RECURRENCE OF RODENT ULCERS AFTER RADIOTHERAPY

Perineural spread of basal cell carcinomas treated with Mohs micrographic surgery

BACKGROUND

Perineural spread is a well-documented feature of cutaneous tumors and may portend a more aggressive course. The incidence of perineural invasion in basal cell carcinoma (BCC) is reportedly 1%. The authors sought to determine whether perineural spread occurs more commonly than previously thought.

METHODS

The authors prospectively evaluated 434 patients with BCC treated with Mohs surgery, assessing the presence or absence of perineural inflammation and invasion in tumors requiring more than one stage of surgery. They also documented the demographic features, clinical characteristics, histologic subtype, and operative data in each case.

RESULTS

Seventy-eight BCCs required more than one stage of Mohs surgery. Perineural inflammation, perineural tumor invasion, or both were present in 29 of the 78 tumors (37%), or 6.7% of all 434 prospectively evaluated cases. Twenty-one of the 78 tumors (26.9%) exhibited perineural inflammation, 3 (3.8%) demonstrated perineural invasion, and 5 (6.4%) exhibited both. Tumors with perineural invasion required 5.3 surgical stages on average for clearance, in contrast to tumors without perineural invasion, which required 2.2 stages. Tumors with perineural inflammation, inflammation plus tumor invasion, and invasion alone were, respectively, 138%, 149%, and 194% greater in area preoperatively than tumors without perineural involvement, and their mean defect areas after Mohs surgery were, respectively, 151%, 121%, and 605% larger than those of tumors without perineural involvement.

CONCLUSIONS

The incidence of perineural invasion among cases of BCC appears higher than previously recognized. Tumor aggressiveness appears to correlate with the presence of perineural invasion. Surgery with horizontal frozen-section margin control enables easy detection of perineural involvement and should therefore be strongly considered for the treatment of high risk BCC patients.

Mohs' micrographic surgery for basal cell carcinoma

Mohs' surgery for basal cell carcinoma (BCC) is widely recommended by dermatologists as first line surgical therapy for recurrent or ill-defined skin tumours. The technique assumes that BCC spread by contiguous growth and that all tumour cells have to be removed. Advocates claim that Mohs' surgery provides a better chance of cure, and because less uninvolved tissue is excised the smaller defect can be readily closed resulting in a superior cosmetic result. This review examines the evidence for these claims.

Recurrent nonmelanoma skin cancer in southern Australia

BACKGROUND AND OBJECTIVE

In retrospective studies of non-melanoma skin cancers, the recurrence rates were relatively high. This study had as its aim to determine the recurrence rate of nonmelanoma skin cancer (NMSC) and prospectively, risk factors for recurrence in southern Australia.

STUDY DESIGN

This is a prospective study of outpatients with histologically confirmed NMSC. All patients seen by a dermatologist between November 1988 and November 1989 were entered into the study and followed for at least 3 years. Any recurrent NMSCS were removed and recorded.

RESULTS

Four hundred and eighty-one patients were entered and 420 followed for at least 3 years. A recurrent NMSC developed in 8% (adjusted for losses). A multivariate analysis determined that the main risk factor for recurrence within the first 3 years of follow-up was the number of NMSC a patient had when entering into the study. Those with 3 to nine NMSC were five times more likely to develop a recurrence than those with less than three NMSC. Those with 10 or more NMSC were 25 times more likely to develop a recurrence. Age, sex, and types of skin cancers removed were not risk factors within the first 3 years of follow-up.

CONCLUSION

Patients who have had multiple skin cancers require careful follow-up because of the risk of developing recurrences.

Mohs surgery of basal cell carcinoma--a critical review

Mohs surgery for basal cell carcinoma (BCC) of the skin attempts to ensure complete tumour removal by histological examination of the entire excision margin and further excision of involved sites. Advocates recommend its use in recurrent or incompletely excised tumours, poorly defined, histologically aggressive or large primary tumours and BCCs situated at high risk or cosmetically important sites. The claimed advantages over other surgical therapies are that it provides a better chance of cure and since less normal tissue is removed the simpler surgical repair ensures a superior cosmetic result. This review examines the published evidence that supports the enthusiasm for the use of Mohs surgery in the treatment of BCC, contrasting cure rates and cosmetic outcome with results achieved by attempted single complete excision and examines the 2 principles upon which Mohs surgery is based, namely that BCCs spread by contiguous growth and that all tumour cells have to be destroyed to achieve a cure.

Basal cell carcinoma recurring after radiotherapy: a unique, difficult treatment subclass of recurrent basal cell carcinoma

Twenty-seven basal cell carcinomas (BCCs) recurring following radiation therapy alone or in addition to other treatment modalities were treated with Mohs micrographic surgery (MMS) from 1983 to 1989. Mean tumor size was 2.1 cm. Of the tumors, 70.4% arose in the mid-face region, 55.6% had undergone multiple previous treatment modalities. The present recurrence rate is 7.4% (mean follow-up: 25 months). Basal cell carcinoma recurring following radiotherapy deserves special subclassification among recurrent BCC. It is very difficult to eradicate, with high recurrence rates following standard surgical excision or further radiotherapy. Tumors are usually large, aggressive, and invasive. Most arise in the cosmetically crucial mid-face region, where extension into subcutaneous tissue planes is common. Mohs surgery, with its inherent abilities to examine all margins, map tumor extension, and conserve tissue, is uniquely suited to treatment of these difficult tumors.

Use of Mohs micrographic surgery to establish quantitative proof of heightened tumor spread in basal cell carcinoma recurrent following radiotherapy

We compared 27 basal-cell carcinomas (BCCs) recurrent following radiotherapy and subsequently excised by Mohs micrographic surgery to a control group of BCCs recurrent following other treatment modalities and similarly excised. Mohs technique permitted precise, quantitative tumor assessment, obtained via a novel method utilizing three parameters: the number of surgical stages required for complete excision, the percentage increase between clinical preoperative tumor area and final postoperative defect area, and the presence of deep subcutaneous tissue invasion. Figures for the postradiation group were larger in all three categories, with the latter two revealing statistically significant differences versus the nonradiation group. This study gives strong, direct quantitative support to the clinical impression that BCC recurrent following radiotherapy is a uniquely aggressive, invasive subset of recurrent BCC.

Mohs surgery is the treatment of choice for recurrent (previously treated) basal cell carcinoma

We reviewed all studies (since 1945) reporting recurrence rates for treatment of recurrent (previously treated) basal cell carcinomas (BCC) using surgical excision, radiotherapy, cryotherapy, curettage and electrodesiccation, and Mohs micrographic surgery. The 5-year recurrence rate for Mohs micrographic surgery is 5.6%. The recurrence rate for non-Mohs modalities of 19.9% is nearly four times higher. Individual recurrence rates for the non-Mohs modalities are 17.4% for surgical excision, 40.0% for curettage and electrodesiccation, and 9.8% for radiation therapy. There are no studies reporting 5-year data for cryotherapy. However, the recurrence rate is 13.0% for cryotherapy when the follow-up period is less than five years. The data support the following conclusions: (1) Mohs surgery is the treatment of choice for recurrent BCC; (2) if the patient is not a surgical candidate and the lesion is small, radiation therapy is an alternative that offers a better chance for cure than the other non-Mohs modalities; and (3) curettage and electrodesiccation should not be used to treat recurrent basal cell carcinoma.

Long-term recurrence rates in previously untreated (primary) basal cell carcinoma: implications for patient follow-up

We reviewed all studies (since 1947) reporting recurrence rates for treatment of primary (previously untreated) basal cell carcinomas using surgical excision, radiotherapy, cryotherapy, curettage and electrodesiccation, and Mohs micrographic surgery. Our findings indicate that recurrences following treatment of primary basal cell carcinoma appear later than is generally acknowledged in the literature. We found that less than one-third of all recurrences appear in the first year following treatment; only 50% appear within the first 2 years following treatment; and only 66%, or nearly two-thirds, appear within the first 3 years following treatment. A good rule of thumb is that the 10-year recurrence rate is double, or 2 times, that of the 2-year recurrence rate. Furthermore, 18% of recurrences appear between the fifth and tenth year following treatment. These results held true, irrespective of treatment modality examined. Seventy-two studies reporting short-term recurrence rates (follow-up less than 5 years) had a weighted average recurrence rate of 4.2%, whereas 34 long-term studies (follow-up of 5 years) had a weighted average recurrence rate of 8.7%, or more than 2 times the short-term rate. Five-year recurrence rates by treatment modality are as follows: Mohs micrographic surgery 1.0%, surgical excision 10.1%, curettage and electrodesiccation 7.7%, radiation therapy 8.7%, and cryosurgery 7.5%. We conclude that the reporting of recurrence rate data for basal cell carcinoma should be standardized using 5-year life table analysis, and even more important is our conclusion that lifetime follow-up is necessary after treatment of primary basal cell carcinoma in order both recurrences and new primaries.

Radiotherapy of periocular basal cell carcinomas: recurrence rates and treatment with special attention to the medical canthus

Basal cell carcinomas of the eyelids, especially those in the medial canthal area, may cause extensive local destruction. Recurrent tumours are more aggressive and become progressively more difficult to treat; this is especially true for postirradiated recurrent, medial canthal, basal cell carcinomas. Tumours in this area should thus be treated by a technique which allows tissue sampling in order to gauge the adequacy of the treatment, with the goal being complete extirpation of the tumour. Excision monitored by frozen section control or Mohs' surgery is our recommendation based on a retrospective analyses of 631 eyelid basal cell carcinomas, half of which were primary tumours and half recurrent.

Mutilating basal cell carcinoma of the face

Two cases of neglected, mutilating basal cell carcinoma are described with observations on their spread. A review of the literature indicates that anatomical site and delay in seeking treatment are the most important factors associated with the development of such lesions.

Basal cell carcinoma in Queensland

An analysis is presented of a referred series of 1411 basal cell carcinomas treated by surgical excision and plastic surgical repair in which 259 were recurrent after previous other treatments. Of the 1,411 BCCs treated there were 10 BCCs which recurred (0.7% recurrence rate). A further 10 BCCs were primarily re-excised because of inadequate clearance around the tumour found on histological examination. (0.7% primary re-excision). The cases recurrent after previous treatment did not behave badly in terms of subsequent recurrence as they were widely excised and carefully observed in the postoperative years. Surgery must aim to be curative. We clearly define the tumour margin using magnification and mark an adequate clearance of surrounding normal tissue. This is then excised in width and depth. Repair of the defect is carried out to restore the area to as near normal as possible. Surgical repair is able to bring new tissue into the area to further enable it to withstand the rigours of the climate and not leave behind a premalignant scarred area.