Effect of pre-existing conditions on bladder cancer stage at diagnosis: a cohort study using electronic primary care records in the UK

Abstract

BackgroundPre-existing concurrent medical conditions (multimorbidity) complicate cancer diagnosis when they provide plausible diagnostic alternatives for cancer symptoms.AimTo investigate associations in bladder cancer between: first, pre-existing condition count and advanced-stage diagnosis; and, second, comorbidities that share symptoms with bladder cancer and advanced-stage diagnosis.Design and settingThis observational UK cohort study was set in the Clinical Practice Research Datalink with Public Health England National Cancer Registration and Analysis Service linkage.MethodIncluded participants were aged ≥40 years with an incident diagnosis of bladder cancer between 1 January 2000 and 31 December 2015, and primary care records of attendance for haematuria, dysuria, or abdominal mass in the year before diagnosis. Stage at diagnosis (stage 1 or 2 versus stage 3 or 4) was the outcome variable. Putative explanatory variables using logistic regression were examined, including patient-level count of pre-existing conditions and ‘alternative-explanations’, indicating whether pre-existing condition(s) were plausible diagnostic alternatives for the index cancer symptom.ResultsIn total, 1468 patients (76.4% male) were studied, of which 399 (35.6%) males and 217 (62.5%) females had alternative explanations for their index cancer symptom, the most common being urinary tract infection with haematuria. Females were more likely than males to be diagnosed with advanced-stage cancer (adjusted odds ratio [aOR] 1.62; 95% confidence interval [CI] = 1.20 to 2.18; P = 0.001). Alternative explanations were strongly associated with advanced-stage diagnosis in both sexes (aOR 1.69; 95% CI = 1.20 to 2.39; P = 0.003).ConclusionAlternative explanations were associated with advanced-stage diagnosis of bladder cancer. Females were more likely than males to be diagnosed with advanced-stage disease, but the effect was not driven entirely by alternative explanations.

Quantifying the impact of pre-existing conditions on the stage of oesophagogastric cancer at diagnosis: a primary care cohort study using electronic medical records

“…Previous research established associations between multimorbidity and advanced-stage diagnosis of ovarian, laryngeal, breast and colorectal cancers ( 12 , 14–16 ). Findings related to gastric/liver cancers were inconclusive, although separate effects for gastric and liver cancers or for men and women were not investigated ( 19 ).…”

“…Both CPRD and NCRAS have missing data. In line with convention, we interpreted the absence of a code for a clinical event as its non-occurrence ( 14 , 20 , 24 ). We classified participants with no recorded features of cancer and/or no diagnostic codes for comorbid conditions as not presenting with alternative explanations.…”

“…Expedited diagnosis may occur in patients whose conditions require routine monitoring, by increasing opportunities for symptom reporting (the surveillance hypothesis) ( 11–13 ). In contrast, diagnosis may be delayed if cancer symptoms mimic those of the pre-existing condition (the alternative-explanations hypothesis) ( 13 , 14 ), or the primary-care consultations are dominated by condition management (the competing-demands hypothesis) ( 13 ).…”

Comorbidity and the diagnosis of symptomatic-but-as-yet-undiagnosed cancer

“…8 Chronic conditions offering 'alternative explanations' were found to be associated with a higher risk of diagnosis of advanced stage bladder cancer. 5 The study by Carney et al did not directly examine the 'surveillance effect' hypothesis, where chronic disease monitoring for underlying morbidities might lead to earlier detection of new illness through more frequent contacts with healthcare professionals. 6,[8][9][10] However, some of the study findings would be consistent with such a mechanism.…”

“…Carney et al, in this issue of the BJGP, shed light on this complex question in the context of the diagnosis of bladder cancer. 5…”