Association of the Depth of Invasion With Recurrence Rates of Basal Cell Carcinoma in a Tertiary Health Care Facility: A Retrospective Study Over a Period of Six Years

Background Basal cell carcinoma (BCC) is one of the most common types of cutaneous malignancies and the most frequently occurring form of cancer worldwide. The incidence of basal cell carcinoma is difficult to determine due to its wide geographic variations; however, it has been increasing worldwide with an annual increase of 7% in the number of reported cases. Although BCC is more prevalent in the aging population, diagnosis in younger individuals is steadily increasing. BCC has overall low mortality, however, it leads to significant economic and physical impact on patients and their families along with adding burden to the healthcare system. The primary risk factor for the development of BCC is increased cumulative sun exposure, particularly to UV radiation. The UV index of Karachi averages around 12 (extremely high) during summer months, putting the population at a significantly higher risk of developing BCC in the long term. Objectives This audit was undertaken with the following primary objectives: to use the data collected to determine possible prognostic factors for BCC, to measure the rate of recurrence and the number of new primary tumors detected, to study the completeness of follow-up by patients, and to co-relate histopathological findings with the recurrence rate of basal cell carcinoma. Methods A retrospective analysis was performed for all patients with BCC who had undergone surgical resection over a six-year time period. Patient charts were reviewed for demographic information, tumor size, onset-to-diagnosis, anatomic location, clinical subtype, histologic differentiation, method of surgical treatment, and recurrence. Data were entered and analyzed in SPSS version 23 (IBM Corp., Armonk, NY). Results The review identified cases of BCC in 99 patients. Of the 99 patients, 60.39% were men and 38.38% were women. The most frequent age group was 65-85-year-olds (42 patients, 42.85%) for BCC. Based on the aesthetic units of the face, the most common location was the nasal unit (30 cases, 30.30%) for BCC. Most of the lesions were closed primarily; however; local flaps were used in the case of surgical defects. The recurrence rate was 19.19% for BCC in this study. Our study included 1.0% of patients who were classified as Clark classification level 2 of BCC, 6.1% as Clark level 3, 23.4% as Clark level 4, and 0.16% as Clark level 5. Recurrence rates were seen to increase with increasing Clark classification level in this study. Conclusion In our study, many characteristics of BCC were compared to previously published reports and the results were seen to be generally similar. This study correlates the recurrence of BCC with Clark’s classification, showing that depth of invasion is a significant factor in predicting recurrence. There is a paucity of literature regarding the depth of invasion of BCC along with its’ Clarks classification and recurrence. Further studies can help explore and establish the characteristics of BCC.