Concordance in survival among first-degree relatives diagnosed with indolent lymphoid malignancies including chronic lymphocytic leukemia

Concordance in survival among first-degree relatives diagnosed with indolent lymphoid malignancies including chronic lymphocytic leukemia

Objectives

To investigate concordance in survival time among first‐degree relatives with lymphoid malignancies.

Methods

By linkage of national Swedish registers, we identified 66 430 patients diagnosed with a lymphoid malignancy 1958‐2016 with information on first‐degree relationships and follow‐up until 2017. Among these, we identified pairs of first‐degree relatives with any (N = 3326) or a similar (N = 690) lymphoid malignancy subtype. We defined survival in the first‐degree relative as good, expected, or poor based on tertiles of deviance residuals from a multivariable Cox regression model. Next, we used Cox regression to estimate hazard ratios (HR) of death with 95% confidence intervals (CI) among patients, using the survival of their first‐degree relative as exposure and adjusting for confounders.

Results

There was no concordance in survival among first‐degree relatives with any lymphoid malignancy (HR_good = 1.00 (reference), HR_Expected = 1.02, 95% CI: 0.89‐1.17, HR_Poor = 1.12, 95% CI: 0.98‐1.27, P_trend = .08). Among first‐degree relatives with indolent lymphoma, including chronic lymphocytic leukemia, those with a first‐degree relative to an expected or poor survival had worse outcome compared to those with a first‐degree relative with good survival (HR_Expected = 1.44, 95% CI: 0.82‐2.53, HR_Poor = 1.79, 95% CI: 1.07‐3.00, P_trend = .03).

Conclusion

Our results support a role of inherited factors in the outcome of indolent lymphoma, including chronic lymphocytic leukemia.