Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths [1]. Surgical resection remains the primary treatment modality for curative therapy in patients with CRC [9]. The main goals of curative surgery include the removal of the primary tumor, as well as the section of the intestine and arterial arch containing regional lymph nodes [10]. However, there is still controversy surrounding surgical decisions for colon cancer, particularly in cases involving colon resection [11]. There is a wide debate about the ideal extent of bowel resection and lymph node dissection in colon cancer. Currently, many surgeons prioritize oncological considerations and often sacrifice more bowel tissue and perform extensive lymph node clearance to achieve a more thorough therapeutic outcome. Stage III colon cancer is characterized by lymph node metastasis, but the occurrence of the third-stage lymph node metastasis is rare in T2 and lower-stage colon cancer [7]. The potential impact of surgical procedures on the survival of Stage III T1-2 CC patients remains unclear. This study compares the long-term survival outcomes of Stage III T1-2 colon cancer patients treated with partial colon resection and curative colon resection and establishes independent risk factors affecting the prognosis of colorectal cancer. Using these risk factors, we have developed a nomogram to visualize the results of the regression analysis, which can also be used to predict the survival probability of colorectal cancer patients.
For patients with colorectal cancer, surgical resection, including both curative and palliative procedures, is considered a beneficial treatment option [12]. Hemicolectomy and partial colectomy are common surgical choices for colorectal cancer. Partial colectomy involves the removal of a segment of the colon located within 10 centimeters of the tumor, as lymph node metastases typically do not spread beyond this distance from the primary tumor. Hemicolectomy, on the other hand, entails the resection of the entire left or right colon and a portion of the transverse colon [13]. The primary distinction between these two surgical options lies in the extent of colon removal. Both procedures provide sufficient lymph node clearance for the treatment of colorectal cancer. Most surgeons tend to prefer hemicolectomy over partial colectomy [5, 14]. Wang et al. [15] reported no significant differences in terms of anastomotic dehiscence, reoperation, and mortality between left hemicolectomy and partial colectomy. Gilles Manceau et al. suggested that in splenic flexure cancer patients, splenic flexure colectomy is a safe and viable option with outcomes similar to other surgical procedures. Subtotal colectomy and left hemicolectomy do not appear to offer any clinical advantages, and there is no support for combining segmental colectomy with colocolonic anastomosis due to an increased risk of dehiscence [16]. De'angelis et al. demonstrated that patients undergoing sigmoid colectomy (58%) experienced a higher rate of postoperative complications compared to splenic flexure colectomy and left hemicolectomy patients [17]. However, the type of surgery was not a significant predictor of 5-year overall survival or disease-free survival. A meta-analysis conducted by Hajibandeh et al. [18] showed that, after analyzing data from four studies involving 512 patients, there was no significant difference in the risk of overall postoperative complications and severe complications between patients who underwent left hemicolectomy and segmental colectomy. Stefan Morarasu et al. research indicated that segmental colectomy reduced operative time and decreased the risk of bowel obstruction. In contrast, extensive colectomy resulted in a lower rate of anastomotic leakage, but segmental colectomy yielded fewer lymph nodes, but there were no differences in terms of postoperative complications, disease recurrence, or overall survival [19]. In this study, the results suggest that partial colectomy may provide better long-term survival compared to hemicolectomy, without increasing the risk of tumor recurrence. Therefore, extensive colon resection may not be necessary, and partial colectomy could be a preferable option. The potential advantages of partial colectomy over hemicolectomy, including a smaller resection area and reduced surgical trauma, imply that surgeons should carefully consider their choices in surgical planning rather than rushing into extensive surgery.
The characteristics of stage III colon cancer involve the presence of lymph node metastasis, while for T1-2 rectal cancer that has not infiltrated beyond the muscular layer, the occurrence of lymph node metastasis at the base of blood vessels is quite rare [7]. In colorectal cancer, lymph node status serves as a crucial prognostic indicator and plays a significant role in guiding decisions regarding adjuvant therapy [20]. Clinical guidelines recommend evaluating a minimum of 12 lymph nodes to attain a confidence level of acceptable lymph node status [21]. In comparison to other pathological factors such as lymphovascular invasion, histological differentiation, and tumor deposit, the depth of invasion has a less prominent role as a predictive factor, and it does not act as an independent risk factor for lymph node metastasis [22]. The study conducted by Xu Guan et al [23]. revealed that in patients undergoing various surgical treatments, the median number of lymph nodes increased with the T stage, and the rate of positive lymph nodes demonstrated a positive correlation with the T stage. This highlights the significance of determining the optimal cutoff point for the number of lymph nodes required for surgical treatment in stage III colon cancer. Some studies propose that the HC group clears a greater number of lymph nodes than the PC group. However, the PC and HC groups exhibited a similar count of positive lymph nodes cleared. Several other studies with limited sample sizes have arrived at comparable conclusions [24, 25]. In the context of this study, survival analyses confirmed that there was no significant difference in CSS between patients with ≥ 10 lymph nodes harvested and those with ≥ 12 lymph nodes harvested. Notably, a threshold of 10 proves to be more effective in distinguishing between patients with a favorable prognosis and those with a less favorable one than a threshold of 12. As a result, this study has established that the optimal threshold for the number of lymph nodes to be harvested in the surgical treatment of stage III T1-2 colon cancer is 10.
The relationship between tumor size and prognosis in colorectal cancer patients has long been a topic of great concern for clinical professionals. According to Peter Kornprat et al. [26], tumor size has been proven to be an independent prognostic factor in colorectal cancer patients. Optimal cutoff values vary among different parts of the large bowel. Furthermore, within the colon, its prognostic significance is particularly strong. Weixing Dai et al. reported results indicating that tumor size has an impact on both OS and DFS in patients with infiltrative colorectal adenocarcinoma, a larger tumor diameter signifies a more advanced stage of cancer, potentially involving deeper layers of the colorectal wall or adjacent tissues and organs, which negatively affects patient prognosis [27]. However, in some studies, a negative correlation between tumor size and prognosis has been observed in colon cancer. When the tumor exceeds 4 cm in size, its adverse impact on prognosis appears to be weaker, as the tumor, after invading to a certain depth vertically, cannot infiltrate deeper blood vessels and lymphatic vessels [28]. In another study by Huang and colleagues, they hypothesized that in patients with severe invasion of the colonic wall, a smaller tumor may reflect a phenotype with greater biological invasiveness [29]. Younger age and higher CEA levels seem to be reliable preoperative predictive factors for Lymph Node Metastasis in T1-2 colorectal cancer. It's worth noting that when assessing the risk of Lymph Node Metastasis in T1 colorectal cancer, factors such as tumor size and histological type should also be considered [22]. In my research, survival analysis confirmed that patients with a tumor size of ≥ 4.7 cm exhibited a better CSS than patients with a tumor size of < 4.7 cm. This factor better distinguishes between patients with a favorable and unfavorable prognosis.
The strengths of this study are the large number of patients and the long follow-up period, which suggests that the results accurately reflect reality and may be a powerful resource for determining overall trends. However, this study has several limitations. First, confusing terminology and uncertainty about the exact extent of surgery are common in the literature regarding hemicolectomy versus segmental resection [30]. Second, our study was a retrospective data analysis and therefore subject to the limitations common to this study design. However, PSM was performed to adjust for confounding factors and to overcome potential selection bias. Third, as with all registry studies based on the SEER database, more detailed information on oncological outcomes, including the site of tumor recurrence, was not provided. This issue needs to be further investigated in cohorts with detailed oncologic outcome data [31].