Should primary tumor be resected for non-small cell lung cancer with malignant pleural disease unexpectedly found during operation?-a systemic review and meta-analysis

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the Classification of Residual Tumor After Resection for the Forthcoming (Ninth) Edition of the TNM Classification of Lung Cancer

INTRODUCTION

The goal of surgical resection is to completely remove a cancer; it is useful to have a system to describe how well this was accomplished. This is captured by the residual tumor (R) classification, which is separate from the TNM classification that describes the anatomic extent of a cancer independent of treatment. The traditional R-classification designates as R0 a complete resection, as R1 a macroscopically complete resection but with microscopic tumor at the surgical margin, and as R2 a resection that leaves gross tumor behind. For lung cancer, an additional category encompasses situations in which the presence of residual tumor is uncertain.

METHODS

This paper represents a comprehensive review of evidence regarding these R categories and the descriptors thereof, focusing on studies published after the year 2000 and with adjustment for potential confounders.

RESULTS

Consistent discrimination between complete, uncertain, and incomplete resection is revealed with respect to overall survival. Evidence regarding specific descriptors is generally somewhat limited and only partially consistent; nevertheless, the data suggest retaining all descriptors but with clarifications to address ambiguities.

CONCLUSION

On the basis of this review, the R-classification for the ninth edition of stage classification of lung cancer is proposed to retain the same overall framework and descriptors, with more precise definitions of descriptors. These refinements should facilitate application and further research.

The Prognostic Impact of Lymph Node Dissection on Primary Tumor Resection for Stage IV Non-Small Cell Lung Cancer: A Population-Based Study

Objective

Selected patients with stage IV non–small cell lung cancer (NSCLC) who underwent primary tumor resection have witnessed a survival benefit. Whether additional lymph node dissection (LND) would result in a better effect remain unknown. We investigated the prognostic impact of LND on patients with stage IV NSCLC who received primary tumor resection (PTR).

Methods

Patients with stage IV NSCLC who underwent PTR were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2016. Propensity-score matching was performed to minimize the confounding effect, and lung cancer-specific survival (CSS) and overall survival (OS) were compared after matching. Multivariable Cox regression was used to identify prognostic factors and to adjust for covariates in subgroup analysis. The effect of the number of lymph nodes examined on the CSS was evaluated by repeating the Cox analysis in a binary method.

Results

A total of 4,114 patients with stage IV NSCLC who receive surgery met our criteria, of which 2,622 (63.73%) underwent LND and 628 patients were identified 1:1 in LND and non-LND groups after matching. Compared with the non-LND group, the LND group had a longer CSS (median: 23 vs. 16 months, p < 0.001) and OS (median: 21 vs. 15 months, p < 0.001). Multivariable regression showed that LND was independently associated with favorable CCS [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.69–0.89, P < 0.001] and OS (HR = 0.79, 95% CI 0.70–0.89, P < 0.001). Subgroup analysis suggested that LND is an independent favorable predictor to survival in the surgical patients who were older age (>60 years old), female, T3-4, N0, and M1a stage and those who underwent sublobar resection. In addition, a statistically significant CCS benefit was associated with an increasing number of lymph nodes examined through 25 lymph nodes.

Conclusions

LND with a certain range of lymph nodes number examined was associated with improved survival for patients with stage IV NSCLC who received primary tumor resection. The results may have implications for guidelines on lymph nodes management in selective advanced NSCLC for surgery.

Development and External Validation of a Nomogram for Predicting Cancer-Specific Survival of Non-Small Cell Lung Cancer Patients With Ipsilateral Pleural Dissemination

Background

Non-small-cell lung cancer (NSCLC) patients with ipsilateral pleural dissemination are defined as M1a in the eighth of American Joint Committee on Cancer (AJCC) TNM staging. We aimed to build a nomogram to predict lung cancer specific survival (LCSS) of NSCLC patients with ipsilateral pleural dissemination and to compare the impact of primary tumor resection (PTR) on LCSS among patients with different features.

Methods

A total of 3,918 NSCLC patients with ipsilateral pleural dissemination were identified from the Surveillance, Epidemiology, and End Results (SEER) database. We selected and integrated significant prognostic factors based on competing risk regression to build a nomogram. The model was subjected to internal validation within SEER cohort and external validation with the cohort of 97 patients from Peking University People’s Hospital.

Results

Age (P < 0.001), gender (P = 0.037), T stage (P = 0.002), N stage (P < 0.001), metastasis pattern (P = 0.005), chemotherapy (P < 0.001), and PTR (P < 0.001) were independent prognostic factors. The calibration curves presented a good consistency and the Harrell’s C-index of nomogram were 0.682 (95%CI: 0.673–0.691), 0.687 (95%CI: 0.670–0.704) and 0.667 (95%CI: 0.584–0.750) in training, internal, and external validation cohort, respectively. Interaction tests suggested a greater LCSS difference caused by PTR in patients without chemotherapy (P < 0.001).

Conclusions

We developed a nomogram based on competing risk regression to reliably predict prognosis of NSCLC patients with ipsilateral pleural dissemination and validated this nomogram in an external Chinese cohort. This novel nomogram might be a practical tool for clinicians to anticipate the 1-, 3- and 5-year LCSS for NSCLC patients with pleural dissemination. Subgroup analysis indicated that patients without chemotherapy could get more benefit from PTR. In order to assess the role of PTR in the management of M1a patients more accurately, further prospective study would be urgently required.

Surgical Resection of Primary Tumors Provides Survival Benefits for Lung Cancer Patients With Unexpected Pleural Dissemination

Background: Surgery is not generally recommended for non-small cell lung cancer (NSCLC) patients with malignant pleural dissemination (PD). However, in some cases, PD is found unexpectedly during surgery. There is no consensus on whether surgical intervention can provide survival benefit for them. We investigated the role of surgery in NSCLC patients with unexpected PD by a cohort study.

Methods: Clinical data of consecutive patients who intended to undergo radical surgery for NSCLC between January 2010 and December 2015 at Shanghai Chest Hospital and Huadong Hospital were collected from a lung cancer database. Patients diagnosed with unexpected malignant pleural nodules intraoperatively were enrolled in this retrospective study.

Results: A total of 181 NSCLC patients were diagnosed with unexpected malignant PD intraoperatively and confirmed with postoperatively histological examinations. Out of these, 80 (44.2%) patients received pleural nodule biopsies alone, and 101 (55.8%) received primary tumor resection (47 with sublobar resection and 54 with lobectomy). The median progression-free survival and overall survival for all patients were 13 and 41 months respectively. Patients in the resection group had significantly better progression-free survival (19.0 vs. 10.0 months, P < 0.0001) and overall survival (48.0 vs. 33.0 months, P < 0.0001) than patients in the biopsy group. In the resection group, there was no statistical difference between patients with sublobar resection and lobectomy (P = 0.34). Univariate and multivariate analyses identified primary tumor resection, targeted adjuvant therapy, and tumor size (≤ 3 cm) as independent prognostic factors.

Conclusions: NSCLC patients with unexpected intraoperative PD potentially benefited from surgical resection of the primary tumor and multidisciplinary targeted therapy, particularly when tumor size did not exceed 3 cm. Our data demonstrated that the resection type was not associated with survival differences, which remains to be defined with a larger sample size.

New horizons in non-small-cell lung cancer patients with ipsilateral pleural dissemination (M1a): review of the literature

Non-small cell lung cancer (NSCLC) with ipsilateral pleural dissemination (pM1a) is generally contraindicated for surgery owing to the extremely poor survival. However, some studies have demonstrated that primary tumor resection (PTR) may prolong the survival of these patients. Besides, with the development of systemic therapy, it is still hard to decide the best therapy model for pM1a patients. Thus, we reviewed essential studies about NSCLC with pleural disease and summarized the progress of new techniques in recent years, trying to provide promising new horizons about the management of pM1a patients. Firstly, we suggest performing PTR for highly selected pM1a patients, combined with appropriate systemic therapies and follow-up strategies. Secondly, hyperthermic intrathoracic chemotherapy (HITHOC) can control the symptoms and prolong the survival of NSCLC patients with malignant pleural effusion (MPE). It could also combine with PTR together. Finally, application of genetic testing and circulating tumor DNA (ctDNA) monitoring may furthermore make it possible for personalized management of pM1a patients in the future.

Surgical choice of non-small cell lung cancer with unexpected pleural dissemination intraoperatively

BACKGROUND

Whether patients with non-small cell lung cancer (NSCLC) with unexpected pleural dissemination (UPD) could get survival benefit from tumor resection remained controversial.

METHODS

Totally, 169 patients with NSCLC with UPD were included between 2012 and 2016. Patients were divided into the tumor resection and open-close group. Progression-free survival (PFS) and overall survival (OS) were compared with a log-rank test. The multivariable Cox analysis was applied to identify prognostic factors.

RESULTS

Sixty-five patients received open-close surgery and 104 patients underwent main tumor and visible pleural nodule resection. Tumor resection significantly prolonged OS (hazard ratio [HR]: 0.408, P < 0.001), local PFS (HR: 0.283, P < 0.001), regional PFS (HR: 0.506, P = 0.005), and distant metastasis (HR: 0.595, P = 0.032). Multivariable Cox analysis confirmed that surgical method was an independent prognostic factor for OS, local PFS and regional PFS, except distant metastasis. Subgroup analyses indicated that tumor resection could not improve OS in the patients who received targeted therapy (HR: 0.649, P = 0.382), however, tumor resection was beneficial for the patients who received adjuvant chemotherapy alone (HR: 0.322, P < 0.001). In the tumor resection group, lobectomy (HR: 0.960, P = 0.917) and systematic lymphadenectomy (HR: 1.512, P = 0.259) did not show survival benefit for OS.

CONCLUSIONS

Main tumor and visible pleural nodule resection could improve prognosis in patients with UPD who could not receive adjuvant targeted therapy. Sublobar resection without systematic lymphadenectomy may be the optimal procedure.

Pleural staging using local anesthetic thoracoscopy in dry pleural dissemination and minimal pleural effusion

BACKGROUND

Dry pleural dissemination (DPD) and minimal (<10 mm thick) pleural effusion (PE) may be discovered intraoperatively as unexpected metastases. A definitive diagnostic procedure such as pleural biopsy is rarely attempted in such patients preoperatively. We retrospectively investigated the use and safety of local anesthetic thoracoscopy (LAT) as a pleural staging tool in the diagnosis of DPD and minimal PE.

METHODS

We reviewed 18 patients with non-small cell lung cancer (radiological DPD and minimal PE in 13 and five patients, respectively) who underwent LAT using a flex-rigid pleuroscope for pleural staging from April 2015 to September 2020.

RESULTS

The median age of the patients was 72 years. Nine patients (50%) were men. The dominant histological type was adenocarcinoma (n = 16). Three patients each with radiological DPD and minimal PE had visible PE on the LAT. Pleural biopsy was performed in the 16 cases in which pleural abnormalities were identified. On pleural staging, five cases were diagnosed without pleural dissemination (M0), and 13 cases were diagnosed with pleural dissemination (M1a). Only one case in which the lesion could not be identified because of pleural adhesions was false-negative. The success rates for pleural staging, sensitivity, specificity, positive predictive value, and negative predictive value were 94.4% (17/18), 92.8% (13/14), 100% (4/4), 100% (13/13), and 80.0% (4/5), respectively. There were no lung lacerations or other severe complications caused by the procedure or during blunt dissection.

CONCLUSION

LAT might be a useful tool for accurate pleural staging in cases with DPD and minimal PE suspected radiologically.

Is surgical resection of primary tumour superior to exploratory thoracotomy without resection in treating lung cancer patients with unexpected pleural metastasis detected during operation?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In lung cancer patients with unexpected pleural metastasis detected during operation, is surgical resection of primary tumour superior to exploratory thoracotomy without resection in improving long-term survival?'. Altogether, 1443 papers were found using the reported search, of which 1 meta-analysis and 10 retrospective observational cohort studies represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. One meta-analysis and 9 cohort studies found that surgical resection of the primary tumour, on the discovery of pleural metastases, yielded a better overall survival than exploratory thoracotomy alone, while 1 cohort study showed no difference. Six studies found that main tumour resection was an independent favourable prognostic factor for overall survival in lung cancer patients with unexpected pleural metastasis detected during operation, while 3 cohort studies also showed improved progression-free survival over exploratory thoracotomy. Therefore, we conclude that surgical resection of the primary tumour is superior to exploratory thoracotomy in treating lung cancer patients with unexpected pleural metastasis detected during operation.

Wait-and-See Treatment Strategy Could be Considered for Lung Adenocarcinoma with Special Pleural Dissemination Lesions, and Low Genomic Instability Correlates with Better Survival

BACKGROUND

This study aimed to evaluate the feasibility of a wait-and-see strategy for non-small cell lung cancer (NSCLC) patients with special pleural dissemination lesions (r-pM1a and s-pM1a). Furthermore, the study characterized genomic alternations about disease progression.

METHODS

For this study, 131 NSCLC patients with a diagnosis of pM1a were retrospectively selected. Survival differences were evaluated among patients treated with three different initial postoperative treatments: chemotherapy, targeted therapy, and wait-and-see strategy. Whole-exome sequencing (WES) was performed on primary and metastatic tumors of 10 patients with dramatic progression and 13 patients with gradual progression.

RESULTS

The wait-and-see group showed better progression-free survival (PFS) than the chemotherapy group (p < 0.001) but PFS similar to that of targeted group (p = 0.984). This pattern persisted in epidermal growth factor receptor (EGFR)-positive patients. For patients with EGFR-negative/unknown status, PFS was longer in the wait-and-see group than in the two treatment groups. Furthermore, better overall survival (OS) was observed for the patients who received chemotherapy or targeted therapy after the wait-and-see strategy than for those who received chemotherapy or targeted therapy immediately. Lymph node status was an independent prognostic factor for PFS and OS. Finally, WES analysis showed that a high genomic instability index (GIS) and chromosome 18q loss were more common in metastatic tumors, and low GIS was significantly associated with better PFS (p = 0.016).

CONCLUSIONS

The wait-and-see strategy could be considered for special pM1a patients without lymph nodes metastasis, and patients with a low GIS may be suitable for this strategy.

Primary tumour resection in non-small-cell lung cancer patients with ipsilateral pleural dissemination (M1a): a population-based study

OBJECTIVES

Non-small-cell lung cancer (NSCLC) patients with ipsilateral pleural dissemination (M1a) are generally contraindicated for surgery. However, several small-sample studies have demonstrated that they might benefit from surgery. We investigated the effects of primary tumour resection on survival in these patients.

METHODS

Stage IV NSCLC patients with ipsilateral pleural dissemination were identified from the US National Cancer Institute Surveillance, Epidemiology and End Results database entries from 2010 to 2015. Survival analysis was performed before and after matching. Multivariable regression models were built to identify prognostic factors.

RESULTS

Of the 5513 patients with ipsilateral pleural dissemination, 309 underwent primary tumour resection. In the entire cohort, surgery was associated with improved overall survival (OS) in both the unmatched and matched cohorts (both log rank, P < 0.001). In the surgery-recommended cohort, patients treated with surgery also had significantly longer OS before and after matching. Multivariable regression models showed that surgery was an independent favourable prognostic factor for OS [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.48-0.65; P < 0.001] and lung cancer-specific mortality (subhazard ratio 0.60, 95% CI 0.51-0.70; P < 0.001). Surgery was independently associated with improved survival in all subgroups except for those with pericardial effusion (P = 0.065) or N3 disease (P = 0.17). In the surgical cohort, patients who underwent lobe/bilobectomy had significantly better OS than those who underwent sublobar resection (log rank, P < 0.001).

CONCLUSIONS

Inclusion of primary tumour resection in multimodal therapy of NSCLC was associated with improved survival in selected patients with ipsilateral pleural dissemination, except for those with pericardial effusion or N3 disease.

Primary tumor resection of non-small cell lung cancer patients with ipsilateral pleural dissemination (M1a) in the era of targeted therapy

Background

Non‐small cell lung cancer (NSCLC) patients with ipsilateral pleural dissemination (M1a) are generally contraindicated for surgery. Recently, several studies have demonstrated that these patients might benefit from primary tumor resection (PTR). However, whether PTR is beneficial for driver oncogene‐positive patients treated with targeted therapy, remains unclear. Here, we investigated the effects of PTR on survival in the era of targeted therapy.

Methods

In total, 105 NSCLC patients with ipsilateral pleural dissemination were identified. The mode of systemic treatment was assessed in this study. Survival analysis was performed with the Kaplan‐Meier method and Cox proportional hazards regression. The overall survival (OS) of patients with or without PTR was compared between propensity score‐matched groups (caliper: 0.02).

Results

In the entire cohort, PTR was associated with improved OS in both unmatched (median survival time [MST]: 50.0 vs. 29.6 months, P = 0.019) and matched (MST: 50.0 vs. 34.4 months, P = 0.052) cohorts. Multivariate regression models showed that surgery was an independent favorable prognostic factor for OS. A total of 70 patients underwent genetic testing, and targeted therapies, such as EGFR‐TKIs or ALK‐TKIs, were used in the driver oncogene‐positive patients. Subgroup analysis showed that PTR did not improve OS in the targeted therapy group (MST: 57.1 months vs. 50.4 months, P = 0.840). However, surgery significantly prolonged survival in the nontargeted therapy group (MST: 39.8 vs. 14.2 months, P = 0.002).

Conclusions

The results of this study indicated that PTR could prolong OS in stage IV NSCLC patients with ipsilateral pleural dissemination, especially in patients who are not candidates for targeted therapy.

Key points

Non‐small cell lung cancer patients with ipsilateral pleural dissemination can benefit from primary tumor resection.

Primary tumor resection could prolong overall survival (OS) in non‐small cell lung cancer patients with ipsilateral pleural dissemination who are not candidates for targeted therapy.

Construction of a Nomogram After Using Propensity Score Matching to Reveal the Prognostic Benefit of Tumor Resection of Stage IV M1a Nonsmall Cell Lung Cancer Patients

The aim of this work was to determine whether tumor resection could improve the prognosis of M1a nonsmall-cell lung cancer (NSCLC) patients. We obtained patient data from the Surveillance, Epidemiology, and End Results (SEER) database and used propensity score matching (PSM) to reduce the influence of confounding variables. Univariate and multivariate Cox regression analyses were used to identify independent prognostic factors, and the prediction results were visualized using the nomogram. A total of 772 patients with and without tumor resection were enrolled after PSM, and the nomogram combined with independent prognostic factors including age, sex, histological type, grade, T stage, N stage, chemotherapy, and surgery showed great prediction and discriminatory ability. Tumor resection is possibly a better choice for these patients.

[Observation - An Favorable Option Forthoracic Dissemination Patients with Lung Adenocarcinoma or Squamous Carcinoma]

背景与目的

手术非晚期期患者治疗的标准治疗，但是大量的回顾性研究显示胸腔内播散型肺癌接受主病灶切除后获益明显。非标准治疗之后患者该选择何种治疗策略？本研究通过回顾性数据去探究接受了主病灶切除的胸腔内播散型肺癌患者接下来何总治疗方式更优。

方法

回顾性收集早期肺腺癌或肺鳞癌且复发模式为胸腔内播散型患者；或拟行肺癌根治术，但术中胸腔探查发现胸腔内播散，接受主病灶切除的肺腺癌或肺鳞癌患者的一般资料、病理、淋巴结状态、基因突变状态、初始治疗方式等，随访至进展、死亡或失访，记录患者无进展生存时间、总生存时间、从确诊到开始治疗的时间。通过Kaplan-Meier绘制生存曲线，Log-rank检验比较组间生存差异，Cox比例回归风险模型分析无进展生存期（progression-free survival, PFS）和总生存期（overall survival, OS）相关预后因子。

结果

研究共纳入141例患者，70例r-M1a和71例s-M1a1患者。化疗组、靶向组、随访观察组患者中位PFS分别是14.7个月、41.0个月和31.0个月（95%CI: 19.01-26.01; P < 0.001），靶向治疗组和随访观察组患者PFS差异无统计学意义（P=0.600）。中位OS分别为39.0个月、42.6个月和38.1个月（95%CI: 32.47-45.33; P=0.478）。TTI < 3个月组和TTI≥3个月组患者的中位PFS分别是15.2个月和31.0个月（95%CI: 19.01-26.06; P<0.001），中位OS分别是41.7个月和38.7个月（95%CI: 32.47-45.33; P=0.714）。多因素分析显示性别（P=0.027）、淋巴结状态（P=0.036）、初始治疗方式（P<0.001）是PFS独立预后因子。

结论

随访观察不会缩短胸腔内播散腺癌和鳞癌患者的生存时间，是一种可选的治疗策略。

Lung adenocarcinoma with intraoperatively diagnosed pleural seeding: Is main tumor resection beneficial for prognosis?

OBJECTIVE

To evaluate whether main tumor resection improves survival compared with pleural biopsy alone in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding.

METHODS

Forty-three patients with lung adenocarcinoma with pleural seeding diagnosed unexpectedly during surgery performed between January 2006 and December 2014 were included in this retrospective study using a prospectively collected lung cancer database. Each surgeon decided whether to perform main tumor resection or pleural biopsy alone.

RESULTS

Main tumor and visible pleural nodule resection was performed in 30 patients (tumor resection group). The remaining 13 patients underwent pleural nodule biopsy alone (open-close group). The clinical T stage was higher in the open-close group than in the tumor resection group (P = .02). The tumor resection group had longer operative times compared with the open-close group (mean, 141.8 vs 80.3 minutes). There were no other statistically significant differences in perioperative parameters. The surgical method was the sole statistically significant prognostic factor. Patients in the tumor resection group had better progression-free survival (3-year survival: 44.5% vs 0%; P = .009) and overall survival (3-year survival: 82.9% vs 38.5%; P = .013) than did the open-close group. There was no significant survival difference between sublobar resection and lobectomy for the main tumor resection.

CONCLUSIONS

Our study demonstrated improved progression-free and overall survival after main tumor and visible pleural nodule resection in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding. Further randomized trials are needed to define the role of main tumor resection in these patients.