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

Population Survival Kinetics Derived from Clinical Trials of Potentially Curable Lung Cancers

Using digitized data from progression-free survival (PFS) and overall survival Kaplan-Meier curves, one can assess population survival kinetics through exponential decay nonlinear regression analyses. To demonstrate their utility, we analyzed PFS curves from published curative-intent trials of non-small cell lung cancer (NSCLC) adjuvant chemotherapy, adjuvant osimertinib in resected EGFR-mutant NSCLC (ADAURA trial), chemoradiotherapy for inoperable NSCLC, and limited small cell lung cancer (SCLC). These analyses permit assessment of log-linear curve shape and estimation of the proportion of patients cured, PFS half-lives for subpopulations destined to eventually relapse, and probability of eventual relapse in patients remaining progression-free at different time points. The proportion of patients potentially cured was 41% for adjuvant controls, 58% with adjuvant chemotherapy, 17% for ADAURA controls, not assessable with adjuvant osimertinib, 15% with chemoradiotherapy, and 12% for SCLC. Median PFS half-life for relapsing subpopulations was 11.9 months for adjuvant controls, 17.4 months with adjuvant chemotherapy, 24.4 months for ADAURA controls, not assessable with osimertinib, 9.3 months with chemoradiotherapy, and 10.7 months for SCLC. For those remaining relapse-free at 2 and 5 years, the cure probability was 74%/96% for adjuvant controls, 77%/93% with adjuvant chemotherapy, 51%/94% with chemoradiation, and 39%/87% with limited SCLC. Relatively easy population kinetic analyses add useful information.

Progression-Free Survival and Time to Progression as Potential Surrogate Endpoints for Overall Survival in Chemoradiotherapy Trials in Limited-Stage Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Purpose

To investigate whether progression-free survival (PFS) or time to progression (TTP) could be a valid surrogate endpoint for overall survival (OS) in patients with limited-stage small-cell lung cancer (LS-SCLC) receiving combined chemoradiotherapy.

Methods

Literature searching was performed in PubMed, Embase, and The Cochrane Library up to 2021. Prediction models were firstly established using data from phase III randomized controlled trials (RCTs) and then externally validated in phase II and retrospective studies. Correlation analysis was evaluated by a weighted linear regression model at both trial and arm levels. Cross-validation was performed to assess the consistency and robustness of the established models.

Results

37 studies, including 15 phase III RCTs, 12 phase II studies, and 10 retrospective studies, were selected in the final analysis. In trial-level surrogacy, a very good correlation was observed between hazard ratios (HRs) of PFS/TTP and OS (R2 = 0.783, 95% CI 0.771–0.794). In arm-level surrogacy, very good correlations were also observed between 2-year (R2 = 0.823, 95% CI 0.814–0.832), 3-year (R2 = 0.843, 95% CI 0.833–0.850), 5-year (R2 = 0.852, 95% CI 0.843–0.859) PFS/TTP, and 5-year OS. An excellent correlation was observed between 4-year PFS/TTP and 5-year OS (R2 = 0.906, 95% CI 0.901–0.910). Cross-validation demonstrated reasonable overall consistency. External validation in phase II and retrospective studies showed good agreement (R2, 0.728–0.824).

Conclusions

PFS/TTP was a valid surrogate endpoint for OS in patients with LS-SCLC receiving combined chemoradiotherapy. The finding provides high-level evidence to support PFS/TTP as the primary endpoint in clinical trials so as to speed up introducing novel agents to the treatment of LS-SCLC.

Moderately Hypofractionated Once-Daily Compared With Twice-Daily Thoracic Radiation Therapy Concurrently With Etoposide and Cisplatin in Limited-Stage Small Cell Lung Cancer: A Multicenter, Phase II, Randomized Trial

PURPOSE

Chemotherapy and concurrent thoracic radiation therapy (CCTRT) followed by prophylactic cranial irradiation (PCI) is the standard of care for limited-stage small cell lung cancer (LS-SCLC). We aimed to compare the efficacy and toxicity of moderately hypofractionated once-daily CCTRT with that of a standard twice-daily regimen.

METHODS AND MATERIALS

This multicenter, phase 2, randomized study enrolled patients aged 18 to 75 years old who had pathologically confirmed LS-SCLC and an Eastern Cooperative Oncology Group performance status of 0 to 1. Eligible patients received 4 to 6 cycles of etoposide-cisplatin chemotherapy and were randomized to receive twice-daily CCTRT at 45 Gray (Gy) in 30 fractions or once-daily CCTRT at 65 Gy in 26 fractions, commencing with cycles 1 to 3 of chemotherapy. PCI was given to good responders. The primary endpoint was progression-free survival (PFS).

RESULTS

The analyses included 182 patients, with 94 in the twice-daily group and 88 in the once-daily group. CCTRT started with cycle 3 of chemotherapy for most patients (80.2%). At a median follow-up of 24.3 months, the median PFS was 13.4 months (95% confidence interval [CI], 10.8-16.0) in the twice-daily group versus 17.2 months (95% CI, 11.8-22.6) in the once-daily group (P = .031), with 2-year PFS rates of 28.4% (95% CI, 18.2-38.6) and 42.3% (95% CI, 31.1-53.5), respectively. The estimated overall survival was 33.6 months in the twice-daily group versus 39.3 months in the once-daily group (P = .137). The median locoregional PFS was 23.9 months in the twice-daily group and was not reached in the once-daily group (P = .017). The incidences of most toxicities were similar in both groups, except for a higher incidence of ≥grade 3 acute lymphopenia in the once-daily group (71.7% vs 40.2% in the twice-daily group; P < .001). There was no difference in the incidences of ≥grade 3 esophagitis (17.4% vs 15.3%, respectively), pneumonitis (3.3% vs 2.4%, respectively) or treatment-related death (2.2% vs 1.2%, respectively) between the once-daily and twice-daily groups.

CONCLUSIONS

Moderately hypofractionated, once-daily CCTRT showed improved PFS and similar toxicities compared with twice-daily CCTRT in LS-SCLC. This regimen should be evaluated for comparison in a phase 3 randomized trial.

Thoracic radiotherapy in small cell lung cancer-a narrative review

Small-cell lung cancer (SCLC) represents 10–15% of all lung cancers and has a poor prognosis. Thoracic radiotherapy plays a central role in current SCLC management. Concurrent chemoradiotherapy (CTRT) is the standard of care for localised disease (stage I−III, limited-stage, LS). Definitive thoracic radiotherapy may be offered in metastatic patients (stage IV, extensive stage, ES-SCLC) after chemotherapy. For LS-SCLC, the gold standard is early accelerated hyperfractionated twice-daily CTRT (4 cycles of cisplatin etoposide, starting with the first or second chemotherapy cycle). Modern radiation techniques should be used with involved-field radiotherapy based on baseline CT and PET/CT scans. In ES-SCLC, thoracic radiotherapy should be discussed in cases of initial bulky mediastinal disease/residual thoracic disease not progressing after induction chemotherapy. This strategy was however not assessed in recent trials establishing chemo-immunotherapy as the standard first line treatment in ES-SCLC. Future developments include technical radiotherapy advances and the incorporation of new drugs. Thoracic irradiation is delivered more precisely given technical developments (IMRT, image-guided radiotherapy, stereotactic radiotherapy), reducing the risks of severe adverse events. Stereotactic ablative radiotherapy may be discussed in rare early stage (T1 to 2, N0) inoperable patients. A number of current clinical trials are investigating immunoradiotherapy. In this review, we highlight the current role of thoracic radiotherapy and describe ongoing research in the integration of biological surrogate markers, advanced radiotherapy technologies and novel drugs in SCLC patients.

Systemic therapy for limited stage small cell lung carcinoma

Systemic treatment in small cell lung carcinoma has been a challenge for oncologists for decades. The high propensity for recurrence is usually due to distant metastasis, which makes systemic treatment an essential component of treatment in small cell lung carcinoma. The regimen of cisplatin and etoposide (established in the mid-1980’s) concurrently with thoracic radiotherapy followed by prophylactic cranial irradiation (PCI) remains the standard of care in limited stage disease. Despite numerous trials, this regimen has not been improved upon. The standard combination regimen of cisplatin and etoposide has been compared to alternative platinum-containing regimens with drugs like epirubicin, irinotecan, paclitaxel, topotecan, pemetrexed, amrubicin and belotecan. Non-platinum containing regimens like ifosfamide and etoposide have also been tested. Attempts to intensify therapy have included the addition of a third drug like paclitaxel, ifosfamide, tirapazamine, tamoxifen, and thalidomide. Maintenance therapy following induction with chemotherapy, vandetanib and interferon-alpha have also been attempted. Molecularly directed targeted therapies and immunotherapeutic agents are areas of active research. In this review, we discuss the various systemic therapy options in limited stage small cell lung carcinoma, from the historical regimens to the modern-day therapy and promising areas of research. We also discuss the role of growth factors, the optimal number of chemotherapy cycles, the use of prognostic and predictive factors, the optimal timing of chemotherapy and the treatment of special populations of patients including older patients, and patients with comorbidities.

Is There a Role for Hypofractionated Thoracic Radiation Therapy in Limited-Stage Small Cell Lung Cancer? A Propensity Score Matched Analysis

Purpose

Various radiation schedules are used in concurrent chemoradiation therapy for limited-stage small cell lung cancer (LS-SCLC). Since there is currently no randomized evidence comparing hypofractionated radiation therapy (HFRT) and conventionally fractionated radiation therapy (CFRT), the aim of this study was to compare overall survival (OS), progression-free survival (PFS), and toxicity of HFRT and CFRT in LS-SCLC.

Methods and Materials

Patients with LS-SCLC treated between 2000 and 2013 with HFRT (40 Gy/15 fractions, 45 Gy/15 fractions, 45 Gy/20 fractions) or CFRT (60 Gy/30 or 66 Gy/33 fractions) were included. Propensity scores were generated using a multivariable logistic regression model. Patients were matched on a 1:1 ratio with a caliper distance of 0.20. OS and PFS were estimated by the Kaplan-Meier method and compared using log-rank tests. As a sensitivity analysis, univariable and multivariable Cox regression was performed including all patients without matching. Logistic regression was performed to identify predictors of pulmonary and esophageal adverse events.

Results

In the overall group of 117 patients, there were significant baseline differences between the HFRT and CFRT cohorts. Patients who received CFRT were older, more often smoked concurrently with treatment, had higher Eastern Cooperative Oncology Group performance status, different T and N stage patterns, and more commonly received concurrent chemoradiation therapy and prophylactic cranial irradiation. After propensity score matching for these differences, 72 patients were included, 36 in the HFRT and CFRT cohorts, respectively. There was no difference in OS (P = .724), PFS (P = .862), or any pulmonary (P = .350) or esophageal (P = .097) adverse events between cohorts. Skin adverse events were significantly higher for CFRT (41.7%) compared with HFRT (16.7%, P = .020). Multivariable Cox regression also revealed no differences in OS (P = .886) or PFS (P = .717) between all HFRT and CFRT patients, without matching. No grade 5 adverse events were observed.

Conclusions

In LS-SCLC patients, HFRT was associated with comparable survival and toxicity outcomes and may be considered as an alternative to CFRT, should its efficacy be confirmed in prospective studies.

A Meta-Analysis of the Efficacy and Toxicity of Twice-Daily vs. Once-Daily Concurrent Chemoradiotherapy for Limited-Stage Small Cell Lung Cancer Based on Randomized Controlled Trials

Background: Currently, the accepted standard management of limited-stage small cell lung cancer (SCLC) is concurrent chemoradiotherapy (CCRT), but the frequency of radiotherapy is controversial. Therefore, this meta-analysis, which compared the efficacy and toxicity between twice-daily (BID) and once-daily (OD) CCRT, was performed to help clinicians make better decisions. Methods: Relevant randomized controlled trials (RCTs) were collected by searching the PubMed, Ovid MEDLINE, Embase, ScienceDirect, Web of Science, the Cochrane Library, Scopus and Google Scholar databases to assess antitumor effects (overall survival, OS; progression-free survival, PFS; overall response rate, ORR) and toxicity (adverse effects, AEs). Results: We screened 1499 articles and included 5 RCTs including 1421 patients. We found that BID CCRT improved OS (hazard ratio, HR = 0.88, 95% confidence interval, CI 0.78-0.99, p = 0.03), the 1-year OS rate (OSR-1y, risk ratio, RR = 1.07, 95%CI 1.01-1.13, p = 0.03), and OSR-4y (RR = 1.22, 95%CI 1.03-1.43, p = 0.02), with better trends in OSR-2y, OSR-3y, and OSR-5y, compared to OD CCRT. In addition, BID CCRT had a higher complete response (CR, RR = 1.31, 95%CI 1.01-1.70, p = 0.04) than OD CCRT. PFS (HR = 0.92, 95%CI 0.79-1.07, p = 0.29), annual PFS rate, ORR (RR = 0.99, 95%CI 0.93-1.05, p = 0.72), and AEs for all grades (RR = 1.00, 95%CI 0.98-1.01, p = 0.57), and grades 3-5 (RR = 1.02, 95%CI 0.95-1.09, p = 0.60) were similar between the two arms. Conclusions: BID CCRT appears to be better than OD CCRT for limited-stage SCLC, with better antitumor effects (OS, OSR, and CR) and similar AEs. However, the high levels of AEs in both arms should be taken as a sign of caution. More large sample and high-quality RCTs need to be conducted to confirm our conclusions.

Treatment time to the end of thoracic radiotherapy has more predictive power for survival than radiation dose intensity in patients with limited-stage small-cell lung cancer receiving concurrent chemoradiation of more than 45 Gy

The optimal protocol for thoracic radiotherapy (TRT) in combination with chemotherapy in patients with limited-stage small-cell lung cancer (LS-SCLC) remains elusive. The present study aimed to evaluate radiation parameters in association with survival outcomes. A total of 101 patients with LS-SCLC who completed TRT at ≥45 Gy and concurrent chemotherapy were retrospectively reviewed. The median dose and duration of TRT were 50 Gy and 38 days, respectively. The median duration from the start of either therapy to the end of TRT (SER) was 60 days. The median survival for all patients was 26.9 months. The 3-year local control (LC), progression-free survival (PFS) and overall survival (OS) rates were 52.0, 29.5 and 37.6%, respectively, and the 5-year LC, PFS and OS rates were 50.1, 28.3 and 26.7%, respectively. Univariate analysis revealed that patient age, tumor stage, timing and dose of TRT, SER, prophylactic cranial irradiation (PCI), and tumor response were significantly associated with treatment outcomes. Multivariate analysis revealed that stage was the only significant prognostic factor for LC (P=0.011), PFS (P<0.001) and OS (P<0.001). Tumor response (P=0.014), PCI (P=0.007) and SER (P=0.005) were significant predictors of OS. OS was improved in patients who achieved complete response, and their SER was ≤70 days (P<0.001). Short treatment duration (SER ≤70 days) was a significant predictor of OS in patients with LS-SCLC who completed planned TRT at ≥45 Gy with concurrent chemoradiotherapy.

Timing of thoracic radiotherapy is more important than dose intensification in patients with limited-stage small cell lung cancer: a parallel comparison of two prospective studies

PURPOSE

The optimal radiotherapy dose/fraction for limited-stage small cell lung cancer (SCLC) is undefined. Our objectives were to compare efficacy between hyperfractionated thoracic radiotherapy (TRT; 1.5 Gy 2 times per day [bid] in 30 fractions) and hypofractionated TRT (2.5 Gy once per day [qd] in 22 fractions), and to explore prognostic factors influencing the prognosis, such as the timing of TRT.

METHODS

Patients enrolled in two independent prospective studies were combined and analyzed. The primary endpoint was local/regional control (LRC). The prognosis was analyzed using the Cox proportional hazards regression model.

RESULTS

Ninety-two and 96 patients were treated with hyperfractionated TRT and hypofractionated TRT, respectively. The 1‑ and 2‑year LRC rates of the two arms were 82.1 and 60.7%, and 84.9 and 68.8% (P = 0.27), respectively. The median overall survival (OS) times (months) were 28.3 (95% confidence interval, CI 16.4-40.1) and 22.0 (95% CI 16.4-27.5), while the 1‑year, 3‑year, and 5‑year OS rates were 85.2, 40.8, and 27.1%, and 76.9, 34.3, and 26.8% (P = 0.37), respectively. Using a multivariate Cox regression study, time (days) from the initiation of chemotherapy to TRT (TCT) ≤43 was associated with improved LRC (hazard radio, HR 0.39, 95% CI 0.20-0.76; P = 0.005). Time (days) from the start of chemotherapy to the end of TRT (SER) ≤63 (HR 0.50, 95% CI 0.32-0.80; P = 0.003) and prophylactic cranial irradiation (HR 0.43; 95% CI 0.29-0.63; P = 0.000) were favorably related to OS. Grade 2/3 acute radiation esophagitis was observed in 37.0 and 17.7% of patients in the hyperfractionated and hypofractionated arms, respectively (P = 0.003).

CONCLUSION

Both hyperfractionated and hypofractionated TRT schedules achieved good LRC and OS for patients with limited-stage SCLC in this study. Keeping TCT ≤43 and SER ≤63 resulted in a better prognosis. The incidence of acute esophagitis was significantly higher in the hyperfractionated arm.

Increasing PET Use in Small Cell Lung Cancer: Survival Improvement and Stage Migration in the VA Central Cancer Registry

Background: Accurate staging for small cell lung cancer (SCLC) is critical for determining appropriate therapy. The clinical impact of increasing PET adoption and stage migration is well described in non-small cell lung cancer but not in SCLC. The objective of this study was to evaluate temporal trends in PET staging and survival in the Veterans Affairs Central Cancer Registry and the impact of PET on outcomes. Patients and Methods: Patients diagnosed with SCLC from 2001 to 2010 were identified. PET staging, overall survival (OS), and lung cancer-specific survival (LCSS) were assessed over time. The impact of PET staging on OS and LCSS was assessed for limited-stage (LS) and extensive-stage (ES) SCLC. Results: From 2001 to 2010, PET use in a total of 10,135 patients with SCLC increased from 1.1% to 39.2%. Median OS improved for all patients (from 6.2 to 7.9 months), those with LS-SCLC (from 10.9 to 13.2 months), and those with ES-SCLC (from 5.0 to 7.0 months). Among staged patients, the proportion of ES-SCLC increased from 63.9% to 65.7%. Among 1,536 patients with LS-SCLC treated with concurrent chemoradiotherapy, 397 were staged by PET. In these patients, PET was associated with longer OS (median, 19.8 vs 14.3 months; hazard ratio [HR], 0.78; 95% CI, 0.68-0.90; P<.0001) and LCSS (median, 22.9 vs 16.7 months; HR, 0.74; 95% CI, 0.63-0.87; P<.0001) with multivariate adjustment and propensity-matching. In the 6,143 patients with ES-SCLC, PET was also associated with improved OS and LCSS. Conclusions: From 2001 to 2010, PET staging increased in this large cohort, with a corresponding relative increase in ES-SCLC. PET was associated with greater OS and LCSS for LS-SCLC and ES-SCLC, likely reflecting stage migration and stage-appropriate therapy. These findings emphasize the importance of PET in SCLC and support its routine use.

A pooled analysis of individual patient data from National Clinical Trials Network clinical trials of concurrent chemoradiotherapy for limited-stage small cell lung cancer in elderly patients versus younger patients

BACKGROUND

Platinum and etoposide with thoracic radiation followed by prophylactic cranial irradiation constitute the standard treatment for limited-stage small cell lung cancer (LS-SCLC). Many patients with LS-SCLC are elderly with comorbidities.

METHODS

Individual patient data were collected from 11 phase 2 or 3 trials for LS-SCLC conducted by the National Clinical Trials Network and activated from 1990 to 2010. The primary endpoint was overall survival (OS); the secondary endpoints were progression-free survival (PFS), the rate of severe adverse events, and off-treatment reasons. The outcomes were compared for patients 70 years old or older (elderly patients) and patients younger than 70 years (younger patients).

RESULTS

Individual patient data from 1049 younger patients (81%) and 254 elderly patients (19%) were analyzed. In the multivariate model, elderly patients, in comparison with younger patients, had worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.18-1.63; median OS for elderly patients, 17.8 months; OS for younger patients, 23.5 months) and worse PFS (HR, 1.19; 95% CI, 1.03-1.39; median PFS for elderly patients, 10.6 months; median PFS for younger patients, 12.3 months). Elderly patients, in comparison with younger patients, experienced more grade 5 adverse events (8% vs 3%; P < .01) and more grade 3 or higher dyspnea (11% vs 7%; P = .03) but less grade 3 or higher esophagitis/dysphagia (14% vs 19%; P = .04) and less grade 3 or higher vomiting (11% vs 17%; P = .01). Elderly patients completed treatment less often, discontinued treatment because of adverse events and patient refusal more frequently, and died during treatment more frequently.

CONCLUSIONS

Elderly patients with LS-SCLC have worse PFS and OS and more difficulty in tolerating therapy. Future trials should incorporate assessments of elderly patients, novel monitoring of adverse events, and more tolerable radiation and systemic therapies.

Impact of radiation dose on concurrent chemoradiotherapy for limited-stage small-cell lung cancer

Purpose

To evaluate clinical outcomes according to radiation dose in patients with limited-stage small-cell lung cancer (LS-SCLC) treated with concurrent chemoradiotherapy (CCRT).

Materials and Methods

From January 2006 to December 2015, 38 patients with LS-SCLC were treated with CCRT with etoposide and cisplatin. Total radiation doses ranged from 45 Gy to 66 Gy (1.8–2 Gy/fraction) and were classified into three groups: 45–54 Gy, 60–63 Gy, and 66 Gy. The impact of radiation dose on survival outcomes were evaluated. Toxicities were evaluated according to the Common Terminology Criteria for Adverse Events version 4.03.

Results

The median follow-up period was 21 months. The 2-year overall survival (OS) and local failure-free survival (LFFS) rates were 45.8% and 67.5%, respectively. The 2-year LFFS rates were 33.3% for 45–54 Gy group, 68.6% for 60–63 Gy group, and 87.1% for 66 Gy group (p = 0.014). In multivariate analysis, radiation dose was a significant factor for LFFS (p = 0.015). Although radiation dose was not a significant factor for OS and disease-free survival (DFS) in multivariate analysis, both OS and DFS of 66 Gy group tended to be better than that of 45–63 Gy group in univariate analysis. However, there were no differences in severe toxicities among three groups.

Conclusion

Higher radiation dose achieved better local control in patients with LS-SCLC treated with CCRT. In addition, a total dose of 66 Gy tended to improve OS and DFS.

Radiation therapy in small cell lung cancer: a national Italian survey

INTRODUCTION

Radiation therapy plays an important role in the management of SCLC both in curative and palliative setting, however, conflicting data from clinical trials incite debate over the appropriate use of radiation therapy regarding prophylactic cranial irradiation (PCI) and/or thoracic consolidative in extensive-stage SCLC (ES-SCLC). This survey is conducted to evaluate the current pattern of care among Italian radiation oncologists.

METHODS

In June 2016, all Italian radiation oncologists were invited to a web-based survey. The survey contained 34 questions regarding the role of RT in SCLC. Questions pertaining the role of RT in the clinical management of both limited-stage (LS) and ES-SCLC were included.

RESULTS

We received 48 responses from Italian radiation oncologists. More than half of respondents had been practicing for more than 10 years after completing residency training and 55% are subspecialists in lung cancer. Preferred management of LS-SCLC favored primary concurrent chemoradiotherapy (89%), even if the 36.9% usually delivered RT during or after the cycle 3 of chemotherapy, due to organizational issues. The most common dose and fractionation schedule in this setting was 60 Gy in 30 once-daily fractions. Furthermore, almost all respondents recommended PCI in patients with LS-SCLC. For ES-SCLC scenario, chemotherapy was defined the standard treatment by all respondents. PCI was recommended in ES-SCLC patients with thoracic complete remission (63% of respondents), with thoracic partial response (45%) and with thoracic stable disease (17%) after first-line chemotherapy. Lastly, the thoracic consolidative RT was recommended by 51% of respondents in patients with ES-SCLC in good response after first-line chemotherapy and a great variability was shown in clinical target volume definition, doses and fractionation schedules.

CONCLUSIONS

Our analysis showed a high adherence to current guidelines among the respondents in regard to chemoradiation approach in LS-SCLC patients and to PCI indications and doses. The great variability in radiation therapy doses and volumes in the thoracic consolidative radiotherapy in ES-SCLC is concerning. Future clinical trials are needed to standardize these treatment approaches to improve treatment outcomes among patients with ES-SCLC.

Thoracic irradiation in 3weeks for limited-stage small cell lung cancer: Is twice a day fractionation really needed?

PURPOSE

Many Canadian institutions treat limited-disease small cell lung cancer with 40Gy in 15 fractions delivered once-a-day in 3weeks concomitantly with chemotherapy. This regimen is convenient and seems to be effective. Here, we report and compare with a literature review the outcomes of patients with limited-stage small cell lung cancer treated in our institution with this hypofractionated regimen.

PATIENTS AND METHODS

From January 2004 to December 2012, patients with limited-stage small cell lung cancer treated curatively with platinum-based chemotherapy and concurrent thoracic radiotherapy at a dose of 40Gy in 16 fractions once-a-day were eligible for this review.

RESULTS

Sixty-eight patients fit the analysis criteria, including ten patients with small pleural effusion. The median age was 66years old. After a median follow-up of 77months for those alive, the median survival was 28months. At 3 and 5years respectively, the locoregional control rates were 67 and 64%, while the overall survival rates were 40 and 35%. Prophylaxis cranial irradiation was delivered to 68% of the patients. Grade 2 and 3 acute esophagitis occurred in respectively 49 and 9% of the patients. There was no grade 4 radiation-induced toxicity. All patients, except for one, completed their thoracic irradiation course without interruption.

CONCLUSION

Once-a-day hypofractionated radiation with concurrent chemotherapy followed by prophylactic cranial irradiation is a practical regimen. Based on our experience and the published literature, it appears to be similarly effective as regimens using twice-daily fractionation in 3weeks, or once-daily in 6 to 7weeks with higher radiotherapy doses. Further prospective comparisons of hypofractionation with the current recommendations are needed.

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 χ² 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.

Duration of Twice-Daily Thoracic Radiotherapy and Time From the Start of Any Treatment to the End of Chest Irradiation as Significant Predictors of Outcomes in Limited-Disease Small-Cell Lung Cancer

BACKGROUND

The hypothesis of this retrospective study was that the duration of twice-daily (BID) thoracic radiotherapy (TRT) and time from the start of any treatment to the end of chest irradiation (SER) would predict outcomes in limited-disease small-cell lung cancer.

MATERIALS AND METHODS

All 81 patients received 45 Gy in 30 fractions BID with a ≥ 6-hour interval and concurrent chemotherapy of platinum and etoposide.

RESULTS

The median radiotherapy duration was 25 days (range, 21-38 days). The 5-year overall survival rates were 26.2% (95% confidence interval [CI], 14.3%-38.0%), and the median survival time was 30 months (95% CI, 15.5-44.5 months). Using multivariate regression analysis, the significant predictors of survival were the sum of the diameters of the primary tumor and metastatic lymph nodes, male gender, age ≥ 60 years, and the duration of BID-TRT (hazard ratio [HR], 1.15; 95% CI, 1.06-1.25; HR, 2.38; 95% CI, 1.13-5.02; HR, 2.38; 95% CI, 1.10-5.17; and HR, 1.08; 95% CI, 1.01-1.15, respectively). A total of 70 of 81 patients (86%) received radiotherapy during the first chemotherapy cycle. The median SER was 29 days (range, 21-109 days). The 5-year local control rate was 48.7% (95% CI, 33.9%-63.6%). The significant predictors of local control were the sum of the diameters of the primary tumor and metastatic lymph nodes, age ≥ 60 years, and SER (HR, 1.18; 95% CI, 1.06-1.31; HR, 4.18; 95% CI, 1.23-14.24; and HR, 1.02; 95% CI, 1-1.04, respectively).

CONCLUSIONS

The duration of BID-TRT and SER were identified as one of the significant predictors of survival and local control in limited-disease small-cell lung cancer treated with concurrent chemoradiotherapy at 45 Gy in 30 fractions, respectively.

[Radiotherapy for small cell lung carcinoma]

Radiotherapy for small cell lung carcinoma has known significant improvements over the past 10 years especially through routine use of PET-CT in the initial work-up and contouring before treatment. Prophylactic cranial irradiation remains a standard of care for locally advanced disease and is a subject of controversy for metastatic disease. A new indication for thoracic radiotherapy may soon arise for metastatic disease, still confirmation studies are ongoing.

Management of small-cell lung cancer with radiotherapy-a pan-Canadian survey of radiation oncologists

BACKGROUND

The management of small-cell lung cancer (sclc) with radiotherapy (rt) varies, with many treatment regimens having been described in the literature. We created a survey to assess patterns of practice and clinical decision-making in the management of sclc by Canadian radiation oncologists (ros).

METHODS

A 35-item survey was sent by e-mail to Canadian ros. The questions investigated the role of rt, the dose and timing of rt, target delineation, and use of prophylactic cranial irradiation (pci) in limited-stage (ls) and extensive-stage (es) sclc.

RESULTS

Responses were received from 52 eligible ros. For ls-sclc, staging (98%) and simulation or dosimetric (96%) computed tomography imaging were key determinants of rt suitability. The most common dose and fractionation schedule was 40-45 Gy in 15 once-daily fractions (40%), with elective nodal irradiation performed by 31% of ros. Preferred management of clinical T1/2aN0 sclc favoured primary chemoradiotherapy (64%). For es-sclc, consolidative thoracic rt was frequently offered (88%), with a preferred dose and fractionation schedule of 30 Gy in 10 once-daily fractions (70%). Extrathoracic consolidative rt would not be offered by 23 ros (44%). Prophylactic cranial irradiation was generally offered in ls-sclc (100%) and es-sclc (98%) after response to initial treatment. Performance status, baseline cognition, and pre-pci brain imaging were important patient factors assessed before an offer of pci.

CONCLUSIONS

Canadian ros show practice variation in sclc management. Future clinical trials and national treatment guidelines might reduce variability in the treatment of early-stage disease, optimization of dose and targeting in ls-sclc, and definition of suitability for pci or consolidative rt.

Increased Biological Effective Dose of Radiation Correlates with Prolonged Survival of Patients with Limited-Stage Small Cell Lung Cancer: A Systematic Review

OBJECTIVE

Thoracic radiotherapy (TRT) is a critical component of the treatment of limited-stage small cell lung cancer (LS-SCLC). However, the optimal radiation dose/fractionation remains elusive. This study reviewed current evidence and explored the dose-response relationship in patients with LS-SCLC who were treated with radiochemotherapy.

MATERIALS AND METHODS

A quantitative analysis was performed through a systematic search of PubMed, Web of Science, and the Cochrane Library. The correlations between the biological effective dose (BED) and median overall survival (mOS), median progression-free survival (mPFS), 1-, 3-, and 5-year overall survival (OS) as well as local relapse (LR) were evaluated.

RESULTS

In all, 2389 patients in 19 trials were included in this study. Among these 19 trials, seven were conducted in Europe, eight were conducted in Asia and four were conducted in the United States. The 19 trials that were included consisted of 29 arms with 24 concurrent and 5 sequential TRT arms. For all included studies, the results showed that a higher BED prolonged the mOS (R2 = 0.198, p<0.001) and the mPFS (R2 = 0.045, p<0.001). The results also showed that increased BED improved the 1-, 3-, and 5-year OS. A 10-Gy increment added a 6.3%, a 5.1% and a 3.7% benefit for the 1-, 3-, and 5-year OS, respectively. Additionally, BED was negatively correlated with LR (R2 = 0.09, p<0.001). A subgroup analysis of concurrent TRT showed that a high BED prolonged the mOS (p<0.001) and the mPFS (p<0.001), improved the 1-, 3-, and 5-year OS (p<0.001) and decreased the rate of LR (p<0.001).

CONCLUSION

This study showed that an increased BED was associated with improved OS, PFS and decreased LR in patients with LS-SCLC who were treated with combined chemoradiotherapy, which indicates that the strategy of radiation dose escalation over a limited time frame is worth exploring in a prospective clinical trial.

Randomized phase II trial comparing twice daily hyperfractionated with once daily hypofractionated thoracic radiotherapy in limited disease small cell lung cancer

BACKGROUND

Concurrent chemotherapy and thoracic radiotherapy (TRT) is recommended for limited disease small cell lung cancer (LD SCLC). Twice daily TRT is well documented, but not universally implemented - probably mainly due to inconvenience and concerns about toxicity. A schedule of three-week hypofractionated TRT is a commonly used alternative. This is the first randomized trial comparing twice daily and hypofractionated TRT in LD SCLC.

MATERIAL AND METHODS

Patients received four courses of cisplatin/etoposide (PE) and were randomized to TRT of 42 Gy in 15 fractions (once daily, OD) or 45 Gy in 30 fractions (twice daily, BID) between the second and third PE course. Good responders received prophylactic cranial irradiation of 30 Gy in 15 fractions.

RESULTS

157 patients were enrolled between May 2005 and January 2011 (OD: n = 84, BID: n = 73). Median age was 63 years, 52% were men, 84% had performance status 0-1, 72% had stage III disease and 11% non-malignant pleural effusion. The treatment arms were well balanced. The response rates were similar (OD: 92%, BID: 88%; p = 0.41), but more BID patients achieved a complete response (OD: 13%, BID: 33%; p = 0.003). There was no difference in one-year progression-free survival (PFS) (OD: 45%, BID: 49%; p = 0.61) or median PFS (OD: 10.2 months, BID: 11.4 months; p = 0.93). The median overall survival in the BID arm was 6.3 months longer (OD: 18.8 months, BID: 25.1 months; p = 0.61). There were no differences in grade 3-4 esophagitis (OD: 31%, BID: 33%, p = 0.80) or pneumonitis (OD: 2%, BID: 3%, p = 1.0). Patients on the BID arm reported slightly more dysphagia at the end of the TRT.

CONCLUSION

There was no difference in severe toxicity between the two TRT schedules. The twice daily schedule resulted in significantly more complete responses and a numerically longer median overall survival, but no firm conclusions about efficacy could be drawn from this phase II trial.

Phase 2 study of accelerated hypofractionated thoracic radiation therapy and concurrent chemotherapy in patients with limited-stage small-cell lung cancer

PURPOSE

To prospectively investigate the efficacy and toxicity of accelerated hypofractionated thoracic radiation therapy (HypoTRT) combined with concurrent chemotherapy in the treatment of limited-stage small-cell lung cancer (LS-SCLC), with the hypothesis that both high radiation dose and short radiation time are important in this setting.

METHODS AND MATERIALS

Patients with previously untreated LS-SCLC, Eastern Cooperative Oncology Group performance status of 0 to 2, and adequate organ function were eligible. HypoTRT of 55 Gy at 2.5 Gy per fraction over 30 days was given on the first day of the second or third cycle of chemotherapy. An etoposide/cisplatin regimen was given to 4 to 6 cycles. Patients who had a good response to initial treatment were offered prophylactic cranial irradiation. The primary endpoint was the 2-year progression-free survival rate.

RESULTS

Fifty-nine patients were enrolled from July 2007 through February 2012 (median age, 58 years; 86% male). The 2-year progression-free survival rate was 49.0% (95% confidence interval [CI] 35.3%-62.7%). Median survival time was 28.5 months (95% CI 9.0-48.0 months); the 2-year overall survival rate was 58.2% (95% CI 44.5%-71.9%). The 2-year local control rate was 76.4% (95% CI 63.7%-89.1%). The severe hematologic toxicities (grade 3 or 4) were leukopenia (32%), neutropenia (25%), and thrombocytopenia (15%). Acute esophagitis and pneumonitis of grade ≥3 occurred in 25% and 10% of the patients, respectively. Thirty-eight patients (64%) received prophylactic cranial irradiation.

CONCLUSION

Our study showed that HypoTRT of 55 Gy at 2.5 Gy per fraction daily concurrently with etoposide/cisplatin chemotherapy has favorable survival and acceptable toxicity. This radiation schedule deserves further investigation in LS-SCLC.

Effect of early chemoradiotherapy in patients with limited stage small cell lung cancer

PURPOSE

We evaluated the effect of early chemoradiotherapy on the treatment of patients with limited stage small cell lung cancer (LS-SCLC).

MATERIALS AND METHODS

Between January 2006 and December 2011, thirty-one patients with histologically proven LS-SCLC who were treated with two cycles of chemotherapy followed by concurrent chemoradiotherapy and consolidation chemotherapy were retrospectively analyzed. The chemotherapy regimen was composed of etoposide and cisplatin. Thoracic radiotherapy consisted of 50 to 60 Gy (median, 54 Gy) given in 5 to 6.5 weeks.

RESULTS

The follow-up period ranged from 5 to 53 months (median, 22 months). After chemoradiotherapy, 35.5% of the patients (11 patients) showed complete response, 61.3% (19 patients) showed partial response, 3.2% (one patient) showed progressive disease, resulting in an overall response rate of 96.8% (30 patients). The 1-, 2-, and 3-year overall survival (OS) rates were 66.5%, 41.0%, and 28.1%, respectively, with a median OS of 21.3 months. The 1-, 2-, and 3-year progression free survival (PFS) rates were 49.8%, 22.8%, and 13.7%, respectively, with median PFS of 12 months. The patterns of failure were: locoregional recurrences in 29.0% (nine patients), distant metastasis in 9.7% (three patients), and both locoregional and distant metastasis in 9.7% (three patients). Grade 3 or 4 toxicities of leukopenia, anemia, and thrombocytopenia were observed in 32.2%, 29.0%, and 25.8%, respectively. Grade 3 radiation esophagitis and radiation pneumonitis were shown in 12.9% and 6.4%, respectively.

CONCLUSION

We conclude that early chemoradiotherapy for LS-SCLC provides feasible and acceptable local control and safety.