Freeman Hugh James
Department of Medicine (Gastroenterology), University of British Columbia, Vancouver, British Columbia, Canada.
Can J Gastroenterol. 2013 Jul;27(7):409-13. doi: 10.1155/2013/920689.
The long-term natural history of early stage colon cancer and the outcome of long-term colonoscopic surveillance in routine specialist clinical practice after removal of the incident cancers have not been fully defined. In the present long-term evaluation up to 25 years, metachronous neoplasia, including both advanced adenomas and carcinomas, was defined.
All early stage colorectal cancer patients evaluated consecutively from a single clinical practice underwent follow-up colonoscopic evaluations after removal of the incident cancer and clearing of neoplastic disease. Colonoscopic surveillance was planned for two phases - initially on an annual basis for five years, followed by continued surveillance every three years up to 25 years with removal of any metachronous neoplastic lesion.
A total of 128 patients (66 men and 62 women) with 129 incident early stage colorectal cancers were evaluated. Virtually all patients were symptomatic, usually with clinical evidence of blood loss. Incident early cancers were located throughout the colon, especially in the rectosigmoid, and showed no pathological evidence of nodal or other metastases. All patients evaluated during the first five years did not experience recurrent disease or have metachronous cancer detected. After five years, a total of 94 patients were evaluated up to 25 years; six of these patients were found to have seven metachronous colon cancers. All developed cancer more than seven years after removal of the incident colorectal cancer, including six asymptomatic adenocarcinomas, of which only one had evidence of single node involvement. Another patient in this cohort developed a poorly differentiated neuroendocrine carcinoma of the colon. In addition, 45% of patients had a total of 217 adenomas removed, including 11% of patients with 33 advanced adenomas. Among 14 patients with advanced adenomas, seven (50%) developed ≥1 late metachronous cancers.
Following removal of an incident symptomatic early stage colorectal cancer, the risk of later metachronous neoplasia persists for an extended period more than five years after removal of the incident colorectal cancer. Moreover, risk for late metachronous cancer appears to be predicted by the presence of multiple adenomas or advanced adenomas; most metachronous cancers in this cohort were detected using colonoscopy before onset of symptoms and at an early stage.
早期结肠癌的长期自然史以及在切除初发癌后常规专科临床实践中的长期结肠镜监测结果尚未完全明确。在本次长达25年的长期评估中，定义了异时性肿瘤，包括高级别腺瘤和癌。
从单一临床实践中连续评估的所有早期结直肠癌患者在切除初发癌并清除肿瘤性疾病后接受随访结肠镜检查。结肠镜监测计划分为两个阶段——最初每年进行一次，共五年，随后每三年继续监测直至25年，并切除任何异时性肿瘤性病变。
共评估了128例患者（66例男性和62例女性），有129例初发早期结直肠癌。几乎所有患者都有症状，通常有失血的临床证据。初发早期癌症遍布整个结肠，尤其是在直肠乙状结肠，且无淋巴结或其他转移的病理证据。在前五年评估的所有患者均未出现复发性疾病或检测到异时性癌症。五年后，共对94例患者进行了长达25年的评估；其中6例患者被发现有7例异时性结肠癌。所有患者在切除初发结直肠癌后七年以上发生癌症，包括6例无症状腺癌，其中只有1例有单个淋巴结受累的证据。该队列中的另一名患者发生了低分化结肠神经内分泌癌。此外，45%的患者共切除了217个腺瘤，包括11%的患者有33个高级别腺瘤。在14例有高级别腺瘤的患者中，7例（50%）发生了≥1例晚期异时性癌症。
切除有症状的初发早期结直肠癌后，异时性肿瘤的风险在切除初发结直肠癌后五年以上的较长时间内持续存在。此外，多个腺瘤或高级别腺瘤的存在似乎可预测晚期异时性癌症的风险；该队列中的大多数异时性癌症是在症状出现前通过结肠镜检查早期发现的。
