Evaluating predictive factors for determining the presence of lateral pelvic node metastasis in rectal cancer patients following neoadjuvant chemoradiotherapy

AIM

The need or otherwise for lateral pelvic node dissection (LPND) in rectal cancer patients with clinical lateral pelvic node metastasis (LPNM) after neoadjuvant chemoradiotherapy (nCRT) is controversial. This study was designed to explore the predictive factors for pathological LPNM in rectal cancer patients with clinical LPNM after nCRT.

METHOD

From January 2010 to February 2018, a consecutive series of patients with rectal cancer and clinical LPNM after nCRT who underwent total mesorectal excision and LPND were reviewed. Patient demographics, operative and pathological outcomes were collected and analysed.

RESULTS

A total of 76 consecutive cases were included in this study: 53 (69.7%) patients underwent unilateral LPND and 23 (30.3%) bilateral LPND. The pathological results showed that LPNM was found in 13 (17.1%) patients. Multivariate logistic regression analysis showed that the post-nCRT lateral pelvic node size ≥ 5 mm (OR = 7.67, 95% CI = 1.45-40.63, P = 0.017) and mucinous/signet-ring adenocarcinoma (OR = 4.60, 95% CI = 1.11-19.08, P = 0.035) were independent risk factors for pathological LPNM.

CONCLUSION

Post-nCRT lateral pelvic node size ≥ 5 mm and mucinous/signet-ring adenocarcinoma were independent predictive factors of pathological LPNM for rectal cancer patients with clinical LPNM after nCRT, and patients with these characteristics may benefit from LPND.

Can chemoradiation allow for omission of lateral pelvic node dissection for locally advanced rectal cancer?

OBJECTIVES

We evaluated the relationship between pretreatment clinical parameters and lateral pelvic node (LPN) recurrence in patients with rectal cancer treated with a combination of curative resection and chemoradiotherapy (CRT) and attempted to identify the patients who might benefit from LPN dissection.

METHODS

This study involved 900 patients between June 2001 and June 2009. Pretreatment clinical parameters including radiological size of LPN were analyzed to identify risk factors associated with long-term outcomes.

RESULTS

Locoregional recurrence developed in 65 patients (7.2%); 42 (64.6%) had LPN recurrence, 20 (47.6%) of which had no distant metastasis. Multivariate analysis showed that LPN short-axis diameter (<5, 5-<10, and ≥10 mm) was significantly associated with LPN recurrence-free survival (5-year survival rate (5YSR), 98.2, 91.7, and 40.1%, respectively, P < 0.05), locoregional recurrence-free survival (5YSR, 95.5, 87.6, and 40.1%, respectively, P < 0.05), relapse-free survival (5YSR, 76.8, 72.5, and 30.3, respectively, P < 0.05), and overall survival (5YSR, 86.3, 83.0, and 57.5%, respectively, P < 0.05).

CONCLUSIONS

Patients with an LPN short-axis diameter ≥10 mm represent a potential subgroup at a high risk of LPN recurrence, even after CRT. Further study is needed to confirm whether LPN dissection is beneficial for these patients.