Table 3.
Kaplan Meier analysis for metastasis‐free survival
| Variable | 5‐year metastasis‐free survival rate (%) | P‐value |
|---|---|---|
| Age at RT, years | 0.459 | |
| <70 | 14% | |
| ≥70 | 48% | |
| Patient sex | 0.361 | |
| Female | 28% | |
| Male | 52% | |
| Histology | 0.022 | |
| SCC | 52% | |
| Other | 10% | |
| Stage | 0.575 | |
| I/II | 45% | |
| III | 29% | |
| Chemotherapy | 0.553 | |
| No | 44% | |
| Yes | 28% | |
| RT type | 0.686 | |
| Proton | 39% | |
| Photon | 20% | |
| RT fractionation | 0.723 | |
| Standard fractionation | 29% | |
| SBRT | 50% | |
| IgG response | 0.285 | |
| Absent | 45% | |
| Present | 14% | |
| IgM response | 0.718 | |
| Absent | 38% | |
| Present | 26% | |
| IgG or IgM response | 0.602 | |
| Absent | 39% | |
| Present | 29% |
RT, radiation therapy; SBRT, stereotactic body radiation therapy; SCC, squamous cell carcinoma.