Would you offer adjuvant chemotherapy, osimertinib, or both to a patient with Stage IB EGFR mutated lung adenocarcinoma found in the lung explant pathology after bilateral lung transplant?

This is such a rare and individualized case that there will likely be no correct answer. My understanding of the facts is that stage IB lung adenocarcinoma was found on the removed explanted lung after a lung transplant. The question posed is what is the role of adjuvant systemic therapy? Ignoring the transplant, the standard of care for stage IB lung adenocarcinoma would be a lobectomy. In this case, the patient had a bilateral lung transplant, so that has been addressed. The variables that are unknown based on your presentation are as follows:

1. Were there high risk features reported in the surgical pathology report such as lymphovascular invasion or poorly-differentiated carcinoma? 
2. Were the mediastinal lymph nodes evaluated and dissected during the bilateral lung transplant? 
3. Did the patient have a drug-sensitizing EGFR mutation, such as EGFR Exon 19 del or L858R?

Assuming the final stage is IB (without high risk features), the role of adjuvant therapy in this stage is controversial. It is important to note that the LACE meta-analysis [Pignon et al., PMID 18506026] only found a nonsignificant trend toward improved OS (HR of death 0.93, 95% CI 0.78-1.10). Similarly, the ADAURA study demonstrated the greatest DFS benefit for stage II and IIIA patients. We do not have overall survival data for patients in ADAURA, though I worry that the OS results will be similar to the recently reported IMPACT trial [Tada et al., PMID 34726958) which failed to show an OS benefit with gefitinib, despite encouraging early data showing a DFS benefit. Additionally, you have to account for possible drug-drug interactions of adjuvant osimertinib with tacrolimus or sirolimus, assuming either of these are going to be part of the immunosuppression plan.

My vote would be ongoing surveillance.