How to improve loco-regional control in stages IIIa-b NSCLC? Results of a three-armed randomized trial from the Swedish Lung Cancer Study Group.

BACKGROUND

A combination of chemotherapy and radiotherapy is the treatment base for locally advanced non-small cell lung cancer (NSCLC). However, both loco-regional and distant failure is frequent. Attempts to improve the loco-regional control were made in three separate phase II studies in Swedish University Hospitals, where accelerated radiotherapy or concurrent daily or weekly chemotherapy with conventional radiotherapy were tested. Comparatively good results from these studies lead to this national randomized phase II study, the RAKET-study, where the different concepts were investigated on a wider basis for further phase III studies.

METHODS

Inoperable stage III non-small cell lung cancer patients in good performance status (PS<2) were equally randomized to either of three arms in eight institutions. All arms started with two cycles of induction chemotherapy: paclitaxel 200 mg/m2 and carboplatin AUC6. Arm A: a third identical cycle was given concomitant with start of accelerated radiotherapy, 1.7 Gy BID to 64.6 Gy in 4.5 weeks. Arm B consisted of daily concomitant paclitaxel 12 mg/m2 with conventionally fractionated radiotherapy: 2 Gy to 60 Gy in 6 weeks. Arm C: weekly concomitant paclitaxel 60 mg/m2 and identical radiotherapy to 60 Gy. Primary endpoint: TTP. Secondary: OS, toxicity, QL and relapse pattern.

RESULTS

Between June 2002 and May 2005 152 patients were randomized and of them 151 were evaluable: 78 men and 73 women, median age 62 years (43-78), 55% had performance status 0 and 45% PS 1. Thirty-four percent had stage IIIa and 66% IIIb.

HISTOLOGY

adenocarcinoma 48%, squamous cell carcinoma 32% and 20% non-small cell carcinoma. The three arms were well balanced. Toxicity was manageable with 12% grades 3-4 esophagitis, 1% grades 3-4 pneumonitis and there was no clear difference between the arms. The QL data did not differ either. Median time to progression was 9.8 (8.3-12.7) months (8.8, 10.3 and 9.3 months for arms A, B and C, respectively). Median survival was 17.8 (14.4-23.7) months (17.7, 17.7 and 20.6 months for A, B and C, respectively). The 1-, 3- and 5-year overall survival was 63, 31 and 24%. Sixty-nine percent of the patients relapsed with distant metastases initially and 31% had loco-regional tumor progression, without significant differences between treatment arms. Thirty-four percent developed brain metastases.

CONCLUSIONS

Treatment results are quite equal by intensifying the loco-regional treatment either by accelerated fractionated radiotherapy or daily or weekly concomitant chemo-radiotherapy both in terms of survival, toxicity and quality of life. The optimal treatment schedule for patients with locally advanced NSCLC is still to be decided and investigated in future clinical studies. Relapse pattern with distant metastases and especially brain metastases is a great problem and need further research for better therapy options and higher cure rate for this patient group.