Thoracic Radiotherapy for Limited-stage Small-cell Lung Cancer: Controversies and Future developments

Determination of Risk Factors Related to Supraclavicular Recurrence for Limited-Stage Small Cell Lung Cancer (SCLC) Patients

BACKGROUND This research aimed to determine high-risk factors of supraclavicular recurrence for limited-stage small cell lung cancer (LS-SCLC) patients to discover a potential subpopulation that can benefit from prophylactic supraclavicular irradiation (PSCI). MATERIAL AND METHODS Between July 2006 and July 2011, LS-SCLC patients without supraclavicular lymph node (SCLN) involvement consecutively treated with concurrent chemo-radiation but without PSCI in the Radiotherapy Department of the Cancer Institute and Hospital of Tianjin Medical University, were retrospectively analyzed. SCLN recurrence rate, overall survival (OS), and distant metastasis-free survival (DMFS) were assessed. Binary logistic regression analysis was conducted to discover the high-risk factors related to the SCLN recurrence. The receiver operating characteristic (ROC) curves were drawn to evaluate logistic regression model prediction performance. RESULTS Eighty-eight LS-SCLC patients were analyzed in this study. During 99 months (ranging from 72 months to 124 months) for survivors, 28 (31.8%) had SCLN recurrence. There were significant differences for median DMFS and OS between LS-SCLC patients with and without SCLN recurrence. The logistic regression model revealed that lymphadenopathy at mediastinal level 2 and level 3 prior to chemotherapy were significantly associated with SCLN recurrence, which was validated by ROC. CONCLUSIONS Lymphadenopathy at mediastinal level 2 and level 3 prior to chemotherapy were the high-risk factors associated with SCLN recurrence for patients with LS-SCLC. Further work is needed to determine whether patients with these factors can benefit from PSCI.

A retrospective analysis of survival outcomes for two different radiotherapy fractionation schedules given in the same overall time for limited stage small cell lung cancer

PURPOSE

To compare survival outcomes for two fractionation schedules of thoracic radiotherapy, both given over 3 weeks, in patients with limited stage small cell lung cancer (LS-SCLC).

METHODS AND MATERIALS

At Radiation Oncology Mater Centre (ROMC) and the Royal Brisbane & Women's Hospital (RBWH), patients with LS-SCLC treated with curative intent are given radiotherapy (with concurrent chemotherapy) to a dose of either 40 Gy in 15 fractions ('the 40 Gy/15# group') or 45 Gy in 30 fractions ('the 45 Gy/30# group'). The choice largely depends on institutional preference. Both these schedules are given over 3 weeks, using daily and twice-daily fractionation respectively. The records of all such patients treated from January 2000 to July 2009 were retrospectively reviewed and survival outcomes between the two groups compared.

RESULTS

Of 118 eligible patients, there were 38 patients in the 40 Gy/15# group and 41 patients in the 45 Gy/30# group. The median relapse-free survival time was 12 months in both groups. Median overall survival was 21 months (95% CI 2-37 months) in the 40 Gy/15# group and 26 months (95% CI 1-48 months) in the 45 Gy/30# group. The 5-year overall survival rates were 20% and 25%, respectively (P = 0.24). On multivariate analysis, factors influencing overall survival were: whether prophylactic cranial irradiation (PCI) was given (P = 0.01) and whether salvage chemotherapy was given at the time of relapse (P = 0.057).

CONCLUSIONS

Given the small sample size, the potential for selection bias and the retrospective nature of our study it is not possible to draw firm conclusions regarding the efficacy of hypofractionated thoracic radiotherapy compared with hyperfractionated accelerated thoracic radiotherapy however hypofractionated radiotherapy may result in equivalent relapse-free survival.

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.

Accelerated hyperfractionated radiotherapy and concomitant chemotherapy in small cell lung cancer limited-disease. Dose response, feasibility and outcome for patients treated in western Sweden, 1998-2004

Addition of thoracic radiation therapy (TRT) to chemotherapy (CHT) can increase overall survival in patients with small cell lung cancer limited-disease (SCLC-LD). Accelerated fractionation and early concurrent platinum-based CHT, in combination with prophylactic cranial irradiation, represent up-front treatment for this group of patients. Optimised and tailored local and systemic treatment is important. These concepts were applied when a new regional treatment programme was designed at Sahlgrenska University Hospital in 1997. The planned treatment consisted of six courses of CHT (carboplatin/etoposide) + TRT +/- prophylactic cranial irradiation (PCI). Standard TRT was prescribed at 1.5 Gy BID to a total of 60 Gy during 4 weeks, starting concomitantly with the second or third course of CHT. However, patients with large tumour burdens, poor general condition and/or poor lung function received 45 Gy, 1.5 Gy BID, during 3 weeks. PCI in 15 fractions to a total dose of 30 Gy was administered to all patients with complete remission (CR) and "good" partial remission (PR) at response evaluation. Eighty consecutive patients were treated between January 1998 and December 2004. Forty-six patients were given 60 Gy and 34 patients 45 Gy. Acute toxicity occurred as esophagitis grade III (RTOG/EORTC) in 16% and as pneumonitis grade I-II in 10%. There were no differences in toxicity between the two groups. Three- and five-year overall survival was 25% and 16%, respectively. Medica survival was 20.8 months with no significant difference between the two groups. In conclusion, TRT with a total dose of 60 to 45 Gy is feasible with comparable toxicity and no difference in local control or survival. Distant metastasis is the main cause of death in this disease; the future challenge is thus further improvement of the systemic therapy combines with optimised local TRT.