, DFSP, AFX, MAC sebaceous carcinoma, etc.) meeting NCCN guidelines On head, neck, hands, genitalia, below knees 2cm tumors on trunk/extremities Deeper than dermis/4mm Recurrent (including SCCIS that failed non-invasive treatment) Moderate-poorly differentiated, infiltrative, micronodular, perineural/vascular/lymphatic invasion Immunocompromised patient (CLL, RA, transplant) Any others you dont want to excise Indications for Mohs

Though Mohs may be excellent in controlling primary tumors 2cm, SLN biopsy is standard care for almost all cases This is currently difficult to coordinate at Faulkner Regarding Merkel

We do not do Mohs on invasive melanoma (due to skip areas) Happy to do wide excisions on melanomas that do not need SLN No mitoses and

Documents

Indications for Mohs Surgery Chrys Schmults, MD, MSCE Christine Liang, MD