How do you approach the management of a patient with extensive small cell lung cancer who has progressed on third-line therapy, with borderline functional status, complicated by paraneoplastic CNS syndrome?

Given the overall poor prognosis of small cell lung cancer, I would be inclined to start with a goal of care discussion. Many clinical trials still require ECOG PS 0-1 and I do not believe in "fudging" PS for borderline patients to enroll on a trial. I may consider single agent chemotherapy - lurbinectedin is my current preference (with dose adjustment if needed). Otherwise, hospice is very reasonable especially given CNS complications.

I am not sure this patient would qualify for a clinical trial with borderline PS. Standard treatment options are limited, such as Topotecan, lurbinectedin, other single agent chemotherapy but if PS is poor, I would have an honest discussion with the patient, involve palliative care, and likely recommend hospice.

Just a point of clarification, I would consider this patient to still be on first-line treatment. Carbo/etop/atezo-->maintenance atezo is really just one line of therapy.

The question of benefit from further treatment is more of a clinical gestalt in this setting than truly guideline- or data-based. If the patient is a reasonable candidate for further treatment, then lurbinectedin would be my choice. But it seems as if hospice might be as good or a better option in a situation like this.