Design: International prospective cohort, 46 referral centres
Population: 277 patients with stage IIB–IVB mycosis fungoides or Sézary syndrome
Primary outcome: Progression-free survival and best response
Effect: Median PFS 4.64 vs 2.72 vs 0.89 years; high vs low risk HR 3.84 (2.21 to 6.66)

In an international prospective cohort across 46 centres, 277 patients with stage IIB to IVB mycosis fungoides or Sézary syndrome were scored on the Cutaneous Lymphoma International Prognostic Index: age over 60, raised lactate dehydrogenase, N3 nodal disease and large-cell transformation in the skin.

Median progression-free survival was 4.64 years at low risk, 2.72 years at intermediate risk and 0.89 years at high risk. Compared with low risk, the high-risk group had nearly four times the hazard of progression or death (HR 3.84, 95% CI 2.21 to 6.66). Adding the index improved prediction over stage alone, and higher scores were linked to poorer response.

The four items are routinely available, making the index easy to apply. It helps counsel patients and plan intensity of treatment, though it has not yet been shown to improve outcomes when used to guide therapy.

Record age, LDH, nodal status and large-cell transformation at diagnosis of advanced disease
Use the index alongside stage when counselling about prognosis
Refer high-risk patients early to a specialist cutaneous lymphoma multidisciplinary team
Request repeat skin biopsy if large-cell transformation is suspected clinically

Why it matters

Stage alone predicts poorly in advanced cutaneous lymphoma, and four routine findings sharpen it.

The statistics, in plain English

An HR of 3.84 means the high-risk group progressed or died at nearly four times the rate of the low-risk group. The wide interval reflects only 40 high-risk patients.