Department of Surgery, Division of General Surgery, Medical University of Graz, Graz, Austria.
Am J Clin Oncol. 2011 Feb;34(1):43-9. doi: 10.1097/COC.0b013e3181cae8dd.
Vertical tumor growth, reflected by T classification, represents the most important prognostic variable in colorectal cancer. Our study aimed to investigate the impact of tumor size, particularly the maximum tumor diameter, on outcome of affected patients.
A total of 381 colorectal cancer specimens were re-evaluated. Tumor size and location were extracted from the medical history and were known for 359 patients (94%). Receiver-operator characteristic analysis was applied to identify the optimal (maximum of sum of sensitivity and specificity) cut-off values with respect to prognostic impact.
Median tumor size was 4.5 cm (range, 0.6-15). Tumor size exceeding 4.5 cm was observed in 159 patients (44%) and was associated with high T and N classification, UICC stage, and tumor grade. At median follow-up of 45 months (range, 0-180), 141 patients (40%) showed tumor progression. Although 4.5 cm was identified as the optimal cut-off value within the whole group of patients, receiver-operator characteristic analysis restricted to different parts of the large bowel determined 5 cm, 5.3 cm, 3.9 cm, and 3.4 cm as cut-off values with the strongest discriminatory capacity in colon, right-sided colon, left-sided colon, and rectum cancers, respectively. Applying these cut-off values, tumor size was significantly associated with progression-free and cancer-specific survival in univariate and multivariate analyses in colon, yet not in rectum cancers.
Tumor size proved to be an independent prognostic parameter for patients with colorectal cancer. Optimal cut-off values vary among different parts of the large bowel. Whereas prognostic significance is strong within the colon, it appears to be of minor value within the rectum.
肿瘤纵向生长（T 分类）反映了结直肠癌最重要的预后变量。我们的研究旨在探讨肿瘤大小，特别是最大肿瘤直径，对受影响患者结局的影响。
总共重新评估了 381 例结直肠癌标本。从病史中提取肿瘤大小和位置，359 例患者（94%）已知肿瘤大小和位置。应用受试者工作特征分析确定与预后影响相关的最佳（最大敏感性和特异性之和）截断值。
中位肿瘤大小为 4.5cm（范围 0.6-15cm）。159 例患者（44%）肿瘤大小超过 4.5cm，与高 T 和 N 分类、UICC 分期和肿瘤分级相关。中位随访时间为 45 个月（范围 0-180 个月），141 例（40%）患者出现肿瘤进展。尽管在整个患者组中，4.5cm 被确定为最佳截断值，但在不同部位的大肠中进行的受试者工作特征分析确定，5cm、5.3cm、3.9cm 和 3.4cm 分别为结肠癌、右半结肠癌、左半结肠癌和直肠癌的最佳截断值，具有最强的区分能力。在单因素和多因素分析中，应用这些截断值，肿瘤大小与结肠癌患者的无进展生存期和癌症特异性生存期显著相关，但在直肠癌中则无相关性。
肿瘤大小是结直肠癌患者独立的预后参数。最佳截断值在大肠的不同部位有所不同。在结肠癌中，预后意义较强，而在直肠癌中则意义较小。
