Table 2: Comparison between RA and carcinomatous polyarthritis features [2-4,9].
| Rheumatoid Arthritis | Carcinomatous polyarthritis |
| Sub-acute onset | Rapid onset |
| Female sex predominance | Male sex predominance |
| Younger age | Older age (except LORA) |
| Symmetrical involvement | Asymmetrical involvement |
| Upper joints (hands and wrists) | Lower joints |
| Seropositive for ACPAs | Seronegative for ACPAs (may be positive for ANAs and RF) |
| Erosions on X-ray and deformities | No erosions or deformities |
| No constitutional symptoms | Constitutional systemic symptoms (fever, weight loss) |
| Responsive to standard therapy | Refractory to corticosteroids |