Relationship Between Radiation Therapy Dose and Outcome in Patients Treated With Neoadjuvant Chemoradiation Therapy and Surgery for Stage IIIA Non-Small Cell Lung Cancer: A Population-Based, Comparative Effectiveness Analysis

Surgical complications and clinical outcomes after dose-escalated trimodality therapy for non-small cell lung cancer in the era of intensity-modulated radiotherapy

BACKGROUND

Trimodality therapy (TMT) with preoperative chemoradiation followed by surgical resection is used for locally-advanced non-small-cell lung cancer (LA-NSCLC). Traditionally, preoperative radiation doses ≤54 Gy are used due to concerns regarding excess morbidity, but little is known about outcomes and toxicities after TMT with intensity-modulated radiotherapy (IMRT) to higher doses.

METHODS

A retrospective analysis of patients who received planned TMT with IMRT for LA-NSCLC at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2008 and 2017 was performed. Clinical and treatment characteristics, pathologic response, and surgical toxicity were assessed. Kaplan-Meier method and log-rank test was used for survival outcomes. Cox proportional-hazards regression was used for multivariable analysis.

RESULTS

Forty-six patients received less than definitive doses of <60 Gy and 30 patients received definitive doses ≥60 Gy. Surgical outcomes, pathologic complete response, and postoperative toxicity did not differ significantly between the groups. With median follow-up of 3.6 years (range: 0.4-11.4), three-year locoregional recurrence-free survival (78.0% vs. 68.3%, p = 0.51) and overall survival (OS) (61.0% vs. 69.4%, p = 0.32) was not significantly different between patients receiving <60 Gy and ≥60 Gy, respectively. On multivariable analysis, older age, clinical stage, and length of hospital stay (LOS) >7 days were associated with OS.

CONCLUSIONS

With IMRT, there was no increased rate of surgical complications in patients receiving higher doses of radiation. Survival outcomes or LOS did not differ based on radiation dose, but increased LOS was associated with worse OS. Larger prospective studies are needed to further examine outcomes after IMRT in patients with LA-NSCLC receiving TMT.

Optimal Radiation Dose for Stage III Lung Cancer-Should "Definitive" Radiation Doses Be Used in the Preoperative Setting?

Introduction

There are currently two recommended radiation strategies for clinical stage III NSCLC: a lower "preoperative" (45-54 Gy) and a higher "definitive/nonsurgical" (60-70 Gy) dose. We sought to determine if definitive radiation doses should be used in the preoperative setting given that many clinical stage III patients planned for surgery are ultimately managed with chemoradiation alone.

Methods

Using the National Cancer Database data from 2006 to 2016, we performed a comparative effectiveness analysis of stage III N2 patients who received chemoradiotherapy. Patients were stratified into subgroups across 2 parameters: (1) radiation dose: lower (45-54 Gy) and higher (60-70 Gy); and (2) the use of surgery (i.e., surgical and nonsurgical treatment approaches). Long-term survival and perioperative outcomes were evaluated using multivariable Cox proportional hazards and logistic regression models.

Results

A cohort of 961 patients received radiation before surgery including 321 who received a higher dose and 640 who received a lower dose. A higher preoperative dose revealed similar long-term mortality risk (hazard ratio = 0.99, 95% confidence interval: 0.82-1.21, p = 0.951) compared with a lower dose. There was no significant association between radiation dose and 90-day mortality (p = 0.982), 30-day readmission (p = 0.931), or prolonged length of stay (p = 0.052) in the surgical cohort. A total of 17,904 clinical-stage IIIA-N2 patients were treated nonsurgically, including 15,945 receiving higher and 1959 treated with a lower dose. A higher dose was associated with a reduction in long-term mortality risk (hazard ratio = 0.64, 95% confidence interval: 0.60-0.67, p < 0.001) compared with a lower dose.

Conclusions

For clinical stage III NSCLC, the administration of 60 to 70 Gy of radiation seems to be more effective than the lower dose for nonsurgical patients without compromising surgical safety for those that undergo resection. This evidence supports the implementation of 60 to 70 Gy as a single-dose strategy for both preoperative and definitive chemoradiotherapy.

Management of Resectable Stage III-N2 Non-Small-Cell Lung Cancer (NSCLC) in the Age of Immunotherapy

Simple Summary

The treatment of resectable stage III non-small-cell lung cancer with N2 lymph node involvement is usually multimodal and is generally based on neoadjuvant chemotherapy +/− radiotherapy followed by surgery, but the cure rate is still low. Immunotherapy based on anti-PD1/PD-L1 immune checkpoint inhibitors has improved survival in advanced and stage III non-resectable NSCLC patients and is being studied in earlier stages to improve the cure rate of lung cancer. In this article, we review all therapeutic approaches to stage III-N2 NSCLC, analysing both completed and ongoing studies that evaluate the addition of immunotherapy with or without chemotherapy and/or radiotherapy.

Abstract

Stage III non-small-cell lung cancer (NSCLC) with N2 lymph node involvement is a heterogeneous group with different potential therapeutic approaches. Patients with potentially resectable III-N2 NSCLC are those who are considered to be able to receive a multimodality treatment that includes tumour resection after neoadjuvant therapy. Current treatment for these patients is based on neoadjuvant chemotherapy +/− radiotherapy followed by surgery and subsequent assessment for adjuvant chemotherapy and/or radiotherapy. In addition, some selected III-N2 patients could receive upfront surgery or pathologic N2 incidental involvement can be found a posteriori during analysis of the surgical specimen. The standard treatment for these patients is adjuvant chemotherapy and evaluation for complementary radiotherapy. Despite being a locally advanced stage, the cure rate for these patients continues to be low, with a broad improvement margin. The most immediate hope for improving survival data and curing these patients relies on integrating immunotherapy into perioperative treatment. Immunotherapy based on anti-PD1/PD-L1 immune checkpoint inhibitors is already a standard treatment in stage III unresectable and advanced NSCLC. Data from the first phase II studies in monotherapy neoadjuvant therapy and, in particular, in combination with chemotherapy, are highly promising, with impressive improved and complete pathological response rates. Despite the lack of confirmatory data from phase III trials and long-term survival data, and in spite of various unresolved questions, immunotherapy will soon be incorporated into the armamentarium for treating stage III-N2 NSCLC. In this article, we review all therapeutic approaches to stage III-N2 NSCLC, analysing both completed and ongoing studies that evaluate the addition of immunotherapy with or without chemotherapy and/or radiotherapy.

Preoperative and postoperative radiotherapy (RT) for non-small cell lung cancer: still an open question

Preoperative and postoperative radiotherapy (PORT) with or without chemotherapy has been used in non-small cell lung cancer (NSCLC) for decades. Numerous trials have investigated the potential survival benefit of this strategy, but despite greater knowledge of the disease, considerable technological developments in imaging and radiotherapy, and significant progress in surgery, many questions remain unsolved. In this review, we summarize the current knowledge on this problem and discuss issues which still require elucidation.

Resection following concurrent chemotherapy and high-dose radiation for stage IIIA non-small cell lung cancer

OBJECTIVE

Concern exists regarding surgery after thoracic radiation. We aimed to assess early results of anatomic resection following induction therapy with platinum-based chemotherapy and full-dose thoracic radiation for resectable N2+ stage IIIA non-small cell lung cancer.

METHODS

Two prospective trials were recently conducted by NRG Oncology in patients with resectable N2+ stage IIIA non-small cell lung cancer with the primary end point of mediastinal node sterilization following concurrent full-dose chemoradiotherapy (Radiation Therapy Oncology Group trials 0229 and 0839). All surgeons demonstrated postinduction resection expertise. Induction consisted of weekly carboplatin (area under the curve, 2.0) and paclitaxel (50 mg/m2) and concurrent thoracic radiation 60 Gy (0839)/61.2 Gy (0229) in 30 fractions. Patients in study 0839 were randomized 2:1 to weekly panitumumab + chemoradiotherapy or chemoradiotherapy alone during induction. Primary results were similar in all treatment arms and reported previously. Short-term surgical outcomes are reported here.

RESULTS

One hundred twenty-six patients enrolled; 93 (74%) had anatomic resection, 77 underwent lobectomy, and 16 underwent extended resection. Microscopically margin-negative resections occurred in 85 (91%). Fourteen (15%) resections were attempted minimally invasively, including 2 converted without event. Grade 3 or 4 surgical adverse events were reported in 26 (28%), 30-day mortality in 4 (4%) and 90-day mortality in 5 (5%). Patients undergoing extended resection experienced similar rates of grade 3 or 4 adverse events (odds ratio, 0.95; 95% confidence interval, 0.42-3.8) but higher 30-day (1.3% vs 18.8%) (odds ratio, 17.54; 95% confidence interval, 1.75-181.8) and 90-day mortality (2.6% vs 18.8%) (odds ratio, 8.65; 95% confidence interval, 1.3-56.9).

CONCLUSIONS

Lobectomy was performed safely following full-dose concurrent chemoradiotherapy in these multi-institutional prospective trials; however, increased mortality was noted with extended resections.

High-dose neoadjuvant chemoradiotherapy versus chemotherapy alone followed by surgery in potentially-resectable stage IIIA-N2 NSCLC. A multi-institutional retrospective study by the Oncologic Group for the Study of Lung Cancer (Spanish Radiation Oncology Society)

Background

The optimal induction treatment in potentially-resectable stage IIIA-N2 NSCLC remains undefined.

Aim

To compare neoadjuvant high-dose chemoradiotherapy (CRT) to neoadjuvant chemotherapy (CHT) in patients with resectable, stage IIIA-N2 non-small-cell lung cancer (NSCLC).

Methods

Retrospective, multicentre study of 99 patients diagnosed with stage cT1-T3N2M0 NSCLC who underwent neoadjuvant treatment (high-dose CRT or CHT) followed by surgery between January 2005 and December 2014.

Results

47 patients (47.5%) underwent CRT and 52 (52.5%) CHT, with a median follow-up of 41 months. Surgery consisted of lobectomy (87.2% and 82.7%, in the CRT and CHT groups, respectively) or pneumonectomy (12.8% vs. 17.3%). Nodal downstaging (to N1/N0) and Pathologic complete response (pCR; pT0pN0) rates were significantly higher in the CRT group (89.4% vs. 57.7% and 46.8% vs. 7.7%, respectively; p < 0.001)). Locoregional recurrence was significantly lower in the CRT group (8.5% vs. 13.5%; p = 0.047) but distant recurrence rates were similar in the two groups. Median PFS was 45 months (CHT) vs. "not reached" (CRT). Median OS was similar: 61 vs. 56 months (p = 0.803). No differences in grade ≥3 toxicity were observed. On the Cox regression analysis, advanced pT stage was associated with worse OS and PFS (p < 0.001) and persistent N2 disease (p = 0.002) was associated with worse PFS.

Conclusions

Compared to neoadjuvant chemotherapy alone, a higher proportion of patients treated with preoperative CRT achieved nodal downstaging and pCR with better locoregional control. However, there were no differences in survival. More studies are needed to know the optimal treatment of these patients.

Multidisciplinary consensus statement on the clinical management of patients with stage III non-small cell lung cancer

Stage III non-small cell lung cancer (NSCLC) is a very heterogeneous disease that encompasses patients with resected, potentially resectable and unresectable tumours. To improve the prognostic capacity of the TNM classification, it has been agreed to divide stage III into sub-stages IIIA, IIIB and IIIC that have very different 5-year survival rates (36, 26 and 13%, respectively). Currently, it is considered that both staging and optimal treatment of stage III NSCLC requires the joint work of a multidisciplinary team of expert physicians within the tumour committee. To improve the care of patients with stage III NSCLC, different scientific societies involved in the diagnosis and treatment of this disease have agreed to issue a series of recommendations that can contribute to homogenise the management of this disease, and ultimately to improve patient care.

Preoperative contralateral lung radiation dose is associated with postoperative pulmonary toxicity in patients with locally advanced non-small cell lung cancer treated with trimodality therapy

PURPOSE

In patients with non-small cell lung cancer (NSCLC) who undergo trimodality therapy (chemoradiation followed by surgical resection), it is unknown whether limiting preoperative radiation dose to the uninvolved lung reduces postsurgical morbidity. This study evaluated whether radiation fall-off dose parameters to the contralateral lung that is unaffected by NSCLC are associated with postoperative complications in NSCLC patients treated with trimodality therapy.

METHODS AND MATERIALS

We retrospectively reviewed NSCLC patients who underwent trimodality therapy between March 2008 and October 2016, with available restored digital radiation plans. Fischer's exact test was used to assess associations between patient and treatment characteristics and the development of treatment-related toxicity. Spearman rank correlation was used to measure the strength of association between dosimetric parameters.

RESULTS

Forty-six patients were identified who received trimodality therapy with intensity modulated radiation (median, 59.4 Gy; range, 45-70) and concurrent platinum doublet chemotherapy, followed by surgical resection. The median age was 64.9 years (range, 45.6-81.6). The median follow-up time was 1.9 years (range, 0.3-8.4). Twenty-four (52.2%) patients developed any-grade pulmonary toxicity and 14 (30.4%) patients developed grade 2+ pulmonary toxicity. There was an increased incidence of any-grade pulmonary toxicity in patients with contralateral lung volume receiving at least 20 Gy (V20) ≥7% compared with <7% (90%, n = 9 vs 41.7%, n = 15; P = .01). Similarly, contralateral lung V10 ≥20% was associated with an increased rate of any-grade pulmonary toxicity compared with V10 <20% (80%, n = 12 vs 38.7%, n = 12; P = .01). Pneumonectomy/bilobectomy was associated with grade 2+ pulmonary toxicity (P = .04).

CONCLUSIONS

Patients who received a higher radiation fall-off dose volume parameter (V20 ≥7% and V10 ≥20%) to the contralateral uninvolved lung had a higher incidence of any-grade postoperative pulmonary toxicity. Limiting radiation fall-off dose to the uninvolved lung may be an important modifiable radiation parameter in limiting postoperative toxicity in trimodality patients.

High-Dose Radiotherapy as Neoadjuvant Treatment in Non-Small-Cell Lung Cancer

BACKGROUND

Trimodality therapy (chemoradiation followed by surgery) provides a benefit in progression-free survival but not overall survival. We sought to determine if a high dose of radiation could be delivered safely and provide a clinical benefit.

METHODS

Consecutive patients with stage IIIA or IIIB non-small-cell lung cancer (NSCLC) treated with concurrent chemoradiotherapy followed by surgery were reviewed with IRB approval.

RESULTS

A total of 48 patients were treated from November 2007 to May 2014. Of these, 64% had stage IIIA disease while 36% had stage IIIB; 46% had adenocarcinoma, 34% squamous, and 23% NSCLC not otherwise specified. The median dose of chemoradiotherapy was 72 Gy (60-72). Overall, 86% of patients received cisplatin (50 mg/m2) and etoposide (50 mg/m2) concurrently with radiotherapy; 72% of patients underwent lobectomy following chemoradiotherapy and 28% underwent pneumonectomy. The 30- and 90-day mortality rates were 0%. The nodal downstaging rate was 82% and there was a 64% rate of pathologic complete response. The overall survival was 29.9 months (95% CI, 19-86 months). The median time to locoregional progression was 35.1 months and the median time to distant progression was 39.3 months. Locoregional failure was 8% and distant failure was 44%.

CONCLUSION

High-dose preoperative chemoradiotherapy was safe and effective. This combination should be further considered.

Neoadjuvant Therapy in Non-Small Cell Lung Cancer

Locally advanced (stage IIIA) non-small cell lung cancer (NSCLC) is confined to the chest, but requires more than surgery to maximize cure. Therapy given preoperatively is termed neoadjuvant, whereas postoperative therapy is termed adjuvant. Trimodality therapy (chemotherapy, radiation, and surgery) has become the standard treatment regimen for resectable, locally advanced NSCLC. During the past 2 decades, several prospective, randomized, and nonrandomized studies have explored various regimens for preoperative treatment of NSCLC. The evaluation of potential candidates with NSCLC for neoadjuvant therapy as well as the currently available therapeutic regimens are reviewed.

Neoadjuvant Chemoradiotherapy vesus Chemotherapy alone Followed by Surgery for Resectable Stage III Non-Small-Cell Lung Cancer: a Meta-Analysis

Neoadjuvant Chemotherapy has been used for the stage III of non-small cell lung cancer (NSCLC) and has shown good clinical effects. However, the survival benefits of radiation therapy added in induction regimens remains controversial. We therefore conducted a meta-analysis of the published clinical trials to quantitatively evaluate the benefit of preoperative chemoradiotherapy. After searching the database of Pubmed, CNKI, EMBASE, ESMO, The Cochrane Library databases, The American Society of Clinical Oncology and Clinical Trials.gov. Trials were selected for meta-analysis if they provided an independent assessment of neoadjuvant chemoradiation and neoadjuvant chemotherapy, odds ratio(OR) for tumor downstaging, mediastinal lymph nodes pathological complete response and local control, hazard ratios (HRs) for 5-year survival and progression-free survival were pooled by the stata software version 12.0. Twelve studies involving 2,724 patients were identified, tumor downstaging (p = 0.01), mediastinal lymph nodes pathological complete responses (p = 0.028) and local control (P = 0.002) were achieved, when compared with neoadjuvant chemotherapy. The meta-analysis demonstrated neither 5-year survival nor progression-free-survival benefit in survival from adding radiation. In conclusion, the addition of radiotherapy into chemotherapy was not superior to neoadjuvant chemotherapy. The higher quality of trials need be investigated combining with the histopathological type and genotyping of lung cancer by clinicians.