Table 3.

Immunologic memory after complete resolution of CT26-KS tumors

A: Mice which resolved their primary CT26-KS tumor after treatment with RFA, huKS-IL2 or combination therapy were challenged simultaneously with CT26 (first exposure) and CT26-KS (2^nd exposure) on opposite flanks. Proportions represent tumor-free mice in each treatment group.

B: Fifteen mice were implanted with 5×10⁵ CT26-KS tumor cells s.c. on the abdomen on day 0. Mice were then divided into groups and treated with complete tumor ablation on day 8 (n=3 mice, 40 seconds RFA), complete tumor excision (n = 8) on day 11, or partial RFA (25 sec, day 11) with huKS-IL2 on days 11–15 (n = 4). Mice were monitored for 30 days for evidence of tumor recurrence and were subsequently rechallenged with both CT26-KS and CT26 tumor cells on opposite flanks. Proportions represent tumor-free mice after rechallenge.

Table 3A
Initial Treatment Group	Proportion of tumor-free mice after challenge
	CT26-KS	CT26
Naïve control	0/4	0/4
RFA alone	5/5	1/5 1
huKS-IL2 alone	3/3	3/3 2
RFA + huKS-IL2	9/9	7/9 3

Table 3B
	Proportion of tumor-free mice after challenge
Initial Treatment Group	CT26-KS1	CT26
RFA	3/3	1/3 3
Surgery	6/8	0/8
RFA + huKS-IL2	4/4	3/4 2

¹p= NS vs. control;

²p = 0.004 vs. control, p = NS vs. RFA alone;

³p = 0.004 vs. control, p = 0.018 vs. RFA alone, p = NS (0.90) vs. huKS-IL2 alone

¹No statistical difference among all three treatment groups.

²p = 0.02 for RFA + huKS-IL2 vs. Surgery, p = NS vs. RFA;

³p = NS vs. Surgery