Cutaneous T-cell lymphoma origins revealed

Scientists have discovered that cutaneous T-cell lymphoma cells originate from the blood, not the skin as previously thought.

The team, from the University of Alberta in Canada, explain that cutaneous T-cell lymphoma was thought to develop as a result of overproduction of mature T cells resident in the skin. However, this theory does not account for some of the key characteristics of the condition.

So they used whole-exome sequencing to look for tumour cell clones in the blood from 29 patients with cutaneous T-cell lymphoma at various stages.

This “proved [the] existence of multiple T-cell clones within the tumour”, and “multiple neoplastic clones in the peripheral blood in all examined patients”.

In the journal Blood recently, the team write: “Based on these findings, we propose that circulating neoplastic T-cell clones continuously replenish the lesions of cutaneous T-cell lymphoma.

“We hypothesise that circulating neoplastic clones might be a promising target for therapy and could be exploited as a potential biomarker.” They hope that this discovery could unlock new ways to treat this rare blood disease.

Researcher Dr Robert Gniadecki said that malignant clone cells in the blood “are less variable than the cells that grow in the skin, they are more immature, so it's easier to kill them.

“The diagnostic delay for cutaneous T-cell lymphoma can be up to five years until somebody actually makes the diagnosis; it's not psoriasis, it's not a bad infection of the skin, it's actually cancer growing in your skin,” Dr Gniadecki said. “It's progressive, and we have no cure for this. It's a huge medical need.”

Source: Iyer A, Hennessey D, O'Keefe S, Patterson J, Wang W, Wong GK, Gniadecki R. (2019) “Skin Colonization by Circulating Neoplastic Clones in Cutaneous T-cell Lymphoma”, Blood, doi: 10.1182/blood.2019002516