1. Criteria to consider primary debulking unfeasible.

Criteria to consider primary debulking unfeasible according to study methods
	Alessi	Shim	Espada	Forstner	Michielsen
Site of tumour involvement
Liver/porta hepatis	Yes	No	No	Yes	Yes
Mesentery	Yes	Yes	Yes	Yes	No
Colon	Yes, when necessitating > 4 bowel resections	No	No	No	Yes, when necessitating multiple bowel resections
Stomach	Yes	No	Yes	No	Yes
Pancreas	Yes	No	No	No	Yes
Duodenum	Yes	No	No	No	Yes
Diaphragm	No	Yes	No	Yes	No
Ascites	No	Yes	No	No	No
Peritoneal carcinomatosis	Yes	Yes	No	No	No
Lesser sac/bursa omentalis	No	No	Yes	Yes	No
Spleen/splenic hilum	No	No	Yes	No	No
Lymph nodes above level of renal vessels/at coeliac axis	No	No	Yes	Yes	Yes
Gastrosplenic ligament	No	No	No	Yes	No
Presacral extraperitoneal disease	No	No	No	Yes	No
Extra‐abdominal distant metastasis	No	No	No	No	Yes
Vessels of coeliac trunk	No	No	No	No	Yes
Hepatoduodenal ligament	No	No	No	No	Yes
Superior mesenteric artery	No	No	No	No	Yes

Yes: site of tumour involvement is selected as one of the criteria to consider primary debulking unfeasible
 No: site of tumour involvement is not selected as a criterion to consider primary debulking unfeasible