Predictors for the use of systemic therapy in stage IB Mycosis fungoides

Cutaneous T Cell Lymphoma (CTCL) is an increasingly prevalent condition that impacts patients of all skin types. The most common subtype of CTCL is Mycosis Fungoides (MF), an indolent non-Hodgkin lymphoma of T cell origin that primarily develops in the skin. Most patients with Stage IB MF receive phototherapy as a first-line treatment; however, some require additional systemic therapy. We conducted an institutional review board (IRB)-approved single-center retrospective study of 172 patients diagnosed with Stage IB MF at NYU Langone Health from January 1990 to April 2021. Our study identified demographic and clinical parameters that may indicate which Stage IB patients will require systemic therapy in order to guide clinical decision making and ensure that these treatments can be offered earlier in the disease course. Of 172 total patients enrolled, 129 (75.0&) received phototherapy only, 33 (19.2&) received phototherapy and a systemic agent, and 10 (5.8&) were excluded for lack of documented treatment modality. Univariate statistical analysis demonstrated that advanced age at diagnosis (p<0.005) and elevated LDH (p<0.001) were statistically significant markers in the systemic therapy group. There were no significant differences in anatomical regions involved for patients on systemic agents. Other variables including ethnicity, Fitzpatrick skin type, and health insurance status were not statistically significant predictors of receiving systemic therapy. These results suggest that clinicians should routinely order LDH upon diagnosis for all patients with Stage IB MF. If elevated, patients should be more closely monitored for earlier initiation of systemic agents. Patients with Stage IB MF with an advanced age of diagnosis are also at higher risk of requiring systemic therapy.