Surgical Treatments of Non-Melnaoma Skin Cancers: A Review

Abstract

Background Non-melanoma skin cancers (NMSC) are the most common cancers diagnosed in Australia. The most common forms of NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The continuing rise in the incidence of NMSC will translate to greater need for surgical interventions. Objective This article aims to review the current literature regarding excisional surgical treatments of NMSC. Data sources A review of all literature using databases of Pubmed and Medline searching for keywords of ‘skin’ or ‘cancer’ or ‘surgery’ was carried out. Review methods All the titles and abstracts of all articles found were searched and relevant articles were selected. A further review of all the references mentioned in the selected studies was carried out and all relevant articles were added to the database. Results Although early or superficial NMSC can be effectively treated with topical agents[ii] [iii], there are numerous factors that call for surgical management[iv]. Broadly ‘surgical’ approaches include surgical excision, curettage, electrodesiccation, cryosurgery, and Mohs micrographic surgery (MMS). Surgical excision, curettage, and MMS are treatments that have the advantage of including histological evaluation. Conclusions Surgical management of NMSC remains the most reliable and the most convenient method of treatment of simple NMSC. The operator needs to remain mindful of the limitations of this modality. The surgeons who maintain an interest in this field should remain abreast of the developments in diagnostic technologies as well topical and non-excisional treatment modalities which are in use by our colleagues in dermatology. AIHW & AACR 2004. Cancer in Australia 2001. AIHW cat. no. CAN 23. Canberra: AIHW (Cancer Series no. 28)[ii] Goette, DK. Topical chemotherapy with 5-fluorouracil. A review. J. Am. Acad. Dermatol. 1981; 4:633[iii] Love WE; Bernhard JD; Bordeaux JS; Topical imiquimod or fluorouracil therapy for basal and squamous cell carcinoma: a systematic review; Arch. Dermatol. 2009; 145: 1431-8[iv] Silverman MK; Kopf AW; Grin CM; Bart RS; Levenstein MJ; Recurrence rates of treated basal cell carcinomas. Part 1: Overview; J. Dermatol. Surg. Oncol. 1991; 17: 713-8 In 2001, there were an estimated 256,000 Australians treated for BCC and a further 118,000 were treated for SCC 1 using surgical treatments. These cancers are usually diagnosed and treated outside hospitals by general practitioners and dermatologists and in skin cancer clinics 2 , but they are not legally notifiable and are not routinely registered by all states and cancer registries. Moreover, many BCC and SCC are treated using cryotherapy, and are not reported histologically, signifying that the incidence of these cancers is perhaps two-fold higher or more. Operator preference, patient preference, need for histological diagnosis, site of lesion, desire to control spread, cosmetic considerations, and failure of prior non-surgical therapy are all features that call for surgical management. Successful surgical excision of the tumour is often determined by complete histological excision of the neoplastic lesion together with a margin of clinically normal surrounding tissue. The peripheral and deep surgical margins of the excised tissue can be examined histologically using formalin fixed postoperative vertical sections or intra-operative frozen section histology may be used if immediate results are required. Wider surgical margins may be used for diffuse primary, incompletely excised, or recurrent lesions. A review of all literature using databases of Pubmed and Medline, searching for keywords of ‘skin’ or ‘cancer’ or ‘surgery’ was carried out. All the titles and abstracts of articles found were searched and relevant articles were selected. A further review of all the references mentioned in the selected studies was carried out and all relevant articles were added to the database. All selected articles were reviewed and categorised into groups based on the technique Surgical Treatments of Non-Melnaoma Skin Cancers: A Review 2 of 6 or the technology being investigated. MOHS MICROGRAPHIC SURGERY MMS is a technique that aims to optimise control of the tumour margins. Under local anaesthesia, the tumour, together with a small rim of clinically normal tissue, is excised and microscopically evaluated. Histological findings from the surgical margins are correlated with the use of a diagram (Mohs map) 3 . If microscopic margins are positive, their locations are noted on the Mohs map and wider reexcision of that part of the involved margin is performed until all margins are negative 4 . MMS is associated with the highest rate of complete clearance of any treatment modality for many high-risk skin cancers, including basal cell carcinoma (BCC) 5 . MMS results in reported five-year cure rates of about 98 to 99% for primary BCC and 95% for more difficult recurrent BCC 6 . There are, however, some significant limitations to MMS. MMS was compared to standard surgical excision in a prospective trial in which 612 patients with BCC on the face (408 primary and 204 recurrent lesions) were randomly assigned to MMS or standard surgical excision 7 . This study suggested that the ultimate cure rates were similar with standard excision and Mohs excision. MMS is also significantly more expensive than standard surgical excision, and it has been shown not to be cost effective for broad clinical usage 8 . A typical MMS procedure lasts two to four hours and more complicated cases take longer. Reconstruction following MMS adds at least another hour to the procedure. A significant amount of the total time is spent with histological preparation and analysis; during this time, patients are temporarily bandaged, and are likely to need repeated administration of local anaesthetics during the length of the procedure. Sedation anaesthesia is used in some centres for some lesions, which may add to the overall cost. Moh’s procedures are useful for selected cases, notably for body regions where wider excision is limited or cosmetically challenging, especially for difficult facial lesions, or for recurrent tumours.