Comparison of Completely versus Incompletely …

1 68 Annals Academy of MedicineIncompletely excised SCCs P Ang et alComparison of Completely versus Incompletely excised CutaneousSquamous Cell CarcinomasP Ang,1 MBBS, MRCP (UK), AWH Tan,2 MBBS, MRCP (UK), CL Goh,3 FAMS, M Med, FRCP (Edin)IntroductionNon-melanoma skin cancer is the most common skincancer worldwide and its incidence has risen in the last Approximately 80% of non-melanoma skin cancersare basal cell carcinomas and the rest are squamous cellcarcinomas (SCCs). While the former grow slowly bycontiguous extension and are largely localised, SCCs have thepotential to metastasize to regional lymph nodes and distantorgans via the blood stream, and hence are associated with ahigher mortality rate. SCCs can be treated with varioustechniques, including curettage and electrodessication,cryotherapy, radiotherapy, surgical excision and Mohsmicrographic We report our data on completelyversus Incompletely excised SCCs in our series of and MethodsAll patients with histologically confirmed SCCs which wereexcised in the National Skin Centre from 1991 to 1995 weretraced from computerised records and the data unconfirmed SCCs, SCCs treated with othermodalities and in situ SCC were excluded.

2 Information regardingthe patients sex, age, aetiological risk factors, tumour duration,tumour characteristics, surgical treatment and outcome wererecorded. All patients were also recalled for physical which were Completely excised and incompletelyexcised were placed into two subgroups and total of 57 patients and 63 SCCs were identified over this1 Consultant2 Registrar3 Medical Director and Senior ConsultantNational Skin Centre, SingaporeAddress for Reprints: Dr Ang Por, National Skin Centre, 1 Mandalay Road, Singapore : This is a retrospective case series of cutaneous squamous cell carcinomas (SCCs)which were Incompletely excised in National Skin Centre, Singapore from 1991 to 1995. Thisstudy compared the characteristics of Completely excised versus Incompletely excised cutaneousSCCs. Materials and Methods: All patients with histologically confirmed SCCs were traced fromcomputerised medical database and information regarding patient profile, tumour characteris-tics, surgical treatment and outcome were collated.

3 All patients were recalled for clinicalexamination and documentation of cure. Completely excised and Incompletely excised SCCswere compared with regards to the patient and tumour characteristics. Results: There were 57patients with 63 SCCs who were treated with surgical excision over the 5-year period. Fifty wererecalled for physical examination. There were 30 males and 27 females and their mean age years. All except 1 were Chinese of Fitzpatrick skin type 4. One-third of patients had dailyor weekly sun exposure in the past and had occupational sun exposure; had priorarsenic exposure and were previously treated with radiotherapy for other mean duration of SCCs was months; of patients had multiple SCCs and underlying actinic keratoses. The mean diameter of the tumours was cm and nearly halfwere located on the head and neck. All the SCCs were primary and localised to the skin; them were Completely excised with a 4 to 6 mm margin.

4 Incompletely excised SCCs wereassociated with the male sex, larger tumours and tumours on the genitals and lower : In our experience, the tumour clearance rate is following conventionalexcision. Incomplete excision is associated with male sex, larger tumours and those on the genitalsand lower Acad Med Singapore 2004;33:68-70 Key words: Incomplete excision, Squamous cell carcinoma, Tumour clearanceOriginal ArticleJanuary 2004, Vol. 33 No. 169 Incompletely excised SCCs P Ang et alperiod. There were 30 males and 27 females, giving a ratio to 1. All were Chinese with Fitzpatrick skin type 4 exceptfor 1 Caucasian. Their ages ranged from 52 to 104 years, witha mean of years. One-third (19/57) of patients had dailyor weekly sun exposure in the past and (12/57) ofpatients had past or present occupational sun exposure. Two( ) patients had prior arsenic exposure and 2 ( ) werepreviously treated with radiotherapy for other were transplant recipients or immunosuppressed.

5 Only 1patient had psoriasis treated with ultraviolet A (UVA) SCCs were present for a mean duration of monthsbefore diagnosis (range; 3 weeks to 120 months). Almost half(30/63, ) of the SCCs were located on the head and neck, (16/63) on the lower limbs, 19% (12/63) on the upperlimbs, (3/63) on the genitals and (2/63) on thetrunk. The mean diameter of the SCCs was cm; (10/63) of tumours had underlying actinic keratoses. None hadmetastases to regional lymph nodes or distant all 63 SCCs which were excised with 4 or 6 mm marginsaccording to hospital guidelines, 10 ( ) were found to beincompletely excised on histology (Table 1). These were from10 different patients. Surgical failure was defined as residualtumour at or within 1 mm to the lateral or deep margins of theexcised specimen. The mean age of the 10 patients was , and 70% were males (Table 1).

6 Four tumours were onthe head and neck, 3 were on the lower limb, 2 were on thegenitals and 1on the upper limb. There was a higher proportionof tumours located in the genitals and lower limbs in thissubgroup. The mean tumour diameter was cm, which wasbigger than that of Completely excised tumours. Sevenunderwent successful re-excision, one had re-excision followedby radiotherapy, one declined further surgery and was treatedwith radiotherapy alone, and 1defaulted on follow-up. The patients in the subgroup of Incompletely excised tumourswere mostly males (70%), and the tumours tended to be slightlylarger ( cm), with a higher proportion on the genitals(20%) and lower limbs (30%).Fifty patients ( ) were contacted or recalled for clinicalexamination. Eight of these patients had died from othercauses. The rest were documented to have been cured of theSCCs at time of last follow-up; none had clinical evidence ofrecurrence.

7 The mean follow-up was months (range, 28 to109 months). Seven patients could not be is a non-melanoma skin cancer with a significantpotential for invasive growth, metastasis and death. Knownrisk factors for the development of SCCs include ultravioletradiation, fair skin, phototherapy with psoralen and UVA(PUVA), ionising radiation, chemical carcinogens (such asarsenic and polycyclic aromatic hydrocarbons), immuno-suppression, certain genodermatoses (such as xerodermapigmentosum and chronic scars) and inflammatory factors for recurrence of SCCs include size >2 cm,certain anatomical sites (such as lips, ears, central face andgenitals) rapid growth, recurrent tumour, immunosuppression,site of previous irradiation or chronic inflammatory process,poorly differentiated histology, depth >4 mm and perineural orvascular ,5 The recommended surgical margins forexcision of SCC are 4 mm for low-risk SCCs and 6 mm forhigh-risk Low-risk SCCs are <2 cm in diameter,primary, well-defined, occurring in non-immunocompromisedTable 1.

8 Patient and Tumour Characteristics of Completely and Incompletely excised SCCsVariableAll SCCsCompletely excised SCCI ncompletely excised SCC(57 patients, 63 tumours)(n = 53)(n = 10) (30/57) (23/47)70% (7/10) (27/57) (24/47)30% (3/10)Mean age (Range) (52-104) (52-104) (54-99) yearsPrimary or recurrentPrimaryPrimaryPrimaryPast history of non-melanoma skin (3/57) (3/47)0%Past (2/57) (1/47)10% (1/10)Past arsenic (2/57) (1/47)10% (1/10)Mean tumour size (Range) ( ) ( ) ( ) cmMean duration of tumour (Range) ( ) (2-120) ( ) moLocation of SCCsHead and (30/63) (24/53) (4/10) (2/63) (2/53)0% (0/10) (3/63) (1/53) (2/10)Lower (16/63) (13/53) (3/10)Upper (12/63) (11/53) (1/10)SCCs: squamous cell carcinomas70 Annals Academy of MedicineIncompletely excised SCCs P Ang et alpatients, slow-growing, without neurological symptoms, well-differentiated and without perineural or vascular ,5 High-risk SCCs have the opposite patients in our case series are predominantly Chinesewith skin type 4, with the exception of 1 Caucasian.

9 The sexratio and age group in our cohort correspond to those in otherepidemiological ( ) of our patients reported frequent sun exposureand a small proportion were exposed to radiography arsenic orPUVA. Surprisingly, none were immunosuppressed, transplantrecipients or had tumours arising from chronically SCCs were mostly located on the head and neck, whichcorrespond to areas of sun exposure. They can be classified aspredominantly low risk as most of them were <2 cm in size,primary, in non-immunosuppressed patients and not in sites ofprevious radiotherapy or chronic disease. None were associatedwith enlarged lymph evaluated the clearance rate of conventional excisionwith postoperative margin assessment in our hospital, whichdoes not offer Mohs micrographic surgery. Mohs micrographicsurgery is a technique of serial surgical excision followed byon-the-spot histological assessment of margins in a horizontalplane by the surgeon.

10 This method offers high cure rates withmaximal preservation of normal tissue and is useful for clearanceof skin cancers like basal cell carcinomas and SCCs. However,it is time- and success rate in achieving tumour clearance withconventional excision is ; subsequent treatment forincompletely excised tumours achieved a cure rate of at least90% with a mean follow-up of months. This success couldbe partly due to the low-risk nature of SCCs in the series. Mostaudits and studies of surgical clearance rates pertain to basalcell carcinomas with surgical failure rates of between 4%to16%.7-11 One study reported a surgical failure rate of SCCs with conventional difference in anatomical sites for both subgroups couldbe due to the difficulty of surgery in the genital area oranticipated problems with surgical closure in the lower limbs,hence a more conservative margin.