A comparison of analytic approaches for investigating the obesity paradox in kidney cancer.

PURPOSE: Body mass index (BMI) and kidney cancer mortality are inconsistently associated in the scientific literature. To understand how study design affects results, we contrasted associations between pre-diagnosis BMI and mortality under different analytic scenarios in a large, population-based prospective cohort study. METHODS: Using data from the NIH-AARP Diet and Health Study (1995-2011), we constructed two cohorts: a "full at-risk" cohort with no kidney cancer history at baseline (n = 252,845) and an "incident cancer" subset who developed kidney cancer during follow-up (n = 1,652). Cox Proportional Hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) between pre-diagnosis BMI and mortality for different outcomes (all-cause and cancer-specific mortality), in the different cohorts (full at-risk vs. incident cancer cohort), and with different covariates (minimally vs. fully adjusted). For the incident cancer cohort, we also examined time to mortality using different timescales: from enrollment or diagnosis. RESULTS: In the full at-risk study population, higher pre-diagnosis BMI was associated with greater cancer-specific mortality in fully adjusted multivariable models, particularly for obese participants [HR, (95% CI): 1.76, (1.38-2.25)]. This association was less pronounced in the incident cancer cohort [1.50, (1.09-2.07)]. BMI was not strongly associated with all-cause mortality in either cohort in fully adjusted models [full cohort: 1.03, (1.01, 1.06); incident cancer cohort: 1.20, (0.97, 1.48)]. CONCLUSIONS: Populations characterized by high adult BMI will likely experience greater population burdens of mortality from kidney cancer, partially because of higher rates of kidney cancer diagnosis. Questions regarding overall mortality burden and post-diagnosis cancer survivorship are distinct and require different study designs.

Adolescent use of hair dyes, straighteners and perms in relation to breast cancer risk.

Hair products can contain hormonally active and carcinogenic compounds. Adolescence may be a period of enhanced susceptibility of the breast tissue to exposure to chemicals. We therefore evaluated associations between adolescent hair product use and breast cancer risk. Sister Study participants (ages 35-74 years) who had completed enrollment questionnaires (2003-2009) on use of hair dyes, straighteners/relaxers and perms at ages 10 to 13 years (N = 47 522) were included. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for associations between hair products and incident breast cancer (invasive cancer or ductal carcinoma in situ), with consideration of heterogeneity by menopausal status and race/ethnicity. Over an average of 10 years of follow-up, 3380 cases were diagnosed. Frequent use of straighteners and perms was associated with a higher risk of premenopausal (HR = 2.11, 95% CI: 1.26-3.55 and HR = 1.55, 95% CI: 0.96-2.53, respectively) but not postmenopausal breast cancer (HR = 0.99, 95% CI: 0.76-1.30 and HR = 1.09, 95% CI: 0.89-1.35, respectively). Permanent hair dye use during adolescence was uncommon (<3%) and not associated with breast cancer overall (HR = 0.97, 95% CI: 0.78-1.20), though any permanent dye use was associated with a higher risk among black women (HR = 1.77, 95% CI: 1.01-3.11). Although frequency of use of perms (37% non-Hispanic white vs 9% black) and straighteners (3% non-Hispanic white vs 75% black) varied by race/ethnicity, associations with breast cancer did not. Use of hair products, specifically perms and straighteners, during adolescence may be associated with a higher risk of premenopausal breast cancer.

Use of patient-reported controls for secular trends to study disparities in cancer-related job loss.

PURPOSE: Racial/ethnic minorities experience greater job loss than whites during periods of economic downturn and after a cancer diagnosis. Therefore, race/ethnicity-matched controls are needed to distinguish the impact of illness on job loss from secular trends METHODS: Surveys were administered during and 4-month post-completion of breast cancer treatment. Patients were pre-diagnosis employed women aged 18-64, undergoing treatment for stage I-III breast cancers, who spoke English, Chinese, Korean, or Spanish. Each patient was asked to: (1) nominate peers who were surveyed in a corresponding timeframe (active controls), (2) report a friend's work status at baseline and follow-up (passive controls). Both types of controls were healthy, employed at baseline, and shared the nominating patient's race/ethnicity, language, and age. The primary outcome was number of evaluable patient-control pairs by type of control. A patient-control pair was evaluable if work status at follow-up was reported for both individuals. RESULTS: Of the 180 patients, 25% had evaluable active controls (45 patient-control pairs); 84% had evaluable passive controls (151 patient-control pairs). Although patients with controls differed from those without controls under each strategy, there was no difference in the percentage of controls who were working at follow-up (96% of active controls; 91% of passive controls). However, only 65% of patients were working at follow-up. CONCLUSIONS: The majority of patients had evaluable passive controls. There was no significant difference in outcome between controls ascertained through either method IMPLICATIONS FOR CANCER SURVIVORS: Passive controls are a low-cost, higher-yield option to control for secular trends in racially/ethnically diverse samples.

Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women.

Many hair products contain endocrine-disrupting compounds and carcinogens potentially relevant to breast cancer. Products used predominately by black women may contain more hormonally-active compounds. In a national prospective cohort study, we examined the association between hair dye and chemical relaxer/straightener use and breast cancer risk by ethnicity. Sister Study participants (n = 46,709), women ages 35-74, were enrolled between 2003 and 2009, and had a sister with breast cancer but were breast cancer-free themselves. Enrollment questionnaires included past 12-month hair product use. Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between hair products and breast cancer; effect measure modification by ethnicity was evaluated. During follow-up (mean = 8.3 years), 2,794 breast cancers were identified. Fifty-five percent of participants reported using permanent dye at enrollment. Permanent dye use was associated with 45% higher breast cancer risk in black women (HR = 1.45, 95% CI: 1.10-1.90), and 7% higher risk in white women (HR = 1.07, 95% CI: 0.99-1.16; heterogeneity p = 0.04). Among all participants, personal straightener use was associated with breast cancer risk (HR = 1.18, 95% CI 0.99-1.41); with higher risk associated with increased frequency (p for trend = 0.02). Nonprofessional application of semipermanent dye (HR = 1.28, 95% CI 1.05-1.56) and straighteners (HR = 1.27, 95% CI 0.99-1.62) to others was associated with breast cancer risk. We observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women. These results suggest that chemicals in hair products may play a role in breast carcinogenesis.

Women With Breast Cancer Who Work For Accommodating Employers More Likely To Retain Jobs After Treatment.

Breast cancer affects one in eight women across the United States, and low-income minority survivors of breast cancer are at increased risk of job loss, compared to higher-income white survivors. Employer accommodations, such as schedule flexibility, have been associated with job retention in higher-income whites, but the role of such accommodations in job retention among low-income minorities is not well understood. We conducted a longitudinal study of 267 employed women ages 18-64 who were undergoing treatment for early-stage breast cancer and spoke English, Chinese, Korean, or Spanish. We categorized patients by income level and by race/ethnicity. The category with the lowest job retention after treatment was low-income women (57 percent). Job retention varied widely by race/ethnicity, ranging from 68 percent among Chinese women to 98 percent among non-Latina whites. Women who had accommodating employers were more than twice as likely to retain their jobs as those without accommodating employers. Low-income women were less likely than higher-income women to have accommodating employers, however. More uniform implementation of accommodations across low- and high-paying jobs could reduce disparities in employment outcomes among workers with a cancer diagnosis. Additional research is needed to better understand the barriers that employers, particularly those with low-income workers, may face in providing accommodations.

Early predictors of not returning to work in low-income breast cancer survivors: a 5-year longitudinal study.

Low-income women may be especially vulnerable to job loss after a breast cancer diagnosis. The identification of early risk factors for not returning to work in the long term could inform interventions to help survivors avoid this outcome. A consecutive sample of low-income, employed, underinsured/uninsured women treated for stage 0-III breast cancer was surveyed 6, 18, 36, and 60 months after diagnosis. Participants were classified according to the survey in which they first reported return to work. If they were not working in every survey they were classified as not returning to work. Correlates of not returning to work were identified. Of 274 participants, 36 % returned to work by 6 months, an additional 21 % by 18, 10 % by 36, and 5 % by 60 months. 27 % never returned to work. Of those not working at 6 months, 43 % never returned. Independent predictors of never returning to work included lowest annual income (<$10,000), Latina ethnicity, high comorbidity burden, and receipt of chemotherapy. Very poor women who stop working during chemotherapy for breast cancer are at risk of not returning to work months and years following treatment. These findings may have clinical and policy implications. Conversely, radiation therapy, axillary node dissection, age, and job type do not appear to be associated with return to work. Clinicians should discuss work-related concerns with patients and facilitate early return to work when desired by the patient. Additional research is needed to develop interventions to optimize return to work.