• Skin-directed therapy in mycosis fungoides: creams, light and small radiotherapy fields: Early mycosis fungoides is treated on the skin, not through the bloodstream.
• What it costs to aim at a lineage antigen: Almost every lymphoma drug that finds the cancer by a surface marker finds healthy cells carrying the same marker.
• Allogeneic stem cell transplant (allo-SCT): Replacing a patient's blood system with a donor's: chemotherapy wipes out the marrow, donor stem cells rebuild it, and the donor's immune cells hunt down leftover leukaemia.
• Infection prophylaxis in lymphoma: PJP, herpes, fungal risk and vaccination: Several lymphoma treatments knock out the part of the immune system that keeps a particular lung infection, Pneumocystis, at bay.
• Central venous access (port, PICC line): A long-term line into a large vein near the heart, either a small disc under the skin (port) or a tube from the arm (PICC), so chemotherapy can be given and blood drawn without repeated needle sticks.
• Financial toxicity: The harm caused to patients by the cost of cancer care: depleted savings, debt, skipped medication and worse survival.
• Neutropenia: A shortage of neutrophils, the white blood cells that fight bacteria, caused by chemotherapy hitting the bone marrow.
• Febrile neutropenia: Fever in a patient whose infection-fighting white cells have been wiped out by chemotherapy.
• Cancer-related fatigue (tiredness): Fatigue from cancer and its treatment is exhaustion that rest does not fix; for most people it improves after treatment ends, and physical activity, a regular sleep routine, eating well and planning the day around what matters most are the things shown to help.
• Late effects and survivorship toxicity: Health problems appearing months or decades after treatment ends: heart damage, infertility, second cancers, lymphoedema, dry mouth, memory problems, weak bones.

Biomarker results to ask for: Sezary cell count of 1,000 per microlitre or more, or CD4:CD8 ratio of 10 or more with loss of CD7 or CD26, Clonal T-cell receptor rearrangement matching in skin and blood, CCR4 expression (mogamulizumab target), CD30 expression (brentuximab vedotin).

Scans and tests linked to this cancer: Multidisciplinary tumour boards, Multiparameter flow cytometry MRD.

Bring copies of scan reports, pathology and blood results, and a list of every medicine and supplement.

• First-line systemic: Extracorporeal photopheresis with or without interferon or bexarotene (EORTC 2023). (Methoxsalen (extracorporeal photopheresis), Bexarotene, Interferon alfa-2a/2b, Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome))
• Sezary syndrome: treatment aimed at the blood as well as the skin: Sezary syndrome is the leukaemic form: erythroderma covering most of the body, lymphadenopathy, intractable itch and a clone of malignant T cells in the blood. It is treated as advanced disease from the start, and treatment has to reduce the blood compartment, not only the skin. Extracorporeal photopheresis is the treatment most specific to it: the patient's white cells are drawn off, exposed to methoxsalen and ultraviolet A light, and returned, usually on two consecutive days every two to four weeks. It is well tolerated, works slowly over months, and is often combined with interferon alfa or bexarotene. It has been approved for the skin manifestations of cutaneous T-cell lymphoma in the United States since 1999. Mogamulizumab is the systemic drug of choice where the blood is heavily involved, because in MAVORIC the response rate in the blood compartment was 68 per cent, far above its skin response; median progression-free survival was 7.7 against 3.1 months for vorinostat. Other options are bexarotene, interferon, low-dose methotrexate, romidepsin, alemtuzumab at low subcutaneous dose, chlorambucil with prednisolone for an older patient, and allogeneic transplant with reduced-intensity conditioning for fit younger patients, which is the only treatment that produces durable remission. Skin care, control of itch and prevention of staphylococcal sepsis matter at least as much as the lymphoma treatment; erythrodermic skin loses heat, fluid and protein and is an open door to infection. (Methoxsalen (extracorporeal photopheresis), Mogamulizumab, Bexarotene, Interferon alfa-2a/2b, Methotrexate, Romidepsin, Alemtuzumab, Chlorambucil, Prednisone, Allogeneic stem cell transplantation, MAVORIC: mogamulizumab versus vorinostat in previously treated cutaneous T-cell lymphoma, Skin-directed therapy in mycosis fungoides: creams, light and small radiotherapy fields, Infection prophylaxis in lymphoma: PJP, herpes, fungal risk and vaccination)
• Later lines: Mogamulizumab (MAVORIC), methotrexate, pralatrexate, brentuximab vedotin for CD30-positive disease, romidepsin or vorinostat; allogeneic transplant for fit responders. (Mogamulizumab, MAVORIC, Methotrexate, Pralatrexate, Brentuximab vedotin, Romidepsin, Vorinostat, Allogeneic stem cell transplant (allo-SCT))

From the standard of care recorded for this cancer; which apply depends on your stage and biomarkers. Ask which the team recommends and why.