Low:
- 1 single organ involved with 1 or 2 lesions or mild ascites/microscopic peritoneal dissemination with no other sites
Moderate:
- 1 single involved organ with 3-5 lesions
- 2 involved organs with <3 lesions per organ
High:
- 1 single organ involved with >5 lesions
- 3 or more involved organs
Very high:
- Baseline sum of total diameters >15 cm
- Moderate or severe ascites
- Diffuse peritoneal metastases with nodules >2-3 cm
- CNS metastases
- 3 or more bone metastases
- Liver tumour burden >50%