Treatment of Basal Cell Carcinoma Using a One-stop-shop With Reflectance Confocal Microscopy: a Randomized Controlled Multicenter Trial

Basal cell carcinoma (BCC) is the most common cancer diagnosed in white populations worldwide. The rising incidence of BCCs is becoming a major worldwide public health problem (1,11). Between 1973 and 2009, the European standardized rate quadrupled from 40 to 165 per 100,000 person-years for men and from 34 to 157 for women, most probably as a result of more intensive UV exposure (12). This is supported by previous published epidemiological literature indicating that ultraviolet radiation is an important risk factor for BCC with a significant increase among outdoor workers (13,14). Despite the low mortality from BCC, multiple and recurring tumors confer a high morbidity and considerable burden for health care providers and health budgets. Although BCC does not seem to have a high effect on patients' quality of life, patients suffering from BCC are definitely interested in efficacy, low recurrence rates and cosmetic outcome of their therapies.(15). Meanwhile resources available at hospitals have not increased proportionally and therefore optimizing effectiveness of present treatment modalities in daily dermatologic practice is mandatory (16).

Clinically, BCC are characterized by small, translucent, or pearly papules, with raised teleangiectatic edges (17) . Most of the BCC occur in sun-exposed skin of the head and neck area (18,19). Sensitivity and positive predictive value for the clinical diagnosing of BCC by dermatologists has been reported to be 95.4% and 85.9%, respectively (20). However, dividing between BCC subtypes is not always possible upon clinical assessment. To date, histological analysis of punch biopsy remains the golden standard to confirm the clinical diagnosis of BCCs and dividing between the following subtypes: nodular (nBCC), micronodular (mnBCC), infiltrating (iBCC) and superficial (sBCC) (10). Of those, nBCC and sBCC have a less aggressive growth pattern in comparison to mnBCC and iBCC. Additionally, mixed type BCC (mtBCC) can be defined as a combination of subtypes and are frequently composed of aggressive subtypes (21). Surgical excision remains the standard of treatment, with Mohs micrographic surgery typically utilized for high-risk lesions (22). Based upon the histological growth pattern, BCC are surgically removed with a margin of either 3mm (nBCC and sBCC) or 5mm (mnBCC, iBCC) in accordance with current Dutch guidelines (10).

Due to the rising incidence of BCC there is a need for more efficient, non-invasive methods to diagnose BCCs. The use of real-time in vivo reflectance confocal microscopy (RCM) to diagnose BCCs has proven successful to address this need. Various studies have demonstrated that RCM is safe and accurate (sensitivity and specificity) to diagnose BCCs(2-6). Reported sensitivity and specificity for RCM in diagnosing BCC range from 83%-100% and 79%-97%, respectively (7). Furthermore, Peppelman et al. and Longo et al. recently reported on RCM features that might divide between nodular, micronodular, superficial and infiltrative subtypes of BCC (8,9).

In 2012, van der Geer et al reported on the feasibility of a one-stop-shop (OSS) concept for the treatment of skin cancer patients (23). One-stop-shop implies that at the day of the initial outpatient clinic consultation, diagnosis and treatment plan both take place. In their study, pre-operative frozen section histology was used to confirm BCC diagnosis and subtype. The mean throughput time was 4 hours and 7 min, no complications were observed, and patient satisfaction was high (23). Incorporating RCM as non-invasive diagnostic tool in a BCC OSS concept for lesions suitable for conventional surgical excision might further reduce time between clinical diagnosis and treatment, administrative workload and costs.

The aim of our study is to assess the efficacy and safety of the one-stop-shop concept, using real-time in vivo reflectance confocal microscopy (Vivascope 1500; Lucid Technologies, Henrietta, NY, USA) as diagnostic tool, prior to surgical management of new primary BCCs, of all subtypes, in the general population.