In our study, the prevalence of non-melanoma skin cancers was 11.8%, lower than the 26% reported in Brazil [8], 25% in Tanzania [12], 23% in South Africa [13] and 20,98% in Nigeria [14], but higher than the 4.6% reported in France [15]. The reason for our low rate would be that other PWA in more remote areas, which do not even have access to health care centres, have not been affected by these activities. While the mobile consultation strategy is the one we have used in the campaigns, the majority of our consultations are limited to urban PWA. Moreover, PWA are the target of prejudice and social exclusion and have limited access to specialized medical care and resources [8, 16].
The average age of patients in this study was 38.6 years, much lower than that of the general Togolese population (42 years) [10]. However, it is similar to the 35.5 years found in Tanzania [6] with an earlier onset of BCC (median age 35.5 years) compared to SCC (median age 39 years). PWA develop sun damage earlier due to lack of sun protection (covering clothes, wide-brimmed hats, sunscreen, indoor occupations to avoid repeated sun exposure), so malignant tumours occur from the second decade of life [2, 6].
We have identified 54 cases of skin carcinomas dominated by BCC (57.4%), with some patients having more than one tumor, and some of them having more than one (histologically confirmed) diagnosis. This finding of multiple lesions has already been made in the literature in this population [8, 9, 17, 18], including 14% (4 cases) of combined BCC and SCC in Brazil [8], one case of multiple BCC in India [17] and one case of SCC, Bowen's disease in Japan [18]. In our study, there was a predominance of BCC with a BCC/SCC ratio of 1.47. In Nigeria [14], malignant skin lesions comprising 55% of BCCs, 22% of SCCs, 18% basosquamous carcinoma and 5% collision tumour (BCC and SCC). In Brazil [8], it was 62% BCC, 51% SCC and 7% melanoma. These three studies including ours, are cross sectional community based studies. However, most African studies, all retrospective hospital based, show that SCC is the most common cancer in this population [4, 6, 9, 19]. In Tanzania, there were 72 cases (53.7%) of SCC versus 61 (45.5%) of BCC and one case of melanoma (0.75%) [6]. In another study in Nigeria, there were 68.2% SCC, 22.7% BCC and 9.1% melanoma [9]. A review had shown that SCC was observed in 5-88% of cases compared to 9-23% and 1.3-3% respectively for BCC and melanoma [20]. Indeed, the incidence of SCC doubles with every 8-10 degrees of decline in latitude with a maximum incidence at the equator [6]. Finally, melanoma is rare in PWA with a similar incidence in the general population [8], a tumour that we did not find in our study.
Skin cancers develop at sites in the body exposed to ultraviolet radiation [4, 19, 21]. In our study, the lesions were mainly located in the head and neck (33 cases; 61.1%), followed by the upper limbs (15 cases; 27.8%). Head and neck are similar locations reported in other studies [14, 21, 22]. Resellers (21.2%), traders (15.2%) and farmers (12.2%) were the predominant occupations in our study. In Nigeria [9], these were artisans and farmers. These activities chronically expose the head and neck to the sunlight, which is the major risk factor for skin cancer [5, 21].
Limitations of study
One of the limitations of this study is that the two campaigns concerned only 10 towns in Togo, without forgetting that rural areas were not concerned. Although awareness campaigns and statements have been advertised to invite PWA to these campaigns, the number of PWA reached by these activities is far below the estimates of the number of PWAs in Togo according to the National Association of Albinos in Togo (ANAT). Those who lived further away may not have participated either because not knowing of the initiative or because being a day away from work in addition to travel costs would be too expensive. The second limitation is that selection and participation bias may have gone either way: PWAs with skin cancer may have been more or precisely less inclined to participate compared to PWAs without skin cancers.