Treatment selection and survival outcomes in Early-Stage peripheral T-Cell lymphomas: does anaplastic lymphoma kinase mutation impact the benefit of consolidative radiotherapy?

The role of consolidative radiotherapy (RT) is less substantiated in uncommon peripheral T-cell lymphomas (PTCLs). Anaplastic lymphoma kinase (ALK) mutation sub-categorizes PTCLs, with ALK (+) having a distinctly favorable prognosis. We aimed to use the National Cancer Database to examine the potential role of RT in PTCLs and if ALK mutation can be used to predict the benefit of consolidative RT after multi-agent chemotherapy (combined modality therapy). We identified 3670 stage I-II PTCL patients treated with multi-agent chemotherapy alone or combined modality therapy (CMT) between 1998-2012. After adjusting for immortal-time and indication bias, CMT was associated with better OS than multi-agent chemotherapy alone for ALK (-) patients (HR 0.69, 95% CI 0.52-0.92, p = .01); no significant difference was noted for ALK (+) (HR 1.03, 95% CI 0.75-1.41, p = .85). CMT is associated with improved OS for ALK (-) PTCLs; while no such benefit was seen for the ALK (+) subgroup.