Author of

• 11692

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  P2.10 - Poster Session 2 - Chemotherapy (ID 207)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11732

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    P2.10-040 - Prognostic significance, accuracy and usefulness of oncologists' estimates of survival time for patients starting first-line chemotherapy for advanced non-small-cell lung cancer (ANSCLC) (ID 2560)

    09:30 - 09:30  |  Author(s): S. Begbie
    • Abstract

    Background
    Oncologists are frequently required to provide estimates of survival time for their patients with advanced cancer. The aims of this study were to determine the accuracy and prognostic significance of oncologists’ estimates of survival time above and beyond conventional prognostic factors.

    Methods
    Medical oncologists from 26 sites in Australia and New Zealand recorded the “expected survival time in months” for individual patients with ANSCLC prior to randomisation in a trial of first-line chemotherapy with a platinum-based doublet. Blood samples, demographics, tumour and treatment characteristics were collected at baseline along with the oncologist’s rating of each patient using Spitzer’s Quality of Life Index (SQLI). Based on previous studies, we deemed estimates within 0.75-1.33 times observed survival as precise, and expected 50% of patients to live longer (or shorter) than their oncologist’s estimate, 50% to live from half to double their oncologist’s estimate (typical scenario); 5-10% to live ≤¼ of their estimate (worst-case scenario); and, 5-10% to live ≥3 times their estimate (best-case scenario). Associations between estimated and observed survival times in months were assessed with Cox proportional hazards regression before and after adjustment for baseline prognostic factors including age, gender, Eastern Cooperative Oncology Group performance status (ECOG PS), cancer extent, histology, co-morbidities, laboratory results and SQLI.

    Results
    Estimates of survival were available for 244 (98%) of the first 250 patients randomised. Patient characteristics were: median age 64 years; female 40%; adenocarcinoma 64%; ECOG PS 0-1 92%; and distant metastases 71%. After a median follow-up of 21 months there were 172 deaths (69%). The median (interquartile range, IQR) for observed survival was 10 months (5-20) and for estimated survival was 11 months (9-12). Oncologists’ estimates were imprecise (22% from 0.75-1.33 times observed) but well calibrated (47% of patients lived shorter than expected and 53% lived longer than expected). The proportions of patients with observed survival times falling within ranges bounded by simple multiples of their estimated survival times corresponded closely with our a-priori hypotheses: 10% lived ≤1/4 of their estimated survival time, 53% lived from half to double their estimated survival time, and 13% lived ≥3 times their estimated survival time. The oncologist’s estimate of survival time at baseline was the strongest predictor of observed survival in both univariable analysis (HR 0.90, 95% CI 0.86-0.95, p<0.001) and multivariable analysis (HR 0.90, 95% CI 0.86-0.95, p<0.001) accounting for all other independently significant predictors, namely: estimated neutrophil-lymphocyte ratio >5 (HR 3.15, 95% CI 1.76-5.64, p<0.001); haemoglobin <120g/L (HR 1.93, 95% CI 1.3-2.9, p=0.001) and total white cell count >11x10[9]/L (HR 1.55, 95% CI 1.05-2.27, p=0.03).

    Conclusion
    Oncologists' estimates of survival time were independently associated with observed survival time and provided a reasonable basis for estimating worst-case, typical and best-case scenarios for survival. Oncologists’ estimates provide useful additional prognostic information, above and beyond that provided by established prognostic factors.