International phase IV field study to validate the European Organisation for Research and Treatment of Cancer questionnaire for assessing the health-related quality of life of cancer survivors: The EORTC QLQ-SURV100.

Fox L, van Leeuwen M, Jones JM, Al-Omari A, Abaza H, Al-Khaifi M, Eichler M, Hartup S, Velikova G, Friðriksdóttir N, Cho J, Vanlaer N, Rogiers A, Costi S, Soncini S, Kjær TK, Arndt V, Doege D, Alkan A, Ishiki H, Rammant E, Baumann J, Sinn M, Annunziata MA, Arraras JI, Van Hemelrijck M, Pace A, Clatworthy N, King V, Tolstrup LK, Shimomura A, Kontogianni M, Sodergren SC, Vukšić N, Petersen MA, Kieffer JM, Jefford M, Chalk T, Young T, Borda N, Morag O, Harle A, Petranović D, Meggiolaro E, De Padova S, Jansen F, Turhal NS, Navarra CM, Baumann I, Amdal CD, Vassiliou V, Pinto M, Kurosawa S, Vistad I, Al-Balushi M, Al-Ghoche A, Dirven L, Capela A, Elsayed Z, Montemuiño S, Willisch P, Aaronson N, van de Poll-Franse L; EORTC Quality of Life Group. International phase IV field study to validate the European Organisation for Research and Treatment of Cancer questionnaire for assessing the health-related quality of life of cancer survivors: The EORTC QLQ-SURV100. Eur J Cancer. 2026 Jul 22;245:116959. doi: 10.1016/j.ejca.2026.116959.

Introduction: Cancer survivors face unique and persistent health-related quality of life (HRQoL) challenges. Existing HRQoL questionnaires for survivors lack content regarding chronic physical issues and have typically included limited cancer types and languages/cultures, affecting breadth of content and generalisability. We developed and validated the EORTC QLQ-SURV100, a questionnaire to assess HRQoL in disease-free survivors of diverse cancers. A conceptual framework of HRQoL in cancer survivors, developed in previous study phases and conceptualised as survivors' self-reported physical, mental and social functioning and well-being, formed the basis for questionnaire content. 

Methods: The QLQ-SURV100 was administered to 1480 participants across 46 centres in 21 countries (31% breast cancer, 23% colorectal, 22% prostate, 24% other cancers), who had completed primary treatment 1-10 years earlier and had no evidence of active disease. Structural validity of the 21 multi-item questionnaire scales was assessed via confirmatory factor analysis; test-retest reliability via intraclass correlation coefficients (ICCs); construct validity through known-group comparisons; and cross-cultural validity and sex invariance through differential item functioning (DIF). Item response theory (IRT) analyses evaluated item redundancy and performance. 

Results: The QLQ-SURV100 showed strong structural validity (Comparative Fit Index = 0.951; Tucker-Lewis Index = 0.944; Root Mean Square Error of Approximation = 0.046), with most standardised factor loadings > 0.7. Test-retest ICCs exceeded 0.7 for 27 of 35 scales and 0.6 for 34 scales. Known-groups analyses supported most hypotheses, confirming sensitivity to treatment, comorbidity, age, sex, and education. DIF analysis indicated minor cross-cultural item bias, but no sex-related DIF. IRT analysis found no redundant items. 

Conclusions: The EORTC QLQ-SURV100 showed satisfactory structural validity, test-retest reliability and construct validity; limited item redundancy; and measurement invariance across the sex and language groups examined. 

Keywords: Cancer; Cancer survivors; Patient-reported outcome measures; Quality of life; Survivorship. 

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