No abstract

Purpose Long-course chemoradiotherapy (LCRT) has been widely recommended in a majority of rectal cancer patients. Recently, encouraging data on short-course radiotherapy (SCRT) for rectal cancer has emerged. In this study, we aimed to compare these two methods in terms of short-term outcomes and cost analysis under the Korean medical insurance system. Materials and Methods Sixty-two patients with high-risk rectal cancer, who underwent either SCRT or LCRT followed by total mesorectal excision (TME), were classified into two groups. Twenty-seven patients received 5 Gy×5 with two cycles of XELOX (capecitabine 1000 mg/m 2 and oxaliplatin 130 mg/m 2 every 3 weeks) followed by TME (SCRT group). Thirty-five patients received capecitabine-based LCRT followed by TME (LCRT group). Short-term outcomes and cost estimation were assessed between the two groups. Results Pathological complete response was achieved in 18.5% and 5.7% of patients in the SCRT and LCRT groups, respectively ( p =0.223). The 2-year recurrence-free survival rate did not show significant difference between the two groups (SCRT vs. LCRT: 91.9% vs. 76.2%, p =0.394). The average total cost per patient for SCRT was 18% lower for inpatient treatment (SCRT vs. LCRT: $18787 vs. $22203, p <0.001) and 40% lower for outpatient treatment (SCRT vs. LCRT: $11955 vs. $19641, p <0.001) compared to LCRT. SCRT was shown to be the dominant treatment option with fewer recurrences and fewer complications at a lower cost. Conclusion SCRT was well-tolerated and achieved favorable short-term outcomes. In addition, SCRT showed significant reduction in the total cost of care and distinguished cost-effectiveness compared to LCRT.

The ACHIEVE-2 trial, as part of the IDEA Collaboration, was a multicenter trial to randomize patients with high-risk stage II colon cancer to either 3 versus 6 months of adjuvant FOLFOX/CAPOX. The eligibility criteria in the trial included postoperative serum CEA value of <10 ng/ml at registration. Results: Of 514 patients analyzed, median CEA value was 1.9 (range, 0.5e9.9). 48 (9%) patients had a CEA of !5.0 ng/ml and 466 (91%) had a value of <5.0. 3-year DFS was 86% in the !5.0 group and 88% in the <5.0 group, with a hazard ratio (HR; reference, <5.0) of 1.27 (95%CI, 0.58e2.79). Multivariate analysis showed that CEA was not an independent prognostic factor (P¼0.5117). However, in the subgroup of patients with T3N0 tumor (n¼330), 3-year DFS in the !5.0 group was significantly lower than that in the <5.0 group (84% vs 95%) with a HR of 2.83 (1.04e7.75), whereas in patients with T4N0 tumor (n¼184), this relationship was opposite; 3-year DFSs in the !5.0 and <5.0 groups were 88% and 77%, respectively, with a HR of 0.51 (0.12e2.12). The interaction test for T-factor (T3 vs T4) by CEA (!5.0 vs <5.0) was significant (P¼0.0479).Conclusions: Postoperative CEA was prognostic in patients with T3N0 tumor, whereas this association did not hold in T4N0 tumor, suggesting that the characteristics of T4N0 tumor might have diluted the prognostic effect of CEA. Further analyses incorporating T4N0 tumor's features, such as microsatellite status, would be warranted.Clinical trial identification: UMIN000013036.