Postoperative radiotherapy for incompletely resected non-small cell lung cancer: clinical outcomes and prognostic value of the histological subtype

A narrative review of postoperative adjuvant radiotherapy for non-small cell lung cancer

OBJECTIVE

To summarize the principal studies investigating the role of postoperative radiation therapy (PORT) for non-small cell lung cancer (NSCLC) and to discuss the recent major breakthroughs deriving from the Lung ART trial, in order to provide a real-world scenario of the management of resected NSCLC patients.

BACKGROUND

Surgery followed by platinum-based chemotherapy remains the mainstay of adjuvant treatments for completely resected stage II and IIIA NSCLC. Less consistent is the employment of PORT, as no significant benefit was clearly identified from the previous published meta-analysis. Furthermore, the recent results of Lung ART trial questioned for the first time the efficacy of PORT for pathological N2 (pN2) NSCLC patients. Hence, the need to define if PORT still has a role for resected NSCLC and which subgroup of patients could benefit most from this treatment.

METHODS

A literature search of PubMed was performed to identify publications, including prospective and retrospective clinical studies, meta-analysis and systematic review of PORT for NSCLC. No limit concerning years of publication or publication status were applied. Only papers using the English language were selected. The ESMO 2020 and ESMO 2021 online resources were used to analyze the Lung ART trial results. The authors provide a narrative summary of the findings and implications of these studies and how they improve the clinical practice.

CONCLUSIONS

PORT was considered the standard of care for patients with completely resected pN2 NSCLC based on the results of an old meta-analysis that did not demonstrate a detrimental effect. The more recent randomized phase III Lung ART trial concluded that PORT could not anymore be recommended for pN2 NSCLC as a significant benefit in terms of 3 years disease-free survival (DFS) was not reached and an increased rate of radiotherapy related toxicity was observed. Retrospective studies suggest a possible role of PORT for incompletely resected NSCLC patients and those with an extranodal extension (ENE), but this issue needs to be reinforced from randomized prospective trials. The extensive publication of Lung ART trial is largely awaited to define if there is a role of PORT for resected NSCLC patients.

Postoperative radiotherapy in resected non-small cell lung cancer: The never-ending story

This manuscript collects in a joint and orderly manner the existing evidence at the present time about postoperative treatment with radiotherapy in non-small cell lung cancer. It also systematically reviews the current evidence, the international recommendations in the most relevant guidelines, the most controversial aspects in clinical and pathological staging, the specific technical aspects of radiotherapy treatment, and also collects all the potential risk factors that have been postulated as significant in the prognosis of these patients, evaluating the possibility of segmenting a particularly sensitive subpopulation with a high risk of relapse on which an adjuvant treatment with radiotherapy could have an impact on their clinical evolution. Finally, currently active trials that aspire to provide more evidence on this topic are reviewed.

Circulating tumor cells counts are associated with CD8+ T cell levels in programmed death-ligand 1-negative non-small cell lung cancer patients after radiotherapy: A retrospective study

This study aimed to explore the dynamics of circulating tumor cells (CTCs) and CD8+ T cells in stage II-III non-small cell lung cancer patients with CTCs in different programmed death-ligand 1 (PD-L1) status treated with radiotherapy and evaluate the correlation between CTCs and CD8+ T cells.This study was a retrospective study which reviewed 69 stage II-III non-small cell lung cancer patients underwent postoperative radiotherapy and peripheral blood tests of CTCs and T lymphocyte were available before radiation, 1 week after radiation and 1 month after radiation.In this study, 25 patients had PD-L1 positive CTCs and 44 patients had PD-L1 negative CTCs. The CTCs count was significantly decreased compared with baseline in patients with different PD-L1 status CTCs at 1 week and 1 month after radiotherapy. The proportion of CD8+ T cells was significantly increased at 1 month after radiotherapy compared with baseline in the total population (mean change, 7.24 ± 2.12; P < .05) and patients with PD-L1 negative CTCs (mean change, 7.17 ± 2.65; P < .05). One month after radiotherapy, the proportion of CD8+ T cells was negatively correlated with the CTCs count in the total population (r = -0.255, P = .034) and PD-L1 negative patients (r = -0.330, P = .029). In patients with PD-L1 negative CTCs, the CTCs count 1 week after radiotherapy (hazard ratio, 0.150 [95% confidence intervals., 0.027-0.840], P = .031) and the proportion of CD8+ T cells 1 month after radiotherapy (hazard ratio, 7.961 [95% confidence intervals, 1.028-61.68], P = .047) were independent prognostic factors for disease recurrence.After radiotherapy, only PD-L1-negative patients had a significant increase in the CD8+ T cell levels, while it was negatively correlated with CTCs count and was an independent prognostic factors of disease recurrence.

Postoperative radiotherapy for pathological stage IIIA-N2 non-small cell lung cancer with positive surgical margins

Background

The aim of this study was to evaluate the efficacy of postoperative radiotherapy (PORT) in stage pIIIA‐N2 non‐small cell lung cancer (NSCLC) patients with positive surgical margins.

Methods

Between January 2003 and December 2015, patients who had undergone lobectomy or pneumonectomy plus mediastinal lymph node dissection or systematic sampling in our single institution were retrospectively reviewed. Those with pIIIA‐N2 NSCLC and positive surgical margins were enrolled into the study. The Kaplan‐Meier method was used for survival analysis, and the log‐rank test was used to analyze differences between the groups. Univariate and multivariate analyses using Cox proportional hazards regression models were performed to evaluate potential prognostic factors for OS. Statistically significant difference was set as P < 0.05.

Results

Of all the 1547 patients with pIIIA‐N2 NSCLC reviewed, 113 patients had positive surgical margins, including 76 patients with R1 resection and 37 with R2 resection. The median overall survival (OS) was 28.3 months in the PORT group and 22.6 months in the non‐PORT group (P = 0.568). Subset analysis showed that for patients with R1 resection, the median OS was 52.4 months in the PORT group which was nonsignificantly longer than that of 22.6 months in the non‐PORT group (P = 0.127), whereas PORT combined with chemotherapy could significantly improve OS, with a median OS of 52.4 months versus 17.2 months (P = 0.027). For patients with R2 resection, PORT made no significant difference in OS (17.6 vs. 63.8 months, P = 0.529).

Conclusions

For pIIIA‐N2 NSCLC patients with positive surgical margins, PORT did not improve OS, but OS was improved in those patients who underwent R1 resection combined with chemotherapy.

Key points

Significant findings of the study

Significant findings of the study: Postoperative radiotherapy (PORT) has been recommended to treat patients with positive surgical margins. However, the existing evidence is controversial and high‐level evidence is lacking.

What this study adds

What this study adds: The PORT group had markedly, but not statistically significant, longer median OS compared with the non‐PORT group in patients with R1 resection. OS was significantly longer in the patients with R1 resection receiving adjuvant CRT than the surgery alone group.

The Dosimetric Comparisons of CRT, IMRT, ARC, CRT+IMRT, and CRT+ARC of Postoperative Radiotherapy in IIIA-N2 Stage Non-Small-Cell Lung Cancer Patients

Currently, studies about PORT in stage IIIA-N2 NSCLC patients in recent years have mostly adopted the conformal radiation therapy (CRT) technique, while other modern techniques such as intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT, hereinafter referred to as ARC), helical tomotherapy (HT), and so forth are also developing quickly. In this paper, we intended to compare the dosimetric characteristics of CRT, IMRT, ARC, CRT+IMRT, and CRT+ARC of PORT in stage IIIA-N2 NSCLC patients. Ten patients with stage IIIA-N2 completely resected NSCLC, whom were treated by PORT in the radiotherapy department of our hospital from January 1, 2017, to January 1, 2018, were randomly selected in this study. For each patient, the CRT plan, IMRT plan, ARC plan, CRT+IMRT plan, and CRT+ARC plan were designed separately on the same set of CT images. The isodose distribution and dose-volume histogram (DVH) of the five plans were compared to determine the dosimetric parameters of the targets, OAR (organs at risk), and the normal tissue (defined as body subtracted to PTV (planning target volume), B-P). No plan had absolute dosimetry advantages than any other plans. In clinical practice, the plans could be chosen according to their dosimetry characteristics.

Postoperative radiotherapy for lung cancer: Is it worth the controversy?

INTRODUCTION

The role of postoperative radiation therapy (PORT) in patients with completely resected non-small cell lung cancer (NSCLC) with pathologically involved mediastinal lymph nodes (N2) remains unclear. Despite a reduction of local recurrence (LR), its effect on overall survival (OS) remains unproven. Therefore we conducted a review of the current literature.

METHODS

To investigate the benefit and safety of modern PORT, we identified published phase III trials for PORT. We investigated modern PORT in low-risk (ypN0/1 and R0) and high-risk (ypN2 and/or R1/2) patients with stage III-N2 NSCLC treated with induction chemotherapy and resection.

RESULTS

Seventeen phase III trials using PORT were selected. Of all PORT N2 studies, 4 were eligible for evaluation of LR, all in high-risk patients only. In these high-risk patients receiving PORT, the mean LR rate at 5years was 20.9% (95% CI 16-24). Two trials were suitable to assess LR rates after chemotherapy and surgery without PORT. In these low-risk patients, the mean 5-year LR was 33.1% (95% CI 27-39). No significant difference in non-cancer deaths between PORT vs. non-PORT patients was observed in N2 NSCLC.

CONCLUSION

PORT is worth the controversy because data illustrate that PORT may increase the OS. However, prospective randomized trials are needed to verify this.

Outcome and prognostic factors of postoperative radiation therapy (PORT) after incomplete resection of non-small cell lung cancer (NSCLC)

PURPOSE

Current guidelines recommend postoperative radiation therapy (PORT) for incompletely resected non-small cell lung cancer (NSCLC). However, there is still a paucity of evidence for this approach. Hence, we analyzed survival in 78 patients following radiotherapy for incompletely resected NSCLC (R1) and investigated prognostic factors.

PATIENTS AND METHODS

All 78 patients with incompletely resected NSCLC (R1) received PORT between December 2001 and September 2014. The median total dose for PORT was 60 Gy (range 44-68 Gy). The majority of patients had locally advanced tumor stages (stage IIA (2.6%), stage IIB (19.2%), stage IIIA (57.7%) and stage IIIB (20.5%)). 21 patients (25%) received postoperative chemotherapy.

RESULTS

Median follow-up after radiotherapy was 17.7 months. Three-year overall (OS), progression-free (PFS), local (LPFS) and distant progression-free survival (DPFS) rates were 34.1, 29.1, 44.9 and 51.9%, respectively. OS was significantly prolonged at lower nodal status (pN0/1) and following dose-escalated PORT with total radiation doses >54 Gy (p=0.012, p=0.013). Furthermore, radiation doses >54 Gy significantly improved PFS, LPFS and DPFS (p=0.005; p=0.050, p=0.022). Interestingly, survival was neither significantly influenced by R1 localization nor by extent (localized vs. diffuse). Multivariate analyses revealed lower nodal status and radiation doses >54.0 Gy as the only independent prognostic factors for OS (p=0.021, p=0.036).

CONCLUSION

For incompletely resected NSCLC, PORT is used for improving local tumor control. Local progression is still the major pattern of failure. Radiation doses >54 Gy seem to support improved local control and were associated with better OS in this retrospective study.

Postoperative Radiation Therapy Is Associated With Improved Overall Survival in Incompletely Resected Stage II and III Non-Small-Cell Lung Cancer

PURPOSE

To review trends in the use of postoperative radiotherapy (PORT) for stage II and III incompletely resected non-small-cell lung cancer (NSCLC) and evaluate the association between PORT and survival in such patients.

PATIENTS AND METHODS

We identified patients with pathologic stage N0-2, overall American Joint Committee on Cancer stage II or III NSCLC within the National Cancer Data Base who had undergone a lobectomy or pneumonectomy with positive surgical margins. Only patients coded as receiving external-beam PORT at 50 to 74 Gy or observation were included. To account for perioperative mortality, we excluded patients who survived less than 4 months after diagnosis. Multivariable logistic regression was used to determine factors associated with PORT receipt. Cox proportional hazards regression was performed for multivariable analyses of overall survival.

RESULTS

Among 3,395 included patients, 1,207 (35.6%) received PORT. Predictors for the use of PORT among this patient population included age less than 60 years, treatment in a nonacademic facility, earlier year of diagnosis, decreased travel distance, lower nodal stage, and chemotherapy receipt. On multivariable analysis adjusting for demographic and clinicopathologic covariates, PORT (hazard ratio, 0.80; 95% CI, 0.70 to 092) was associated with improved survival. Subset analysis by nodal stage showed that PORT improved survival across all nodal stages.

CONCLUSION

PORT is associated with improved overall survival in patients with incompletely resected stage II or III N0-2 NSCLC. The use of PORT for this population in more recent years has been declining. In the absence of randomized trials evaluating PORT utilization for this patient population, our findings strongly support the delivery of PORT in patients with incompletely resected NSCLC.

Postoperative radiation therapy following the incomplete resection of a non-small cell lung cancer

Purpose

To review the results of postoperative radiation therapy (PORT) for residual non-small cell lung cancer (NSCLC) following surgical resection and evaluate multiple clinicopathologic prognostic factors.

Materials and Methods

A total of 58 patients, who completed scheduled PORT for positive resection margin, among 658 patients treated with PORT from January 2001 to November 2011 were retrospectively analyzed. Radiation therapy was started at 4 to 6 weeks after surgery. Chemotherapy was also administered to 35 patients, either sequentially or concurrently with PORT.

Results

The median age of patients was 63 years (range, 40 to 82 years). The postoperative pathological stage I NSCLC was diagnosed in 10 (17.2%), stage II in 18 (31.0%), and stage III in 30 patients (51.7%). Squamous cell carcinoma was identified in 43, adenocarcinoma in 10, large cell in 1, others in 4 patients. Microscopic residual disease (R1) was diagnosed in 55 patients (94.8%), and the remaining three patients were diagnosed with gross residual disease (R2). The median dose of PORT was 59.4 Gy (range, 50.0 to 64.8 Gy). Chemotherapy was administered to 35 patients (60%), and the median follow-up time was 22.0 months (range, 6.0 to 84.0 months). The 3-year locoregional relapse-free survival and distant metastasis-free survival rates were 82.1% and 52.9%, respectively. The median overall survival was 23.8 months (range, 6.0 to 84.1 months), and the 3-year overall survival rate was 58.2%. Chemotherapy did not influence the failure pattern or survival outcome.

Conclusion

PORT is an effective modality for improving local tumor control in incompletely resected NSCLC patients. Major failure pattern was distant metastasis despite chemotherapy.

Analysis of the surgical treatment for superior sulcus tumors

PURPOSE

This study was undertaken to assess the mortality, complication, and major morbidity rates of surgical treatment for superior sulcus tumors (SSTs), and to estimate the significance of prognostic factors.

METHODS

We retrospectively reviewed the hospital records of 50 consecutive patients undergoing surgical treatment for SSTs between 1992 and 2007. The significance of risk factors for an adverse outcome was investigated.

RESULTS

Both the thirty-day and in-hospital mortality rates were 0 %. Complications developed in 18.0 % (9/50) of the patients. The overall 5-year survival was 32.7 %. Pathological T4 and N1 or more were the risk factors predicting an adverse outcome. Survival was not significantly influenced by the preoperative symptoms, the histological type, the invaded organ or the curability.

CONCLUSION

Surgical treatment for SSTs is associated with acceptable overall morbidity and mortality rates. However, special care must be taken for the patients with pathological T4 and N1 or higher tumors. Preoperative chemoradiotherapy followed by surgical treatment has become a logical strategy for SSTs. Preoperative chemoradiotherapy for SSTs may yield better results than surgery alone.