Prognostic factors for T1-2 colorectal cancer after radical resection: Lymph node distribution is a valuable predictor of its survival

Is tumour location a dominant risk factor of recurrence in early rectal cancer?

BACKGROUND

Impact of rectal tumour location on risk of lymph node metastases (LNM) and recurrence in early RC is poorly studied and elusive. Tumour location as a prognostic factor may contribute to optimise management of early RC in the future. The aim of this study was to investigate rectal tumour location as an independent predictor of oncologic outcome in early rectal cancer (RC).

METHODS

Retrospective multicentre national cohort study on prospectively collected data on all patients with T1-T2 RC, undergoing surgical resection between 2009 and 2021. Tumour location was categorised as distal (0-5 cm), mid (5-10 cm), and proximal (10-16 cm), measured from the anal verge.

RESULTS

Incidence of LNM in the 2424 included T1-T2 RC patients was 18.2%, 17.3% and 21.6% for distal, mid and proximal tumours, respectively. Recurrence was detected in 130 (7.6%) out of 1705 patients available for recurrence analyses (60-month median follow-up). Incidence of recurrence was twice as high in distal (11.4%) compared to proximal (5.6%) tumours and was 8.3% in mid located tumours. Distal (HR 2.051, CI 1.248-3.371, P < 0.05) and mid (HR 1.592, CI 1.061-2.388, P < 0.05) tumour location were significant risk factors of recurrence in uni- and multivariate Cox regression analyses.

CONCLUSIONS

This study shows that tumour location significantly affects incidence of recurrence in early RC, with an increasing risk for mid and especially distal location, found to be a predominant risk factor of recurrence. Our findings stress the need for an increased awareness on differences in oncologic outcome related to tumour location in early RC.

Laparoscopic segmental colectomy with extensive D3 lymph node dissection for right transverse colon cancer

OBJECTIVE

We herein propose a novel approach, laparoscopic segmental colectomy with extensive D3 lymph node dissection (ED3LND), for right-sided transverse colon cancer (TCC).

METHODS

Forty-two patients with right-sided TCC were randomly assigned to two groups: Group 1 (segmental colectomy with D3LND) and Group 2 (segmental colectomy with ED3LND). Clinical characteristics, surgical and pathological outcomes, and oncological outcomes were retrospectively compared between the two groups.

RESULTS

The number of lymph nodes retrieved, apical lymph nodes retrieved, and apical lymph node metastases were significantly lower in Group 1 than in Group 2. No significant differences were observed in the operation time, length of hospital stay, estimated blood loss, lymph node metastases, postoperative lymphoceles, or other Clavien-Dindo grade ≥III postoperative complications between the two groups. The 3-year disease-free survival rate was 82.6% in Group 1 and 84.2% in Group 2, with no significant difference.

CONCLUSIONS

Laparoscopic segmental colectomy with ED3LND for right-sided TCC may offer better oncological outcomes than D3LND. A large-scale prospective randomized controlled study is needed to further validate the oncological benefits of this novel procedure.

Impact of lymph node retrieval on prognosis in elderly and non-elderly patients with T3-4/N+ rectal cancer following neoadjuvant therapy: a retrospective cohort study

PURPOSE

The optimal number of lymph nodes to be resected in patients with rectal cancer who undergo radical surgery after neoadjuvant therapy remains controversial. This study evaluated the prognostic variances between elderly and non-elderly patients and determined the ideal number of lymph nodes to be removed in these patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) datasets were used to gather information on 7894 patients diagnosed with stage T3-4/N+ rectal cancer who underwent neoadjuvant therapy from 2010 to 2019. Of these patients, 2787 were elderly and 5107 were non-elderly. A total of 152 patients from the Longyan First Affiliated Hospital of Fujian Medical University were used for external validation. Overall survival (OS) and cancer-specific survival (CSS) were evaluated to determine the optimal quantity of lymph nodes for surgical resection.

RESULTS

The study found significant differences in OS and CSS between elderly and non-elderly patients, both before and after adjustment for confounders (P < 0.001). The removal of 14 lymph nodes may be considered a benchmark for patients with stage T3-4/N+ rectal cancer who undergo radical surgery following neoadjuvant therapy, as this number provides a more accurate foundation for the personalized treatment of rectal cancer. External data validated the differences in OS and CSS and supported the 14 lymph nodes as a new benchmark in these patients.

CONCLUSION

For patients with T3-4/N+ stage rectal cancer who undergo radical surgery following neoadjuvant therapy, the removal of 14 lymph nodes serves as a cutoff point that distinctly separates patients with a favorable prognosis from those with an unfavorable one.

A Retrospective Multicenter Study of Risk Factors, Stratification, and Prognosis of Lymph Node Metastasis in T1 and T2 Colorectal Cancer

BACKGROUND

The objective of this study was to compare the long-term prognosis of patients with T1 and T2 colorectal cancer (CRC) according to lymph node metastasis (LNM) and to identify risk factors for LNM.

METHODS

We retrospectively reviewed patients who underwent curative resection for T1 or T2 CRC at five University-affiliated hospitals between January 2012 and December 2021. The patients were divided into several groups depending on the presence of LNM or the number of risk factors.

RESULTS

Of the total 765 patients, 87 (11.3%) patients had LNM. These patients had poorer recurrence-free survival (RFS) than patients without LNM (72.6% vs. 88.6%). The multivariable analysis showed that high-grade tumors (p = 0.003), lymphovascular invasion (p < 0.001), and rectal location (p = 0.049) were independent predictors of LNM. When divided into groups according to the number of the three risk factors, the risk of LNM increased from 5.4% (ultralow-risk group; no risk factor) to 60.0% (high-risk group; all three risk factors) and the 5-year RFS rate decreased from 96.3% in the ultralow-risk group to 60% in the high-risk group (p < 0.001).

CONCLUSION

Radical surgery should be considered for T1 and T2 CRC patients with these risk factors.

A prognostic nomogram for predicting recurrence-free survival of stage I-III colon cancer based on immune-infiltrating Treg-related genes

PURPOSE

A high postoperative recurrence rate seriously impedes colon cancer (CC) patients from achieving long-term survival. Here, we aimed to develop a Treg-related classifier that can help predict recurrence-free survival (RFS) and therapy benefits of stage I-III colon cancer.

METHODS

A Treg-related prognostic classifier was built through a variety of bioinformatic methods, whose performance was assessed by KM survival curves, time-dependent receiver operating characteristic (tROC), and Harrell's concordance index (C-index). A prognostic nomogram was generated using this classifier and other traditional clinical parameters. Moreover, the predictive values of this classifier for immunotherapy and chemotherapy therapeutic efficacy were tested using multiple immunotherapy sets and R package "pRRophetic".

RESULTS

A nine Treg-related classifier categorized CC patients into high- and low-risk groups with distinct RFS in the multiple datasets (all p < 0.05). The AUC values of 5-year RFS were 0.712, 0.588, 0.669, and 0.662 in the training, 1st, 2nd, and entire validation sets, respectively. Furthermore, this classifier was identified as an independent predictor of RFS. Finally, a nomogram combining this classifier and three clinical variables was generated, the analysis of tROC, C-index, calibration curves, and the comparative analysis with other signatures confirmed its predictive performance. Moreover, KM analysis exhibited an obvious discrepancy in the subgroups, especially in different TNM stages and with adjuvant chemotherapy. We detected the difference between the two risk subsets of immune cell sub-population and the response to immunotherapy and chemotherapy.

CONCLUSIONS

We built a robust Treg-related classifier and generated a prognostic nomogram that predicts recurrence-free survival in stage I-III colon cancer that can identify high-risk patients for more personalized and effective therapy.

The concept of developmental anatomy: the greater omentum should be resected in right-sided colon cancer?

BACKGROUND

The greater omentum is derived from the foregut, and the right hemicolon is derived from the midgut based on developmental anatomy. This study aimed to investigate whether the greater omentum should be resected in laparoscopic complete mesocolic excision based on developmental anatomy for right-sided colon cancer.

METHODS

A total of 183 consecutive patients with right-sided colon cancer were recruited in this study between February 2020 and July 2022. Ninety-eight patients underwent standard laparoscopic complete mesocolic excision surgery (CME group). The presence of isolated tumor cells and micrometastases was detected in resected greater omentum by the HE staining and immunohistochemistry analysis. Based on developmental anatomy, laparoscopic CME surgery with greater omentum preservation (DACME group) was proposed and performed on 85 right-sided colon cancer patients. To overcome selection bias, we performed a 1:1 match between two groups using four variables: age, sex, BMI, and ASA scores.

RESULTS

No isolated tumor cells and micrometastases were found in the resected greater omentum specimen in the CME group. After the propensity score, 81 pairs were balanced and analyzed. Patients in the DACME group showed shorter operative time (194.9 ± 16.4 min vs.201.5 ± 11.5 min, p = 0.002), less blood loss (23.5 ± 24.7 ml vs.33.6 ± 26.3 ml, p = 0.013), and the shorter hospital stays (9.6 ± 1.7 days vs.10.3 ± 2.0 days, p = 0.010) compared with patients in the CME group. In addition, patients in the DACME group had a lower incidence of postoperative complications (4.9% vs.14.8%, p = 0.035) than patients in the CME group.

CONCLUSION

The greater omentum should be preserved during right-sided colon cancer surgery, laparoscopic CME surgery based on developmental anatomy is technically safe and feasible for right-sided colon cancer.

Laparoscopic D3 lymph node dissection with left colic artery and first sigmoid artery preservation in rectal cancer

BACKGROUND

D3 lymph node dissection with left colic artery (LCA) preservation in rectal cancer surgery seems to have little effect on reducing postoperative anastomotic leakage. So we first propose D3 lymph node dissection with LCA and first sigmoid artery (SA) preservation. This novel procedure deserves further study.

METHODS

Rectal cancer patients who underwent laparoscopic D3 lymph node dissection with LCA preservation or with LCA and first SA preservation between January 2017 and January 2020 were retrospectively assessed. The patients were categorized into two groups: the preservation of the LCA group and the preservation of the LCA and first SA group. A 1:1 propensity score-matched analysis was performed to decrease confounding.

RESULTS

Propensity score matching yielded 56 patients in each group from the eligible patients. The rate of postoperative anastomotic leakage in the preservation of the LCA and first SA group was significantly lower than that in the LCA preservation group (7.1% vs. 0%, P=0.040). No significant differences were observed in operation time, length of hospital stay, estimated blood loss, length of distal margin, lymph node retrieval, apical lymph node retrieval, and complications. A survival analysis showed patients' 3-year disease-free survival (DFS) rates of group 1 and group 2 were 81.8% and 83.5% (P=0.595), respectively.

CONCLUSION

D3 lymph node dissection with LCA and first SA preservation for rectal cancer may help reduce the incidence of anastomotic leakage without compromising oncological outcomes compare with D3 lymph node dissection with LCA preservation alone.

The effect of carbon nanoparticles staining on lymph node tracking in colorectal cancer: A propensity score matching analysis

Purpose

The aim of this study was to evaluate the effect of carbon nanoparticles staining (CNS) on colorectal cancer (CRC) surgery, lymph node tracing and postoperative complications using propensity score matching (PSM).

Method

Patients who were diagnosed with CRC and underwent surgery were retrospectively collected from a single clinical center from Jan 2011 to Dec 2021. Baseline characteristics, surgical information and postoperative information were compared between the CNS group and the non-CNS group. PSM was used to eliminate bias.

Results

A total of 6,886 patients were enrolled for retrospective analysis. There were 2,078 (30.2%) patients in the CNS group and 4,808 (69.8%) patients in the non-CNS group. After using 1: 1 ratio PSM to eliminate bias, there were 2,045 patients left in each group. Meanwhile, all of their baseline characteristics were well matched and there was no statistical significance between the two groups (P > 0.05). In terms of surgical information and short-term outcomes, the CNS group had less intraoperative blood loss (P < 0.01), shorter operation time (P < 0.01), shorter postoperative hospital stay (P < 0.01), less metastatic lymph nodes (P = 0.013), more total retrieved lymph nodes (P < 0.01), more lymphatic fistula (P = 0.011) and less postoperative overall complications (P < 0.01) than the non-CNS group before PSM. After PSM, the CNS group had less intraoperative blood loss (P = 0.004), shorter postoperative hospital stay (P < 0.01) and more total retrieved lymph nodes (P < 0.01) than the non-CNS group. No statistical difference was found in other outcomes (P > 0.05).

Conclusion

Preoperative CNS could help the surgeons detect more lymph nodes, thus better determining the patient's N stage. Furthermore, it could reduce intraoperative blood loss and reduce the hospital stay.

Impact of adequate lymph nodes dissection on survival in patients with stage I rectal cancer

Background and Aims

The NCCN guidelines recommended an assessment of ≥ 12 lymph nodes (LN) as an adequate LN dissection (LND) for rectal cancer (RC). However, the impact of adequate LND on survival in stage I RC patients remained unclear. Thus, we aimed to compare the survival between stage I RC patients with adequate and inadequate LND.

Methods

A total of 1,778 stage I RC patients in the SEER database from 2010 to 2017 treated with radical proctectomy were identified. The association between ≥ 12 LND and survival was examined using the multivariate Cox regression and the multivariate competing risk model referenced to &lt; 12 LND.

Results

Stage I RC patients with ≥ 12 LND experienced a significantly lower hazard of cancer-specific death compared with those with &lt; 12 LND in both multivariate Cox regression model (adjusted HR [hazard ratio], 0.44, 95% CI, 0.29-0.66; P &lt; 0.001) and the multivariate competing risk model (adjusted subdistribution HR [SHR], 0.45, 95% CI, 0.30-0.69; P &lt; 0.001). Further, subgroup analyses performed by pT stage. No positive association between ≥ 12 LND and survival was found in pT1N0 RC patients (adjusted HR: 0.62, 95%CI, 0.32-1.19; P = 0.149; adjusted SHR: 0.63, 95%CI, 0.33-1.20; P = 0.158), whereas a positive association between ≥ 12 LND and survival was found in pT2N0 RC patients (adjusted HR: 0.35, 95%CI, 0.21-0.58; P &lt; 0.001; adjusted SHR: 0.36, 95%CI, 0.21-0.62; P &lt; 0.001).

Conclusions

The long-term survival benefit of adequate LND was not found in pT1N0 but in pT2N0 RC patients, which suggested that pT2N0 RC patients should be treated with adequate LND and those with inadequate LND might need additional therapy.

Laparoscopic segmental colectomy with extensive D3 lymph node dissection: a good choice for right transverse colon cancer

Background

Previous research was yet to establish a definite operation for transverse colon cancer (TCC); surgical procedure was often dictated by the surgeon’s preference in clinical practice. The main surgical methods could be summarized in two main points: segmental colectomy (transverse colectomy) and right hemicolectomy.

Method

The first patient was a 78-year-old woman, who was diagnosed with right TCC. Computed tomography revealed a right TCC and a very long transverse colon; laparoscopic exploration revealed an enlarged apical lymph node surrounding the ileocolic vessels. We performed a segmental colectomy with extensive apical lymph node dissection along the superior mesenteric vessels and its main branches for her. To distinguish it from the previous radical operations for TCC, we called this operation a segmental colectomy with extensive D3 lymph node dissection. Then, this surgical intervention was performed on 8 other TCC patients.

Results

The total operating time was 158 min. Pathological examination confirmed 2 apical lymph node metastases; among them, one apical lymph node metastasis was in group No.203. For all 9 patients, the median operative time was 160 min (range, 140–185 min), the average number of lymph node retrieval was 30 (range, 25–39), and the average number of apical lymph node (No.203, No.213, and No.223) retrieval was 5.9 (range, 0–11). Because of the preservation of the ileocecal junction and part of the ascending colon, all patients recovered uneventfully after surgery, and long-term diarrhea, water-electrolyte imbalance, and other Clavien–Dindo grade III or greater postoperative complications did not occur.

Conclusions

Our procedure combined the advantages of segmental colectomy and right hemicolectomy and gave consideration to oncological and functional outcomes. It may be an optimal choice for TCC patients with a very long transverse colon and preoperative diagnosis of lymph node metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02530-4.