PD-L1

After bladder removal, a blood test can now tell who needs immunotherapy and who can safely be spared it. This is the model for MRD-guided adjuvant therapy across cancers: treat the blood-positive, watch the blood-negative.

Patients with limited-stage small-cell lung cancer who complete chemoradiotherapy without progression should now be offered up to two years of durvalumab consolidation, which extends life by almost two years on average. This is the first survival improvement for limited-stage disease since twice-daily radiotherapy and prophylactic cranial irradiation, and small-cell lung cancer is no longer a disease where immunotherapy gives only marginal gains.

Patients fit enough for cisplatin whose bladder cancer has invaded the muscle wall should now be offered durvalumab with their pre-operative chemotherapy and for about a year after surgery, which improves the chance of cure without compromising the operation. The trial cannot say whether the adjuvant phase is necessary, or how to treat cisplatin-ineligible patients, for whom other trials are ongoing.

Patients with newly diagnosed advanced stomach or oesophageal adenocarcinoma whose tumour is HER2-negative and PD-L1 positive (CPS 5 or more, or at least 1 in some regions) should receive chemotherapy with nivolumab (or pembrolizumab, from KEYNOTE-859), which adds about three months of median survival and doubles the chance of being alive at three years. The benefit in PD-L1-negative tumours is doubtful, and these patients may be better served by chemotherapy alone or by trials.

Patients with advanced liver cancer and good liver function should be offered atezolizumab plus bevacizumab (or durvalumab plus tremelimumab) rather than sorafenib as first treatment; median survival is now around 19 months and about a quarter of patients respond. Endoscopy to treat varices before starting bevacizumab is essential because of bleeding risk. Patients with poorer liver function (Child-Pugh B) or autoimmune disease or transplants were not studied.

Most patients with newly diagnosed advanced non-squamous lung cancer that lacks a targetable mutation should receive chemotherapy plus pembrolizumab; those with PD-L1 of 50% or more may reasonably receive pembrolizumab alone. About one in five patients is alive at five years, compared with roughly one in ten with chemotherapy alone. Patients with EGFR or ALK alterations were excluded and should have targeted therapy first.

Patients with stage III lung cancer that cannot be removed surgically should receive a year of durvalumab after completing chemoradiotherapy, provided they have not progressed. This roughly doubles the chance of being alive without progression at five years. Whether the benefit extends to PD-L1-negative tumours is contested, and the EGFR-mutated subgroup is better served by osimertinib (LAURA).

Tumours hide from T cells by displaying PD-L1; blocking that interaction lets the immune system attack. This is the mechanism of pembrolizumab, nivolumab, atezolizumab and their relatives, which now treat more than 20 cancer types.