Samuel O. Antwi

Prognostic impact of definitive local therapy of the primary tumor in men with metastatic prostate cancer at diagnosis: A population-based, propensity score analysis

BACKGROUND This study investigated whether definitive local therapy [radical prostatectomy (RP) or brachytherapy (BT)] of the primary tumor improves survival in men with metastatic prostate cancer (PrCA) at diagnosis. METHODS Data on newly diagnosed metastatic PrCA cases (stage IV, N=7858) were obtained from the Surveillance Epidemiology and End Results (SEER) program. Conventional multivariable survival analysis and propensity score analysis were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (95% CI) comparing men who underwent definitive local therapy of the primary tumor to those who did not. RESULTS After adjusting for sociodemographic and tumor attributes, having RP after diagnosis with metastatic PrCA was associated with 73% (HR=0.27, 95% CI: 0.20-0.38) lower risk of all-cause mortality and 72% (HR=0.28, 95% CI: 0.20-0.39) reduced risk of death from PrCA. Having BT also was associated with 57% (HR=0.43, 95% CI: 0.31-0.59) and 54% (HR=0.46, 95% CI: 0.33-0.64) lower risk of all-cause and PrCA-specific mortality. Similar results were observed in propensity score-adjusted analysis as well as when stratified by age and extent of tumor metastasis. CONCLUSIONS These findings suggest that definitive local therapy improves survival in men with metastatic PrCA at diagnosis. Future work should consider comorbidities, diet, physical activity and smoking status.

Pancreatic cancer: associations of inflammatory potential of diet, cigarette smoking and long-standing diabetes

Epidemiologic studies show strong associations between pancreatic cancer (PC) and inflammatory stimuli or conditions such as cigarette smoking and diabetes, suggesting that inflammation may play a key role in PC. Studies of dietary patterns and cancer outcomes also suggest that diet might influence an individuals risk of PC by modulating inflammation. We therefore examined independent and joint associations between inflammatory potential of diet, cigarette smoking and long-standing (≥5 years) type II diabetes in relation to risk of PC. Analyses included data from 817 cases and 1756 controls. Inflammatory potential of diet was measured using the dietary inflammatory index (DII), calculated from dietary intake assessed via a 144-item food frequency questionnaire, and adjusted for energy intake. Information on smoking and diabetes were obtained via risk factor questionnaires. Associations were examined using multivariable-adjusted logistic regression. Higher DII scores, reflecting a more proinflammatory diet, were associated with increased risk of PC [odds ratio (OR)Quintile 5 versus 1 = 2.54, 95% confidence interval (CI) = 1.87-3.46, P trend < 0.0001]. Excess risk of PC also was observed among former (OR = 1.29, 95% CI = 1.07-1.54) and current (OR = 3.40, 95% CI = 2.28-5.07) smokers compared with never smokers, and among participants with long-standing diabetes (OR = 3.09, 95% CI = 2.02-4.72) compared with nondiabetics. Joint associations were observed for the combined effects of having greater than median DII score, and being a current smoker (OR = 4.79, 95% CI = 3.00-7.65) or having long-standing diabetes (OR = 6.03, 95% CI = 3.41-10.85). These findings suggest that a proinflammatory diet may act as cofactor with cigarette smoking and diabetes to increase risk of PC beyond the risk of any of these factors alone.

Nucleotide excision repair gene polymorphisms, meat intake and colon cancer risk.

PURPOSE Much of the DNA damage from colon cancer-related carcinogens, including heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH) from red meat cooked at high temperature, are repaired by the nucleotide excision repair (NER) pathway. Thus, we examined whether NER non-synonymous single nucleotide polymorphisms (nsSNPs) modified the association between red meat intake and colon cancer risk. METHODS The study consists of 244 African-American and 311 white colon cancer cases and population-based controls (331 African Americans and 544 whites) recruited from 33 counties in North Carolina from 1996 to 2000. Information collected by food frequency questionnaire on meat intake and preparation methods were used to estimate HCA and benzo(a)pyrene (BaP, a PAH) intake. We tested 7 nsSNPs in 5 NER genes: XPC A499V and K939Q, XPD D312N and K751Q, XPF R415Q, XPG D1104H, and RAD23B A249V. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression. RESULTS Among African Americans, we observed a statistically significant positive association between colon cancer risk and XPC 499 AV+VV genotype (OR=1.7, 95% CI: 1.1, 2.7, AA as referent), and an inverse association with XPC 939 QQ (OR=0.3, 95%CI: 0.2, 0.8, KK as referent). These associations were not observed among whites. For both races combined, there was interaction between the XPC 939 genotype, well-done red meat intake and colon cancer risk (OR=1.5, 95% CI=1.0, 2.2 for high well-done red meat and KK genotype as compared to low well-done red meat and KK genotype, pinteraction=0.05). CONCLUSIONS Our data suggest that NER nsSNPs are associated with colon cancer risk and may modify the association between well-done red meat intake and colon cancer risk.

Association between prevalence of chronic obstructive pulmonary disease and health-related quality of life, South Carolina, 2011.

Introduction We investigated the prevalence of chronic obstructive pulmonary disease (COPD) in various population subgroups in South Carolina and examined associations between COPD and 4 core measures of health-related quality of life (HRQOL). Methods Data from 12,851 participants of the 2011 South Carolina Behavioral Risk Factor Surveillance System (BRFSS) were analyzed. COPD prevalence rates were age-adjusted to the 2000 standard US population. Logistic regression models were used to estimate adjusted odds ratios (AOR’s) and 95% confidence intervals (CIs). Results The overall age-adjusted prevalence of self-reported diagnosis of COPD among community-dwelling adults in South Carolina in 2011 was 7.1% (standard error [SE] ±0.3). Prevalence of self-reported diagnosis of COPD was highest among women (8.9%; SE, ±0.5), those aged 65 years or older (12.9%; SE, ±0.5), current smokers (15.9%; SE, ±0.7), and those with low levels of education and income. Compared with community-dwelling adults without COPD, those with COPD were more likely to report fair or poor general health status (AOR, 3.97; 95% CI, 3.13–5.03), 14 or more physically unhealthy days (AOR, 2.10, 95% CI, 1.57–2.81), 14 or more mentally unhealthy days (AOR, 1.72; 95% CI, 1.21–2.43), and 14 or more days of activity limitation (AOR, 2.22; 95% CI, 1.53–3.22) within the previous 30 days. Conclusion COPD is a highly prevalent disease in South Carolina, especially among older people and smokers, and it is associated with poor HRQOL. Future work aimed at reducing risk factors may decrease the disease prevalence, and increasing early detection and improving access to appropriate medical treatments can improve HRQOL for those living with COPD.

Plasma carotenoids and tocopherols in relation to prostate-specific antigen (PSA) levels among men with biochemical recurrence of prostate cancer

BACKGROUND Although men presenting with clinically localized prostate cancer (PrCA) often are treated with radical prostatectomy or radiation therapy with curative intent, about 25-40% develop biochemically recurrent PrCA within 5 years of treatment, which has no known cure. Studies suggest that carotenoid and tocopherol intake may be associated with PrCA risk and progression. We examined plasma carotenoid and tocopherol levels in relation to prostate-specific antigen (PSA) levels among men with PSA-defined biochemical recurrence of PrCA. METHODS Data analyzed were from a 6-month diet, physical activity and stress-reduction intervention trial conducted in South Carolina among biochemically recurrent PrCA patients (n=39). Plasma carotenoids and tocopherol levels were measured using high-performance liquid chromatography (HPLC). Linear regression was used to estimate least-square means comparing PSA levels of men with high versus low carotenoid/tocopherol levels, adjusting for covariates. RESULTS After adjusting for baseline PSA level, plasma cis-lutein/zeaxanthin level at 3 months was related inversely to PSA level at 3 months (P=0.0008), while α-tocopherol (P=0.01), β-cryptoxanthin (P=0.01), and all-trans-lycopene (P=0.004) levels at 3 months were related inversely to PSA levels at 6-months. Percent increase in α-tocopherol and trans-β-carotene levels from baseline to month 3 were associated with lower PSA levels at 3 and 6 months. Percent increase in β-cryptoxanthin, cis-lutein/zeaxanthin and all-trans-lycopene were associated with lower PSA levels at 6 months only. CONCLUSIONS Certain plasma carotenoids and tocopherols were related inversely to PSA levels at various timepoints, suggesting that greater intake of foods containing these micronutrients might be beneficial to men with PSA-defined PrCA recurrence.

Racial Disparities in Survival After Diagnosis of Prostate Cancer in Kentucky, 2001-2010

Whether the African American race remains a significant predictor of poorer prostate cancer survival after adjusting for other sociodemographic and treatment-related factors remains unclear. We examined whether disparities in survival among 18,900 African American and Caucasian men diagnosed with prostate cancer in Kentucky remained after adjusting for health insurance (payor source), cancer treatment, cancer stage at diagnosis, prostate-specific antigen (PSA) level, smoking status, and Appalachian region. After adjusting for these predictors, African American men living in Kentucky had poorer prostate cancer survival after 5 years (hazard ratio [HR] = 1.33; 95% confidence interval = 1.11, 1.59) and 10 years (HR = 1.39; 95% CI = 1.18, 1.28) of follow-up, and for the entire follow-up period (HR = 1.41; 95% CI = 1.26, 1.65) compared to their Caucasian counterparts. Thus, health insurance status, cancer treatment, cancer stage at diagnosis, PSA level at diagnosis, smoking status, and geographic location did not explain the racial gap in survival in Kentucky.

Association between inherited germline mutations in cancer predisposition genes and risk of pancreatic cancer

Importance Individuals genetically predisposed to pancreatic cancer may benefit from early detection. Genes that predispose to pancreatic cancer and the risks of pancreatic cancer associated with mutations in these genes are not well defined. Objective To determine whether inherited germline mutations in cancer predisposition genes are associated with increased risks of pancreatic cancer. Design, Setting, and Participants Case-control analysis to identify pancreatic cancer predisposition genes; longitudinal analysis of patients with pancreatic cancer for prognosis. The study included 3030 adults diagnosed as having pancreatic cancer and enrolled in a Mayo Clinic registry between October 12, 2000, and March 31, 2016, with last follow-up on June 22, 2017. Reference controls were 123 136 individuals with exome sequence data in the public Genome Aggregation Database and 53 105 in the Exome Aggregation Consortium database. Exposures Individuals were classified based on carrying a deleterious mutation in cancer predisposition genes and having a personal or family history of cancer. Main Outcomes and Measures Germline mutations in coding regions of 21 cancer predisposition genes were identified by sequencing of products from a custom multiplex polymerase chain reaction–based panel; associations of genes with pancreatic cancer were assessed by comparing frequency of mutations in genes of pancreatic cancer patients with those of reference controls. Results Comparing 3030 case patients with pancreatic cancer (43.2% female; 95.6% non-Hispanic white; mean age at diagnosis, 65.3 [SD, 10.7] years) with reference controls, significant associations were observed between pancreatic cancer and mutations in CDKN2A (0.3% of cases and 0.02% of controls; odds ratio [OR], 12.33; 95% CI, 5.43-25.61); TP53 (0.2% of cases and 0.02% of controls; OR, 6.70; 95% CI, 2.52-14.95); MLH1 (0.13% of cases and 0.02% of controls; OR, 6.66; 95% CI, 1.94-17.53); BRCA2 (1.9% of cases and 0.3% of controls; OR, 6.20; 95% CI, 4.62-8.17); ATM (2.3% of cases and 0.37% of controls; OR, 5.71; 95% CI, 4.38-7.33); and BRCA1 (0.6% of cases and 0.2% of controls; OR, 2.58; 95% CI, 1.54-4.05). Conclusions and Relevance In this case-control study, mutations in 6 genes associated with pancreatic cancer were found in 5.5% of all pancreatic cancer patients, including 7.9% of patients with a family history of pancreatic cancer and 5.2% of patients without a family history of pancreatic cancer. Further research is needed for replication in other populations.

Carotenoid intake and adipose tissue carotenoid levels in relation to prostate cancer aggressiveness among African-American and European-American men in the North Carolina-Louisiana prostate cancer project (PCaP).

Associations between carotenoid intake and prostate cancer (CaP) incidence have varied across studies. This may result from combining indolent with aggressive disease in most studies. This study examined whether carotenoid intake and adipose tissue carotenoid levels were inversely associated with CaP aggressiveness.

Dietary, supplement, and adipose tissue tocopherol levels in relation to prostate cancer aggressiveness among African and European Americans: The North Carolina-Louisiana Prostate Cancer Project (PCaP).

Controversies remain over the safety and efficacy of vitamin E (i.e., α‐tocopherol) supplementation use for the prevention of prostate cancer (CaP); however, associations of different tocopherol forms and CaP aggressiveness have yet to be examined.

Inflammatory potential of diet and risk of pancreatic cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial: DII and pancreatic cancer risk in the PLCO study

Inflammation plays a central role in pancreatic cancer etiology and can be modulated by diet. We aimed to examine the association between the inflammatory potential of diet, assessed with the Dietary Inflammatory Index (DII®), and pancreatic cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial prospective cohort. Our study included 101,449 participants aged 52–78 years at baseline who completed both baseline questionnaire and a diet history questionnaire. Energy‐adjusted DII (E‐DII) scores were computed based on food and supplement intake. Cox proportional hazards models and time dependent Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with participants in the lowest E‐DII quintile (most anti‐inflammatory scores) as referent. After a median 8.5 years of follow‐up, 328 pancreatic cancer cases were identified. E‐DII scores were not associated with pancreatic cancer risk in the multivariable model (HRQ5vsQ1 = 0.94; 95% CI = 0.66–1.35; p‐trend = 0.43). Time significantly modified the association (p‐interaction = 0.01). During follow up <4 years, there was suggestive evidence of an inverse association between E‐DII and pancreatic cancer (HRQ5vsQ1 = 0.60; 95% CI = 0.35–1.02; p‐trend = 0.20) while there was a significant positive trend in the follow up ≥4 years (HRQ5vsQ1 = 1.31; 95% CI = 0.83–2.08; p‐trend = 0.03). Similar results were observed for E‐DII from food only. Our study does not support an association between inflammatory potential of diet and pancreatic cancer risk; however, heterogeneous results were obtained with different follow‐up times. These divergent associations may result from the influences of undetected disease in the short‐term.