OP170 Are patients with acute myeloid leukaemia (AML) or myelodysplastic syndromes (MDS) more likely than the general population to have a preceding cancer? An analysis from the UK’s population-based haematological malignancy research network (HMRN)

Background

Around 5,000 people are newly diagnosed with either AML or MDS in the UK each year. These blood cancers are more common in males and are typically diagnosed in people in their 70s. Forming part of the same disease continuum and with a similar disease pathogenesis, the causes of these aggressive cancers are largely unknown, but one recognised risk factor is treatment for a previous cancer (chemotherapy/radiotherapy). To understand this association further, and the impact on survival, we compared prior cancer registration frequencies in AML/MDS patients to that of general population controls.

Methods

Data are from an established population-based registry of blood cancers diagnosed since 2004 in a catchment population of ~4 million (www.hmrn.org). For patients diagnosed 2009–2015, a second cohort of 10 age- and sex-matched controls exists, with both cohorts linked to national cancer registrations and mortality. The present analysis includes patients newly diagnosed with AML/MDS 2009–2015 (cases; n=1,776) and their matched controls (n=17,757). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression, and net survival was calculated using the Pohar Perme estimator.

Results

Median age at diagnosis was 75 years, 60% of subjects were male, and median time from cancer registration to AML/MDS was 6.3 years. Cases were 55% more likely than their matched controls to have had a previous cancer registration (15.1% vs. 10.3%; OR 1.56 [95%CI:1.36–1.80]), with the difference between cases and controls being greater among females than males: 1.97 (1.60–2.43) vs. 1.31 (1.09–1.59), respectively. Cases were significantly more likely to have had a previous myeloma (7.27 [2.93–18.08]) or non-Hodgkin lymphoma (5.51 [3.34–9.09]). For prior malignancies that were not haematological, the largest difference was seen for cancers of the digestive organs (1.40 [1.04–1.88]), and among women for cancers of the breast (1.65 [1.22–2.23]) or genital organs (1.89 [1.23–2.91]). Preceding cancer registration was associated with poorer survival in both AML and MDS patients. One-year net survival was 24.7% (16.9–32.5) in AML patients with a previous cancer compared to 35.8% (32.3–39.4) in those without; and in MDS there was a 20% difference in survival between those with and without a previous cancer (51.5% [42.9–60.0] vs. 71.7% [68.3–75.1], respectively).

Conclusion

The findings confirm that having a preceding cancer is a risk factor for developing AML/MDS, which is likely to be related to the therapy received. Importantly, this impacts on outcome, with survival being markedly poorer among AML/MDS cases with a previous cancer registration.