Discovery related publications - 2014
Discovery related publications - 2014
These are publications derived from Discovery research data and databases and/ or research collaborations with other research staff outside the Discovery programme.
Walker S, Hyde C, Hamilton W. Risk of breast cancer in symptomatic women in primary care: a case-control study using electronic records. Br J Gen Pract. 2014 Dec;64(629):e788-93. doi: 10.3399/bjgp14X682873.
Breast cancer is the most common cancer in the UK. GPs are encouraged to refer all women whose symptoms may represent cancer, rather than selecting those at highest risk.
To identify and quantify features of breast cancer in primary care.
DESIGN AND SETTING:
A UK case-control study using the Clinical Practice Research Database (CPRD).
Possible features of breast cancer were identified in the year before diagnosis, and odds ratios calculated using conditional logistic regression. Positive predictive values (PPVs) were estimated for consulting women.
A total of 3994 women aged ≥40 years with breast cancer between 2000 and 2009, and 16 873 age-, sex-, and practice-matched controls were studied. Median age at diagnosis was 63 years (interquartile range 55-74 years). Four features were significantly associated with breast cancer: breast lump (odds ratio [OR] 110; 95% confidence interval [CI] = I88 to 150), breast pain (OR = 4.2; 95% CI = 3.0 to 6.0), nipple retraction (OR = 26; 95% CI = 10 to 64), nipple discharge (OR = 19; 95% CI = 8.6 to 41): all P-values <0.01. In the year before diagnosis, 1762 (44%) of cases had a breast lump compared with 132 (0.8%) controls. The PPV of breast cancer with a breast lump was 4.8% in women aged 40-49 years, rising to 48% in women aged >70 years. PPVs were lower in women who also reported breast pain.
Generally, the figures support current referral practice. However, the low likelihood of cancer for all the non-lump symptoms means that the current guidance recommends investigation for possible cancer at a more liberal risk threshold than for other cancers. Although supported by patients, this may not meet current NHS criteria for cost-benefit.
Early diagnosis is a key focus of cancer control because of its association with survival. Delays in diagnosis can occur throughout the diagnostic pathway, within any one of its three component intervals: the patient interval, the primary care interval and the secondary care interval.
A key focus for help-seeking research in patients with symptoms of cancer has been the concept of 'delay'. The literature is plagued by definitional and semantic problems, which serve to hinder comparison between studies. Use of the word 'delay' has been criticised as judgemental and potentially stigmatising, because of its implications of intent. However, the suggested alternatives (time to presentation, appraisal interval, help-seeking interval and postponement of help-seeking) still fail to accurately define the concept in hand, and often conflate three quite separate ideas; that of an interval, that of an unacceptably long interval, and that of a specific event which caused delay in the diagnostic process. We discuss the need to disentangle current terminology and suggest the term 'prolonged interval' as a more appropriate alternative. Most studies treat the patient interval as a dichotomous variable, with cases beyond a specified time point classified as 'delay'. However, there are inconsistencies in both where this line is drawn, ranging from one week to three months, and how, with some studies imposing seemingly arbitrary time points, others utilising the median as a divisive tool or exploring quartiles within their data. This not only makes comparison problematic, but, as many studies do not differentiate between cancer site, also imposes boundaries which are not necessarily site-relevant. We argue that analysis of the patient interval should be based on presenting symptom, as opposed to pathology, to better reflect the context of the help-seeking interval, and suggest how new definitional boundaries could be developed.
The word 'delay' is currently (conf)used to describe diverse conceptualisations of 'delay' and more mindful, and discerning language needs to be developed to enable a more sophisticated discussion. By stratifying help-seeking by presenting symptom(s), more accurate and informative analyses could be produced which, in turn, would result in more accurately targeted early diagnosis interventions.
Hamilton F, Carroll R, Hamilton W, Salisbury C. The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records. Br J Cancer. 2014 Sep 23;111(7):1410-2. doi: 10.1038/bjc.2014.433. Epub 2014 Aug 5.
The risk of cancer with hypercalcaemia in primary care is unknown.
This was a cohort study using calcium results in patients aged ≥40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified.
Participants (54 267) had calcium results: 1674 (3%) were ≥2.6 mmol l 1-1. Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17-3.93, P=<0.001; positive predictive value (PPV) 11.5%; females: OR 1.86, 95% CI 1.39-2.50, P<0.001: PPV 4.1%.
Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women.
New Discovery Research publication
The SYMPTOM Study team's research into symptom appraisal for colorectal cancer has been published in BMJ Open. This is a unique piece of research which compares the appraisal and help seeking experiences of patients with colorectal cancer symptoms who go on to have cancer and those who turn out to have non-cancer conditions. The research did not identify any clear differences between the two groups but did identify important barriers to presentation around the ‘private nature’ of colorectal symptoms which will prove useful to policy makers and the design of awareness campaigns. To read more about the research paper see the results section here.
Discovery conference slides available & new research publications
The Discovery Programme held its research conference at the Royal College of General Practitioners on June 2nd 2015. The team presented their research findings and outlined the impact of the programme to a wide range of patient groups, clinicians, policy makers, researchers and journalists. The PowerPoint slides used during the presentation have been uploaded to this website and can be viewed here.
There are also 2 new research papers to report. Chantal Balasooriya-Smeekens has published the literature review of her PhD in Psycho-Oncology, "The role of emotions in time to presentation for symptoms suggestive of cancer: a systematic review of quantitative studies". Abstract and publication details are here and further papers from Chantal's PhD will be published soon.
Nafees Din has published a new paper under the Discovery related research umbrella. The paper uses Discovery data drawn from the CAPER (theme 2) studies and considers "Age and Gender Variations in Cancer Diagnostic Intervals in 15 Cancers". Full publication details and abstract can be found here.