EPIDEMIOLOGICAL AND HUMANISTIC BURDEN OF CUTANEOUS T‐CELL LYMPHOMAS: RESULTS OF a SYSTEMATIC REVIEW

Abstract

Introduction: Cutaneous T‐cell Lymphomas (CTCL) are characterised by the expansion of malignant T cells within the skin. Many patients with aggressive subtypes relapse following first‐line systemic chemotherapy. Various novel systemic therapies are therefore under investigation for treatment of relapsed disease. Methods: A systematic review was performed in December 2016 to identify published evidence for the epidemiology of CTCL and impact on quality of life (QoL). Results: Thirteen studies reported the incidence of CTCL (US, n =8; Europe, n = 3; Iran, n = 2). The age‐adjusted incidence was found to range between 0.16 and 0.87 per 105 person‐year (n = 7) and the annual incidence ranged from 0.39 to 0.9 per 105 (n = 6), with higher values being reported for the US compared with Europe or Asia. Evi- dence from seven studies (US, n = 4; Europe, n = 3) indicate that the incidence of CTCL has increased over time. An analysis of Surveillance, Epidemiology and End Results (SEER) data from 1973 to 2002 reported an increase in incidence of 2.9 × 10−6 per decade to 0.96 per 105 persons for 1998–2002. Various CTCL subtypes are recognised: myco- sis fungoides (MF) is the most common subtype (45%), peripheral T‐cell lymphomas accounts for 25% of cases and Sezary syndrome (SS), a par- ticularly aggressive subtype for 1.3%. Twelve studies reported the impact of CTCL on QoL, with more advanced disease stage associated with poorer QoL. Various aspects of QoL (emotion, symptom, and function) were affected in patients with CTCL, with symptoms including fatigue, pain, insomnia, and pruritus reported. Pruritus is a frequently reported outcome in CTCL and was associated with all stages of disease and with poorer QoL. There is no standard therapy, but recommended options include skin‐directed agents for early disease and systemic cytotoxic and targeted therapies for advanced disease. However, approximately, 65% of patients relapse following first‐line therapy. For example, one study (n = 168) reported a response rate of 39% (complete response rate, 6.5%) to first‐line therapy (includ- ing skin‐directed therapies or systemic therapies) and an overall response rate of 15% (complete response rate, 1.7%) to second‐line therapies. Five‐year overall survival (OS) for patients with MF/SS diag- nosed with advanced disease is generally less than 50%. For example, a study of 1502 patients with MF/SS from a single centre in the UK reported 5‐year OS to range from 47% for patients with stage IIIA dis- ease to 18% for patients with stage IVB disease. Conclusions: CTCLs are rare malignancies, but the incidence appears to be increasing. Many patients with more aggressive disease relapse following first‐line systemic therapy. Pruritus, a common and often severe symptom at all stages of disease, adversely affects QoL. There is a need for better treatments which address this burden, especially for patients with aggressive relapsed disease. Keywords: cutaneous T‐cell lymphoma (CTCL); mycosis fungoides (MF); Sezary syndrome. 445