Pre-diagnosis lipid levels and mortality after obesity-related cancer diagnosis in the Women's Health Initiative cardiovascular disease biomarker cohort.

BACKGROUND: Published studies have demonstrated inconclusive relationships between serum lipid levels and mortality after cancer. METHODS: The primary objective was to evaluate the relationship between fasting lipid levels and mortality after cancer. Data were obtained on baseline lipids and outcomes after cancer from 1263 postmenopausal women diagnosed with 13 obesity-related cancers who were part of the Women's Health Initiative (WHI) lipid biomarkers cohort. Obesity-related cancers included incident invasive cancers of the breast, colorectum, endometrium, esophagus (adenocarcinoma), kidney, liver, gallbladder, pancreas, ovaries, small intestine, thyroid, stomach, as well as multiple myeloma. Baseline lipid measurements included high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and non-HDL-cholesterol. Outcomes were all cause, cancer-specific, and CVD mortality. Multivariable Cox proportional hazards models were used to measure associations between lipid levels and mortality (all cause, cancer, and CVD) after a cancer diagnosis, with lipids analyzed as continuous variables. RESULTS: Among women with obesity-related cancer, there were 707 deaths, of which 379 (54%) were due to cancer and 113 (16%) were due to CVD. Mean time from blood draw to cancer diagnosis was 5.1 years (range: 0.05-10 years). LDL-C values above the 95th percentile were associated with higher risk of all-cause mortality (p < 0.001), and cancer-specific mortality (p < 0.001), but not mortality due to CVD. Non-HDL-C values above the 65th percentile were associated with higher risk of all-cause mortality (p = 0.01) and mortality due to CVD (p = 0.003), but not cancer-specific mortality (p = 0.37). HDL-C values above the 95th percentile were associated with lower all-cause mortality (p = 0.002), and above the 65th percentile with lower cancer-specific mortality (p = 0.003), but no significant relationship with mortality due to CVD was observed. CONCLUSIONS: The relationship between pre-diagnosis fasting lipid levels and mortality after cancer diagnosis is complex. These results suggest that improved lipid control through lifestyle and anti-lipid medications could have a meaningful impact on outcomes after cancer.

Cardiometabolic risk factors and survival after cancer in the Women's Health Initiative.

BACKGROUND: Cardiometabolic abnormalities are a leading cause of death among women, including women with cancer. METHODS: This study examined the association between prediagnosis cardiovascular health and total and cause-specific mortality among 12,076 postmenopausal women who developed local- or regional-stage invasive cancer in the Women's Health Initiative (WHI). Cardiovascular risk factors included waist circumference, hypertension, high cholesterol, and type 2 diabetes. Obesity-related cancers included breast cancer, colorectal cancer, endometrial cancer, kidney cancer, pancreatic cancer, ovarian cancer, stomach cancer, liver cancer, and non-Hodgkin lymphoma. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for important predictors of survival. RESULTS: After a median follow-up of 10.0 years from the date of the cancer diagnosis, there were 3607 total deaths, with 1546 (43%) due to cancer. Most participants (62.9%) had 1 or 2 cardiometabolic risk factors, and 8.1% had 3 or 4. In adjusted models, women with 3 to 4 risk factors (vs none) had a higher risk of all-cause mortality (HR, 1.99; 95% CI, 1.73-2.30), death due to cardiovascular disease (CVD) (HR, 4.01; 95% CI, 2.88-5.57), cancer-specific mortality (HR, 1.37; 95% CI, 1.1-1.72), and other-cause mortality (HR, 2.14; 95% CI, 1.70-2.69). A higher waist circumference was associated with greater all-cause mortality (HR, 1.17; 95% CI, 1.06-1.30) and cancer-specific mortality (HR, 1.22; 95% CI, 1.04-1.42). CONCLUSIONS: Among postmenopausal women diagnosed with cancer in the WHI, cardiometabolic risk factors before the cancer diagnosis were associated with greater all-cause, CVD, cancer-specific, and other-cause mortality. These results raise hypotheses regarding potential clinical intervention strategies targeting cardiometabolic abnormalities that require future prospective studies for confirmation. LAY SUMMARY: This study uses information from the Women's Health Initiative (WHI) to find out whether cardiac risk factors are related to a greater risk of dying among older women with cancer. The WHI is the largest study of medical problems faced by older women in this country. The results show that women who have 3 or 4 risk factors are more likely to die of any cause, heart disease, or cancer in comparison with women with no risk factors. It is concluded that interventions to help to lower the burden of cardiac risk factors can have an important impact on survivorship among women with cancer.