Prophylactic cranial irradiation (PCI) is the standard of care in patients who respond to initial chemotherapy for ES-SCLC, although several studies have questioned its benefit with regard to overall survival.
Here we report an updated result on a single-centred ES-SCLC cohort in a regional cancer centre in New Zealand. All ES-SCLC patients who had at least one cycle of chemotherapy from 2001 through April 2017 were included. The available records were reviewed to extract age, sex, comorbidities, metastatic sites, chemotherapy [regimen, and number of chemotherapy lines (NCL)], radiotherapy [palliative, consolidation chest radiotherapy (CCRT), or PCI], and overall survival (OS). Patients were stratified by PCI status (received vs. not received). Penalised regression was used for selecting variables for Cox’s regression, which was then used to adjust for confounders that affect survival by PCI status.
Of 328 ES-SCLC patients evaluable, 295 received ≥1 cycle of chemotherapy. In the 68 patients (23%) who received PCI, the median OS was 14.0 months (95% CI: 11.2-16.6), compared to 5.8 months (95% CI: 4.9-7.1) in patients who did not receive PCI (unadjusted hazard ratio (HR) for death: 0.40, 95% CI: 0.30-0.53). After adjusting for three significant covariates (NCL, whether ≥4 cycles of first-line chemotherapy was given, and whether CCRT was delivered), patients who received PCI were found to have a significantly longer survival (adjusted HR: 0.63, 95% CI: 0.43-0.90). Patients (N = 109, 33%) who had <4 cycles of first-line chemotherapy (and later did not receive more chemotherapy) had a very poor prognosis (median OS: 2.93 months, 95%CI: 2.0-3.4).
ES-SCLC patients treated with PCI appear to have a better survival in our cohort, although this difference could be affected by lack of baseline cranial imaging to exclude patients with asymptomatic brain metastases. PCI should still be used judiciously considering its toxicities and potential negative impact on quality of life.
Clinical trial identification
Legal entity responsible for the study
Waikato District Health Board.
Has not received any funding.
All authors have declared no conflicts of interest.