Department of Public Health, Nagoya City University Graduate School of Medical Science, Nagoya, Japan.
Division of Cancer Statistics Integration, Center for Cancer Control and Information Services, National Cancer Center, Tokyo, Japan.
BMC Cancer. 2019 May 9;19(1):431. doi: 10.1186/s12885-019-5644-y.
Colorectal cancer (CRC) is globally one of the most common cancers. Although studies have found a significant prognostic impact of cancer location for right-sided colon cancers compared with those of the left-side, evidence is lacking in a Japanese population. Therefore, we investigated 5-year net survival in colon cancer by tumor site in a Japanese population.
Diagnoses obtained between 2006 and 2008 in 21 population-based cancer registries from the Monitoring of Cancer Incidence in Japan (MCIJ) project were used. Colon cancer patients were categorized as having right-sided (C18.0-18.4) or left-sided colon cancer (C18.5-C18.7). We calculated the 5-year net survival for subjects diagnosed from 2006 until 2008 by anatomical subsite according to sex, age groups, tumor stage at diagnosis. We applied the excess mortality model to calculate excess hazard ratios (EHRs) and 95% confidential intervals (CIs) with and without adjustment for age, sex and cancer stages to evaluate the effect of location of colon cancer.
This study analyzed a total of 62,350 colon cancer subjects. Five-year net survivals for subjects with left- and right-sided colon cancer were 74.0% (95% CI, 73.4-74.7%) and 70.4% (95% CI, 69.7-71.0%), respectively. Compared with left-sided colon cancers, the EHR for right-sided colon cancers was 1.20 (95% CI, 1.16-1.25) after adjustment for age, sex and stage.
Our study found that the net survival for right-sided colon cancer was significantly lower than that for left-sided colon cancer. The anatomical site of cancer in the colon might be an important stratification factor in future studies of colon cancer.
结直肠癌（CRC）是全球最常见的癌症之一。尽管研究发现右侧结肠癌与左侧结肠癌相比，癌症位置对预后有显著影响，但在日本人群中尚无相关证据。因此，我们调查了日本人群中肿瘤部位对结肠癌 5 年净生存率的影响。
使用日本癌症发病率监测（MCIJ）项目 21 个基于人群的癌症登记处 2006 年至 2008 年期间获得的诊断数据。将结肠癌患者分为右侧（C18.0-18.4）或左侧结肠癌（C18.5-C18.7）。根据性别、年龄组、诊断时的肿瘤分期，我们计算了 2006 年至 2008 年期间诊断为结肠癌的患者的 5 年净生存率。我们应用超额死亡率模型计算了有无年龄、性别和癌症分期调整的超额危险比（EHR）及其 95%置信区间（CI），以评估结肠癌部位的影响。
本研究共分析了 62350 例结肠癌患者。左、右侧结肠癌患者的 5 年净生存率分别为 74.0%（95%CI，73.4-74.7%）和 70.4%（95%CI，69.7-71.0%）。与左侧结肠癌相比，调整年龄、性别和分期后，右侧结肠癌的 EHR 为 1.20（95%CI，1.16-1.25）。
我们的研究发现，右侧结肠癌的净生存率明显低于左侧结肠癌。结肠癌的解剖部位可能是未来结肠癌研究中的一个重要分层因素。
