Table 7.
ISCL/USCLC/EORTC response in skin for primary cutaneous lymphomas other than lymphomatoid papulosis
| Response | Definition | Additional criteria for PCLs |
|---|---|---|
| CR* | 100% clearance of skin lesions‡ | |
| PR | 50 to <100% clearance of skin disease‡ from baseline without advancement in stage. May designate subset of Very Good PR based on 90 to <100% clearing of total body involvement | Without new tumors (T3) in MF/SS patients with T1, T2, or T4 |
| SD | <25% increase or <50% clearance in skin disease from baseline‡ | Without new tumors (T3) in MF/SS patients with T1, T2, or T4 |
| PD† | 1. ≥25% increase in skin disease from baseline‡ 2. Loss of response: in those with CR or PR, increase of skin score of greater than the sum of nadir plus 50% baseline score |
New tumors (T3) in MF/SS patients with T1, T2, or T4 only skin disease Additional suggestions for confirming PD in T1 MF and T1 non-MF/non-SS PCLs may be considered depending on the aims of the study§ |
A biopsy of normal appearing skin is unnecessary to assign a CR. However, a skin biopsy should be performed of a representative area of the skin if there is any question of residual disease (persistent erythema or pigmentary change) where otherwise a CR would exist. If histologic changes are suspicious or suggestive of PCL, the response should be considered a PR only.
Whichever criterion occurs first.
One form of assessment of skin disease should be used throughout a given clinical trial. For a global response score and a designation of Very Good PR, a comparison of total body skin assessment based on mSWAT assessment or sum of the product of perpendicular tumor measurements (SLAT score is one example) at baseline is necessary. Regional or lesional skin scoring may also have CR, PR, SD and PD response but may not be representative of the response of skin disease on the entire body skin surface and cannot be used to assess global response.
For patients with limited T1 stage disease, there is a potential for a ≥25% increase in patch/plaque skin score to lead to a PD despite an insignificant change in total skin lymphoma. This is of particular concern in studies where global response is the primary endpoint and skin the primary determinant of that response. In these cases, study design may elect to add additional requirements for PD in patients with T1 disease at BL, including a T1 to T2 change in skin classification in addition to the ≥25% increase in skin score.