**4. Various treatment modalities and tumour down-staging**

According to Wright et al [10], marked difference in pathologic response based on the induction therapy is favouring CT/RT. Surgical resection of Pancoast tumours after neoadju‐ vant high-dose CT/RT was carried out in 40.5% of patients according to Kwong et al [18].

Pathological downstaging although it does not correlate with the radiological appearance [16] is reported to be impressively above 30% in various series. As per Pourel et al [15], pathological complete response was observed in 39.5% of the patients, necrosis of tumoural tissues between 50% and 95% in 22.5% and less than 50% in 38% of the patients. Along the same lines JCOG reported [17] pathologic downstaging of the tumour in 40% of the patients; No residual viable tumour cells in the resected specimens, was achieved in 16% of the treated patients. Finally SWOG [16] summarised that pathologic no residual microscopic tumour was seen in one third of the resected specimens and minimal microscopic residual (few scattered tumour foci within a mostly necrotic or fibrotic mass), was observed in one third of the resected specimens.
