Egyptian Dermatology Online Journal 2 (1): 13, June 2006

Abstract

Introduction

Non-melanoma skin cancer (NMSC) generally refers to cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC).[1,2,3] It constitutes a major world public health problem as it is the most common cancer. World-wide efforts have been made to study NMSC, determine the etiology, the population at risk, prevention, and control.[4] This urged us to conduct a study on the prevalence, risk factors and clinico-pathological characteristics of NMSC in Benha.

         In Egypt, there are 28 governorates. Benha is the capital of Qalyubiyah governorate located in the middle of Delta-Nile valley. It is surrounded by different villages within the governorates whose main field of work is agriculture. Benha University Hospital is the main center that drains most of the referral from different hospitals and health centers in the villages around. Hence, this study would almost reflect the prevalence of NMSC in the whole governorate.

Patients and Methods

This study was conducted along one year period starting in January 2002. The total number of patients attending the Dermatology Outpatient Clinic and the number of patients presenting clinically with NMSC were recorded daily. Age, Sex, special habits, occupation, exposure to chemicals, leisure activities and the frequency of sunlight exposure were noted for each patient presenting with NMSC.

For each, a past history was taken as regards the presence of a chronic debilitating disorder, intake of immunosuppressive therapy or radiotherapy or the presence of other skin disorders. A family history of skin tumors and related genodermatoses was noted. Patients were questioned for the onset, duration, and previous management. They were examined for the skin color, the clinical presentation and the site of the tumor, and manifestations of photo-damage e.g. freckling, pigmentation, or solar elastosis. They were also examined for the presence of premalignant lesions e.g. Bowen's disease, chronic scarring or ulceration, solar and arsenical keratoses and leukoplakia. The patients were included only once regardless of the total number of NMSC lesions presented at the time of examination.

Wedge shaped incisional or excisional biopsy was taken. Paraffin-embedded sections stained with Hematoxylin and Eosin (H&E) were examined by light microscopy.

The patients with SCC were further investigated for routine laboratory and radiological studies and lymph node biopsy was performed in cases with lymphadenopathy. SCC was graded into four grades according to Lever and Schaumburg classification[5] :

The degree of cellular differentiation and grading of SCC:

The test of proportion (Z) was used as a test of significance for comparing two percentages. The significance of the result; the corresponding P-value was considered significant if it is <0.05.

Results

Thirsty-seven patients with non melanoma skin cancer (NMSC) were identified among 18927 patients who attended the Dermatology Outpatient Clinic of Benha University Hospital, Over a period of one year 2002 - 2003 with a prevalence of 0.19%.

Twenty two patients (59. 5%) had BCC, 10 males (45.4%), and 12 females (54.6%). Fifteen patients (40.5%) had SCC, 8 males (53.3%) and 7 females (46.7%) . A total of 18 males and 19 females presented with NMSC. Sex distribution in relation to the type of the tumor was not statistically significant, table (1).

Table (1): sex distribution of NMSC patients:

The age range for NMSC patients was 17-90 years. The mean age in years for BCC was (55.2 ±15.2) and for SCC was (57.9±15.6). The age distribution in relation to the type of the tumor is shown in table (2).

Table(2): Age distribution in relation to the type of the tumor:

Both BCC and SCC occurred significantly more above the age of 40 years. Fig (1) shows age distribution in relation to sex and type of tumor. Males were at an older age group than females and males with SCC were at an older age group than those with BCC.
 

Fig. (1): Age distribution of patients in relation to sex and tumor type

Basal cell carcinoma had a long duration ranging from 1-15 year with a mean of (5.7±4.6), while SCC duration ranged from 1m-7 years with a mean of (1.5 ± 2.0). Two patients; one BCC and one with SCC had tumor recurrence at the same site of the original one.

Of the studied group, 33 patients (89.2%) had dark complexion and only 4 (10.8%) had light complexion. Both BCC and SCC were significantly more in patients with dark complexion and skin type IV-V, table (3).

Table(3): skin color in relation to the type of tumor:         

Nine SCC patients (60%) had precancerous lesions including solar keratoses (2), Bowen's disease (2), leukoplakia (2), and long standing ulcer (3).Eleven patients (73.3%) had smoking habits, and 7 had insignificant association with chronic renal failure, viral hepatitis, diabetes mellitus, hypertension and osteoarthritis .The overall number of patients chronically exposed to UVR was 25 (67.5%) through field work and different outdoor occupational activities. Family history was irrelevant for both BCC and SCC.

Head and neck were significantly the site of predilection for both BCC and SCC (31 patients , 83.8%), table (4).

Table(4): site of predilection in respect to the type of NMSC:

The tumor size for BCC ranged from 0.5-1 cm in 20 lesions, 2 cm in 3 lesions and 5 cm in one tumor. SCC diameter size ranged from 0.5-3 cm.

Table (5) shows the histopathological variants of BCC in regards to sex. The noduloulcerative pattern constituted the majority of BCC (15 patients, 68.3%), and was found more among females (9 patients, 41%). Females had statistically significant direct correlation with the solid histopathological variant of BCC (r0.3, P<0.05).

Table(5):Histopathological subtypes of BCC in regards to sex:             

Nine patients with SCC presented with ulcerating nodule on the head, 2 with deep malignant ulcers on the lower limb, 3 on the genitalia and one as superficial plaque on the chest. Of the 15 patients with SCC, 7(46.6%) had well differentiated tumors and an equal number of 4 (26.6%) for both moderately and poorly differentiated tumors, table (6). One patient with ulcerating nodule on the vulva had regional inguinal lymph node metastases.