Table 2.
Histologic and Molecular Characteristics of Ri-PNS BCs
| Patient number | Sample type | Nottingham grade | HER2 IHC expression | ER | PR | Tumor-PNS delaya, mo | Neurologic features | Genetic alteration on NOVA1 or NOVA2 gene | NOVA 1 CNV | NOVA 2 CNV |
| 1 | PBT | III | − | + | − | 4.5 | Extracerebellar | p.A155P (NOVA2) | None | None |
| 2 | PBT | II | − | + | + | −0.2 | Cerebellar | None | None | None |
| 3 | MLN | II | − | + | + | −3.7 | Cerebellar | None | None | None |
| 4 | PBT | II | − | + | − | −19.8 | Extracerebellar | None | None | None |
| 5 | PBT | II | − | + | + | 13.9 | Cerebellar | None | None | None |
| 6 | PBT | II | − | + | − | −8.5 | Cerebellar | None | Gain | Gain |
| 7 | PBT | III | +++ | + | − | 7.6 | Cerebellar | None | NA | NA |
| 8 | PBT | III | +++ | + | + | 0 | Cerebellar | None | NA | NA |
| 9 | PBT | II | +++ | + | + | 13 | Extracerebellar | NA | NA | NA |
| 10 | MLN | NA | − | + | − | 0.4 | Cerebellar | NA | NA | NA |
| 11 | MLN | NA | − | + | − | 0.2 | Extracerebellar | NA | NA | NA |
| 12 | PBT | II | − | + | + | −12.8 | Extracerebellar | NA | NA | NA |
Abbreviations: BC = breast cancer; CNV = copy number variation; ER = estrogen receptor; HER2 = cErbB2 protein; IHC = immunohistochemistry; MLN = metastatic lymph node; NA = not available; PBT = primary breast tumor; PNS = paraneoplastic neurologic syndrome; PR = progesterone receptor.
The delay between the tumor and the PNS was calculated using tumor diagnosis as Day 0; negative interval thus corresponds to a patient for whom PNS was diagnosed before the tumor.