State of the art in surgery for early stage NSCLC-does the number of resected lymph nodes matter?

The concept of broad exposure facilitates uniportal video-assisted thoracoscopic mediastinal lymph nodes dissection

Background

Systematic lymph node dissection is an important part of radical resection for lung cancer. Insufficient incision of the mediastinal pleura results in a tapered or tunnel-like operation surface, which increases the difficulty of uniportal video-assisted thoracoscopic mediastinal lymph node dissection. The objective of this study was to report our concept of broad exposure and investigate the efficacy and safety of this concept in uniportal video-assisted thoracoscopic mediastinal lymph nodes dissection.

Methods

We retrospectively analyzed the clinical data of the 204 non-small cell lung cancer patients who underwent uniportal video-assisted thoracoscopic surgery for anatomical lobectomy and systematic lymph node dissection following the concept of broad exposure. SPSS 23.0 software was used for statistical analysis.

Results

All operations were completed under uniportal video-assisted thoracoscopic surgery following the concept of broad exposure. The median surgery time was 102 (range, 76–285) minutes and the median blood loss was 50 (range, 20–900) milliliters. The median chest tube duration time was 2 (range, 1–6) days, the median postoperative hospital duration time was 5 (range, 4–10) days. The median number of dissected lymph node stations and dissected lymph nodes were 8 (range,6–9) and 15(range,12–19), respectively. The median number of dissected mediastinal lymph nodes stations and dissected mediastinal lymph nodes were 5(range,3–6) and 11(range,10–15), respectively. The up-staging rate of N staging was 6.86%. The postoperative complication rate was 10.29% and there was no perioperative death.

Conclusions

According to our results, it’s effective and safe to perform uniportal video-assisted thoracoscopic mediastinal lymph nodes dissection following the concept of broad exposure. This new concept not only emphasizes sufficient exposure, but also focuses on protection of important tissues.

Effect of Lymph Node Assessment on Outcomes in Surgery for Limited Stage Small Cell Lung Cancer

BACKGROUND

The National Comprehensive Cancer Network guidelines recommend surgery for limited stage small cell lung cancer (SCLC). However, there is no literature on minimum acceptable lymph node retrieval in surgery for SCLC.

METHODS

The National Cancer Database was queried for adult patients undergoing lobectomy for limited stage (cT1-2N0M0) SCLC from 2004 to 2015. Patients with unknown survival, staging, or nodal assessment, and patients who received neoadjuvant therapy were excluded. The number of lymph nodes assessed was studied both as a continuous variable and as a categoric variable stratified into distribution quartiles. The primary outcome was overall survival and the secondary outcome was pathologic nodal upstaging.

RESULTS

A total of 1051 patients met study criteria. In multivariable analysis, only a retrieval of eight to 12 nodes was associated with a significant survival benefit (hazard ratio 0.73; 95% confidence interval, 0.56 to 0.98). However, when modeled as a continuous variable, there was no association between number of nodes assessed and survival (hazard ratio 1.00; 95% confidence interval, 0.98 to 1.02). The overall rate of pathologic nodal upstaging was 19%. Modeled as a continuous variable, more than seven lymph nodes assessed at time of resection was significantly associated with nodal upstaging in multivariable regression (odds ratio 1.03; 95% confidence interval, 1.01 to 1.06).

CONCLUSIONS

In this study, there was no clear difference in survival based on increasing the number of lymph nodes assessed during lobectomy for limited stage SCLC. However, the number of retrieved lymph nodes was associated with pathologic nodal upstaging. Therefore, patients may benefit from retrieval of more than seven lymph nodes during lobectomy for SCLC.

The dosimetric effects of limited elective nodal irradiation in volumetric modulated arc therapy treatment planning for locally advanced non-small cell lung cancer

Objective

Contemporary radiotherapy guidelines for locally advanced non-small cell lung carcinoma (LA-NSCLC) recommend omitting elective nodal irradiation, despite the fact that evidence supporting this came primarily from older reports assessing comprehensive nodal coverage using 3D conformal techniques. Herein, we evaluated the dosimetric implications of the addition of limited elective nodal irradiation (LENI) to standard involved field irradiation (IFI) using volumetric modulated arc therapy (VMAT) planning.

Method

Target volumes and organs-at-risk (OARs) were delineated on CT simulation images of 20 patients with LA-NSCLC. Two VMAT plans (IFI and LENI) were generated for each patient. Involved sites were treated to 60 Gy in 30 fractions for both IFI and LENI plans. Adjacent uninvolved nodal regions, considered high risk based on the primary tumor site and extent of nodal involvement, were treated to 51 Gy in 30 fractions in LENI plans using a simultaneous integrated boost approach.

Results

All planning objectives for PTVs and OARs were achieved for both IFI and LENI plans. LENI resulted in significantly higher esophagus D_mean (15.3 vs. 22.5 Gy, p < 0.01), spinal cord D_max (34.9 vs. 42.4 Gy, p = 0.02) and lung D_mean (13.5 vs. 15.9 Gy, p = 0.02), V₂₀ (23.0 vs. 27.9%, p = 0.03), and V₅ (52.6 vs. 59.4%, p = 0.02). No differences were observed in heart parameters. On average, only 32.2% of the high-risk nodal volume received an incidental dose of 51 Gy when untargeted in IFI plans.

Conclusion

The addition of LENI to VMAT plans for LA-NSCLC is feasible, with only modestly increased doses to OARs and marginal expected increase in associated toxicity.

Prognostic value of number of negative lymph node in patients with stage II and IIIa non-small cell lung cancer

Background

The definitive validation evidence of the implications of lymph node metastases regarding the survival of Non-Small Cell Lung Cancer (NSCLC) patients is lacking. We aimed to evaluate the prognostic impact of several lymph node metastases-associated risk factors including Number of Negative Lymph Node (NLN) and risk-stratify NSCLC patients into subsets with different prognosis.

Method

A total of 482 patients with N1 and N2 NSCLC were included in this study. The prognostic importance of a set of risk factors was examined by univariate and multivariate analysis. The cut-off points and 5 years survival rates were calculated to test the best grouping system to stratify the patients with difference outcome.

Results

Our analysis indicated that both Ratio of the Metastatic Lymph nodes (RML) and Number of Negative Lymph Node (NLN) were associated with overall survival (OS) and disease free survival (DFS). RML percentage 20% and 55%, and NLN counts 10 and 30 were proved as the optimal cut-off points to predict OS by classifying patients into 3 groups, respectively. RML and NLN actually are more powerful in predicting survival outcome for male patients compared to female patients. Stratified survival analyses using combined factors indicated that the 5-year survival rate (5-YSR) is high in RML I + NLN I/III subgroup (5-YSR = 57.1% and 43.3%) and low in RML III + NLN II/III subgroup (5-YSR = 0.0 % each).

Conclusions

NLN is a strong prognostic factor for OS and DFS of stage II/IIIa NSCLC patients, and provides a useful classification scheme for NSCLC patients when combined with RML.

Evaluation of new classifications of N descriptor in non-small cell lung cancer (NSCLC) based on the number and the ratio of metastatic lymph nodes

Background

The aim of the study was to evaluate the prognostic power of new classifications of N descriptor created basing on the number (NLN) and the ratio of metastatic lymph nodes (RLN) in NSCLC compared to the current classification (CLN).

Methods

The data of 529 patients with NSCLC operated with the intention of radical resection, were analyzed. The new categories of N descriptor were created as follows: 1) NLN - median number of metastatic nodes was 3, thus in NLN0 the number of metastatic nodes =0, in NLN1 1-2, in NLN2 ≥ 3, 2) RLN - median ratio (number of metastatic lymph nodes to all nodes removed) was 12.4 %, thus in RLN0 the ratio was 0, in RLN1 < 13 %, in RLN2 > 13 %. The prognostic value of each classification was calculated on the basis of hazard ratios defined in multivariate Cox proportional hazard model.

Results

The new classifications of N descriptor turned out to be an independent strong prognostic factor (p <0.001) with a 5-year survival rate NLN0-62 %, NLN1-39 %, NLN2-26 % and RLN0-62 %, RLN1-37 % and RLN2-26 %. For 5-year survival rates in CLN0-62 %, CLN1-42 %, CLN2-24 % (p < 0.001), a higher prognostic value of new classifications was not demonstrated, the hazard ratio amounted to 2.22, 2.08, 2.49 for NLN2, RLN2 and CLN2 respectively.

Conclusion

Despite the significantly high prognostic power, the new classifications cannot be considered superior over CLN. There are some deficiencies in the current classification, therefore further studies on its improvement are needed.