Mediastinal lymph nodes: ignore? sample? dissect? The role of mediastinal node dissection in the surgical management of primary lung cancer

Prognostic significance of 4R lymph node dissection in patients with right primary non-small cell lung cancer

Background

To investigate the prognostic significance of station 4R lymph node (LN) dissection in patients who underwent operations for right primary non-small cell lung cancer (NSCLC).

Methods

We performed a retrospective study involving patients with right primary NSCLC who received lobotomy or pneumonectomy with mediastinal LN dissection between January 2011 and December 2017. Propensity score matching was performed. Disease-free survival (DFS) and overall survival (OS) were compared between patients with and without station 4R dissection.

Results

Our study included 2070 patients, with 207 patients having no station 4R dissection (S4RD− group) and 1863 patients having station 4R dissection (S4RD+ group). The 4R LN metastasis rate was 13.4% (142/1748), higher than that for other mediastinal LN metastases. Compared with the S4RD− group, the S4RD+ group had higher 5-year DFS (48.1% vs. 39.1%, P = 0.009) and OS (54.4% vs. 42.8%, P = 0.025). Station 4R dissection was an independent risk factor for DFS (odds ratio, OR, 1.28, 95% confidence interval, CI, 1.08–1.64, P = 0.007) and OS (OR 1.31, 95% CI 1.04–1.63, P = 0.018). Patients with adjuvant chemotherapy had a better prognosis after station 4R dissection than those without adjuvant chemotherapy (57.4% vs. 52.3%, P = 0.006). The 5-year OS in the station 4R metastasis group was lower than that in the station 4R non-metastasis group (26.9% vs. 44.3%, P = 0.006) among N2 patients. The 5-year OS of the single-station 4R metastasis group was lower than that of the single-station 7 metastasis group (15.7% vs. 51.6%, P = 0.002).

Conclusions

Station 4R metastasis was the highest among all the mediastinal station metastases in right primary NSCLC patients. Station 4R dissection can improve the prognosis and should be recommended as a routine procedure for these patients.

The clinical value of a new method of functional lymph node dissection in video-assisted thoracic surgery right non-small cell lung cancer radical resection

Background

To evaluate the safety, thoroughness and feasibility of "tunnel-type en bloc mediastinal lymph node dissection" in video-assisted thoracic surgery (VATS) for right non-small cell lung cancer (NSCLC) radical resection, which functionally dissected the lymph nodes of station 2R/4R/7.

Methods

A retrospective study was performed in the clinical data of 196 patients with VATS right NSCLC radical resection. According to the different methods of lymph node dissection of station 2R, 4R and 7, they were divided into the tunnel-type group (n=102) and the routine group (n=94). The clinical data of two group were compared.

Results

The analyses of the baselines of the two groups are comparable. For lymph nodes dissection of station 2R/4R/7, operation time, the total number, positive number and metastasis incidence shown no significant difference between two groups (P>0.05). However, the amount of bleeding, postoperative thoracic drainage volume, extubation time, hospitalization days, the incidence of postoperative pulmonary infection and chronic cough were significantly lower in the tunnel-type group (P<0.05). There was no significant difference in 3-year recurrence and metastasis and in 3-year survival between tunnel-type group and routine group.

Conclusions

The tunnel-type group has more advantages, such as less surgical trauma, shorter hospitalization time, faster postoperative rehabilitation, even less postoperative chronic cough compared with the routine group. Therefore, we believe that the tunnel-type en bloc mediastinal lymph node dissection is a safe, thorough and feasible surgical method, which is worthy of being popularized and applied in the VATS right NSCLC radical resection.

Intraoperative nodal staging: role of sentinel node technology

In cases of superficial malignancies such as melanoma or breast cancer, intraoperative lymph node mapping with a sentinel lymph node (SLN) biopsy is an effective and minimally invasive alternative to inguinal or axillary lymph node dissection for early-stage tumors. For primary lung cancer, although much effort has been made to investigate a variety of tracers, such as dyes, radioisotopes, magnetite, and iopamidol, for discerning SLNs, an appropriate agent that produces high identification and accuracy rates has yet to be developed. Further studies are needed to find an ideal tracer for practical use in patients with non-small cell lung cancer.