Measures of body fatness and height in early and mid-to-late adulthood and prostate cancer: risk and mortality in The Pooling Project of Prospective Studies of Diet and Cancer

BACKGROUND

Advanced prostate cancer etiology is poorly understood. Few studies have examined associations of anthropometric factors (e.g. early adulthood obesity) with advanced prostate cancer risk.

PATIENTS AND METHODS

We carried out pooled analyses to examine associations between body fatness, height, and prostate cancer risk. Among 830 772 men, 51 734 incident prostate cancer cases were identified, including 4762 advanced (T4/N1/M1 or prostate cancer deaths) cases, 2915 advanced restricted (same as advanced, but excluding localized cancers that resulted in death) cases, 9489 high-grade cases, and 3027 prostate cancer deaths. Cox proportional hazards models were used to calculate study-specific hazard ratios (HR) and 95% confidence intervals (CI); results were pooled using random effects models.

RESULTS

No statistically significant associations were observed for body mass index (BMI) in early adulthood for advanced, advanced restricted, and high-grade prostate cancer, and prostate cancer mortality. Positive associations were shown for BMI at baseline with advanced prostate cancer (HR = 1.30, 95% CI = 0.95-1.78) and prostate cancer mortality (HR = 1.52, 95% CI = 1.12-2.07) comparing BMI ≥35.0 kg/m2 with 21-22.9 kg/m2. When considering early adulthood and baseline BMI together, a 27% higher prostate cancer mortality risk (95% CI = 9% to 49%) was observed for men with BMI <25.0 kg/m2 in early adulthood and BMI ≥30.0 kg/m2 at baseline compared with BMI <25.0 kg/m2 in early adulthood and BMI <30.0 kg/m2 at baseline. Baseline waist circumference, comparing ≥110 cm with <90 cm, and waist-to-hip ratio, comparing ≥1.00 with <0.90, were associated with significant 14%-16% increases in high-grade prostate cancer risk and suggestive or significant 20%-39% increases in prostate cancer mortality risk. Height was associated with suggestive or significant 33%-56% risks of advanced or advanced restricted prostate cancer and prostate cancer mortality, comparing ≥1.90 m with <1.65 m.

CONCLUSION

Our findings suggest that height and total and central adiposity in mid-to-later adulthood, but not early adulthood adiposity, are associated with risk of advanced forms of prostate cancer. Thus, maintenance of healthy weight may help prevent advanced prostate cancer.

Continued 5α-Reductase Inhibitor Use after Prostate Cancer Diagnosis and the Risk of Reclassification and Adverse Pathological Outcomes in the PASS

PURPOSE

Outcomes in patients who enroll in active surveillance programs for prostate cancer while receiving 5α-reductase inhibitors have not been well defined. We sought to determine the association of 5α-reductase inhibitor use with the risk of reclassification in the PASS (Canary Prostate Active Surveillance Study).

MATERIALS AND METHODS

Participants in the multicenter PASS were enrolled between 2008 and 2016. Study inclusion criteria were current or never 5α-reductase inhibitors use, Gleason score 3 + 4 or less prostate cancer at diagnosis, less than a 34% core involvement ratio at diagnosis and 1 or more surveillance biopsies. Included in study were 1,009 men, including 107 on 5α-reductase inhibitors and 902 who had never received 5α-reductase inhibitors. Reclassification was defined as increase in the Gleason score and/or an increase to 34% or greater in the ratio of biopsy cores positive for cancer. Adverse pathology at prostatectomy was defined as Gleason 4 + 3 or greater and/or nonorgan confined disease (pT3 or N1).

RESULTS

On multivariable analysis there was no difference in reclassification between men who had received and those who had never received 5α-reductase inhibitors (HR 0.81, p = 0.31). Patients who had received 5α-reductase inhibitors were less likely to undergo radical prostatectomy (8% vs 18%, p = 0.01) or any definitive treatment (19% vs 24%, p = 0.04). In the 167 participants who underwent radical prostatectomy there was no suggestion of a difference in the rate of adverse pathology findings at prostatectomy between 5α-reductase inhibitor users and nonusers.

CONCLUSIONS

Continued 5α-reductase inhibitor use after an initial diagnosis of prostate cancer was not associated with the risk of reclassification on active surveillance in men in the PASS cohort.

Inter-Rater Reliability of Provider Interpretations of Irritable Bowel Syndrome Food and Symptom Journals

There are currently no standardized methods for identifying trigger food(s) from irritable bowel syndrome (IBS) food and symptom journals. The primary aim of this study was to assess the inter-rater reliability of providers’ interpretations of IBS journals. A second aim was to describe whether these interpretations varied for each patient. Eight providers reviewed 17 IBS journals and rated how likely key food groups (fermentable oligo-di-monosaccharides and polyols, high-calorie, gluten, caffeine, high-fiber) were to trigger IBS symptoms for each patient. Agreement of trigger food ratings was calculated using Krippendorff’s α-reliability estimate. Providers were also asked to write down recommendations they would give to each patient. Estimates of agreement of trigger food likelihood ratings were poor (average α = 0.07). Most providers gave similar trigger food likelihood ratings for over half the food groups. Four providers gave the exact same written recommendation(s) (range 3–7) to over half the patients. Inter-rater reliability of provider interpretations of IBS food and symptom journals was poor. Providers favored certain trigger food likelihood ratings and written recommendations. This supports the need for a more standardized method for interpreting these journals and/or more rigorous techniques to accurately identify personalized IBS food triggers.

The feasibility, usability, and clinical utility of traditional paper food and symptom journals for patients with irritable bowel syndrome

BACKGROUND

Paper food and gastrointestinal (GI) symptom journals are used to help irritable bowel syndrome (IBS) patients determine potential trigger foods. The primary aim of this study was to evaluate the feasibility, usability, and clinical utility of such journals as a data collection tool. A secondary aim was to explore a method for analyzing journal data to describe patterns of diet and symptoms.

METHODS

Participants (N=17) were asked to log three sets of 3-day food and symptom journals over a 15-day period. Feasibility was evaluated by journal completion rates, symptom logging compliance, and logging fatigability. The feasibility, usability, and clinical utility of journaling were also assessed by a customized evaluation and exit interview. For each journal, regression analyses were conducted to examine relationships between key meal nutrients and subsequent symptoms.

KEY RESULTS

Most participants were young (mean age 35±12) Caucasian (N=13) women (N=14). Journal completion rates were 100% for all participants with no logging fatigability. Over half perceived paper journaling of food and symptoms as feasible, usable, and clinically useful. Thirteen participants demonstrated a strong association with at least one symptom and meal nutrient. Patterns of associations differed among participants.

CONCLUSIONS AND INFERENCES

Paper journaling of food and GI symptoms for 9 days over a 15-day period appeared to be a feasible and usable data collection tool for IBS patients. Over half perceived journaling as at least somewhat clinically useful. Findings from this study support the anecdote that food trigger(s) and associated symptom(s) vary for each individual.

A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment

BACKGROUND

Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss.

METHODS

Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation.

RESULTS

After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ² test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight.

CONCLUSIONS

Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC.

Associations of Obesity with Prostate Cancer Risk Differ Between U.S. African-American and Non-Hispanic White Men: Results from the Selenium and Vitamin E Cancer Prevention Trial

African-American (AA) men have the highest rates of prostate cancer incidence and mortality in the US. Understanding underlying reasons for this disparity could identify preventive interventions important to AA men. PURPOSE: To determine whether the association of obesity with prostate cancer risk differs between AA and non-Hispanic white (NHW) men and whether obesity modifies the excess risk associated with AA race. METHODS: This is a prospective study among 3398 AA and 22673 NHW men who participated in the Selenium and Vitamin E Cancer Prevention Trial (2001–2011). Using Cox regression, we estimated hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) associated with AA and NHW race and body mass index (BMI) [kg/m2] on total, low- (Gleason score &lt;7), and high-grade (Gleason score ≥7) prostate cancer incidence while adjusting for relevant covariates. RESULTS: There were 270, 148, and 88 cases of total, low-, and high-grade prostate cancers among AA men and a corresponding 1453, 898, and 441 cases in NHW men (median follow-up of 5.6 years). BMI was not associated with risk of total cancer among NHW men, but was positively associated with risk among AA men (BMI &lt; 25 kg/m2 vs. ≥35 kg/m2, HR = 1.49; 95% CI, 0.95–2.34; Ptrend = 0.03). Consequently, the risk associated with AA race increased from 28% (HR = 1.28; 95% CI, 0.91–1.80) among men with BMI &lt; 25 kg/m2 to 103% (HR = 2.03; 95% CI, 1.38–2.98) among AA men with BMI≥35 kg/m2 (Ptrend = 0.03). BMI was inversely associated with low-grade prostate cancer risk among NHW men (BMI &lt; 25 kg/m2 vs. ≥35 kg/m2, HR = 0.80; 95% CI, 0.58–1.09; Ptrend = 0.02), but positively associated with risk among AA men (BMI &lt; 25 kg/m2 vs. ≥35 kg/m2, HR = 1.77; 95% CI, 1.14–2.76; Ptrend = 0.05). BMI was positively associated with risk of high-grade prostate cancer in both NHW (BMI &lt; 25 kg/m2 vs. ≥35 kg/m2, HR = 1.33; 95% CI, 0.90–1.97; Ptrend = 0.01) and AA men (BMI &lt; 25 kg/m2 vs. ≥35 kg/m2, HR = 1.81; 95% CI, 0.79–4.11; Ptrend = 0.02), but associations were not significantly different. CONCLUSION: Obesity is more strongly associated with increased prostate cancer risk among AA than NHW men and reducing obesity among AA men could reduce the racial disparity in cancer incidence. Research is needed to test mechanisms underpinning these associations.