Background

Millions of people worldwide are exposed to arsenic-contaminated water. In the largest city in northern Chile (Antofagasta), more than 250,000 people were exposed to high arsenic drinking water concentrations from 1958 until 1970 when a water treatment plant was installed. Because of its unique geology, limited water sources, and good historical records, lifetime exposure and long-term latency patterns can be assessed in this area with better accuracy than in other arsenic-exposed areas worldwide.

Methods

We conducted a population-based case-control study in northern Chile from October 2007 to December 2010 involving 232 bladder and 306 lung cancer cases and 640 age- and gender-matched controls, with detailed information on past exposure and potential confounders, including smoking and occupation.

Results

Bladder cancer ORs for quartiles of average arsenic concentrations in water before 1971 (<11, 11-90, 91-335, and >335 μg/L) were 1.00, 1.36 [95% confidence interval (CI), 0.78-2.37], 3.87 (2.25-6.64), and 6.50 (3.69-11.43), respectively. Corresponding lung cancer ORs were 1.00, 1.27 (0.81-1.98), 2.00 (1.24-3.24), and 4.32 (2.60-7.17). Bladder and lung cancer ORs in those highly exposed in Antofagasta during 1958 to 1970 but not thereafter were 6.88 (3.84-12.32) and 4.35 (2.57-7.36), respectively.

Conclusions

The lung and bladder cancer risks that we found up to 40 years after high exposures have ended are very high.

Impact

Our findings suggest that prevention, treatment, and other mortality reduction efforts in arsenic-exposed countries will be needed for decades after exposure cessation.

BACKGROUND: Patients diagnosed with low-risk prostate cancer (PCa) are confronted with a difficult decision regarding whether to undergo definitive treatment or to pursue an active surveillance protocol. This is potentially further complicated by the possibility that patients and physicians may place different value on factors that influence this decision. We conducted a qualitative investigation to better understand patient and physician perceptions of factors influencing treatment decisions for low-risk PCa. METHODS: Semi-structured interviews were conducted among 43 racially and ethnically diverse patients diagnosed with low-risk PCa, who were identified through a population-based cancer registry, and 15 physicians who were selected to represent a variety of practice settings in the Greater San Francisco Bay Area. RESULTS: Patients and physicians both described several key individual (e.g., clinical) and interpersonal (e.g., healthcare communications) factors as important for treatment decision-making. Overall, physicians perceptions largely mirrored patients perceptions. First, we observed differences in treatment preferences by age and stage of life. At older ages, there was a preference for less invasive options. However, at younger ages, we found varying opinions among both patients and physicians. Second, patients and physicians both described concerns about side effects including physical functioning and non-physical considerations. Third, we observed differences in expectations and the level of difficulty for clinical conversations based on information needs and resources between patients and physicians. Finally, we discovered that patients and physicians perceived patients prior knowledge and the support of family/friends as facilitators of clinical conversations. CONCLUSIONS: Our study suggests that the gap between patient and physician perceptions on the influence of clinical and communication factors on treatment decision-making is not large. The consensus we observed points to the importance of developing relevant clinical communication roadmaps as well as high quality and accessible patient education materials.

Background

Factors that influence prostate cancer treatment decisions are complex, multifaceted, and personal, and may vary by race/ethnicity. Although research has been published to quantify factors involved in decision-making, these studies have been limited to primarily white, and to a lesser extent, Black patients, and quantitative studies are limited for discerning the cultural and contextual processes that shape decision-making.

Methods

We conducted 43 semi-structured interviews with a racially and ethnically diverse sample of patients diagnosed with low- and very-low risk prostate cancer who had undergone treatment for their prostate cancer. Interviews were transcribed, independently coded, and analyzed to identify themes salient for decision-making, with attention to sociocultural differences.

Results

We found racial and ethnic differences in three areas. First, we found differences in how socialized masculinity influenced patient's feelings about different treatment options. Second, we found that for some men, religion and spirituality alleviated anxiety associated with the active surveillance protocol. Finally, for racially and ethnically minoritized patients, we found descriptions of how historic and social experiences within the healthcare system influenced decision-making.

Conclusions

Our study adds to the current literature by expounding on racial and ethnic differences in the multidimensional, nuanced factors related to decision-making. Our findings suggest that factors associated with prostate cancer decision-making can manifest differently across racial and ethnic groups, and provide some guidance for future research.