Table 2:

PRGS at initial assessment, depending on the organ of origin.

	Complete or high-grade regression, PRGS 1 and 2	Vital tumor or minor regression, PRGS 3 and 4
Gastric cancer, n=33	27 (81.8 %)	6 (8.2 %)
HBP cancer, n=20	15 (75.0 %)	5 (25.0 %)
Other primaries, n=44	14 (31.8 %)	30 (68.1 %)
All tumors, n=97	56 (57.7 %)	41 (42.3 %)

The proportion of PRGS 1 (no tumor cells detected in multiple peritoneal biopsies) and PRGS 2 (high-grade regression) at initial assessment was significantly higher in HBP and gastric cancer (mean PRGS 1.57, CI 5–95 % 1.42–1.72) than in other histologies (mean PRGS 2.48, CI 5–95 % 2.22–2.74, p<0.001).