Would you offer radiation alone to localized recurrence of extensive stage small cell lung cancer while on maintenance immunotherapy or would you start alternative systemic therapy?

Would it matter the site of recurrence (ie lung nodule vs bone lesion)?

1 Answer

Mednet MemberInvited Expert

Medical Oncology · Indiana University School of Medicine

Answered on

The role of local therapy for the treatment of patients with ES SCLC has been evaluated in a number of phase 3 trials. The first trial, which was published by Jeremic et al., PMID 10561263 over 20 years ago, reported a survival advantage for adding thoracic radiation to chemotherapy compared with chemotherapy alone. The CREST trial was a randomized study of thoracic radiation plus PCI versus PCI alone in patients with ED SCLC, who had responded to initial chemotherapy. That study reported a better 2-year OS favoring the group who received thoracic XRT (13% vs. 3%). PFS also favored those who received thoracic XRT.

Neither of these trial designs, however, was conducted in the patient population that is the subject of the writer's question. Namely, if a patient has been receiving chemotherapy plus immunotherapy for ES SCLC and has local PD while on maintenance immunotherapy, should you add local XRT or switch systemic therapies? There are no randomized trials that have addressed this question, so we are left to extrapolate from studies answering similar questions along with our clinical experience and judgment.

In my experience, local progression only in a patient with ES SCLC receiving systemic therapy is not common. The much more common scenario is multi-sites of recurrence. I would consider local XRT and continuing immunotherapy, only in the circumstance in which the patient has had a prolonged response to initial chemoimmunotherapy and truly has only 1 site of PD. Efficacy of second-line systemic therapy (lurbinectedin, topotecan, taxanes, gemcitabine, anthracyclines, temozolomide, and IO agents) is modest.

I have utilized this strategy of local XRT and continuing the same systemic therapy in patients with ES SCLC a handful of times. My experience in these cases has not been favorable; therefore, my advice is to do it in very limited scenarios.