结直肠癌（CRC）是全球最常见的癌症之一。机械性左侧结肠梗阻的原因有多种，但CRC约占50％的病例，其中10-30％的病例以其为首发综合征。大多数情况下，左半结肠受累。目前，处理急症情况下阻塞性左侧CRC的治疗选择范围广泛（原发手术切除和分期手术切除加应用自膨胀金属支架），而国际上对每种情况的临床建议尚未经过验证。这种巨大的变异影响了关于即时和长期手术和肿瘤学结果的科学证据。CROSCO-1（结肠切除手术、造口或自膨胀金属支架治疗阻塞性左结肠癌）研究是一项国家级多中心前瞻性观察研究，旨在比较这些治疗方案在阻塞性左侧CRC患者中的临床结果。CROSCO-1研究的主要目标是进行急症原发手术切除（Hartmann手术或原发手术切除和吻合术）的患者1年造口率与进行分期手术切除的患者进行比较。次要结果包括30天和90天的重大并发症和死亡率、1年生活质量以及两组化疗启动时间。未来的CROSCO研究将评估两种治疗策略的长期肿瘤学结果。一项大型前瞻性队列研究的结果将分析在管理患有阻塞性左侧CRC的常见临床实践中实际发生的情况，旨在了解在手术和肿瘤学结果方面哪种策略是最佳的。实际上，CROSCO-1研究将分析阻塞性左侧CRC患者的早期手术结果。未来的CROSCO研究将评估两种治疗策略的长期肿瘤学结果。

Colorectal cancer (CRC) is one of the most common cancers worldwide. There are several causes of a mechanical left bowel obstructive but CRC accounts for approximately 50% of cases and in 10-30% of whom it is the presenting syndrome. In most cases, the left colon is involved. At present, the range of therapeutic alternatives in the management of obstructive left CRC in emergency conditions (primary resection vs staged resection with applied self-expanding metallic stents) is broad, whereas internationally validated clinical recommendations in each condition are still lacking. This enormous variability affects the scientific evidence on both the immediate and long-term surgical and oncological outcomes.CROSCO-1 (Colonic Resection, Stoma or Self-expanding Metal Stents for Obstructive Left Colon Cancer) study is a national, multi-center, prospective observational study intending to compare the clinical results of all these therapeutic regimens in a cohort of patients treated for obstructive left-sided CRC.The primary aim of the CROSCO-1 study is the 1-year stoma rate of patients undergoing primary emergency surgical resection (Hartmann procedure or primary resection and anastomosis) compared with patients undergoing staged resection. Secondary outcomes are 30-day and 90-day major morbidity and mortality, 1-year quality of life and the timing of chemotherapy initiation in the two groups. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies.The results of a large prospective cohort study which will analyze what really happens in the common clinical practice of managing patients with obstructive left CRC will have the aim of understanding which is the best strategy in terms of surgical and oncological outcomes. Indeed, the CROSCO-1 study will analyze the early surgical outcomes for patients with obstructed left CRC. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies.