Background:It has been suggested that cancer registries in England are too dependent on processing of information from death certificates, and consequently that cancer survival statistics reported for England are systematically biased and too low.Methods:We have linked routine cancer registration records for colorectal, lung, and breast cancer patients with information from the Hospital Episode Statistics (HES) database for the period 2001–2007. Based on record linkage with the HES database, records missing in the cancer register were identified, and dates of diagnosis were revised. The effects of those revisions on the estimated survival time and proportion of patients surviving for 1 year or more were studied. Cases that were absent in the cancer register and present in the HES data with a relevant diagnosis code and a relevant surgery code were used to estimate (a) the completeness of the cancer register. Differences in survival times calculated from the two data sources were used to estimate (b) the possible extent of error in the recorded survival time in the cancer register. Finally, we combined (a) and (b) to estimate (c) the resulting differences in 1-year cumulative survival estimates.Results:Completeness of case ascertainment in English cancer registries is high, around 98–99%. Using HES data added 1.9%, 0.4% and 2.0% to the number of colorectal, lung, and breast cancer registrations, respectively. Around 5–6% of rapidly fatal cancer registrations had survival time extended by more than a month, and almost 3% of rapidly fatal breast cancer records were extended by more than a year. The resulting impact on estimates of 1-year survival was small, amounting to 1.0, 0.8, and 0.4 percentage points for colorectal, lung, and breast cancer, respectively.Interpretation:English cancer registration data cannot be dismissed as unfit for the purpose of cancer survival analysis. However, investigators should retain a critical attitude to data quality and sources of error in international cancer survival studies.

BackgroundData linkage studies find that depression before or after a breast cancer diagnosis predicts reduced survival. This study aimed to determine whether depression or bipolar recorded in routine hospital admission data independently predicts survival in English breast cancer patients and whether onset in relation to cancer diagnosis is significant.MethodsData on 77 173 women diagnosed with breast cancer (ICD‐10 C50) in South East England, 2000–2009, were included. Of these, 131 women had a diagnosis of bipolar affective disorder (ICD‐10 F31) and 955 of depression (either depressive episodes (ICD‐10 F32) or depressive disorder (ICD‐10 F33)) recorded in Hospital Episode Statistics between 3 years before and a year following cancer diagnosis. Kaplan–Meier plots were used to examine overall survival. Cox regression analyses were carried out overall and separately for mood disorder diagnoses before and after the cancer diagnosis and adjusted for confounding variables.ResultsA record of depression was a predictor of worse overall survival in breast cancer patients (adjusted HR = 1.33, 95% CI: 1.20–1.48, p < 0.001), while the effect of bipolar was not statistically significant (adjusted HR = 1.33, 95% CI: 0.97–1.82, p = 0.079). New recordings of depression and bipolar diagnoses following a cancer diagnosis appeared better predictors of overall survival than a prior history of either.ConclusionsThere is evidence that English breast cancer patients with depression and bipolar recorded in routine hospital data have worse overall survival than those without these mood disorders. Further work exploring the concordance of records within administrative health data with clinical diagnosis and cause‐specific death within these patient groups is needed. © 2015 The Authors. Psycho‐Oncology Published by John Wiley & Sons Ltd.