Aim

Patients with loco-regional right-sided colorectal tumors have a worse overall survival (OS). Here we investigate the difference in disease free survival (DFS) between colorectal patients with right and left sided tumors in the SCOT study.

Methods

The SCOT study showed 3-months of oxaliplatin-containing adjuvant chemotherapy (OxFp) is non-inferior to 6-months for patients with stage III and high-risk stage II colorectal cancer. We divided the cohort into patients with left and right sided tumors, and evaluated the effect on DFS and the principle 3 versus 6-months analysis.

Results

6088 patients with Stage III/high risk Stage II colorectal cancers were randomized between 27^th March 2008 and 29^th November 2013 from 244 centers internationally. In February 2017 (3-years FU) information on sidedness was available for 3309 patients (1238 R-sided, 2071 L-sided). Patients with right-sided tumors had a significantly worse DFS (3-year DFS right: 73.3% (se = 1.3%), left: 80.2% (se = 0.9%) HR 1.423 (95% CI 1.237-1.637; P < .0001). Adjusting for T and N-stage reduced the HR to 1.230 (95% CI 1.066-1.420, P = .005). The data did not suggest that sidedness affected the impact of chemotherapy duration on 3-year DFS (R: HR 1.024 [0.831-1.261], L: HR 0.944 [0.783-1.139]). Test for heterogeneity, P = .571. Further sub-set analysis was limited due to cohort size.

Conclusions

This is the first study to show that unselected patients with right-sided tumors had a worse DFS compared to left-sided tumors. Tumor sidedness did not impact upon the 3-months versus 6-months comparison in SCOT.

中文翻译：

---

SCOT：肿瘤单侧性和辅助化疗持续时间对无病生存 (DFS) 的影响

目的

局部区域右侧结直肠肿瘤患者的总生存期 (OS) 较差。在这里，我们在 SCOT 研究中调查了患有右侧和左侧肿瘤的结直肠患者之间的无病生存期 (DFS) 的差异。

方法

SCOT 研究表明，对于 III 期和高危 II 期结直肠癌患者来说，3 个月的含奥沙利铂辅助化疗 (OxFp) 并不劣于 6 个月。我们将队列分为左侧肿瘤患者和右侧肿瘤患者，并评估对 DFS 的影响以及原则 3 个月与 6 个月分析。

结果

^{2008年3月27日}至2013年11月29^日期间，来自国际上244个中心的6088名III期/高危II期结直肠癌患者被随机分组​​。2017 年 2 月（3 年 FU），可获得 3309 名患者的单侧信息（1238 名 R 侧，2071 名 L 侧）。右侧肿瘤患者的 DFS 显着较差（3 年 DFS 右侧：73.3%（se = 1.3%），左侧：80.2%（se = 0.9%）HR 1.423（95% CI 1.237-1.637；P < . 0001).调整 T 和 N 期将 HR 降低至 1.230 (95% CI 1.066-1.420, P  = .005)。数据并未表明单向性影响化疗持续时间对 3 年 DFS 的影响 (R: HR 1.024 [0.831-1.261]，L：HR 0.944 [0.783-1.139]）。异质性检验，P = .571。由于队列规模，进一步的子集分析受到限制。

结论

这是第一项研究表明，与左侧肿瘤相比，未经选择的右侧肿瘤患者的 DFS 较差。肿瘤单侧性不影响 SCOT 中 3 个月与 6 个月的比较。