A new cohort unlocks more rich data and useful comparators

This cohort allows us to compare the health of patients with blood cancer to similar people in the general population who are cancer-free. These comparisons are helping us find out more about how blood cancers relate to other conditions and illnesses.

To create the cohort, we matched 18,000 patients with blood cancer or related disorders, on age and sex, to ten randomly selected individuals from the NHS Central Register (180,000 controls in total). Looking at the comparison cohort and patient cohort side-by-side means that we can track patterns of co-morbidities and healthcare activity; uncovering novel associations and highlighting important connections and areas where extra monitoring and care may be needed.

HMRN database

HMRN now has two large cohorts feeding into its research on blood cancers (leukaemias, lymphomas, myelomas): 

The cancer cohort

Since 2004 we have tracked all patients (40,000 approx.) diagnosed with a haematological malignancy within HMRN’s catchment population of around 4 million people through local clinical systems. They are then routinely linked to national databases on deaths, cancers, hospital admissions, and hospital outpatient attendances (Hospital Episode Statistics, HES). The HMRN population is broadly representative of the UK as a whole and clinical practice across the HMRN region adheres to national guidelines.  All patients are included regardless of age, treatment intent, trial entry, or whether they are NHS or private patients. About 2,500 new diagnosis are made each year. This vital information is disseminated to researchers, clinicians, patients and commissioners to give them the best picture of the burden of these diseases across the population as a whole (www.hmrn.org/about)  

The new comparison cohort

The new comparison cohort is made up of people from the same area, with the same characteristics (age and sex), as people in the cancer cohort. Their data are linked by NHS Digital to nationwide administrative databases for deaths, cancer registrations and hospital episode statistics (HES) just as the patient cohort is.  In this way the health of the cancer patients can be compared to that of unaffected individuals in the general population. This is enabling new research examining associations with other cancers and diseases, as well as short and long-term levels of hospital activity.

To create the new cohort, all patients newly diagnosed with a blood cancer between 2009 and 2015 (18,127 patients) were matched on year of birth, sex and residency in the HMRN study area to 10 randomly selected unaffected individuals (181,270 people). This very large matching process was a first for NHS Digital, the national provider of information, data and IT systems for the NHS.

Key findings so far

The new cohort has already been used successfully to look at the relationship between immune system problems and the development of mature B-cell malignancies and autoimmune conditions:

1. The annual rheumatology outpatient episode rates for male and female patients in the 10 years preceding their diagnosis of diffuse large B-cell lymphoma (DLBCL) clearly shows that DLBCL patients were significantly more likely to have a history of rheumatoid disorders compared to their general-population cohort comparators. Read the research
2. HMRN also collects data on premalignancies. Here we found that individuals with monoclonal gammopathy of undetermined significance (MGUS) experienced excess morbidity in the 5 years before their premalignancy was diagnosed, compared to the general population. After haematology (which is to be expected), outpatient attendances increased markedly for nephrology and rheumatology just before and after MGUS diagnosis. Read the research

Main strengths of the new, improved HMRN

Our population-based cohort main strengths are:

1. Large well-defined population within which all blood cancers and related clonal disorders are diagnosed, monitored and coded using up-to-date standardised procedures.
2. World class diagnostics, completeness of case ascertainment, adherence to national guidelines and detailed follow-up of every patient, mean that data quality is of the highest standard
3. Predicated on infrastructures within the NHS where universal healthcare is freely provided on the basis of clinical need
4. 10 individually age- and sex- matched controls for all patients diagnosed in 2009-2015

Professor Eve Roman, ECSG's Director, comments on these new developments and what they mean for cancer research in the UK:

“Embedding high-quality, population-based, epidemiological, clinical and biological research within the framework of NHS clinical practice, HMRN’s multifaceted cohorts have not been replicated elsewhere in the world. The incorporation of a new general-population cohort, allows us to compare the health of those who have blood cancer to those who do not – both in the years before cancer is diagnosed and the years after.  Thus far, many of the findings have been striking and unexpected.  We are currently examining longer term health (survivorship); looking, for example, to see whether the health of patients successfully treated for cancer ever returns to the level it would have been, had they not had cancer”

Read the full research