Effective dissection for rectal cancer with lateral lymph node metastasis based on prognostic factors and recurrence type

Long-term outcomes of S-1 and oxaliplatin neoadjuvant chemotherapy with total mesorectal excision and lateral lymph node dissection for rectal cancer

PURPOSE

Chemoradiotherapy (CRT) for rectal cancer is limited by its harmful side effects and its insufficient benefit on lateral lymph node metastases. The purpose of this study was to evaluate the long-term outcomes of S-1 and oxaliplatin with total mesorectal excision (TME) and lateral lymph node dissection (LLND) without radiation for rectal cancer.

METHODS

The inclusion criteria were patients with stage II or III rectal cancer located within 10 cm from the anal verge. Fifty-two patients who underwent neoadjuvant chemotherapy (NAC) followed by TME and LLND were evaluated. The primary endpoint was the 3-year local recurrence. The secondary endpoints were the 3-year rates of relapse-free survival and overall survival. Expected post-NAC and surgical outcomes were prospectively analyzed.

RESULTS

The overall recurrence rate was 15.4%, with eight patients developing distant recurrences. The local recurrence rate was 7.7% (n = 4). Among the 4 patients with local recurrence, 3 (5.8%) patients had central pelvis recurrence, and 1 (1.9%) patient had lateral pelvic recurrence. The 3-year survival rate was 98.1%, and the 3-year relapse-free survival rate was 84.6%. The risk factors for local recurrence were mucinous carcinoma (p = 0.016) and a positive resection margin (p = 0.009). Pathological mesorectal lymph node metastasis and local recurrence were independent risk factors for poor survival.

CONCLUSIONS

Although preoperative chemotherapy and TME with LLND are sufficient to control local recurrence, some cases will require more aggressive chemotherapy with radiation therapy.

Management of internal iliac and obturator lymph nodes in mid-low rectal cancer

In rectal cancer treatment, the diagnosis and management of lateral pelvic lymph nodes (LLN) are critical for preventing local recurrence. Over time, scholars have reached a consensus: when imaging suggests LLN metastasis, combining neoadjuvant chemoradiotherapy (nCRT) with selective LLN dissection (LLND) can mitigate the risk of recurrence. Selective LLND typically encompasses lymph nodes in the internal iliac and obturator regions. Recent studies emphasize distinctions between internal iliac and obturator lymph nodes regarding prognosis and treatment outcomes, prompting the need for differentiated diagnostic and treatment approaches.

The influence of neoadjuvant chemoradiotherapy combined with lateral lymph nodes dissection or not on the local recurrence of low to intermediate-stage II/III rectal cancer

BACKGROUND

Currently, the treatment options for stage II/III rectal cancer with preoperative lateral lymph nodes (LLN) enlargement are highly controversial between East and West, and the indications for diagnosing suspiciously positive enlarged LLN are inconsistent both nationally and internationally. Oriental scholars (especially Japanese) consider the LLN as a regional disease, they consider that prophylactic lateral lymph nodes dissection (LLND), regardless of whether the LLN is enlarged or not, is considered necessary if the tumor is found beneath the peritoneal reflex and invades the muscle layer. Western scholars regard LLN as distant metastases, recommending neoadjuvant chemoradiotherapy (nCRT) in conjunction with total rectal mesenteric resection (TME). In recent years, it has been found that neither of the two standard treatment regimens, East and West, significantly improved local control of tumors in patients with LLN enlargement. In contrast, nCRT combined with LLND significantly lowers the local recurrence (LR) rate. It has also been suggested that combination therapy regimens do not improve patient prognosis but increase treatment-related complications. Therefore, the suitable therapeutic option for rectal cancer with an enlarged LLN needs to be further explored.

AIM

Exploring appropriate treatment options for low to intermediate-stage II/III rectal cancer with LLN enlargement, as well as risk variables that may affect the LR in these patients with LLN enlarged.

METHODS AND PATIENTS

In this research, we retrospectively analyzed 110 patients with locally advanced mid-low (low boundary of tumor is no more than 10 cm from the anus) rectal cancer who were treated at Harbin Medical University Cancer Hospital arranged from 2017.1 to 2020.6. These patients had received nCRT and TME, and their initial rectal nuclear magnetic resonance imaging (MRI) revealed an enlarged LLN (short axis of LLN, SA ≥ 5 mm). Of these, 40 patients underwent LLND, thus, 110 patients were grouped into two groups: nCRT+TME (LLND-, n = 70) and nCRT+TME + LLND (LLND+, n = 40), and their 3 years prognoses were compared.

RESULTS

After a median follow-up of 49.0 months, the 3-year LR rate of the LLND- group was notably greater than the LLND+ group (22.8% vs. 7.5%, p = 0.04). However, there was no noteworthy difference in the 3-year progression-free survival (PFS, 70.5% vs. 77.5%, p > 0.05) rate or distant metastasis (DM) rate (20.0% vs. 17.5%, p > 0.05). Additionally, the LLND+ group experienced significantly more postoperative complications than the LLND- group (15.0% vs. 4.2%, p = 0.05). Subgroups analysis for the LLND- group revealed that patients with LLN short axis regression (ΔSA) > 35.9% after nCRT had significantly lower 3-year LR rate than patients with ΔSA ≤ 35.9% (9.1% vs. 35.1%, p = 0.01). Patients in the LLND- group with ΔSA > 35.9%, however, had comparable 3-year LR rate and DM rates to those in the LLND+ group.

CONCLUSION

LLN is an independent indicator for prognosis among people with low to intermediate-stage II/III malignant rectal tumors. Patients with poor SA regression (ΔSA ≤ 35.9%) after nCRT have a greater risk of positive LLN and a more substantial LR, and nCRT combined with LLND reduced the LR rate significantly, but considerably prolonged operative time, surgical bleeding, and postoperative complications. Patients with better SA regression (ΔSA > 35.9%), however, have a lower possibility of LR and might not need LLN clearance, in these cases, nCRT+TME is advised.

A nomogram for preoperative differentiation of tumor deposits from lymph node metastasis in rectal cancer: A retrospective study

The objective is to develop and validate a combined model for noninvasive preoperative differentiating tumor deposits (TDs) from lymph node metastasis (LNM) in patients with rectal cancer (RC). A total of 204 patients were enrolled and randomly divided into 2 sets (training and validation set) at a ratio of 8:2. Radiomics features of tumor and peritumor fat were extracted by using Pyradiomics software from the axial T2-weighted imaging of MRI. Rad-score based on extracted Radiomics features were calculated by combination of feature selection and the machine learning method. Factors (Rad-score, laboratory test factor, clinical factor, traditional characters of tumor on MRI) with statistical significance were integrated to build a combined model. The combined model was visualized by a nomogram, and its distinguish ability, diagnostic accuracy, and clinical utility were evaluated by the receiver operating characteristic curve (ROC) analysis, calibration curve, and clinical decision curve, respectively. Carbohydrate antigen (CA) 19-9, MRI reported node stage (MRI-N stage), tumor volume (cm3), and Rad-score were all included in the combined model (odds ratio = 3.881 for Rad-score, 2.859 for CA19-9, 0.411 for MRI-N stage, and 1.055 for tumor volume). The distinguish ability of the combined model in the training and validation cohorts was area under the summary receiver operating characteristic curve (AUC) = 0.863, 95% confidence interval (CI): 0.8-0.911 and 0.815, 95% CI: 0.663-0.919, respectively. And the combined model outperformed the clinical model in both training and validation cohorts (AUC = 0.863 vs 0.749, 0.815 vs 0.627, P = .0022, .0302), outperformed the Rad-score model only in training cohorts (AUC = 0.863 vs 0.819, P = .0283). The combined model had highest net benefit and showed good diagnostic accuracy. The combined model incorporating Rad-score and clinical factors could provide a preoperative differentiation of TD from LNM and guide clinicians in making individualized treatment strategy for patients with RC.

Distant Metastasis is the Dominant Cause of Treatment Failure after Lateral Lymph Node Dissection in Patients with Lateral Lymph Node Metastasis: Results of the Large Multicenter Lateral Node Study in China

Background: Lateral lymph node (LLN) metastases (LLNM) are often associated with poor prognosis. This study aimed to investigate the prognostic significance and postoperative recurrence pattern in rectal cancer patients with LLNM after LLN dissection (LLND). Materials and Methods: This is a multicenter retrospective case-control study where propensity score-matched (PSM) analysis was introduced. From January 2012 to December 2019, 259 patients with clinical suspicion of LLNM who underwent LLND without neoadjuvant therapy were included in the study. They were divided into the negative (n = 197) and positive (n = 62) LLN groups. Primary endpoints were 3-year recurrence-free survival (RFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS). Results: After PSM, the DMFS rate in the positive LLN group was significantly worse (67.9 vs. 52.5%, P = 0.012). Pathological LLNM (HR, 3.07; 95% CI, 1.55-6.05; P = 0.001) were independent prognostic factors for DMFS. Patients in the positive LLN group had a higher proportion of distant metastases in all recurrence patterns (92.3% vs 82.6%). Among patients with LLN metastasis, metastases to the common iliac and external iliac arteries were the independent prognostic factor for DMFS (HR: 2.85; 95% CI, 1.31-4.67; P = 0.042). No significant different was observed for prognosis between patients with metastases to the obturator or internal iliac vessels and patients with a N2b stage. Conclusion: Distant metastasis is the main cause of treatment failure after LLND in patients with LLNM. Because of the low completion rate of adjuvant chemotherapy, preoperative chemotherapy or total neoadjuvant therapy may be considered before LLND. In addition, patients with metastasis to external iliac and common iliac vessels have an extremely poor prognosis, and systemic chemotherapy instead of LLND should be recommended.

Predictive value of a nomogram based on DCE-MRI and DWI quantitative parameters and serum CEA level for risk of postoperative recurrence/metastasis of rectal cancer

BACKGROUND

The prognosis of rectal cancer is poor, and early prediction of recurrence and metastasis after radical surgery is of great significance for improving its prognosis. This study integrated multiple influencing factors such as multimodal magnetic resonance imaging (MRI) parameters, tumor markers, and clinicopathological features to develop a nomogram to provide a basis for the development of clinical intervention measures for this malignancy.

AIM

To develop a nomogram based on dynamic contrast enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) quantitative parameters and serum carcinoembryonic antigen (CEA) level, and to analyze the predictive value of this model for the risk of postoperative recurrence and metastasis of rectal cancer, so as to guide the development of clinical intervention measures for this malignancy.

METHODS

A total of 120 patients who underwent laparoscopic-assisted radical resection of rectal cancer at our hospital from March 1, 2019 to February 28, 2022 were selected as research subjects. According to the presence of recurrence/metastasis within 1 year after surgery, the patients were divided into a recurrence/metastasis group (n = 29) and a no recurrence/metastasis group (n = 91). The relevant parameters [apparent diffusion coefficient (ADC), transfer rate constant (Ktrans), blood return constant (Kep), and extravascular extracellular space volume fraction (Ve)] of multimodal MRI imaging techniques were compared between the two groups to analyze their predictive value for postoperative recurrence/metastasis. Univariate analysis with Lasso model screening for predictive factors related to postoperative recurrence/metastasis was performed, and logistic regression analysis was used to analyze the influencing factors of postoperative recurrence/metastasis. A nomogram was developed based on the influencing factors identified, and the predictive value of the model for postoperative recurrence/metastasis was assessed. Calibration curve and decision curve analysis (DCA) were used to verify the calibration degree and clinical effectiveness of the model, respectively.

RESULTS

ADC in the recurrence/metastasis group was lower than that in the no recurrence/metastasis group, while Ktrans and Kep were higher than those in the no recurrence/metastasis group (P < 0.05). Obstruction, degree of differentiation, clinical stage, lymph node metastasis, postoperative CEA, ADC, Ktrans, and Kep were identified to be independent influencing factors on postoperative recurrence/metastasis (P < 0.05). The area under the curve of the nomogram was higher than that of ADC, Ktrans, and Kep combined (P < 0.05), and the nomogram had good calibration and clinical efficacy.

CONCLUSION

The nomogram developed based on DCE-MRI and DWI quantitative parameters and serum CEA level has appreciated predictive value for postoperative recurrence/metastasis of rectal cancer, and clinical intervention measures can be formulated according to these high risk factors to reduce the risk of postoperative recurrence/metastasis.

Clinical study on risk factors related to postoperative recurrence or metastasis of rectal cancer: a retrospective cohort study

Background

Rectal cancer is usually treated by surgery, but recurrence or metastasis seriously affect the quality of life and survival of patients. Identifying the risk factors for postoperative recurrence or metastasis of rectal cancer has important guiding value for the treatment of rectal cancer. However, the research on risk factors of postoperative recurrence or metastasis of rectal cancer has not been unified.

Methods

The data of all patients undergoing rectal cancer surgery in The Fifth People's Hospital of Shanghai, Fudan University, from 2016 to 2020 were collected and analyzed. A total of 185 patients were included for statistical analysis and were divided into a recurrence or metastasis group and a non-recurrence or metastasis group. Patients were followed up according to National Comprehensive Cancer Network (NCCN) guidelines by enhanced CT or MRI, and colonoscopy. The cut-off of the research was recurrence, metastasis, or death. Logistic regression analysis and Cox regression analysis were used to analyze the risk factors related to postoperative recurrence or metastasis of rectal cancer, and the survival curve was drawn.

Results

Multiple logistic regression analysis showed involvement of the mesorectal fascia (MRF) [OR (odds ratio) =2.9, 95% confidence interval (CI): 1.16-7.29, P=0.023], nerve and vascular invasion (OR =1.7, 95% CI: 1.08-2.59, P=0.022), intraoperative blood transfusion (OR =3.7, 95% CI: 1.45-9.40, P=0.006), and Dukes staging (OR =2.3, 95% CI: 1.26-4.35, P=0.007) were independent risk factors for postoperative recurrence or metastasis of rectal cancer. Involvement of mesenteric fascia infiltration (OR =11.5, 95% CI: 1.49-88.79, P=0.019) and Dukes stage (OR =3.0, 95% CI: 1.46-6.26, P=0.003) were independent risk factors for liver metastasis, while nerve and vascular invasion (OR =2.4, 95% CI: 1.19-5.00, P=0.015) was an independent risk factor for pulmonary metastasis.

Conclusions

Postoperative recurrence or metastasis of rectal cancer is related to many factors. These findings have clinical guiding value and significance for the follow up and prognosis of patients with rectal cancer after surgery. Large-scale prospective clinical studies are needed.

Management of inguinal lymph node metastases from rectal and anal canal adenocarcinoma

AIM

The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification.

METHODS

This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis.

RESULTS

Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55).

CONCLUSION

The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

Effective dissecting range and prognostic significance of lateral pelvic lymph node dissection for middle-low rectal cancer patients with lateral pelvic lymph node metastasis: Results of a large multicenter lateral node collaborative group in China

Background

Lateral pelvic lymph node (LPN) metastasis causes increased lateral local recurrence and poor prognosis. We aimed to investigate the prognostic significance and effective range of dissection for the LPN dissection (LPND) in rectal cancer patients with LPN metastasis.

Materials and methods

Through this large, multicenter retrospective cohort study, we evaluated the therapeutic effect of LPND. From January 2012 to December 2019, 387 rectal cancer patients with clinical evidence of LPN metastasis who underwent total mesorectal excision with LPND were included in the study. According to pathological findings, they were divided into negative (n = 296) and positive (n = 91) LPN groups. Primary endpoints were 3-year overall survival (OS), recurrence-free survival (RFS), and local recurrence-free survival (LRFS).

Results

The OS, RFS, and LRFS in the positive group were significantly worse than those in the negative group; However, LPN metastases were not independent prognostic risk factors for LRFS (hazard ratio [HR]: 2.42; 95% confidence interval [CI], 0.77–7.64; P=0.132). Among patients with pathological LPN metastases, LPN metastases to the common and external iliac arteries were independent prognostic risk factors both for OS (HR: 4.74; 95% CI, 1.74–12.90; P=0.002) and RFS (HR: 2.70; 95% CI, 1.16–6.29; P=0.021). No significant difference was observed in the 3-year OS (72.3% vs. 70.2%, P=0.775) and RFS rates (60.9% vs. 52.6%, P=0.408) between patients with metastases to the obturator or internal iliac arteries and patients at N2b stage.

Conclusions

LPND may be effective in controlling local recurrence in patients with LPN metastasis but not systemic metastases. Patients with LPN metastasis limited to the internal iliac and obturator regions achieve a long-term survival benefit from LPND, and their prognoses may be comparable to those at the N2b stage. Further metastasis to the external iliac or common iliac region should be considered systemic disease, and LPND should be avoided.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT04850027.