Table 1.
Clinicopathological characteristics of the investigated cohort discontinuing ICI therapy
| Clinicopathological features | N (%) |
|---|---|
| Median age at initiation of ICI (range) | 73 (53–97) |
| Gender | |
| Female | 9/20 (45%) |
| Male | 11/20 (55%) |
| Primary tumor | |
| Localization | |
| CUP1 | 7/20 (35%) |
| Upper limb | 5/20 (25%) |
| Lower limb | 5/20 (25%) |
| Head–neck area | 2/20 (10%) |
| Trunk | 1/20 (5%) |
| Positive MCPyV2 status | 4/7 (57%)4 |
| Metastatic lesion | |
| Metastatic sites | |
| Lung | 3/20 (15%) |
| Liver | 4/20 (20%) |
| Nodal | 16/20 (80%) |
| Cutaneous | 9/20 (45%) |
| Cerebral | 0/20 |
| Other (Bone, muscles, pancreas, adrenal glands) | 7/20 (35%) |
| Elevated LDH serum levels at beginning of ICI | 11/18 (61.1%)5 |
| ECOG3-status ≥ 1 at beginning of ICI | 9/20 (45%) |
| Pre-existing immunosuppression (HIV, transplantation, medication) | 0/20 |
| Treatments | |
| Previous treatments (conventional chemotherapy) | 9/20 (45%) |
| Treatment with Checkpoint-inhibitors (first-line) | |
| Pembrolizumab | 12/20 (60%) |
| Nivolumab | 1/20 (5%) |
| Avelumab | 7/20 (35%) |
| Median treatment duration (range) | 10.0 months (3–27 months) |
| Median response durability (range) | 10.0 months (1–24 months) |
| Treatment-related adverse events | 9/20 (45%) |
| Initiation of immunosuppressive treatment | 4/20 (20%) |
| Discontinuation of ICI-treatment | 7/20 (35%) |
| Progress after ICI discontinuation | 12/20 (60%) |
| Rechallenge of ICI | 8/12 (66.7%) |
| Median time interval between ICI discontinuation and re-induction (range) | 7.0 months (1–20 months) |
| Median response durability upon ICI rechallenge (range) | 6.0 months (1–18 months) |
| Follow-up | |
| Median follow-up period upon ICI discontinuation | 13.2 months |
| Overall observation period, median (range) | 20.5 months (4–37 months) |
| Deceased | 5/20 (25%) |
1CUP cancer of unknown primary, 2MCPyV Merkel cell polyomavirus, 3ECOG Eastern Cooperative Oncology Group; Percentages based on the total number of patients with known MCPyV and LDH-serum levels