Once-daily radiotherapy to > or =59.4 Gy versus twice-daily radiotherapy to > or =45.0 Gy with concurrent chemotherapy for limited-stage small-cell lung cancer: a comparative analysis of toxicities and outcomes

Outcome of dose-escalated intensity-modulated radiotherapy for limited disease small cell lung cancer

PURPOSE

An optimal once-daily radiotherapy (RT) regimen is under investigation for definitive concurrent chemoradiotherapy (CCRT) in limited disease small cell lung cancer (LD-SCLC). We compared the efficacy and safety of dose escalation with intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Between January 2016 and March 2021, patients treated with definitive CCRT for LD-SCLC with IMRT were retrospectively reviewed. Patients who received a total dose <50 Gy or those with a history of thoracic RT or surgery were excluded. The patients were divided into two groups (standard and dose-escalated) based on the total biologically effective dose (BED, α/β = 10) of 70 Gy. The chemotherapeutic regimen comprised four cycles of etoposide and cisplatin.

RESULTS

One hundred and twenty-two patients were analyzed and the median follow-up was 27.8 months (range, 4.4 to 76.9 months). The median age of the patients was 63 years (range, 35 to 78 years) and the majority had a history of smoking (86.0%). The 1- and 3-year overall survival rates of the escalated dose group were significantly higher than those of the standard group (93.5% and 50.5% vs. 76.7% and 33.3%, respectively; p = 0.008), as were the 1- and 3-year freedom from in-field failure rates (91.4% and 66.5% vs. 73.8% and 46.9%, respectively; p = 0.018). The incidence of grade 2 or higher acute and late pneumonitis was not significantly different between the two groups (p = 0.062, 0.185).

CONCLUSION

Dose-escalated once-daily CCRT with IMRT led to improved locoregional control and survival, with no increase in toxicity.

Analysis of Once-Daily Thoracic Radiotherapy Dose According to the Underlying Lung Disease in Patients with Limited-Stage Small Cell Lung Cancer Undergoing Concurrent Chemoradiotherapy

PURPOSE

In the treatment of concurrent chemoradiotherapy (CCRT) in limited-stage small cell lung cancer, the optimal once-daily radiotherapy (RT) dose/fractionation remain unclear although it is the most frequently used. Therefore, this study aimed to compare the treatment outcomes and toxicities of modest dose RT (≤ 54 Gy) with those of standard dose RT (> 54 Gy) and investigate the benefit of the high dose based on patient factors.

MATERIALS AND METHODS

Since 2004, our institution has gradually increased the thoracic RT dose. Among the 225 patients who underwent CCRT, 84 patients (37.3%) received > 54 Gy. Because the patients treated with RT > 54 Gy were not randomly assigned, propensity score matching (PSM) was performed.

RESULTS

The proportion of patients treated with > 54 Gy increased over time (p=0.014). Multivariate analysis revealed that the overall tumor stage and dose > 54 Gy (hazard ratio, 0.65; p=0.029) were independent prognostic factors for overall survival (OS). PSM confirmed that thoracic RT doses of > 54 Gy showed significantly improved progression-free survival (3-year, 42.7% vs. 24.0%; p < 0.001) and OS (3-year, 56.2% vs. 38.5%; p=0.003). Sensitivity analysis also showed that 60 Gy resulted in better survival than 54 Gy. However, in patients with underlying lung disease, OS benefit from > 54 Gy was not observed but considerable rates of severe pulmonary toxicities were observed (p=0.001).

CONCLUSION

Our analysis supports that the 60 Gy RT dose should be considered in the once-daily regimen of CCRT for limited-stage small cell lung cancer without underlying lung disease, but RT dose > 54 Gy did not seem to benefit for patients with chronic obstructive pulmonary disease or interstitial lung disease. Further study is needed to validate these results.

Comparative effectiveness and toxicity of radiotherapy regimens in limited stage small cell lung cancer: A network meta-analysis

PURPOSE

The aim of this Network Meta-analysis was to compare the current radiotherapy regimens of limited-stage small cell lung cancer (LS-SCLC), in terms of overall survival (OS), progression-free survival (PFS), and the incidence of acute radioactive esophagitis and radioactive pneumonia.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were comprehensively searched until January 2022. The studies were included, comparing radiotherapy regimens in LS-SCLC patients. We compared hypofractionated radiotherapy (HypoTRT), hyperfractionated radiotherapy (HyperTRT), and conventionally fractionated radiotherapy (ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy)).

RESULTS

There was similar efficacy among the contemporary radiotherapy regimens for PFS of LS-SCLC. HypoTRT and HyperTRT significantly improved the OS of LS-SCLC compared with ConvTRT1 (<60 Gy), while not improving the OS of LS-SCLC compared with ConvTRT2 (≥60 Gy). There was no significant difference between HypoTRT and HyperTRT, between ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy), respectively. HyperTRT developed the highest odds of acute radioactive esophagitis compared to ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy). There was no significant difference in the incidence of acute radioactive esophagitis between HypoTRT and HyperTRT, ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy), respectively and between ConvTRT1 and ConvTRT2. There was no statistically significant difference among radiotherapy regimens for the incidence of acute radioactive pneumonia.

CONCLUSION

The current radiotherapy regimens are similar in efficacy and toxicity for LS-SCLC, except for ConvTRT1(<60 Gy). Given the lower costs and convenient logistics management of HypoTRT comparatively, it is an acceptable alternative for LS-SCLC.

Twice-daily vs higher-dose once-daily thoracic radiotherapy for limited-disease small-cell lung cancer: A PRISMA-compliant meta-analysis

INTRODUCTION

The optimal dose and fractionation of thoracic radiotherapy (RT) for limited-disease small-cell lung cancer (LD-SCLC) remain controversial. This meta-analysis was performed to compare the efficacy and RT toxicity between twice-daily thoracic RT (45 Gy with 1.5 Gy twice daily) and higher-dose once-daily RT (60-72 Gy with 1.8 Gy/2 Gy once daily) administered with chemotherapy in LD-SCLC patients.

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library were searched up to March 19, 2020 for studies that compared twice-daily thoracic RT (45 Gy with 1.5 Gy twice daily over 3 weeks) with higher-dose once-daily RT (60-72 Gy with 1.8 Gy/2 Gy once daily over 6-8 weeks) in LD-SCLC patients.

RESULTS

Five studies involving 13,726 patients were included in this analysis. Compared with the once-daily thoracic RT group, the 1-year overall survival (OS) rate (P < .001), the 2-year OS rate (P < .001), the 5-year OS rate (P < .001), the mOS (P < .001), and the 1-year LRFS rate (P = .048) were significantly improved in the twice-daily RT group. The toxic effects of RT (esophagitis: P = .293; pneumonitis: P = .103) were similar in both groups.

CONCLUSION

Compared with the higher-dose once-daily regimen, the twice-daily thoracic radiotherapy regimen improved efficacy but did not increase RT toxicity in LD-SCLC patients.

Long-term outcome comparison for standard fractionation (>59 Gy) versus hyperfractionated (>45 Gy) radiotherapy plus concurrent chemotherapy for limited-stage small-cell lung cancer

Background

Concurrent chemoradiotherapy (CCRT) is commonly employed in limited-stage small-cell lung cancer (LS-SCLC); however, the optimal radiotherapy regimen is still unknown. This 3-institution analysis compares long-term disease control and survival outcomes for once- (QD) versus twice-daily (BID) radiotherapy at contemporary doses.

Methods and Materials

Data were collected for LS-SCLC patients treated with platinum-based CCRT and planned RT doses of >5940 cGy at >180 cGy QD or >4500 cGy at 150 cGy BID. Comparative outcome analyses were performed for treatment groups.

Results

From 2005 through 2014, 132 patients met inclusion criteria for analysis (80 QD, 52 BID). Treatment groups were well-balanced, excepting higher rate of advanced mediastinal staging, longer interval from biopsy to treatment initiation, and lower rate of prophylactic cranial irradiation for the QD group, as well as institutional practice variation. At median survivor follow-up of 33.5 months (range, 4.6-105.8), 80 patients experienced disease failure (44 QD, 36 BID), and 106 died (62 QD, 44 BID). No differences in disease control or survival were demonstrated between treatment groups.

Conclusion

The present analysis did not detect a difference in disease control or survival outcomes for contemporary dose QD versus BID CCRT in LS-SCLC.

Comparing Treatment Strategies for Stage I Small-cell lung Cancer

INTRODUCTION

The diagnosis of stage I small-cell lung cancer (SCLC) is increasing in incidence with the advent of low-dose screening computed tomography. Surgery is considered the standard of care but there are very few data to guide clinical decision-making. The purpose of this study was to compare outcomes for patients receiving definitive surgery, stereotactic body radiation therapy (SBRT), or external beam radiation therapy (EBRT) for stage I SCLC.

PATIENTS AND METHODS

Patients with a primary diagnosis of stage I SCLC were identified in the National Cancer Database. Patients were defined as having a first course of treatment of either surgery, EBRT, or SBRT. Overall survival (OS) was determined using the Kaplan-Meier method and Cox proportional hazards regression methods were used to estimate risk of overall mortality.

RESULTS

A total of 2678 patients were included in the analysis. The 2- and 3-year OS for the whole cohort was 62% and 50%. Comparing treatment strategies in a multivariate model, surgical resection showed improved OS over EBRT (P < .001) and SBRT (P < .001), however, the OS benefit over SBRT did not persist for patients who underwent limited resection. When excluding patients who underwent surgery, SBRT showed improved OS compared with EBRT (P = .04). Additional use of chemotherapy with any treatment modality resulted in improved OS (P < .001).

CONCLUSION

In this hospital-based registry study, definitive surgical resection and use of chemotherapy resulted in improved survival for patients with early stage SCLC. For patients who are not candidates for surgery, SBRT may offer a survival benefit compared with standard EBRT.

Hypo- or conventionally fractionated radiotherapy combined with chemotherapy in patients with limited stage small cell lung cancer

BACKGROUND

Previous data from our institution showed that hypofractionated thoracic radiotherapy (HypoTRT) with concurrent etoposide/platinum chemotherapy yielded favorable survival in patients with limited-stage small cell lung cancer (LS-SCLC). The present study retrospectively compared the survival outcomes, failure patterns and toxicities between groups of LS-SCLC patients treated with conventionally fractionated thoracic radiotherapy (ConvTRT) or HypoTRT combined with chemotherapy.

METHODS

Medical records of LS-SCLC patients between January 2010 and December 2013 at Fudan University Shanghai Cancer Center were retrospectively reviewed. All patients treated with chemotherapy and ConvTRT (2 Gy per fraction daily, DT ≥ 56 Gy) or HypoTRT (2.5 Gy per fraction daily, DT = 55 Gy) were eligible for analysis. Progression-free survival (PFS) and overall survival (OS) were generated for different populations using the Kaplan-Meier method and compared using the log-rank test. Comparisons of failure patterns and toxicity were analyzed using the χ 2 test.

RESULTS

A total of 170 patients treated with HypoTRT (n = 69) or ConvTRT (n = 101) were eligible for analysis. The median PFS and OS were 13.7 and 25.3 months, respectively, in the ConvTRT cohort, which was similar to the HypoTRT cohort (PFS 18.2 months, p = 0.991, and OS 27.2 months, p = 0.698), with a median follow-up of 30 months. Multivariate analysis revealed that PCI and TNM stage were prognostic factors for PFS and that PCI was prognostic for OS. The patterns of failure (stratified by local-regional recurrence, distant metastasis or both as first relapse) were similar between the dose cohorts (p = 0.693, p = 0.330, p = 0.572). Distant metastasis remained the main failure pattern. The brain was the most frequent remote failure site, followed by bone, liver and adrenal gland. PCI improved the 2-year survival rate from 46.1% to 70.0% and the 2-year PFS rate from 20.9% to 45.3%, respectively (p < 0.001). Grade ≥3 esophagitis and pneumonitis occurred in 9.9% and 11.9%, respectively, of the patients in the ConvTRT cohort and in 11.6% and 10.0%, respectively, of those in the HypoTRT cohort (p = 0.815).

CONCLUSION

This retrospective analysis demonstrated that HypoTRT or ConvTRT combined with etoposide/platinum chemotherapy yielded statistically similar survival, treatment failure outcomes, and toxicity profiles. PCI correlated with improved PFS and OS.

Once Daily High-dose Radiation (≥60 Gy) Treatment in Limited Stage Small Cell Lung Cancer

BACKGROUND

To investigate outcomes and prognostic factors in patients treated with once daily high-dose (≥60 Gy) radiation therapy (HDRT) and concurrent platinum-based chemotherapy in limited stage small cell lung cancer (LS-SCLC). While we await current phase III trials to determine optimal radiation dose fractionation schemes in LS-SCLC, we report our experience in LS-SCLC with once daily HDRT. We hypothesized that HDRT would achieve similar efficacy and tolerability as twice daily therapy.

METHODS

We conducted a single institution retrospective review of all patients with LS-SCLC who underwent curative intent treatment from 2005-2013. Patients treated with HDRT (≥60 Gy) and concurrent chemotherapy (cisplatin or carboplatin and etoposide) were included in our analysis. Clinicopathologic variables assessed include gender, performance status, time to treatment, response to treatment, toxicity, volumetric tumor response at 3 months, and use of prophylactic cranial irradiation (PCI).

RESULTS

42 patients with LS-SCLC who initiated concurrent chemoradiation from 2005 to 2013 were included in the analysis. 38 patients (90%) completed definitive treatment to the lung; 16 (38%) also completed PCI. Median failure free survival (FFS) and overall survival (OS) were 11.9 and 23.1 months, respectively. Two-year and 5-year OS rates were 47% (CI=30-62%) and 21% (CI=7-38%), respectively. On univariate analysis, PCI was associated with improved FFS but this was not significant (p=0.18). Gender was the only co-variate significantly associated with statistical differences in FFS (p=0.03) and OS (p=0.02). Grade 3 and 4 esophagitis were 10.5% and 2.6%, respectively. Pre-HDRT tumor volume and 3-month post-treatment tumor volume were both associated with FFS (p<0.01) but not OS.

CONCLUSIONS

In this single institution series, daily HDRT demonstrated a 2-year OS of 47% in LS-SCLC. This compares well to the historical survival of daily fractionation (47%) from INT 0096 reported by Turrisi et. al. Male gender was predictive of significantly worse FFS and OS. Once daily HDRT has similar OS to twice-daily radiation schemes; however, further studies assessing once daily HDRT for LS-SCLC are warranted.

Efficacy of 3D conformal thoracic radiotherapy for extensive-stage small-cell lung cancer: A retrospective study

The aim of the present study was to evaluate the effect of 3-dimensional conformal thoracic radiotherapy (TRT) on extensive-stage small-cell lung cancer (ES-SCLC). A total of 165 patients with ES-SCLC were enrolled in the present study, including 82 patients receiving chemotherapy combined with TRT (the ChT/TRT group) and 83 patients receiving chemotherapy alone (the ChT group). The overall survival (OS) and progression-free survival (PFS) rates were compared between the ChT/TRT and ChT groups, and the prognostic factors for OS rate were identified. It was found that the patients had a median OS time of 15 months, and 2- and 5-year OS rates of 31.5 and 2.4%, respectively. The 2- and 5-year OS rates were 35.3 and 2.4% in the ChT/TRT group, and 14.5 and 2.4% in the ChT group, respectively (P<0.05). The 1- and 2-year PFS rates were 35.4 and 6.0% in the ChT/TRT group, and 20.5 and 6.0% in the ChT group, respectively (P<0.05). The median PFS was 11 months in the 20 patients receiving TRT at 45 Gy/30 fractions twice daily, and 9 months in the 22 patients receiving TRT at 60 Gy/30 fractions daily (P=0.043). Multivariate analysis revealed that receiving ≥4 cycles of chemotherapy (P=0.001) and TRT (P=0.008) were favorable prognostic factors for OS. It was concluded that the addition of TRT improves the OS and PFS rates of patients with ES-SCLC, and TRT administration at 45 Gy/30 fractions twice daily is feasible and tolerable for the treatment of ES-SCLC. Thus, TRT and receiving ≥4 cycles of chemotherapy are independent, favorable prognostic factors for OS in patients with ES-SCLC.

Comparison of once daily radiotherapy to 60 Gy and twice daily radiotherapy to 45 Gy for limited stage small-cell lung cancer

Background

This study was designed to compare toxicities, disease control, and survival outcomes for limited disease small-cell lung cancer (LD-SCLC) treated with once daily (QD) versus twice daily (BID) radiotherapy.

Methods

All of the patients received four to six cycles of platinum plus etoposide. In the QD group, irradiation was given via conventional radiotherapy with a dose of 60 Gy at 2 Gy per once-daily fraction. In the BID group, the dose was 45 Gy at 1.5 Gy per twice-daily fraction.

Results

Data from a total of 143 LD-SCLC patients treated at the Shandong Cancer Hospital & Institute were retrospectively analyzed. Statistically significant differences were found in the rates of both grade 2 or higher esophagitis (P = 0.036) and pneumonitis (P = 0.043) between QD and BID groups, respectively. Grade 3 esophagitis occurred in 6% of patients receiving QD and 19% of those receiving BID therapy. The median overall survival (OS) of all patients was 30.4 months: 29.5 months for QD therapy, and 31.4 months for BID therapy. The two-year OS rate was 43.3% for QD therapy, and 48.8% for BID therapy. The two-year locoregional recurrence-free survival (LRFS) rate was 45% versus 63.4% for the QD group versus the BID group, respectively.

Conclusions

Pneumonitis was more common in the QD group, and esophagitis was more common in the BID group. Although there were no significant differences in OS and LRFS between the QD and BID groups, there was a trend toward improved local control in the BID group.

A pooled analysis of limited-stage small-cell lung cancer patients treated with induction chemotherapy followed by concurrent platinum-based chemotherapy and 70 Gy daily radiotherapy: CALGB 30904

INTRODUCTION

Standard therapy for limited-stage small-cell lung cancer (L-SCLC) is concurrent chemotherapy and radiotherapy (RT) followed by prophylactic cranial radiotherapy. Although many consider the standard RT regimen to be 45 Gy in 1.5 Gy twice-daily fractions, this has failed to gain widespread acceptance. We pooled data of patients assigned to receive daily RT of 70 Gy from three, consecutive prospective Cancer and Leukemia Group B L-SCLC cancer trials and report the results here.

METHODS

All patients from consecutive Cancer and Leukemia Group B L-SCLC trials (39808, 30002, and 30206) using high-dosage daily RT with concurrent chemotherapy were included, and analyzed for toxicity, disease control, and survival. Overall survival (OS) and progression-free survival (PFS) were modeled using Cox proportional hazards models. Prognostic variables for OS-rate and PFS-rate were assessed using logistic regression model.

RESULTS

Two hundred patients were included. The median follow-up was 78 months. Grade 3 or greater esophagitis was 23%. The median OS for pooled population was 19.9 months (95% confidence interval [CI]: 16.7-22.3), and 5-year OS rate was 20% (95% CI: 16-27%). The 2-year PFS was 26% (95% CI: 21-32%). Multivariate analysis found younger age (p = 0.02; hazard ratio [HR]: 1.023; 95% CI: 21-32), and female sex (p = 0.02; HR:0.69; 95% CI: 0.50-0.94) independently associated with improved overall survival.

CONCLUSION

Two-Gy daily RT to a total dosage of 70 Gy was well tolerated with similar survival to 45 Gy (1.5 Gy twice-daily). This experience may aid practitioners decide whether high-dosage daily RT with platinum-based chemotherapy is appropriate outside of a clinical trial.

Does routine clinical practice reproduce the outcome of large prospective trials? The analysis of institutional database on patients with limited-disease small-cell lung cancer

We performed the analysis of database on 409 patients with LD-SCLC to evaluate as to what extent the clinical outcome of large prospective trials was reproduced in routine practice. The analysis has shown that the hazard rate of death in the absence of prophylactic cranial irradiation (PCI) adjusted for the effects of confounding factors, appeared larger than that reported in the trials on PCI in LD-SCLC, and was comparable to that estimated for extensive disease. Less intense routine staging procedures, compared to the trial settings, contributed for such outcome. Hyperfractionated thoracic radiotherapy provided survival advantage similar to that reported in the literature.

Timing of Failure in Limited Disease (Stage I-III) Small-Cell Lung Cancer Patients Treated with Chemoradiotherapy: A Retrospective Analysis

Aims and background

Follow-up in limited disease (stage I-III) small cell lung cancer could be further optimized by assessment of the temporal and locational distribution of treatment failure after completion of chemoradiotherapy.

Methods and study design

Follow-up was retrospectively analyzed in 125 limited disease (stage I-III) small cell lung cancer patients with initial performance status WHO <3 who had successfully completed chemoradiotherapy. Thoracic irradiation was applied in the concurrent or sequential mode. Time from initial pathological diagnosis and treatment end to local, distant and brain recurrence was documented.

Results

One- and two-year progression-free survival rates were 50% and 27.2% in patients treated with concurrent and 45.2% and 14.2% in those treated with sequential chemoradiotherapy, respectively. Local relapse was documented in 14% patients treated with concurrent and 16% with sequential chemoradiotherapy. The distant failure rate was 43% in both subgroups. Up to the end of the follow-up period, more patients treated with concurrent chemoradiotherapy had developed brain metastases than those treated sequentially (37% vs 20%, P = 0.049). Median time (in days) to local relapse was 376 and 401 from the initial diagnosis, 200 and 309 from the end of chemotherapy, and 316 and 196 from the end of thoracic irradiation; to distant failure was 275 and 298 from the initial diagnosis, 151 and 157 from the end of chemotherapy and 180 and 84 from the end of thoracic irradiation; to brain relapse was 330 and 273 from the initial diagnosis, 123 and 151 from the end of chemotherapy and 213 and 73 from the end of thoracic irradiation in patients treated with concurrent and sequential chemoradiotherapy, respectively. There was no significant difference in the temporal distribution of treatment failure in either subgroup.

Conclusions

In more than half of the patients who developed a distant recurrence, including brain metastases, treatment failure occurred in the first year after the initial diagnosis. Intensified follow-up can be recommended at least in the first year, because no sufficient eradication of the systemic small cell lung cancer with the applied chemoradiotherapy protocol could be achieved.

Functional promoter rs2868371 variant of HSPB1 associates with radiation-induced esophageal toxicity in patients with non-small-cell lung cancer treated with radio(chemo)therapy

PURPOSE

We investigated the association between single-nucleotide polymorphisms (SNPs) in the heat shock protein beta-1 (HSPB1) gene and the risk of radiation-induced esophageal toxicity (RIET) in patients with non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

The experimental dataset comprised 120 NSCLC patients who were treated with radio(chemo)therapy between 2005 and 2009, when novel radiation techniques were implemented at MD Anderson. The validation dataset comprised 181 NSCLC patients treated between 1998 and 2004. We genotyped two SNPs of the HSPB1 gene (rs2868370 and rs2868371) by TaqMan assay.

RESULTS

Univariate and multivariate analyses of the experimental dataset showed that the CG/GG genotypes of HSPB1 rs2868371 were associated with significantly lower risk of grade ⩾3 RIET than the CC genotype (univariate hazard ratio [HR] 0.30; 95% confidence interval [CI], 0.10-0.91; P=0.033; multivariate HR 0.29; 95% CI, 0.09-0.97; P=0.045). This difference in risk was replicated in the validation cohort despite the different radiation techniques used during that period.

CONCLUSIONS

The CG/GG genotypes of HSPB1 rs2868371 were associated with lower risk of RIET, compared with the CC genotype in patients with NSCLC treated with radio(chemo)therapy. This finding should be validated in large multi-institutional prospective trials.