ObjectiveTo assess the representativeness of National Cancer Patient Experience Survey (CPES) responders compared with the English cancer registry population in term of age, sex, socioeconomic deprivation, ethnicity, disease stage and median survival.DesignPopulation-based case-control study.SettingEngland.PopulationWe identified 103 186 colorectal, lung, breast and prostate cancer patients responding to at least one survey during 2010–2014 and randomly selected one non-responder from the cancer registry matched on cancer type and yearly quarter of diagnosis.Main outcome measureWe compared age, sex, socioeconomic deprivation, ethnicity and disease stage between the two groups using logistic regression. We also compared survival (in years) using the Mann-Whitney test.ResultsAcross all cancer types survey responders were younger, more likely to have a White ethnic background, to be resident in less deprived areas and diagnosed with earlier stage disease although they varied between cancers. Median survival for responders was also higher than for the cancer registry population (colorectal: 4.8 vs 3.2; lung: 2.0 vs 0.3; breast: 5.7 vs 5.4; and prostate: 5.7 vs 5.2 years; all p-values<0.001).ConclusionCPES responders with the four most common cancers do not necessarily represent all patients with these cancers in terms of demographic characteristics and tumour stage at diagnosis. These limitations should be considered when interpreting findings. To capture the experiences of patients currently underrepresented in CPES, different approaches may need to be taken.