Stage I and II nonsmall cell lung cancer treatment options.

Chest radiography, computed tomography (CT) and positron emission tomography (PET)-CT are required for staging nonsmall cell lung cancers. Stage I cancers may be up to 4 cm in maximal diameter, with stage IA tumours being up to 3 cm and stage IB up to 4 cm. A lung cancer becomes stage II if the tumour is between 4 and ≤5 cm (stage IIA), or it spreads to ipsilateral peribronchial or hilar lymph nodes (stage IIB). Stage IA tumours should be surgically resected, ideally using minimally invasive methods. Lobectomy is usually performed, although some studies have shown good outcomes for sublobar resections. If surgery is not possible, stereotactic body radiotherapy is a good alternative. This involves delivering a few high-dose radiation treatments at very high precision. For stage IB to IIB disease, combinations of surgery, chemotherapy or immunotherapy and radiotherapy are used. There is evidence that neoadjuvant treatment (immunotherapy with nivolumab and chemotherapy for stage IB and II) optimises outcomes. Adjuvant chemotherapy with a platinum-based doublet (typically cisplatin+vinorelbine) should be offered for resected stage IIB tumours and considered for resected IIA tumours. Adjuvant pembrolizumab is used for stage IB-IIIA following resection and adjuvant platinum-based chemotherapy. Osimertinib may be used for resected stage IB to IIIA cancers which have relevant mutations (epidermal growth factor receptor exon 19 deletions or exon 21 (L858R) substitution). There are no fixed guidelines for follow-up, but most centres recommend 6-monthly CT scanning for the first 2-3 years after definitive treatment, followed by annual scans.