Table 2.
Clinical features, numbers, and types of 24 secondary malignancies (SM)
| Type of all 24 secondary malignancies, n (%) | |
|---|---|
| Non-melanoma skin cancers (NMSC) | 11 (45.8) |
| - Basal cell carcinoma | 6 (25.0) |
| - Squamous cell cancer | 2 (8.3) |
| - Othersa | 3 (12.5) |
| Melanoma skin cancers (MSC) | 2 (8.3) |
| Solid “non-skin” cancers | 9 (37.5) |
| - Breast cancer | 4 (16.7) |
| - Colon cancer | 2 (8.7) |
| - Other solid cancersb | 3 (12.5) |
| Hematological malignanciesc | 2 (8.3) |
| Median age at SM diagnosis, years (range) | 69.7 (29.6–89.5) |
| Median time between PV diagnosis and SM diagnosis, years (range) | 7.2 (0.1–22.9) |
| Number of SM according to “PV survival score”d at diagnosis, n (%) | |
| - High risk | 8 (33.3) |
| - Intermediate risk | 9 (37.5) |
| - Low risk | 7 (29.2) |
| Number of RUX-therapy associated SM, n (%) | 10 (41.7) |
| Number of SM occurring in patients without RUX treatment, n (%) | 14 (58.3) |
a) Merkel cell carcinoma (n = 1), Bowen´s disease (n = 1), actinic keratosis (n = 1)
b) Urothelial carcinoma (n = 1), schwannoma (n = 1), lung cancer (n = 1)
c) Aggressive B cell lymphoma (n = 1), indolent B cell lymphoma (n = 1)
d) “PV survival score” [18]: age at first diagnosis (≥ 67 years = 5 points; 55–67 years = 2 points), leukocyte count at diagnosis (≥ 15 × 109/l = 1 point) and venous thrombosis before or at diagnosis (1 point): low-risk (0 points), intermediate-risk (1 or 2 points) and high-risk (≥ 3 points)