Different associations of tumor PIK3CA mutations and clinical outcomes according to aspirin use among women with metastatic hormone receptor positive breast cancer

Introduction: The relationships among PIK3CA mutations, medication use and tumor progression remains poorly understood. Aspirin use post-diagnosis may modify components of the PI3K pathway, including AKT and mTOR, and has been associated with lower risk of breast cancer recurrence and mortality. We assessed time to metastasis (TTM) and survival with respect to aspirin use and tumor PIK3CA mutations among women with metastatic breast cancer.  Methods: Patients with hormone receptor positive, HER2 negative (HR+/HER2-) metastatic breast cancer treated in 2009-2016 who received tumor genotyping were included. Aspirin use between primary and metastatic diagnosis was extracted from electronic medical records. TTM and survival were estimated using Cox proportional hazards regression.  Results: Among 267 women with metastatic breast cancer, women with PIK3CA mutated tumors had longer TTM than women with PIK3CA wildtype tumors (7.1 vs. 4.7 years, p = 0.008). There was a significant interaction between PIK3CA mutations and aspirin use on TTM (p = 0.006) and survival (p = 0.026). PIK3CA mutations were associated with longer TTM among aspirin non-users (HR = 0.60 95% CI:0.44-0.82 p = 0.001) but not among aspirin users (HR = 1.57 0.86-2.84 p = 0.139). Similarly, PIK3CA mutations were associated with reduced mortality among aspirin non-users (HR = 0.70 95% CI:0.48-1.02 p = 0.066) but not among aspirin users (HR = 1.75 95% CI:0.88-3.49 p = 0.110).  Conclusions: Among women who develop metastatic breast cancer, tumor PIK3CA mutations are associated with slower time to progression and mortality only among aspirin non-users. Larger studies are needed to confirm this finding and examine the relationship among aspirin use, tumor mutation profile, and the overall risk of breast cancer progression.</p

Different associations of tumor PIK3CA mutations and clinical outcomes according to aspirin use among women with metastatic hormone receptor positive breast cancer

Introduction: The relationships among PIK3CA mutations, medication use and tumor progression remains poorly understood. Aspirin use post-diagnosis may modify components of the PI3K pathway, including AKT and mTOR, and has been associated with lower risk of breast cancer recurrence and mortality. We assessed time to metastasis (TTM) and survival with respect to aspirin use and tumor PIK3CA mutations among women with metastatic breast cancer.  Methods: Patients with hormone receptor positive, HER2 negative (HR+/HER2-) metastatic breast cancer treated in 2009-2016 who received tumor genotyping were included. Aspirin use between primary and metastatic diagnosis was extracted from electronic medical records. TTM and survival were estimated using Cox proportional hazards regression.  Results: Among 267 women with metastatic breast cancer, women with PIK3CA mutated tumors had longer TTM than women with PIK3CA wildtype tumors (7.1 vs. 4.7 years, p = 0.008). There was a significant interaction between PIK3CA mutations and aspirin use on TTM (p = 0.006) and survival (p = 0.026). PIK3CA mutations were associated with longer TTM among aspirin non-users (HR = 0.60 95% CI:0.44-0.82 p = 0.001) but not among aspirin users (HR = 1.57 0.86-2.84 p = 0.139). Similarly, PIK3CA mutations were associated with reduced mortality among aspirin non-users (HR = 0.70 95% CI:0.48-1.02 p = 0.066) but not among aspirin users (HR = 1.75 95% CI:0.88-3.49 p = 0.110).  Conclusions: Among women who develop metastatic breast cancer, tumor PIK3CA mutations are associated with slower time to progression and mortality only among aspirin non-users. Larger studies are needed to confirm this finding and examine the relationship among aspirin use, tumor mutation profile, and the overall risk of breast cancer progression.</p

Community and individual level characteristics of sub-districts and the study population.

Community and individual level characteristics of sub-districts and the study population.</p

Results of OLS regression with spatial weights matrix for community level factors.

Results of OLS regression with spatial weights matrix for community level factors.</p

Identified High-High and Low-Low sub-district clusters*.

*created in ArcGIS version 10.6.1 (Esri, Redlands, CA).</p

Community level factors for identified High-High (HH) and Low-Low (LL) sub-districts.

Community level factors for identified High-High (HH) and Low-Low (LL) sub-districts.</p

Crude and age standardized presentation rates per 100,000 women.

Crude and age standardized presentation rates per 100,000 women.</p

Multivariable regression for individual level factors associated with patients presenting from identified HH and LL sub-districts.

Multivariable regression for individual level factors associated with patients presenting from identified HH and LL sub-districts.</p

Univariate analysis of Individual level factors for patients presenting from identified HH and LL sub-districts.

Univariate analysis of Individual level factors for patients presenting from identified HH and LL sub-districts.</p

Age- standardized presentation rates to the MDT clinic in Gaborone, Botswana per sub-district*.

*created in ArcGIS version 10.6.1 (Esri, Redlands, CA).</p