Patients with Sezary syndrome, particularly those with high levels of circulating Sezary cells, may achieve sustained anti-cancer responses following treatment with extracorporeal photopheresis, according to a recent article published by the journal Blood.
Sezary syndrome is a cancer that involves T-lymphocytes (T-cells). T-cells are immune system cells that attack foreign substances in the body. Sezary syndrome is characterized by cancerous T-cells called “Sezary cells” which manifest in the skin, causing generalized scaliness and redness of the skin as well as enlarged lymph nodes. Sezary cells can be found circulating in the blood in advanced stages of Sezary syndrome. Standard treatment for Sezary syndrome includes systemic or topical chemotherapy, interferon or interleukin-2 (biologic agents that stimulates the immune system), electron beam or proton irradiation and/or retinoids (vitamin A derivatives).
Extracorporeal photopheresis (ECP) is a type of treatment that has been evaluated since the 1980’s for the treatment of cutaneous T-cell lymphoma. ECP works in the following manner: the patient’s blood is filtered in order to collect the cancerous cells. The cancer cells are then treated outside the body with a substance (8-MOP) that becomes active when exposed to ultraviolet (UV) light. Following treatment with 8-MOP, the cancer cells are exposed to UV light which disables them. The disabled cancer cells are then re-infused back into the patient. Through biological processes not yet determined, the treated cancer cells stimulate an immune response against the other cancer cells in the body.
Researchers from London recently conducted a clinical trial in an attempt to determine if specific characteristics in patients with Sezary syndrome effect responses to treatment with ECP. This trial involved 23 patients, 10 of whom had previously undergone chemotherapy. ECP was performed as sole treatment once a month for a year. Approximately 60% of patients achieved an anti-cancer response, defined as at least a 25% reduction in the number of Sezary cells in the skin and circulating blood. Treatment was generally well-tolerated and the responses lasted through the year, while patients were receiving treatment. The only predictor of responses was a high level of Sezary cells in the blood prior to treatment.
These findings suggest that patients with Sezary syndrome may achieve sustained anti-cancer responses with treatment involving ECP. However, these results indicate that patients must have hematological (blood) involvement of their disease in order for ECP to be effective. Patients with Sezary syndrome may wish to speak with their physician about the risks and benefits of ECP or the participation in clinical trials evaluating novel therapies. Two sources of information regarding ongoing clinical trials include comprehensive, easy-to-use listing services provided by the National Cancer Institute (cancer.gov) and eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients. (Blood, Vol 98, No. 5, pp 1298-1391, 2001)