Research on esophageal cancer: With personal perspectives from studies in China and Kenya

The most common form of esophageal cancer (EC), esophageal squamous cell carcinoma (ESCC), is prevalent in many unindustrialized societies, among people with lower socioeconomic status and those who frequently use tobacco and alcohol. In some areas, ESCC mortality ranked top among all cancer. In this review, we begin with discussions of the extensive research on EC in Linxian in northern China that started 60 years ago and the recent studies in Kenya from our personal perspectives. Based on the results obtained from these studies and information from the literature, we summarize our current understanding about the risk factors for ESCC including lifestyle factors (smoking, alcohol, consumption of food and beverages at high temperature and other unhealthy habits), poor diet and nutritional insufficiencies and genetic susceptibility. Elimination or minimization of these environmental risk factors, as well as early detection and treatment of precancerous lesions, would be effective means for the prevention of ESCC. Current knowledge of molecular alterations in ESCC (gene mutations, hypermethylation and amplification or overexpression), as well as treatment of ESCC and the potential of targeted therapy, are also discussed. Finally, we propose effective approaches for the prevention of ESCC by adapting a healthy lifestyle, including a healthy diet that would also prevent other diseases. Community outreach, public education and international collaboration are important for achieving this public health goal.

Association between anthropometry and lifestyle factors and risk of B-cell lymphoma: An exposome-wide analysis

To better understand the role of individual and lifestyle factors in human disease, an exposome-wide association study was performed to investigate within a single-study anthropometry measures and lifestyle factors previously associated with B-cell lymphoma (BCL). Within the European Prospective Investigation into Cancer and nutrition study, 2402 incident BCL cases were diagnosed from 475 426 participants that were followed-up on average 14 years. Standard and penalized Cox regression models as well as principal component analysis (PCA) were used to evaluate 84 exposures in relation to BCL risk. Standard and penalized Cox regression models showed a positive association between anthropometric measures and BCL and multiple myeloma/plasma cell neoplasm (MM). The penalized Cox models additionally showed the association between several exposures from categories of physical activity, smoking status, medical history, socioeconomic position, diet and BCL and/or the subtypes. PCAs confirmed the individual associations but also showed additional observations. The PC5 including anthropometry, was positively associated with BCL, diffuse large B-cell lymphoma (DLBCL) and MM. There was a significant positive association between consumption of sugar and confectionary (PC11) and follicular lymphoma risk, and an inverse association between fish and shellfish and Vitamin D (PC15) and DLBCL risk. The PC1 including features of the Mediterranean diet and diet with lower inflammatory score showed an inverse association with BCL risk, while the PC7, including dairy, was positively associated with BCL and DLBCL risk. Physical activity (PC10) was positively associated with DLBCL risk among women. This study provided informative insights on the etiology of BCL.

Dissecting the journey to breast cancer diagnosis in sub-Saharan Africa: Findings from the multicountry ABC-DO cohort study

Most breast cancer patients in sub-Saharan Africa are diagnosed at advanced stages after prolonged symptomatic periods. In the multicountry African Breast Cancer-Disparities in Outcomes cohort, we dissected the diagnostic journey to inform downstaging interventions. At hospital presentation for breast cancer, women recalled their diagnostic journey, including dates of first noticing symptoms and health-care provider (HCP) visits. Negative binomial regression models were used to identify correlates of the length of the diagnostic journey. Among 1429 women, the median (inter-quartile range) length (months) of the diagnostic journey ranged from 11.3 (5.7-21.2) in Ugandan, 8.2 (3.4-16.4) in Zambian, 6.5 (2.4-15.7) in Namibian-black to 5.6 (2.3-13.1) in Nigerian and 2.4 (0.6-5.5) in Namibian-non-black women. Time from first HCP contact to diagnosis represented, on average, 58% to 79% of the diagnostic journey in each setting except Nigeria where most women presented directly to the diagnostic hospital with advanced disease. The median number of HCPs visited was 1 to 4 per woman, but time intervals between visits were long. Women who attributed their initial symptoms to cancer had a 4.1 months (absolute) reduced diagnostic journey than those who did not, while less-educated (none/primary) women had a 3.6 months longer journey than more educated women. In most settings the long journey to breast cancer diagnosis was not primarily due to late first presentation but to prolonged delays after first presentation to diagnosis. Promotion of breast cancer awareness and implementation of accelerated referral pathways for women with suspicious symptoms are vital to downstaging the disease in the region.

Blood Metal Levels and Amyotrophic Lateral Sclerosis Risk: A Prospective Cohort

OBJECTIVE

Metals have been suggested as a risk factor for amyotrophic lateral sclerosis (ALS), but only retrospective studies are available to date. We compared metal levels in prospectively collected blood samples from ALS patients and controls, to explore whether metals are associated with ALS mortality.

METHODS

A nested ALS case-control study was conducted within the prospective EPIC (European Prospective Investigation into Cancer and Nutrition) cohort. Cases were identified through death certificates. We analyzed metal levels in erythrocyte samples obtained at recruitment, as a biomarker for metal exposure from any source. Arsenic, cadmium, copper, lead, manganese, mercury, selenium, and zinc concentrations were measured by inductively coupled plasma-mass spectrometry. To estimate ALS risk, we applied conditional logistic regression models.

RESULTS

The study population comprised 107 cases (65% female) and 319 controls matched for age, sex, and study center. Median time between blood collection and ALS death was 8 years (range = 1-15). Comparing the highest with the lowest tertile, cadmium (odds ratio [OR] = 2.04, 95% confidence interval [CI] = 1.08-3.87) and lead (OR = 1.89, 95% CI = 0.97-3.67) concentrations suggest associations with increased ALS risk. Zinc was associated with a decreased risk (OR = 0.50, 95% CI = 0.27-0.94). Associations for cadmium and lead remained when limiting analyses to noncurrent smokers.

INTERPRETATION

This is the first study to compare metal levels before disease onset, minimizing reverse causation. The observed associations suggest that cadmium, lead, and zinc may play a role in ALS etiology. Cadmium and lead possibly act as intermediates on the pathway from smoking to ALS. ANN NEUROL 20209999:n/a-n/a.