Adverse Pathological Features and Worse Prognosis in Rectal Cancer Compared With Colon Cancer in T1 and T2 Stages.
Rectal cancers show more aggressive features and higher recurrence rates than colon cancers, indicating a need for more rigorous follow-up and treatment strategies.
Where it sits
this study against the rest of the palopegteriparatide corpusSummary and findings
This study evaluated clinicopathological features and outcomes of rectal versus colon cancers at Tis, T1, and T2 stages. It involved patients treated by endoscopic or surgical resection at a single center in Japan from 2001 to 2022. The findings indicated that rectal cancers exhibited more aggressive features and higher recurrence rates compared to colon cancers.
Abstract
<h4>Background and aim</h4>Emerging endoscopic techniques are expanding opportunities for minimally invasive therapy in early colorectal cancers (CRCs). Data regarding the clinicopathological features and outcomes of colon versus rectal cancers in Tis, T1, and T2 stages remain limited. This study evaluates and compares these two entities to clarify their oncologic differences.<h4>Methods</h4>We retrospectively analyzed patients with pTis-T2 CRCs treated by endoscopic or surgical resection at a single Japanese center between 2001 and 2022. Tumor location was classified as rectum (Ra, Rb) or colon (cecum to RS). Clinical variables (sex and age), pathological features (tumor size, differentiation, lymphatic invasion [Ly], vascular invasion [V], and tumor budding), and recurrence and metastasis rates were compared according to tumor location.<h4>Results</h4>The proportion of rectal cancer rose with invasion depth, from 16.2% (271/1673) in Tis to 18.5% (248/1337) in T1 and 26.4% (178/675) in T2 (<i>p</i> < 0.01). Compared with T1 colon cancer, T1 rectal cancer showed higher rates of Ly1-2 (35.1% vs. 27.4%), V1-2 (37.9% vs. 24.6%), and recurrence (4.4% vs. 0.6%) (all <i>p</i> < 0.05). Similarly, T2 rectal cancer showed higher V1-2 (68.5% vs. 54.1%) and recurrence rates (13.5% vs. 5.0%) compared with colon cancer (all <i>p</i> < 0.05). No significant differences were observed in lymph node or distant metastasis at either T1 or T2 stages.<h4>Conclusions</h4>Rectal cancers demonstrate more aggressive features and higher recurrence rates than colon cancers. Consequently, these patients require more stringent therapeutic approaches and rigorous postoperative surveillance, even in early stages.<h4>Trial registration</h4>Umin Clinical Trials Registry, UMIN 000042622.
Background
This paper addresses the differences in clinicopathological features and outcomes between rectal and colon cancers at early stages (Tis, T1, T2). Prior knowledge indicated that rectal cancers might have distinct characteristics compared to colon cancers, but data on their comparative outcomes were limited. Understanding these differences is crucial for optimizing treatment strategies and surveillance protocols.
Methods
The study was a retrospective analysis of patients with pTis-T2 colorectal cancers treated at a single Japanese center between 2001 and 2022. The population included individuals with tumors classified as rectal or colon cancers. Clinical variables such as sex and age, along with pathological features like tumor size, differentiation, lymphatic invasion, vascular invasion, and tumor budding, were compared based on tumor location.
Results
The proportion of rectal cancer increased with invasion depth: 16.2% in Tis, 18.5% in T1, and 26.4% in T2, all with p<0.01. T1 rectal cancer exhibited higher rates of lymphatic invasion (Ly1-2) at 35.1% compared to 27.4% in colon cancer, and vascular invasion (V1-2) at 37.9% compared to 24.6%, both with p<0.05. The recurrence rate for T1 rectal cancer was 4.4% versus 0.6% for colon cancer, p<0.05. For T2, rectal cancer showed higher vascular invasion at 68.5% versus 54.1% in colon cancer and a recurrence rate of 13.5% compared to 5.0%, both with p<0.05.
Interpretation
The findings suggest that rectal cancers have more aggressive pathological features and higher recurrence rates compared to colon cancers, which aligns with some existing literature. However, the clinical significance of these differences should be interpreted cautiously, as the effect sizes may not translate into substantial changes in management for all patients. Limitations such as the single-center design and retrospective nature may affect the robustness of the conclusions drawn.
Key findings
- 16.2% rectal cancer in Tis stage, n=1673, p<0.01.
- 18.5% rectal cancer in T1 stage, n=1337, p<0.01.
- 26.4% rectal cancer in T2 stage, n=675, p<0.01.
- T1 rectal cancer had 35.1% Ly1-2 vs 27.4% in colon cancer, p<0.05.
- T1 rectal cancer had 37.9% V1-2 vs 24.6% in colon cancer, p<0.05.
- T1 rectal cancer recurrence rate was 4.4% vs 0.6% in colon cancer, p<0.05.
Limitations
- retrospective study design
- single-center analysis
- limited generalizability
- no long-term follow-up data reported