The absence of lymph nodes removed (pNx status) impacts survival in patients with lung cancer treated surgically.

OBJECTIVES: We aimed to study the clinical significance of the lack of lymph node assessment (pNx status) and its impact on survival in non-small-cell lung cancer patients. METHODS: We retrospectively analysed the Polish Lung Cancer Study Group database. pNx status was defined as 0 lymph nodes removed. We included 17,192 patients. RESULTS: A total of 1080 patients (6%) had pNx status. pNx patients were more likely to be younger, be female, have a different pT distribution, have squamous cell carcinoma, undergo open thoracotomy, be operated on in non-academic hospitals, and have a lower rate of some comorbidities. pNx was more likely to be cN0 than pN1 and pN2 but less likely than pN0 (p < 0.001). pNx patients were less likely to undergo preoperative invasive mediastinal diagnostics than pN1 and pN2 patients but more likely than pN0 patients (p < 0.001). Overall, the five-year overall survival rates were 64%, 45%, 32% and 50% for pN0, pN1, pN2 and pNx, respectively. In pairwise comparisons, all pN descriptors differed significantly from each other (all p < 0.0001 but pNx vs. pN1 p = 0.016). The placement of the pNx survival curve and survival rate depended on histopathology, surgical approach and pT status. In multivariable analysis, pNx was an independent prognostic risk factor (HR = 1.37, 95%CI: 1.23-1.51, p < 0.01). CONCLUSION: The resection of lymph nodes in lung cancer remains a crucial step in the surgical treatment of this disease. The survival of pNx patients is similar to that of pN1 patients. pNx survival curve placement depends on the other variables which could be useful in clinical decisions.

The effectiveness of surgical treatment of lung cancer in Polish academic and nonacademic centers.

Background: The theoretical advantage of academic hospitals over nonacademic are: more qualified surgeons, adequate diagnostic facilities and infrastructure, including intensive care units. The aim of the study was to compare the effectiveness of surgical lung cancer treatment in academic (ACA) and nonacademic (non-ACA) centers. Methods: This was a retrospective analysis of data from 31,777 patients surgically-treated for lung cancer during the period from 2007 to 2020 in 9 ACA and 21 non-ACA centers. The analysis considered the clinical data of patients, the effectiveness of preoperative diagnostics, the type of procedures performed, the complications, the postoperative mortality and the long-term survival. Results: The median number of anatomical lung resection procedures was 1,218 for ACA and 550 for non-ACA centers. In the ACA group, resection using the video-assisted thoracic surgery (VATS) technique was performed significantly more often than in the non-ACA group (23.6% vs. 14.2%, P<0.001). The pN feature analysis showed significantly lower proportions of pNX (9.2%) in the ACA group than those in the non-ACA group (17.1%) (P<0.001). The rates of postoperative complications in the ACA and non-ACA groups were 30.7% and 33.8%, respectively (P<0.001). There were no significant differences in 5-year survival between the ACA and non-ACA groups (56% and 56%, respectively) (P=0.2). Conclusions: The present study showed that ACA centers are characterized by better preoperative diagnostics, a higher percentage of VATS lobectomies, a lower percentage of postoperative complications and a shorter hospitalization period than non-ACA centers, but there was no impact on 5-year survival.

Effect of 3A lymph node resection on survival in patients with right-sided NSCLC: a retrospective, multicentre, propensity-score matching study.

Background: We aimed to assess the clinical significance and impact on survival of prevascular mediastinal lymph nodes (3A) in patients with right-sided lung cancer. Methods: Prospective data of 6,348 patients, who underwent lung resection from 2005 to 2015, were retrospectively analysed. There were 221 patients who underwent 3A dissection (3ALN+), while 6,127 did not (3ALN-). We performed propensity score matching (PSM) to decrease selection bias (221 vs. 221). Results: The incidence of 3A metastasis was 8%, and it elevated with pT stage. Between pT1c and pT2a, there was a significant increase in the 3A metastasis incidence, which doubled from 4% to 9%. For pT4, the incidence was 15%. The highest incidence was found among patients undergoing pneumonectomy (10%) and in the N2b1 and N2b2 subgroups (33% and 64%). In univariable analysis, we found no differences in 5-year survival between 3ALN+ and 3ALN- (51% vs. 51%, P=0.74). But, non-metastatic 3ALN+, 3ALN-, and metastatic 3ALN+ differed significantly (P<0.0001). pN2 subgroups (pN2a1, pN2a2, pN2b1, pN2b2) within PSM analysis did not differ significantly in terms of survival. 3A metastasis failed to be an independent prognostic factor in the multivariable analysis of matched pN2 subgroups. Conclusions: Regardless of 3A lymph nodes failing to be an independent prognostic factor in our cohort, the incidence of metastases in lymph nodes increases notably in advanced stages. 3A metastasis rate is comparable to other lymph node stations. Therefore, superior mediastinal lymphadenectomy in advanced cancers may improve from resections of the 3A lymph node station.

Sex differences in clinico-pathologic characteristics and long-term survival among 17,192 surgically treated NSCLC patients: Nationwide population-based propensity score-matching study.

INTRODUCTION: More information is needed on gender differences in lung cancer surgery. Thus, we conducted a retrospective study on thoracic treatment of non-small cell lung cancer (NSCLC) patients between 2007 and 2020 in Poland. The aim was to characterize sex differences in survival after complete surgical resection and to compare postoperative complications between Polish men and women. The main aspects that were compared between women and men were as follows: type of surgery and postoperative staging, morbidity and mortality, thoracic surgery complications, comorbidities, and overall survival based on a univariate analysis including propensity score matching (PSM) and a multivariate analysis. MATERIALS AND METHODS: Data were collected retrospectively from the Polish Lung Cancer Study Group database. Patients who were surgically treated for NSCLC between 2007 and 2020 (n = 17,192) were included in the study. RESULTS: The univariate analysis showed significantly better survival in women than in men. Women had better 5-year survival compared to men both for adenocarcinoma and squamous cell carcinoma (66% vs. 53%, p < 0.0001 and 65% vs. 51%, p<0.0001%, respectively), for both smokers and non-smokers (65% vs. 52%, p < 0.0001 and 65% vs. 51%, p < 0.0001, respectively), all age groups, and all stages (IA1 to III B). In the PSM analysis, statistically significant differences in favor of women were found for lower lobectomy (67% vs. 50%, p < 0.0001) and upper lobectomy (67% vs. 56%, p < 0.0001). Overall, postoperative complications occurred in 33.1% of patients and were observed more often in men than in women (35.8% vs. 28.6%, p < 0.001). CONCLUSIONS: Women with NSCLC who were treated surgically had a better long-term outcome compared to men, with no significant difference in disease severity. In addition to gender, the histological type, comorbidities, and type of surgery and surgical approach are also important.

The clinico-pathological characteristics of surgically treated young women with NSCLC.

Background: Non-small cell lung cancer diagnosed in young patients is rare. Younger patients with lung cancer are mostly female and have a more advanced stage at initial diagnosis. To our knowledge, no studies have compared single-surgical treatment in different age groups among women. Our study aimed to elucidate the clinicopathological characteristics and the best strategies for surgically treating young women with non-small-cell lung cancer. Methods: The data were collected retrospectively from the Polish Lung Cancer Study Group database. Women who were surgically treated for non-small-cell lung cancer between 2007 and 2020 were included in the study. The participants (n=11,460) were divided into two subgroups: aged ≤55 and >55 years. Results: Statistically significant differences were found for grades IB, IIA, IIIA, and IIIB (22.8% vs. 24.5%, 5.3% vs. 7.5%, 19.3% vs. 15.8%, 5.8% vs. 3.2%, for younger and older women, respectively, all P<0.001). The univariate analysis showed a higher percentage of 5-year survival in the group of younger women than in older women (0.67 vs. 0.64, P=0.00076). Regarding the stage of advancement, statistically significant differences in survival were found for stages IA1, IA2, and IIIA (0.95 vs. 0.86, P=0.047; 0.88 vs. 0.79, P=0.003; 0.5 vs. 0.42, for younger and older women, respectively, all P=0.01). Postoperative complications were more common in older than younger women (27.6% vs. 23.1%, P<0.001). However, there were no statistically significant differences in the number of hospitalization days since surgery and postoperative 30-day mortality. Conclusions: Younger women treated surgically were characterized by a lower percentage of comorbidities, were treated in a more advanced stage of the disease and had a lower percentage of postoperative complications, which, however, did not affect the hospitalization time. Despite the more advanced stage of the disease, survival in selected stages was much better than in the group of older women.

The influence of the number of lymph nodes removed on the accuracy of a newly proposed N descriptor classification in patients with surgically-treated lung cancer.

INTRODUCTION: The International Association for the Study of Lung Cancer has proposed a new classification of N descriptor based on the number of metastatic lymph nodes (LNs) stations, including skip metastasis. The aim of the study was to determine the effect of removed LNs on the adequacy of this new classification. MATERIALS AND METHODS: The material was collected retrospectively based on the database of the Polish Lung Cancer Group, including information on 8016 patients with non-small cell lung cancer operated in 23 thoracic surgery centers in Poland. The material covered the period from January 2005 to September 2015. We divided patients into two groups: ≤6LNs and >6LNs removed. RESULTS: In the whole group, an average of 13.4 nodes and 4.54 nodal stations were removed. 5-year survivals in the >6LNs group vs ≤ 6LNs group were: 62.3% and 55.1% (N0), 44.5% and 35.9% (N1a), 34.1% and 31,7% (N1b), 37.3% and 26.3% (N2a1), 32.4% and 26.7% (N2a2), 29.4% and 29.2% (N2b1), and 22.0% and 23.0% (N2b2), respectively. Comparing these groups, we detected significant differences at N0 (p < 0.001) and N2a1 (p = 0.022). In the ≤6LNs group, the survival curves for N2a1, N2a2, N2b1, and N2b2 overlapped (p > 0.05). In the >6LNs group, the survival curves were significantly different between grades, with survival for N2a1 better than N1b (p = 0.232). CONCLUSION: The proposed classification N descriptor is potentially better at differentiating patients into different stages. The accuracy of the classification depends on the number of lymph nodes removed. Therefore, the extent of lymphadenectomy has a significant impact on the staging of surgically-treated lung cancer.

The impact of left lower paratracheal (4L) lymph node dissection on survival in patients with surgically treated left-sided NSCLC.

OBJECTIVES: We aimed to investigate the clinical significance of left lower paratracheal nodes (#4L) and their impact on survival in patients with left-sided lung cancer. METHODS: This was a retrospective analysis of prospective data. The study included 5369 patients who underwent surgery between 2005 and 2015. Six hundred fifty-nine patients underwent #4L dissection (4LND+), and 4710 did not (4LND-). Propensity score matching was used to minimize analytic error (659 vs 659). RESULTS: The percentage of #4L metastasis increased with tumour size. Between pT2a and pT2b, it nearly doubled from 8% to 14%. The mean percentage of #4L metastasis in the pN2 group was 46, which was higher in left upper lobectomy compared to left lower lobectomy (63% vs 43%, respectively, P < 0.001). In univariable analysis, no differences in 5-year survival were observed between 4LND+ and 4LND- (48% vs 50%, respectively, P = 0.65). However, we detected a significant difference among non-metastatic 4LND+, 4LND- and metastatic 4LND+ (P < 0.0001). After propensity score matching, there were no significant differences in survival among the pN2 subgroups (pN2a1, pN2a2, pN2b1, pN2b2). Multivariable analysis after propensity score matching for each pN2 subgroup did not confirm the effect of #4L metastasis as an independent prognostic factor. CONCLUSIONS: Despite #4L nodes not being an independent prognostic factor in lung cancer, the percentage of nodal metastases notably increases above pT2a grade and is comparable to the percentage of #5 and #7 metastasis. Therefore, lymphadenectomy in advanced stages of cancer could benefit from resections of the #4L nodes.

Video-assisted versus open thoracotomy lobectomy: comparison on lymphadenectomy and survival in early stage of lung cancer.

BACKGROUND: Video-assisted thoracic surgery (VATS) is increasingly used in the surgical treatment of early lung cancer, but the oncological benefits are still controversial. We aimed to compare video-assisted lobectomy and open thoracotomy lobectomy in terms of lymphadenectomy and long-term survival depending on the location of lobectomy. METHODS: A retrospective, multicenter study was based on the Polish Lung Cancer Study Group and included patients with stage I lung cancer who were surgically treated between 2007 and 2015. We included 1410 patients after video-assisted lobectomy and 4,855 after open thoracotomy. RESULTS: The average number of lymph nodes removed in video-assisted lobectomy was 10.9 and in open thoracotomy lobectomy was 12.9 (P<0.001). The 5-year survival was better in the video-assisted lobectomy group (78.6%) compared to open thoracotomy (73.8%) (P=0.002). Significant differences were found in the case of left lower lobe and left upper lobe lobectomies. Multivariable analysis showed that the prognostic factors for open thoracotomy relative to video-assisted lobectomy are: age over 60 [HR (95% CI): 1.55 (1.17-2.05), P=0.002], female [HR (95% CI): 1.57 (1.07-2.29), P=0.02], squamous cell carcinoma [HR (95% CI): 1.63 (1.12-2.37), P=0.011], left lower lobe [HR (95% CI): 2.69 (1.37-5.27), P=0.004] and left upper lobe [HR (95% CI): 1.53 (1.01-2.33), P=0.047]. CONCLUSIONS: The study showed that the number of lymph nodes removed during video-assisted lobectomy is significantly lower than in the open thoracotomy group. The long-term video-assisted lobectomy results were significantly better compared to open thoracotomy. Better long-term results were achieved on the left side of lobectomy.

Alternative methods of lymph node staging in lung cancer: a narrative review.

The nodal status indicator in non-small cell lung cancer is one of the most crucial prognostic factors available. However, there are still many arguments among scientists regarding whether the currently used nodal status descriptor should be changed in the forthcoming editions of the Tumor Node Metastasis classification or whether it is precise enough and should be maintained as is. We reviewed studies concerning nodal factor classifications to evaluate their accuracy in non-small cell lung cancer patients and to address the previously mentioned challenge. We reviewed the PubMed database regarding the following classifications: ongoing 8th edition of the Tumor Node Metastasis classification, number of positive lymph nodes, number of negative lymph nodes, number of dissected lymph nodes, lymph node ratio, nodal chains, log odds of positive lymph nodes, zone-based classification and one that is based on the number of lymph node stations involved. Moreover, we analysed data regarding various combinations of these classifications. Our analysis showed that the present nodal staging may not accurately categorize every lung cancer patient. The number of positive lymph nodes and lymph node ratio or the log odds of positive lymph nodes (as the mathematical modification of lymph node ratio) are more legitimate, as they possess very robust data and should be considered initially as additional factors that can be incorporated in ongoing nodal staging systems. Forthcoming non-small cell lung cancer staging systems could benefit from the addition of quantitative-based parameters. Additionally, the minimal extent of lymphadenectomy should be established as staging benefits from it. International, prospective validation studies need to be performed to optimize the cut-off values and prognostic groups and to confirm the superiority of the newly suggested descriptors in non-small cell lung cancer nodal staging.