Current status and future direction of lymph node dissection in radical surgery for esophageal cancer

Increased resected lymph node stations improved survival of esophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) and surgery have been recommended as the standard treatments for locally advanced esophageal squamous cell carcinoma (ESCC). In addition, nodal metastases decreased in frequency and changed in distribution after neoadjuvant therapy. This study aimed to examine the optimal strategy for lymph node dissection (LND) in patients with ESCC who underwent nCRT.

METHODS

The hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were calculated using the Cox proportional hazard model. To determine the minimal number of LNDs (n-LNS) or least station of LNDs (e-LNS), the Chow test was used.

RESULTS

In total, 333 patients were included. The estimated cut-off values for e-LNS and n-LNS were 9 and 15, respectively. A higher number of e-LNS was significantly associated with improved OS (HR: 0.90; 95% CI 0.84-0.97, P = 0.0075) and DFS (HR: 0.012; 95% CI: 0.84-0.98, P = 0.0074). The e-LNS was a significant prognostic factor in multivariate analyses. The local recurrence rate of 23.1% in high e-LNS is much lower than the results of low e-LNS (13.3%). Comparable morbidity was found in both the e-LNS and n-LND subgroups.

CONCLUSION

This cohort study revealed an association between the extent of LND and overall survival, suggesting the therapeutic value of extended lymphadenectomy during esophagectomy. Therefore, more lymph node stations being sampled leads to higher survival rates among patients who receive nCRT, and standard lymphadenectomy of at least 9 stations is strongly recommended.

Diaphragmatic hernia after Ivor Lewis esophagectomy for cancer: a retrospective analysis of risk factors and post-repair outcomes

Background

Esophageal cancer surgery has historically been associated with high levels of postoperative morbidity and mortality. Post-esophagectomy diaphragmatic hernia (PEDH) represents a potentially life-threatening surgical complication, with incidence and risk factors not clearly demonstrated. This study evaluates presenting characteristics and repair outcomes in PEDH after Ivor Lewis esophagectomy for cancer.

Methods

All consecutive patients who underwent esophageal cancer surgery between March 1997 and April 2018 at two high-volume centers were included. The patients underwent Ivor Lewis esophagectomy and were managed according to a standardized follow-up care plan. The primary outcomes included PEDH incidence, risk factor identification, and surgical results after hernia repair. Patient characteristics and perioperative data were collected and a multivariate analysis was performed to identify risk factors for PEDH.

Results

A total of 414 patients were enrolled and 22 (5.3%) were diagnosed with PEDH during a median follow-up period of 16 (range, 6–177) months. All patients underwent surgical repair and 16 (73%) required treatment within 24 hours. PEDH repair was mainly performed through a laparoscopic approach (77.3%), with an overall postoperative morbidity of 22.7% and one mortality case. The median length of hospital stay was 6 (range, 2–95) days, and no early recurrences were observed, although three (13.6%) cases relapsed over a median follow-up of 10.1 months after hernia repair. Univariate analysis demonstrated a statistically significant association between PEDH and neoadjuvant chemoradiotherapy (P=0.016), pathological complete response (P=0.001), and lymph node harvest (P=0.024). On the other hand, multivariate analysis identified pathological complete response [3.616 (1.384–9.449), P=0.009] and lymph node harvest [3.029 (1.140–8.049), P=0.026] as the independent risk factors for developing PEDH.

Conclusions

PEDH represents a relevant surgical complication after Ivor Lewis esophagectomy for cancer, including a 5.3% incidence and requiring surgical repair. Pathological complete response and lymph node harvest were found to be independent risk factors for PEDH, independently of the esophagectomy technique.

MEK blockade overcomes the limited activity of palbociclib in head and neck cancer

Head and neck cancer (HNC) is characterized with multiple aberrations in cell cycle pathways, including amplification of cyclin D1. Palbociclib (PAL), a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, has been reported to regulate cell cycle progression in HNC. However, recent studies have revealed the acquired resistance of certain cells to PAL through activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway. Therefore, we investigated whether the inhibition of MEK/ERK pathway by trametinib (TRA) may overcome the limited efficacy of PAL in HNC. We evaluated the effect of PAL alone and in combination with TRA on the viability of HNC cells, and found that the combination treatment synergistically inhibited the proliferation of HNC cells. The combination treatment induced G0/G1 cell cycle arrest and apoptotic cell death. In particular, apoptosis mediated by the combination treatment was accompanied with an increase in caspase-3 activity and the number of TUNEL-positive apoptotic cells. These results were consistent with the decrease in cell cycle progression and mitogen-activated protein kinase (MAPK) pathway activation. In a xenograft mouse model of HNC, PAL and TRA synergistically inhibited tumor growth and enhanced tumor cell apoptosis, consistent with the increase in the number of TUNEL-positive cells. The anti-proliferative effects were evident in tumor tissues subjected to the combination treatment as compared with those treated with single drug. Taken together, our study demonstrates that the combination of PAL and TRA exerts synergistic anticancer effects and inhibits cell cycle check points and MEK/ERK pathway in HNC, suggestive of their potential application for HNC treatment.