Incidence and prognosis of lower rectal cancer with limited extramesorectal lymph node metastasis

Not all Rectal Cancer Patients Could Benefit From the Surgery on the Primary Site

AIM

Previous studies have provided evidence that primary site surgery can improve the prognosis of rectal cancer patients, even in those with advanced age and distant metastasis, though results have been inconsistent. The current study aims to determine if all rectal cancer patients are likely to benefit from surgery in terms of overall survival.

METHODS

This study examined the impact of primary site surgery on the prognosis of rectal cancer patients diagnosed between 2010 and 2019 using multivariable Cox regression analysis. The study also stratified patients by age group, M stage, chemotherapy, radiotherapy, and number of distant metastatic organs. The propensity score matching method was used to balance observed covariates between patients who received and did not receive surgery. The Kaplan-Meier method was used to analyze the data, and the log-rank test was used to determine differences between patients who did and did not undergo surgery.

RESULTS

The study included 76,941 rectal cancer patients, with a median survival of 81.0 months (95% CI: 79.2-82.8 months). Of these patients, 52,360 (68.1%) received primary site surgery, and they tended to be younger, have higher differentiated grade, earlier T, N, M stage, and lower rates of bone, brain, lung, and liver metastasis, chemotherapy, and radiotherapy than those without surgery. Multivariable Cox regression analysis revealed that surgery had a protective effect on the prognosis of rectal cancer patients, including those with advanced age, distant metastasis, and multiple organ metastasis, but not in patients with four organ metastases. The results were also confirmed using propensity score matching.

CONCLUSION

Not all rectal cancer patients could benefit from the surgery on the primary site, especially the patients with more than four distant metastases. The results could help the clinicians to tailor targeted treatment regimens and provide a guideline for making surgical decisions.

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.

Oncologic outcomes after resection of para-aortic lymph node metastasis in left-sided colon and rectal cancer

Aim

The optimal surgical management strategy for para-aortic lymph node (PALN) metastasis has not attracted as much attention as surgery for liver or lung metastasis. The purpose of this retrospective study was to evaluate the oncologic outcomes after synchronous resection of PALN metastasis in left-sided colon and rectal cancer.

Methods

Between January 1986 and August 2016, 29 patients with pathologically positive PALN metastases who underwent curative resection at our hospital were retrospectively reviewed. We examined clinicopathological characteristics, long-term oncologic outcomes, and factors related to favorable prognosis in these patients.

Results

The 3-year overall survival and recurrence-free survival (RFS) rates were 50.5% and 17.2%, respectively. In total, 6 (20.7%) patients experienced no recurrence in the 3 years after surgery, while postoperative complications were seen in 9 (31.0%) patients. The 3-year RFS rate was significantly better in the pM1a group than in the pM1b/pM1c group (26.3% and 0.0%, respectively, p = 0.032).

Conclusion

PALN dissection for patients without other organ metastases in left-sided colon or rectal cancer is a good indication as it is for liver and lung metastasis.

Prognostic impact of the number of lateral pelvic lymph node metastases on rectal cancer

BACKGROUND

This study aimed to clarify the number of lateral pelvic lymph node metastases of colorectal cancer for which prognosis could be improved by dissection.

METHODS

We analysed the data of 30 patients with lateral pelvic lymph node metastases of rectal cancer that underwent a total mesorectal excision with lateral pelvic lymph node dissection at our institute from 1986 to 2016. We performed survival analysis on the number of lateral pelvic lymph node metastases in each of these patients and identified an optimal cut-off point of the number of lateral pelvic lymph node metastases that would predict recurrence-free survival using the receiver operating characteristic curves and an Akaike information criterion value.

RESULTS

The 5-year recurrence-free survival and overall survival of patients with one or two lateral pelvic lymph node metastases were significantly better than that of those with three or more (5-year recurrence-free survival, 63.3 vs. 0.0%, respectively; hazard ratio, 0.23; 95% CI, 0.07-0.72; P = 0.0124) (5-year overall survival, 68.2 vs. 15.6%, respectively; hazard ratio, 0.29; 95% CI, 0.09-0.92; P = 0.0300). All of the metastatic lateral pelvic lymph nodes in the group with one or two lateral pelvic lymph node metastases were restricted to the internal iliac artery or obturator nerve regions.

CONCLUSIONS

The cut-off number of lateral pelvic lymph node metastases in the internal iliac artery or obturator nerve regions of colorectal cancer cases in whom prognosis was improved by lateral pelvic lymph node dissection was 2; patients who had <3 lateral pelvic lymph node metastases had better prognoses than those with ≥3 lateral pelvic lymph node metastases.

Advances in organ preserving strategies in rectal cancer patients

Treatment of rectal cancer patients has been subjected to change over the past thirty years. Total mesorectal excision is considered the cornerstone of rectal cancer treatment, but is also associated with significant morbidity resulting in an impaired quality of life. The addition of neoadjuvant chemoradiotherapy to surgery has shown to improve survival and local control and may lead to a partial or even complete response (CR). This raises questions regarding the necessity for subsequent radical surgery. After careful patient selection local excision and wait-and-see approaches are explored, aiming to improve quality of life without compromising oncological outcome. A multimodality diagnostic approach for optimal staging is crucial in determining the appropriate neoadjuvant treatment regimen. Adequate endoscopic restaging of rectal tumours after multimodality treatment will aid in selecting patients who are eligible for an organ preserving approach. The role and accuracy of imaging in the detection of the primary tumour, residual rectal cancer or local recurrence seems vital. Alternative neoadjuvant regimens are currently explored to increase the rate of clinical CRs, which may support organ preserving approaches. This review aims to generate insight into the advances in diagnostics and treatment modalities in all stages of rectal cancer and will highlight future studies that may support further implementation of organ preservation treatment in rectal cancer.