New strategies for patients with limited-stage small-cell lung cancer
Mené en Chine sur 224 patients atteints d'un cancer du poumon à petites cellules de stade limité (46 % de femmes ; âge médian : 64 ans ; durée médiane de suivi : 46 mois), cet essai randomisé multicentrique de phase III évalue l'efficacité, du point de vue de la survie globale, et la sécurité d'une arc-thérapie volumétrique avec modulation d'intensité, biquotidienne et à forte dose (54 Gy en 30 fractions) avec chimiothérapie concomitante
Small-cell lung cancer (SCLC) accounts for 15% of lung cancers and is characterised by poor long-term survival. About 30% of SCLC cases are limited to the lung and regional nodes, and thereby considered as limited-stage disease (LS-SCLC). Such patients are treated with chemotherapy delivered concurrently with thoracic radiotherapy. 1 Low-dose prophylactic cranial irradiation is recommended to reduce brain relapses, although trials are underway to compare prophylactic cranial irradiation with imaging surveillance (NCT04829708 and NCT04155034). The choice of thoracic radiotherapy schedules is a topic of active debate, and three approaches are in use. A 1999 study 2 compared different doses of 45 Gy, in which 45 Gy was either delivered in twice-daily fractions of 1·5 Gy or in once-daily doses of 1·8 Gy. Overall survival was superior for 45 Gy twice-daily radiotherapy, but once-daily 45 Gy radiotherapy is lower, and therefore less favourable, than doses used for locally advanced non-small-cell lung cancer. Subsequently, the CONVERT 3 and CALGB 4 trials did not show improved survival with higher once-daily doses of 2 Gy delivered over 6–7 weeks to 66–70 Gy. Another approach involves shortening overall treatment time using higher once-daily doses (approximately 2·6–2·8 Gy per fraction) in a hypofractionated approach. Conventional fractionation implies using once-daily doses of around 2 Gy, whereas hypofractionation involves delivery of once-daily radiotherapy with fraction doses of 2·6 Gy or higher, thereby allowing for the total dose to be delivered in a shorter period. Hyperfractionation, however, involves delivery of doses below 2 Gy and delivered two or three times daily in order to complete all of the delivery in a shorter period. A meta-analysis 5 reported similar outcomes using conventional once-daily and twice-daily chemoradiotherapy, and suggested that hypofractionated radiotherapy gave the best patient outcomes.