Risk of cutaneous carcinogenesis with phototherapy in Indian subpopulation: A 10‐year analysis and a review of literature

Phototherapy is an extremely effective and established therapeutic modality in a variety of dermatological disorders. However, there has been a constant concern with respect to its long‐term usage as some of the studies have identified the risk of cutaneous malignancy associated with phototherapy. The carcinogenic potential of PUVA has been demonstrated in most US studies; however, the studies done on Asian and Arabian–African population have not corroborated similar findings, thus suggesting that the darker skin may confer protection against the development of cutaneous malignancy following phototherapy. The main aim of the present study was to assess the safety of phototherapy (bath PUVA and NBUVB) in Indian population (Fitzpatrick skin types IV and V) with respect to its carcinogenic potential and to determine the maximum cumulative dose that our patients could tolerate without developing any untoward complications such as cutaneous malignancy. All patients who received phototherapy between January 2006 and October 2016 were enrolled in the study. Details such as cumulative dose, number of phototherapy sessions received, indication for phototherapy, adverse effects such as pigmentary changes, new growths on the skin surface following the therapeutic sessions were entered in a predesigned proforma. This ambispective study had 1300 patients who had received phototherapy over a period of 10 years. A total of 929 patients had received PUVA, and the remaining 371 patients had received NBUVB for various dermatological indications. The average follow‐up period for PUVA was 3 years and 6.5 years for NBUVB. The maximum cumulative dose of UVA and UVB that could be safely administered in our patients was 2085 J/cm2 and 1985 mJ/cm2, respectively. None of our patients developed any features of cutaneous malignancy during their follow‐up. Both bath‐PUVA and NBUVB are safe and efficacious in treating patients of darker skin types (IV and V). The risk of developing cutaneous malignancy is negligible in this subset of patients. However, more studies need to be done on the Asian population to substantiate the same.