Thoracic and elective brain irradiation with concomitant or delayed multiagent chemotherapy in the treatment of localized small cell carcinoma of the lung: a randomized prospective study by the Southeastern Cancer Study Group

Prophylactic cranial irradiation in SCLC

Prophylactic cranial irradiation (PCI) has well established place in therapy for patients with limited-disease small cell lung cancer who responded to treatment. The data from randomized trials document that PCI reduces brain metastases rate from approximately 60% to 30%, and increases 3-year overall survival by approximately 5%. Currently, the dose of 25 Gy in 10 fractions is considered as standard. In attempt to reduce neuropsychological sequelae attributable to PCI hippocampal sparing techniques are employed. The existing studies suggest the benefit of hippocampal sparing in limiting memory and higher neurocognitive function losses, but with a risk of failures in the spared region. Ongoing studies will further validate the role of hippocampal sparing, both in terms of toxicity reduction and metastases prevention. PCI for patients who have undergone resection for stage I small cell lung cancer (SCLC) is not recommended, PCI may be, however, associated with a favourable outcome in SCLC patients who have undergone complete surgery in stages II−III. The role of PCI in extensive-disease (ED) SCLC has been evolving. Most recent evidence indicate that PCI is controversial in ED patients with response to initial chemotherapy and absence of brain metastases confirmed by contrast-enhanced MRI. The patients who do not receive PCI, must, however, receive periodic MRI examination during follow-up, i.e., remain under active surveillance with access to radiotherapy at brain relapse. The assessment of safety and effectiveness of hippocampal-sparing PCI, with or without drug neuroprotection in consideration of diverse combinations of radiotherapy, chemotherapy and immunotherapy create a background for future directions of research.

WITHDRAWN: Cranial irradiation for preventing brain metastases of small cell lung cancer in patients in complete remission

BACKGROUND

Prophylactic cranial irradiation halves the rate of brain metastases in patients with small cell lung cancer. Individual randomized trials conducted on patients in complete remission were unable to clarify whether this treatment improves survival.

OBJECTIVES

This study aims to test whether prophylactic cranial irradiation prolongs survival of patients with small cell lung cancer in complete remission.

SEARCH METHODS

Published and unpublished trials were eligible. Electronic databases (Medline, Cancerlit, Excerpta Medica, Biosis from 1965 to 1998), reference lists of trial publications, review articles and relevant books were used to identify potentially eligible trials. The search was also guided by discussions with investigators and experts, and the examination of meeting proceedings and of the Physician Data Query clinical trial registry.

SELECTION CRITERIA

Randomized trials comparing prophylactic cranial irradiation with no prophylactic cranial irradiation in patients with small cell lung cancer in complete remission.

DATA COLLECTION AND ANALYSIS

Meta-analysis based on updated individual data. The main endpoint was survival.

MAIN RESULTS

Seven trials with a total of 987 participants were included. The relative risk of death in the treatment group compared to the control group was 0.84 (95% confidence interval=0.73 to 0.97, P=0.01), corresponding to a 5.4 percent increase in the 3-year survival rate (from 15.3 percent in the control group to 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased disease-free survival (relative risk=0.75, 95% confidence interval=0.65 to 0.86, P<0.001) and decreased the risk of brain metastases (relative risk=0.46, 95% confidence interval=0.38 to 0.57, P<0.001). Increasing doses of irradiation decreased the risk of brain metastases when four groups (8 Gy, 24-25 Gy, 30 Gy, 36-40 Gy) were analyzed [trend test, P=0.02], but the effect on survival did not differ significantly according to the dose. We found a trend (P=0.01) for a decrease in the brain metastasis risk in favour of earlier administration of cranial irradiation after the initiation of induction treatment.

AUTHORS' CONCLUSIONS

Prophylactic cranial irradiation significantly improves survival and disease-free survival for patients with small cell lung cancer in complete remission. Further clinical trials are needed to confirm the potential greater benefit on brain metastasis rate suggested when cranial irradiation is given earlier or at higher doses.

Prophylactic cranial irradiation in 399 patients with limited-stage small cell lung cancer

The benefit of prophylactic cranial irradiation (PCI) in limited-stage small-cell lung cancer (LS-SCLC) was established in a meta-analysis performed in 1999. Since then, considerable progress has been made in the diagnosis, staging and treatment of LS-SCLC, including chemotherapy and radiotherapy, which led to a longer survival time in patients. Therefore, the magnitude of the benefit of PCI should be re-evaluated. Furthermore, the optimum timing of PCI for LS-SCLC treatment has not been established and more data is required to demonstrate this. In the present retrospective study, the cases of patients that were diagnosed with LS-SCLC between March 2005 and December 2010 were reviewed. The main eligibility criteria of patients were a diagnosis of LS-SCLC and the achievement of a complete response (CR) or near CR subsequent to receiving ≥3 cycles of cisplatin-based chemotherapy, with or without advanced thoracic radiotherapy. Early and late PCI groups were separated using the median time interval between the start of primary chemotherapy and the start of PCI. In total, 80 patients were excluded from the analysis, including 9 patients that developed brain metastases, 2 during primary chemotherapy and 7 during radiotherapy. The remaining 399 patients were deemed eligible. PCI was administered to 185 patients; 92 patients were in the early PCI group and 93 were in the late PCI group. PCI significantly decreased the incidence of brain metastases [P<0.001; HR, 0.24; 95% confidence interval (CI), 0.15-0.39] and improved the overall survival time of the patients (median survival time, 21.5-38.8 months; P<0.001; HR, 0.60; 95% CI, 0.45-0.79). However, no significant difference was identified between the early and late PCI groups, either in the incidence of brain metastases (P=0.875) or the overall survival time (P=0.361). Multivariate analysis revealed that PCI (P=0.004) and thoracic radiotherapy (P=0.023) were the only 2 independent favorable prognostic factors of overall survival time. The present study demonstrates that PCI may be of considerable benefit to increase the survival rate and time of patients, and early PCI is as effective as late PCI. However, the present study recommends that PCI should be offered as soon as primary chemotherapy is completed, since there is a greater risk of developing brain metastases during thoracic radiotherapy.

Does quality of radiation therapy predict outcomes of multicenter cooperative group trials? A literature review

Central review of radiation therapy (RT) delivery within multicenter clinical trials was initiated in the early 1970s in the United States. Early quality assurance publications often focused on metrics related to process, logistics, and timing. Our objective was to review the available evidence supporting correlation of RT quality with clinical outcomes within cooperative group trials. A MEDLINE search was performed to identify multicenter studies that described central subjective assessment of RT protocol compliance (quality). Data abstracted included method of central review, definition of deviations, and clinical outcomes. Seventeen multicenter studies (1980-2012) were identified, plus one Patterns of Care Study. Disease sites were hematologic, head and neck, lung, breast, and pancreas. Between 0 and 97% of treatment plans received an overall grade of acceptable. In 7 trials, failure rates were significantly higher after inadequate versus adequate RT. Five of 9 and 2 of 5 trials reported significantly worse overall and progression-free survival after poor-quality RT, respectively. One reported a significant correlation, and 2 reported nonsignificant trends toward increased toxicity with noncompliant RT. Although more data are required, protocol-compliant RT may decrease failure rates and increase overall survival and likely contributes to the ability of collected data to answer the central trial question.

[Present role of prophylactic cranial irradiation]

Prophylactic cranial irradiation (PCI) plays a role in the management of lung cancer patients, especially small cell lung cancer (SCLC) patients. As multimodality treatments are now able to ensure better local control and a lower rate of extracranial metastases, brain relapse has become a major concern in lung cancer. As survival is poor after development of brain metastases (BM) in spite of specific treatment, PCI has been introduced in the 1970's. PCI has been evaluated in randomized trials in both SCLC and non-small cell lung cancer (NSCLC) to reduce the incidence of BM and possibly increase survival. PCI reduces significantly the BM rate in both limited disease (LD) and extensive disease (ED) SCLC and in non-metastatic NSCLC. Considering SCLC, PCI significantly improves overall survival in LD (from 15 to 20% at 3 years) and ED (from 13 to 27% at 1 year) in patients who respond to first-line treatment; it should thus be part of the standard treatment in all responders in ED and in good responders in LD. No dose-effect relationship for PCI was demonstrated in LD SCLC patients so that the recommended dose is 25 Gy in 10 fractions. In NSCLC, even if the risk of brain dissemination is lower than in SCLC, it has become a challenging issue. Studies have identified subgroups at higher risk of brain failure. There are more local treatment possibilities for BM related to NSCLC, but most BM will eventually recur so that PCI should be reconsidered. Few randomized trials have been performed. Most of them could demonstrate a decreased incidence of BM in patients with PCI, but they were not able to show an effect on survival as they were underpowered. New trials are needed. Among long-term survivors, neuro-cognitive toxicity may be observed. Several approaches are being evaluated to reduce this possible toxicity. PCI has no place for other solid tumours at risk such as HER2+ breast cancer patients.

Omitting elective nodal irradiation and irradiating postinduction versus preinduction chemotherapy tumor extent for limited-stage small cell lung cancer: interim analysis of a prospective randomized noninferiority trial

BACKGROUND

Controversies exist with regard to thoracic radiotherapy volumes for limited-stage small cell lung cancer (SCLC). This study compared locoregional progression and overall survival between limited-stage SCLC patients who received thoracic radiotherapy to different target volumes after induction chemotherapy.

METHODS

Chemotherapy consisted of 6 cycles of etoposide and cisplatin. After 2 cycles of etoposide and cisplatin, patients were randomly assigned to receive thoracic radiotherapy to either the postchemotherapy or prechemotherapy tumor extent as study arm or control. Elective nodal irradiation was omitted for both arms. Forty-five Gy/30Fx/19 days thoracic radiotherapy was administered concurrently with cycle 3 chemotherapy. Prophylactic cranial irradiation was administered to patients who achieved complete remission. An interim analysis was planned when the first 80 patients had been followed for at least 6 months, for consideration of potential inferiority in the study arm.

RESULTS

Forty-two and 43 patients were randomly assigned to a study arm and a control, respectively. The local recurrence rates were 31.6% (12 of 38) and 28.6% (12 of 42), respectively (P = .81). The isolated nodal failure rates were 2.6% (1 of 38) and 2.4% (1 of 42), respectively (P = 1.00). All isolated nodal failure sites were in the ipsilateral supraclavicular fossa. Mediastinal N3 was the only factor to predict isolated nodal failure (P = .004; odds ratio [OR], 29.33; 95% CI, 2.94-292.38). One-year and 3-year overall survival rates were 80.6%, 36.2%, and 78.9%, 36.4%, respectively (P = .54).

CONCLUSIONS

Preliminary results indicated that irradiated postchemotherapy tumor extent and omitted elective nodal irradiation did not decrease locoregional control in the study arm, and the overall survival difference was not statistically significant between the 2 arms. Further investigation is warranted.

[A prospective randomized study of the radiotherapy volume for limited-stage small cell lung cancer: a preliminary report]

BACKGROUND AND OBJECTIVE

Controversies exists with regard to target volumes as far as thoracic radiotherapy (TRT) is concerned in the multimodality treatment for limited-stage small cell lung cancer (LSCLC). The aim of this study is to prospectively compare the local control rate, toxicity profiles, and overall survival (OS) between patients received different target volumes irradiation after induction chemotherapy.

METHODS

LSCLC patients received 2 cycles of etoposide and cisplatin (EP) induction chemotherapy and were randomly assigned to receive TRT to either the post- or pre-chemotherapy tumor extent (GTV-T) as study arm and control arm, CTV-N included the positive nodal drainage area for both arms. One to 2 weeks after induction chemotherapy, 45 Gy/30 Fx/19 d TRT was administered concurrently with the third cycle of EP regimen. After that, additional 3 cycles of EP consolidation were administered. Prophylactic cranial irradiation (PCI) was administered to patients with a complete response.

RESULTS

Thirty-seven and 40 patients were randomly assigned to study arm and control arm. The local recurrence rates were 32.4% and 28.2% respectively (P = 0.80); the isolated nodal failure (INF) rates were 3.0% and 2.6% respectively (P = 0.91); all INF sites were in the ipsilateral supraclavicular fossa. Medastinal N3 disease was the risk factor for INF (P = 0.02, OR = 14.13, 95% CI: 1.47-136.13). During radiotherapy, grade I, II weight loss was observed in 29.4%, 5.9% and 56.4%, 7.7% patients respectively (P = 0.04). Grade 0-I and II-III late pulmonary injury was developed in 97.1%, 2.9% and 86.4%, 15.4% patients respectively (P = 0.07). Median survival time was 22.1 months and 26.9 months respectively. The 1 to 3-year OS were 77.9%, 44.4%, 37.3% and 75.8%, 56.3%, 41.7% respectively (P = 0.79).

CONCLUSIONS

The preliminary results of this study indicate that irradiant the post-chemotherapy tumor extent (GTV-T) and positive nodal drainage area did not decrease local control and overall survival while radiation toxicity was reduced. But the current sample size has not met designed requirements, and further investigation is warranted before final conclusions could be drawn.

Phase I study of hypofractionated dose-escalated thoracic radiotherapy for limited-stage small-cell lung cancer

PURPOSE

To determine the maximal tolerated dose of hypofractionated thoracic radiotherapy with concurrent chemotherapy for limited-stage small-cell lung cancer patients.

METHODS AND MATERIALS

Three radiotherapy regimens were used. Radiotherapy was given in two phases: patients initially received 20 Gy in 10 fractions to gross tumor plus uninvolved mediastinal nodes, followed by a boost to gross disease of 30, 38, or 42 Gy in 15 fractions. Radiotherapy was planned with conformal techniques. All patients received four cycles of cisplatin (25 mg/m2) and etoposide (100 mg/m2) chemotherapy. Radiotherapy commenced with Day 1 of Cycle 2 of chemotherapy. All complete/near-complete responders were offered prophylactic cranial irradiation. The maximal tolerated dose of radiotherapy was based on the dose that caused unacceptably high rates of radiotherapy-related toxicity.

RESULTS

Thirteen patients were accrued. All patients who commenced radiotherapy received all prescribed chemo- and radiotherapy. There were no treatment-related deaths. There was one Grade 3 acute nonhematologic toxicity in the 50-Gy group. Of the 6 patients given 58 Gy, 3 experienced acute Grade 3 esophagitis. With a median follow-up of 7 months, median overall survival was 9.5 months.

CONCLUSIONS

The maximal tolerated dose of thoracic radiotherapy with concurrent chemotherapy on this trial was 50 Gy in 25 daily fractions.

Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors

Object.Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival.

Methods.A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival.

The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging.

Conclusions.Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors

Object. Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival.

Methods. A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival.

The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging.

Conclusions. Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

Limited-disease small-cell lung cancer

Substantial improvements in treatment outcome for limited-disease small-cell lung cancer (LD SCLC) have been achieved in the last two decades owing to the introduction of chemotherapy (CHT) consisting of cisplatin and etoposide (PE), and the understanding that thoracic radiation therapy (TRT) is an essential component in improving treatment outcome. In addition, a recent metaanalysis confirmed the importance of prophylactic cranial irradiation (PCI) in general treatment plans for patients who show a complete response to treatment. However, numerous questions remain unanswered regarding this disease. While TRT/PE/PCI is considered to be the standard treatment in the majority of centers worldwide, the emergence of new and effective drugs (e.g., topoisomerase I inhibitors and paclitaxel) for the treatment of LD SCLC will likely affect therapy strategies in the near future. Important issues regarding optimal doses and fractionation regimens, as well as the timing of TRT, remain to be resolved. While most centers currently use b.i.d. fractionation as a result of the Intergroup findings, high-dose standard TRT may also be beneficial. TRT volumes are also considered an important issue, since they likely relate to the incidence of both local failure and toxicity. Finally, the optimization of PCI (total dose, fractionation regimen, and timing) is already under way. The value of surgery is limited to peripheral tumors and poorly responding cancer, and to confirm histology or improve local control and survival.

Thoracic radiotherapy for limited-stage small cell lung cancer: issues of timing, volumes, dose, and fractionation

Although meta-analysis of randomized trials comparing chemotherapy alone versus chemotherapy plus thoracic irradiation demonstrated that thoracic radiotherapy reduced mortality by 14%, this analysis probably underestimates the effect of optimally delivered thoracic irradiation integrated with appropriate chemotherapy. However, there remains much debate as to the optimal timing of the radiotherapy and the radiotherapy volume, dose, and fractionation. Theoretically, early use of radiotherapy should reduce the probability of chemotherapy and radiation resistance, accelerated repopulation, and metastatic events. Deferred or sequential radiotherapy potentially allows smaller radiotherapy fields. Of the seven randomized controlled trials examining timing, only those with early chemoradiation have 5-year survival rates in excess of 20%. The "chemoradiation package" can be defined as the time from the start of chemotherapy until the completion of radiotherapy. The best median survival and long-term survival rates have been observed in trials with a chemoradiation package time of less than 6 weeks. Protocols combining chemotherapy and radiotherapy must respect radiobiologic principles concerning the time factor derived from radiotherapy fractionation studies.

Twenty-five years of clinical research for patients with limited-stage small cell lung carcinoma in North America

BACKGROUND

To determine the changes in clinical trials and outcomes of patients with limited-stage small cell lung carcinoma (SCLC) treated on Phase III randomized trials initiated in North America between 1972 and 1992.

METHODS

Phase III trials from 1972 to 1992 for patients with limited-stage SCLC were identified. Patients with limited-stage SCLC treated during a similar time interval were also evaluated in the Surveillance, Epidemiology, and End Results (SEER) database. Trends were tested in the number of trials, in the number and gender of patients entered on trial, and in survival duration over time.

RESULTS

Thirty trials involving 6564 patients were eligible for analyses. Nineteen trials (61%) involving 3626 patients were initiated within the first half of this time period (1972-1981). The median of median survival times of all patients treated on the control arms of the Phase III trials initiated between 1972 and 1981 and between 1982 and 1992 were 12.0 months (range, 10-16 months) and 17.0 months (range, 11-20 months), respectively (P < 0.001). Of 26 studies available for survival analysis, 5 (19%) showed a statistically significant survival prolongation in the experimental arm compared with the control arm with a median prolongation of 3.4 months (range, 1-5.2 months). All five evaluated some aspect of thoracic radiation therapy. Over a similar time period, there was a 6.4-month increase in the median survival of limited-stage SCLC patients listed in the SEER database (P < 0.0001) and a more than doubling of the 5-year survival from 5.2% to 12.1% (P = 0.0001).

CONCLUSIONS

Analyses of the patients with limited-stage SCLC treated on Phase III trials in North America initiated between 1972 and 1992 and those listed in the SEER database show significant improvements in median survivals. Furthermore, the 5-year survival of patients with limited-stage SCLC listed in the SEER database has more than doubled over the last 25 years. Further research will be needed to determine the relative contribution of improved therapy, supportive care, and stage migration to this prolongation in survival.

Prophylactic cranial irradiation in small-cell lung cancer

Prophylactic cranial irradiation is now known to improve survival to a significant degree in small-cell lung cancer (SCLC) patients; this is in addition to its established role in preventing the disabling symptoms of brain metastases. New information indicates that it confers a survival benefit for limited or extensive stage SCLC patients gaining a complete response in the chest. A review of causes of cerebral dysfunction as a complication indicates that such problems can be due to suboptimal radiation fractionation, chemotherapy, or an inappropriate combination of prophylactic brain irradiation with chemotherapy. Optimum treatment with prophylactic brain irradiation has been shown not to cause adverse effects with detailed psychometric testing. Several additional sources of information can be drawn together to suggest a dose-response pattern for prophylactic brain irradiation, leading to the recommendation that a dose of 25-36 Gy is optimal, delivered in 2-3 Gy daily fractions after the completion of chest irradiation and chemotherapy. This will be better defined in future clinical trials.

Chest radiotherapy in limited-stage small cell lung cancer: facts, questions, prospects

OBJECTIVE AND STUDY DESIGN

Limited-disease small cell lung cancer (LD-SCLC) is initially very sensitive to both radiotherapy and chemotherapy. However, the 5-year survival is generally only 10-15%, with most patients failing with therapy refractory relapses, both locally and in distant sites. The addition of chest irradiation to chemotherapy increases the absolute survival by approximately 5%. We reviewed the many controversies regarding optimal timing and irradiation technique.

RESULTS

No strong data support total radiation doses over 50 Gy. According to one phase III trial and several retrospective studies, increasing the volume of the radiation fields to the pre-chemotherapy tumour volume instead of the post-chemotherapy volume does not improve local control.

CONCLUSIONS

The total time in which the entire combined-modality treatment is delivered may be important. From seven randomized trials, it can be concluded that the timing of the radiotherapy as such is not very important. Some phase III trials support the use of accelerated chest radiation together with cisplatin-etoposide chemotherapy, delivered from the first day of treatment, although no firm conclusions can be drawn from the available data. The best results are reported in studies in which the time from the start of treatment to the end of the radiotherapy was less than 30 days. This has to be taken into consideration when treatment modalities incorporating new chemotherapeutic agents and radiotherapy are considered.

Cranial irradiation for preventing brain metastases of small cell lung cancer in patients in complete remission

BACKGROUND

Prophylactic cranial irradiation halves the rate of brain metastases in patients with small cell lung cancer. Individual randomized trials conducted on patients in complete remission were unable to clarify whether this treatment improves survival.

OBJECTIVES

This study aims to test whether prophylactic cranial irradiation prolongs survival of patients with small cell lung cancer in complete remission.

SEARCH STRATEGY

Published and unpublished trials were eligible. Electronic databases, reference lists of trial publications, review articles and relevant books were used to identify potentially eligible trials. The search was also guided by discussions with investigators and experts, and the examination of meeting proceedings and of the Physician Data Query clinical trial registry.

SELECTION CRITERIA

Randomized trials comparing prophylactic cranial irradiation with no prophylactic cranial irradiation in patients with small cell lung cancer in complete remission.

DATA COLLECTION AND ANALYSIS

Meta-analysis based on updated individual data. The main endpoint was survival.

MAIN RESULTS

The relative risk of death in the treatment group compared to the control group was 0.84 (95% confidence interval=0.73 to 0.97, P=0.01), corresponding to a 5.4 percent increase in the 3-year survival rate (from 15.3 percent in the control group to 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased disease-free survival (relative risk=0.75, 95% confidence interval=0.65 to 0.86, P<0.001) and decreased the risk of brain metastases (relative risk=0.46, 95% confidence interval=0.38 to 0.57, P<0.001). Increasing doses of irradiation decreased the risk of brain metastases when four groups (8 Gy, 24-25 Gy, 30 Gy, 36-40 Gy) were analyzed [trend test, P=0.02], but the effect on survival did not differ significantly according to the dose. We found a trend (P=0.01) for a decrease in the brain metastasis risk in favour of earlier administration of cranial irradiation after the initiation of induction treatment.

REVIEWER'S CONCLUSIONS

Prophylactic cranial irradiation significantly improves survival and disease-free survival for patients with small cell lung cancer in complete remission. Further clinical trials are needed to confirm the potential greater benefit on brain metastasis rate suggested when cranial irradiation is given earlier or at higher doses.

Prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission. Prophylactic Cranial Irradiation Overview Collaborative Group

BACKGROUND

Prophylactic cranial irradiation reduces the incidence of brain metastasis in patients with small-cell lung cancer. Whether this treatment, when given to patients in complete remission, improves survival is not known. We performed a meta-analysis to determine whether prophylactic cranial irradiation prolongs survival.

METHODS

We analyzed individual data on 987 patients with small-cell lung cancer in complete remission who took part in seven trials that compared prophylactic cranial irradiation with no prophylactic cranial irradiation. The main end point was survival.

RESULTS

The relative risk of death in the treatment group as compared with the control group was 0.84 (95 percent confidence interval, 0.73 to 0.97; P= 0.01), which corresponds to a 5.4 percent increase in the rate of survival at three years (15.3 percent in the control group vs. 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased the rate of disease-free survival (relative risk of recurrence or death, 0.75; 95 percent confidence interval, 0.65 to 0.86; P<0.001) and decreased the cumulative incidence of brain metastasis (relative risk, 0.46; 95 percent confidence interval, 0.38 to 0.57; P<0.001). Larger doses of radiation led to greater decreases in the risk of brain metastasis, according to an analysis of four total doses (8 Gy, 24 to 25 Gy, 30 Gy, and 36 to 40 Gy) (P for trend=0.02), but the effect on survival did not differ significantly according to the dose. We also identified a trend (P=0.01) toward a decrease in the risk of brain metastasis with earlier administration of cranial irradiation after the initiation of induction chemotherapy.

CONCLUSIONS

Prophylactic cranial irradiation improves both overall survival and disease-free survival among patients with small-cell lung cancer in complete remission.

Should current management of small cell lung cancer include prophylactic cranial irradiation?

The literature on the use of prophylactic cranial irradiation (PCI) in the management of small cell lung cancer (SCLC) is reviewed, focusing on the ten randomized trials published until 1991. Eight out of ten randomized trials have shown some reduction in the frequency of CNS relapse in patients who have had PCI, whereas none have shown any survival benefit associated with PCI. Current data indicate that survival is exclusively dependent on an effect of PCI in only a very limited subgroup of patients (10% of complete responders). It is generally agreed that PCI is not justified in patients who are not in CR, but even in this situation it is unknown whether PCI is necessary. The current therapeutic potentials seem to leave comparable fractions of patients without sufficient palliation of their symptomatic brain metastases regardless of whether or not PCI is given. Data from sufficiently large randomized trials have to be matured and analyzed, before the role of PCI in SCLC can be defined.

Alternating radiotherapy and chemotherapy schedules in limited small cell lung cancer: analysis of local chest recurrences

An analysis of the chest recurrences was conducted in 72 consecutive patients with limited small cell lung cancer treated in two successive phase II trials alternating six induction chemotherapy courses and three series of thoracic radiotherapy, followed by maintenance chemotherapy. The total radiation dose was 45 Gy (3 series of 15 Gy) in the first trial, and 55 (20, 20 and 15 Gy) in the second. The effect of the irradiated volume was investigated by comparing the local relapse rates in the group of patients treated by radiation fields encompassing the initial tumor volume to another group in which the initial target volume was not fully covered by radiation fields. The definition of these two groups was performed retrospectively by examination of radiological, fiberoptic bronchoscopy initial findings, technical radiation charts and check films. The local recurrence rate were 33 and 36% in each group (no significant difference). This finding could suggest that tumor shrinkage after chemotherapy might allow the use of "reduced" radiation volumes. However, the limited number of patients does not permit a definite conclusion. The effect of radiation dose was investigated by comparing the local control rates in the two consecutive trials which delivered 45 and 55 Gy, respectively. No difference in long-term local control was found: the addition of 10 Gy in the second trial only seemed to delay the appearance of local recurrences by 6 months. Twenty percent of patients died from a local relapse without evidence of distant metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

Small cell lung cancer: a problem of tumor heterogeneity

Small cell undifferentiated carcinoma represents a subtype of lung cancer that possesses biologic and clinical characteristics that make it significantly distinct from other forms. A major impact on the natural history of this disease has been accomplished during the past 15 years, including the potential for cure by non-surgical treatment modalities. Further progress in the management of this disorder has been impaired by a number of factors that appear to be inherent to the biology of the tumor and its clinical features. Analysis of initial clinical trials and more detailed examination of this tumor in vitro have permitted the elucidation of many barriers to curative outcome presently being evaluated at the laboratory and clinical levels. These include clear biologic and morphologic heterogeneity; problems with chemotherapy responsiveness including drug resistance; the potential for combining chemotherapy and radiation modalities; the re-examination of the role of surgical intervention in selected patients; and the need to deal with central nervous system dissemination of tumor cells. Further advances in this disease will be dependent on the successful integration of laboratory and clinical disciplines.

Alternating radiotherapy and chemotherapy schedules in small cell lung cancer, limited disease

Sixty-three evaluable patients with limited small cell lung carcinoma were entered into two pilot studies alternating 6 cycles of combination chemotherapy (Doxorubicin 40 mg/m2 d 1; VP16213 75 mg/m2 d 1, 2, 3; Cyclophosphamide 300 mg/m2 d 3, 4, 5, 6; and Methotrexate 400 mg/m2 d 2--plus folinic acid rescue--or Cis-Platinum 100 mg/m2 d 2) with 3 courses of mediastinal radiotherapy as induction treatment. The first course of radiotherapy started 10 days after the second cycle of chemotherapy; there was a 7 day rest between chemotherapy and radiotherapy courses. This 6 month induction treatment was followed by a maintenance chemotherapy. The total mediastinal radiation dose was increased from 4500 rad in the first study to 5500 rad in the second. Both protocols obtained a complete response (CR) rate of greater than 85% (with fiberoptic bronchoscopy and histological verification). Local control at 2 years was 61% in the first study and 82% in the second. Relapse-free survival at 2 years was 32 and 37%, respectively. Toxicity was acceptable. We conclude that our results justify further clinical research in alternating radiotherapy and chemotherapy schedules.

The role of radiation therapy in the treatment of small cell lung cancer

Patients with small cell lung cancer (SCLC) are candidates for aggressive therapy because of their potential for long-term survival, especially patients with limited-stage disease. Although no treatment protocol can be considered "standard", the best results in limited-stage SCLC appear to be produced by a combination of chemotherapy and thoracic irradiation. Ongoing protocols testing the efficacy of thoracic irradiation should be able to settle question of the optimal treatment approach in limited-stage SCLC over the next 1 to 2 years. Careful attention to volume treated and the use of shrinking fields produce the best results with the minimum of toxicity. Treatment of extensive-stage SCLC has not been substantially improved to date with the addition of local or systemic irradiation. Prophylactic cranial irradiation reduces the incidence of CNS failure in SCLC and should be given, at a minimum, to patients achieving complete response status. Whether patients with partial response should also receive prophylactic cranial irradiation remains controversial. Finally, half-body radiation in SCLC is an experimental research technique that has shown some promise but remains quite toxic when combined with systemic chemotherapy.

Esophageal complications from combined chemoradiotherapy (cyclophosphamide + Adriamycin + cisplatin + XRT) in the treatment of non-small cell lung cancer

Esophageal complications from combined chemoradiotherapy (CCRT) were analyzed in 55 patients with limited non-small cell lung cancer. CCRT consisted of chemotherapy (cyclophosphamide, doxorubicin (Adriamycin), and cisplatin: CAP) and chest irradiation (5000 rad in 25 fractions/5 weeks). Forty-five patients received two courses of CAP, followed by five weekly courses of low dose CAP and irradiation followed by maintenance courses of CAP (Group 1). Ten patients received concomitant CCRT from the onset of treatment (Group 2). Esophagitis occurred in 80% of all patients. Severe esophagitis occurred in 27% of patients of Group 1 and 40% of patients of Group 2. Esophageal stricture or fistula developed in 1 of 45 (2%) patients in Group 1, and 3 of 10 (30%) patients in Group 2 (p less than 0.025). Weekly low-dose chemotherapy administered concomitantly with chest irradiation (R) at the onset of treatment significantly increases esophageal complications. A review of the literature suggests that CCRT may be used safely with split courses of R. The duration between onset of chemotherapy either before or after R should be greater than one week.

Combination chemotherapy in small cell lung carcinoma. A randomized study of two intensive regimens

From April, 1979 to November, 1981, 293 patients with small cell lung carcinoma (SCLC) were entered on a randomized, controlled study comparing the two induction regimens of high-dose CAV (HD-CAV) (cyclophosphamide [CTX] 1200 mg/m2, doxorubicin [ADR] 70 mg/m2 and vincristine [VCR] 1 mg/m2 intravenously (IV) on days 1 and 21) versus, conventional-dose CAV + VP-16 (etoposide) (CAV-VP) (CTX 1000 mg/m2, ADR 40 mg/m2, VCR 1 mg/m2 IV on days 1 and 21 with VP-16 100 mg/m2 on days 1-3, and 21-23). Responding and stable patients were continued on conventional-dose CAV for 5 consolidation courses. Prophylactic brain irradiation delivered after the first consolidation course in responders was optional. Patients were included in the study if they had extensive disease (i.e., beyond one hemithorax), no prior chemotherapy, or radiotherapy and performance status of 50 or above. After 2 induction courses, 215 cases are evaluable. Of these, 76 of 106 (72%) patients treated with HD-CAV have responded (greater than 50% regression), including 13 complete responders (CRs) versus 80 of 108 (74%) patients on CAV-VP, including 15 CRs. Of the 130 evaluable patients who have completed consolidation (HD-CAV, 65; CAV-VP, 65), an additional 22 patients achieved CR (HD-CAV, 12; CAV-VP, 10) for an overall CR rate of 24%. Median duration of remission was 33.6 weeks for HD-CAV and 35.6 weeks for CAV-VP (P = 0.61). Median duration of complete response for HD-CAV was 33.8 weeks and for CAV-VP 36.7 weeks (P = 0.81). Survival curves were similar for the two regimens, with medians of 42.1 weeks for HD-CAV and 42.3 weeks for CAV-VP (P = 0.35). Survival correlated with performance status and quality of response. As anticipated, the major toxicity for both induction regimens was leukopenia. During induction, granulocyte nadirs of less than 500/mm3 occurred in 81% of patients on HD-CAV and 77% of patients on CAV-VP. Thus, dose intensification appears to produce high response rates and modest complete response rates in extensive SCLC, but it does not appear to improve materially survival compared to prior reports of conventional-dose therapy.

Combined modality treatment of short duration in small cell lung cancer

Fifty-seven patients with small cell lung cancer (SCLC) (limited disease = LD in 23, extensive disease = ED in 34) received the combination of CCNU, cyclophosphamide, vincristine and methotrexate (CCOM). A mean number of only 6 (range 1-17) courses of chemotherapy were given. All LD patients received consolidation locoregional radiation (30 Gy) after two courses of chemotherapy. A complete response (CR) was obtained in 61% of LD and 12% of ED patients, and a partial response in 22 and 35% respectively. Median survival was 54 and 34 weeks for LD and ED respectively. Five LD patients survived more than 2 yr, three of them remaining disease-free 4 yr after the cessation of treatment. A subset of 12 LD patients achieving a CR after two courses of chemotherapy was randomized to receive maintenance chemotherapy or observation only after the consolidation radiotherapy. In this small-sized randomized trial maintenance treatment showed a significant decrease of the patients' quality of survival compared to no maintenance treatment. We conclude that combined modality treatment of short duration proved effective in SCLC. Future randomized studies are necessary to show whether prolonged chemotherapy has a meaningful impact on survival, or otherwise the resulting morbidity will plead against it.

Radiotherapy quality assurance in clinical trials

The goal of radiation therapy is to yield the greatest possible uncomplicated local and regional tumor control. An acceptable quality of life with few severe complications, anatomical defects or psychological disturbances should be an integral objective of excellent radiation therapy. Inasmuch as higher doses of irradiation and adequacy of treatment portals (volume irradiated) appear to correlate with greater probability of tumor control and major complications, there is a critical need to optimize treatment planning and quality assurance in radiation therapy. Along with this, techniques must be developed for reliable patient reposition and immobilization so that the optimized treatment plan can be translated into precise delivery of the irradiation. It is obvious that in clinical trials the basic parameters of therapy need to be optimally observed, in order to make comparison of experimental arms more reliable. It is easier to achieve uniformity of technical factors in a study at a single institution than in multi-institutional cooperative groups. Thus, stringent criteria must be incorporated into the protocol describing the requirements and techniques for planning and delivery of the radiation therapy. Furthermore, the dosimetry checks carried out by the Radiological Physics Center should be an integral part of this program. In some studies it is necessary to do an initial review of dosimetry factors and portal films. This alerts the radiation oncologist to variations from the protocol and, with prompt feedback and correction of the potential error, will ensure the complete evaluability of the case. Since an increasing number of reports point out that the doses of irradiation delivered and the volume treated may affect therapeutic results, a completed case review should always be carried out. Some cooperative group studies strongly suggest a correlation between the compliance with the protocol and the results of the trial. Costs of these programs in clinical trials should be justified since, for a small investment, the evaluability rate in a protocol can be increased by 10%. The increase of patient evaluability significantly decreases the cost per evaluable patient. Furthermore, the reliability of the data of the trial will be greatly enhanced by a strong quality assurance program.

Combined modality treatment of regional small cell undifferentiated carcinoma of the lung: a cooperative study of the RTOG and ECOG

Between 1975 and 1979, 271 patients with regional small cell undifferentiated (including oat cell) carcinoma of the lung were entered into a study involving treatment by radiation therapy (4500 cGy (rad) in five weeks) to the primary tumor, mediastinum and supraclavicular lymph nodes, and a randomization to receive or not receive prophylactic treatment of the brain (3000 cGy in two weeks) and a randomization to prophylactic or delayed chemotherapy (cyclophosphamide and CCNU). Analysis of the data indicates that the median survival for responders (53 weeks) was significantly longer than that of the non-responders and partial responders (37 and 34 weeks). Median survival by treatment arm was 48 weeks for thoracic irradiation (TI), brain irradiation (BI), and early chemotherapy (CT), 44 weeks for TI alone, 41 weeks for TI and CT, 38 weeks for TI and BI. Regional complete and partial tumor responses were 52 and 25% for prophylactic chemotherapy and 44 and 35% for delayed chemotherapy. The site of first failure was regional in 12%, regional and distant simultaneously in 21%, and distant only in 46%. Elective brain irradiation significantly reduced the incidence of brain metastases from 21 and 5%, but did not improve survival.

The impact of surgical quality control in multi-institutional group trials involving adjuvant cancer treatments

Quality control involving surgical treatment in multi-institutional cancer trials is important because the results of postoperative adjuvant therapy might be obscured by inadequate surgery or pathologic examination of the specimen. In 1975, the Southeastern Cancer Study Group (SEG) initiated a randomized clinical trial of adjuvant immunotherapy (Corynebacterium parvum vs. bacillus Calmette-Guerin) in melanoma patients with nodal metastases. During the course of reviewing the results several years later, 20 of 136 patients (15%) entered into this study were judged as surgically ineligible. The reasons were: 1) biopsy of a metastatic node only without any subsequent regional lymph node dissection (12 patients), 2) partial lymph node dissection (six patients), or 3) too few nodes surgically removed or pathologically identified in the specimen (six patients). All 20 patients were entered into the study by medical oncologists. Thirteen of these 20 surgically ineligible patients have relapsed so far; many were taken off the study as "immunotherapy failures," when, in fact, they were surgical failures. Compared to the 116 surgically eligible patients, the 20 ineligible patients had a shorter median survival (4 months vs. 25 months) and a lower 1-year disease-free survival rate (36% vs. 62%, p = 0.01). The two groups were balanced equally with respect to prognostic factors. Because of these findings, minimum surgical and pathologic guidelines were established for each adjuvant therapy protocol in the SEG. Surgical quality control was reviewed by a surgeon in each institution prior to randomization and again by a surgical investigator centrally. Pathologic criteria were also defined more precisely. The problems with surgically ineligible patients have since been virtually eliminated. Quality control measures for surgical patients entered into cooperative group trials is an essential part of the protocol design and data review. In order to evaluate properly the impact of adjuvant therapy, each clinical trial must comprise a uniform group of surgically treated patients.

The influence of radiation therapy quality control on survival, response and sites of relapse in oat cell carcinoma of the lung: preliminary report of a Southwest Oncology Group study

Two hundred and ninety-eight patients with limited (confined to chest and supraclavicular area, encompassable by a single radiation portal) small cell carcinoma of the lung were entered on Southwest Oncology Group Protocol 7628. Patients were treated with multi-agent chemotherapy and radiation therapy with or without BCG. Radiation therapy quality control analysis, including dosimetric reconstruction and port film review was introduced after the protocol was activated and was retrospectively applied. Patients who were considered major protocol variations had statistically worse survival (40 weeks versus 60 weeks; P = .002), a lesser improvement in response rate after induction chemotherapy (27 versus 48%; P = .05) and a higher chest failure rate (77 versus 55%; P = .047) than evaluable patients. Five patients relapsed in the brain, all associated with chest failure. Quality control is essential in cooperative group studies.