Local failure in patients treated with radiotherapy and multidrug chemotherapy for small cell lung cancer

Comparison of 2 common radiation therapy techniques for definitive treatment of small cell lung cancer

PURPOSE

Two choices are widely used for radiation delivery, 3-dimensional conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT). No randomized comparisons have been conducted in the setting of lung cancer, but theoretical concerns suggest that IMRT may negatively impact disease control. We analyzed a large cohort of limited-stage small-cell lung cancer (LS-SCLC) patients treated before and after institutional conversion from 3DCRT to IMRT to compare outcomes.

METHODS AND MATERIALS

Patients with LS-SCLC treated with definitive radiation at our institution between 2000 and 2009 were retrospectively reviewed. Both multivariable Cox regression and propensity score matching were used to compare oncologic outcomes of 3DCRT and IMRT in the context of other clinically relevant covariables. Acute and chronic toxicities associated with the 2 techniques were compared using Fisher exact and log-rank tests, respectively.

RESULTS

A total of 223 patients were treated during the study period, with 119 receiving 3DCRT and 104 receiving IMRT. Their median age was 64 years (range, 39-90 years). Median follow-up times for 3DCRT and IMRT were 27 months (range, 2-147 months) and 22 months (range, 4-83 months), respectively. Radiation modality was not associated with differences in overall survival or disease-free survival in either multivariable or propensity score-matched analyses. IMRT patients required significantly fewer percutaneous feeding tube placements (5% vs 17%, respectively, P=.005).

CONCLUSIONS

IMRT was not associated with worse oncologic outcomes than those of 3DCRT. IMRT was associated with a lower rate of esophagitis-related percutaneous feeding tube placements.

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.

Positron emission tomography/computed tomography-guided intensity-modulated radiotherapy for limited-stage small-cell lung cancer

PURPOSE

Omitting elective nodal irradiation from planning target volumes does not compromise outcomes in patients with non-small-cell lung cancer, but whether the same is true for those with limited-stage small-cell lung cancer (LS-SCLC) is unknown. Therefore, in the present study, we sought to determine the clinical outcomes and the frequency of elective nodal failure in patients with LS-SCLC staged using positron emission tomography/computed tomography and treated with involved-field intensity-modulated radiotherapy.

METHODS AND MATERIALS

Between 2005 and 2008, 60 patients with LS-SCLC at our institution underwent disease staging using positron emission tomography/computed tomography before treatment using an intensity-modulated radiotherapy plan in which elective nodal irradiation was intentionally omitted from the planning target volume (mode and median dose, 45 Gy in 30 fractions; range, 40.5 Gy in 27 fractions to 63.8 Gy in 35 fractions). In most cases, concurrent platinum-based chemotherapy was administered. We retrospectively reviewed the clinical outcomes to determine the overall survival, relapse-free survival, and failure patterns. Elective nodal failure was defined as recurrence in initially uninvolved hilar, mediastinal, or supraclavicular nodes. Survival was assessed using the Kaplan-Meier method.

RESULTS

The median age of the study patients at diagnosis was 63 years (range, 39-86). The median follow-up duration was 21 months (range, 4-58) in all patients and 26 months (range, 4-58) in the survivors. The 2-year actuarial overall survival and relapse-free survival rate were 58% and 43%, respectively. Of the 30 patients with recurrence, 23 had metastatic disease and 7 had locoregional failure. We observed only one isolated elective nodal failure.

CONCLUSIONS

To our knowledge, this is the first study to examine the outcomes in patients with LS-SCLC staged with positron emission tomography/computed tomography and treated with definitive intensity-modulated radiotherapy. In these patients, elective nodal irradiation can be safely omitted from the planning target volume for the purposes of dose escalation and toxicity reduction.

[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.

Progress in the therapy of small cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 14% of all cases of lung cancer. Combination chemotherapy is the most effective treatment modality for SCLC and recently, several new active drugs have emerged. Combinations of platinum agents with CPT-11 or gemcitabine have been successfully compared in phase III trials against the cisplatin/etoposide standard. Modest improvements in the outcome of patients with SCLC have been noted over the last two decades. Thoracic irradiation given concurrently with chemotherapy improves survival compared with sequential chemotherapy and radiation, but this approach is associated with more toxicity. Moreover, the optimal doses and fractionation of thoracic irradiation remain to be determined. Three-dimensional treatment planning is under investigation. Prophylactic cranial irradiation (PCI) has established a role in the management of patients who have achieved a complete response to the initial therapy. Novel molecular targeted therapies are among the strategies currently being investigated in SCLC.

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.

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.

[Discussion on the role of radiotherapy in non-small cell lung cancer apropos of 137 non-metastatic cases]

PURPOSE

Retrospective analysis of 137 patients with limited stage small cell lung carcinoma who received radiotherapy between 1978 and 1990 and literature review.

MATERIALS AND METHODS

The population was divided into two groups according to the total dose of radiation delivered to the thorax: 45 Gy (1.8 Gy by fraction) or the equivalent irradiation dose administered by hypofractionation (group 1, 29 patients) and 65 Gy (1,8 Gy by fraction) or the equivalent irradiation dose administered by hypofractionation (group 2, 96 patients).

RESULTS

The actuarial survival rate was 20% at 2 years and 9% at 5 years. It was 25% at 2 years and 17% at 5 years for 12 patients with surgical resection. For patients who did not undergo surgical resection, it was 20% at 2 years and 9% at 5 years for 96 patients belonging to group 2, while it was 14% at 2 years and 3.5% at 5 years for group 1. Deaths due to local relapse reached 48% in the group treated with 45 Gy and 33% in the group treated with 65 Gy (NS). For the 33 patients who were more than 70 years old at the time of treatment, the actuarial survival rate was 18% at 2 years and 6% at 5 years with death from other causes twice as high as that of patients who were less than 70 years old at the time of treatment. For the 59 patients who were less than 70 years old at the time of treatment, in whom supraclavicular node, pleural effusion or superior vena cava syndrome were not depicted and who were treated with the highest dose (4% of the total number of patients), the actuarial survival rate was 20% at 2 years and 14% at 5 years. Literature analysis shows that treatment of limited small cell lung cancer with chemotherapy and thoracic irradiation increased the overall survival rate from 16.5% to 23% at 2 years and the local control from 23% to 48%, in comparison with chemotherapy alone.

CONCLUSION

Although these results are modest, they seem to be improved with more effective chemotherapy, especially with the association of radiotherapy and concomitant chemotherapy.