Risk of Gynecological and Breast Cancers in Workers Exposed to Diesel Exhaust: A Systematic Review and Meta-Analysis Of Cohort Studies.

BACKGROUND: This study aimed to explore the association between occupational exposure to diesel exhaust (DE) and gynaecological and breast cancers. METHODS: A systematic review was performed to identify cohort studies reporting results on the association between occupational exposure to DE and risk of gynaecological and breast cancers. STROBE guidelines and PECOS criteria were followed. We identified 6 studies for breast cancer (BC), 4 for cervical cancer (CC), 4 for endometrial cancer (EC) and 7 for ovarian cancer (OC). Random-effects meta-analyses were conducted on the relationship between DE exposure and BC, CC, EC, and OC risk; 95% confidence intervals (CI) and prediction intervals (PI) were reported. We investigated between-study heterogeneity and potential publication bias using Egger's test. RESULTS: No associations were observed between occupational DE exposure and risk of BC [RR=0.93; CI: 0.77-1.13; PI:0.50-1.73, I2=80.31%], EC [RR=0.89; CI: 0.75-1.05; PI:0.61-1.30, I2=0.78%], and OC [RR=1.08; CI: 0.89-1.32, PI: 0.76-1.56, I2=11.87%]. A weak association was observed for CC [RR=1.41; CI: 1.17-1.17; PI:0.85-2.30, I2=6.44%]. No between-study heterogeneity or publication bias was detected. CONCLUSIONS: This study identified an association between DE exposure and CC, which was not adjusted for potential confounders. No evidence of an association was found with BC, EC, and OC.

Risk of Skin Cancer in Workers Exposed to Diesel Exhaust: A Systematic Review and Meta-Analysis of Cohort Studies.

BACKGROUND: Our objective was to study the association between occupational exposure to diesel exhaust (DE) and skin cancer. METHODS: A systematic review following STROBE guidelines and PECOS criteria was conducted to identify cohort studies describing the association between occupational DE exposure and the risk of skin cancer. We extracted 12 independent risk estimates for melanoma skin cancer (MSC), 8 for non-melanoma skin cancer (NMSC), and 3 for skin cancer not otherwise specified (SC-NOS). Random effects meta-analyses were performed, site-specific and stratified by geographic region and quality score. 95% confidence intervals (CI) were reported. Between-study heterogeneity and potential publication bias were investigated. RESULTS: There was no overall evidence of an increased risk of MSC [RR=0.90, 95% CI: 0.73-1.11; I2=92.86%, 95% CI: 82.83-97.03%], NMSC [RR=1.04, 95% CI: 0.88-1.23; I2=60.79%, 95% CI: 0-87.34%] or SC-NOS [RR=0.72, 95% CI: 0.54-0.97; I2=26.60%, 95% CI: 0-94.87%] in workers exposed to DE. No difference between low-quality and high-quality studies was found. A stratified analysis by geographical region did not reveal any significant differences. There was no evidence of publication bias. CONCLUSIONS: No evidence of an association between skin cancer and occupational DE exposure was found. Residual confounding and other sources of bias cannot be ruled out.

Occupational exposure to diesel exhaust and head and neck cancer: a systematic review and meta-analysis of cohort studies.

Exposure to diesel exhaust (DE) and other fossil fuels in the workplace can cause several health effects including cancer. We conducted a systematic review and meta-analysis of cohort studies examining the association between occupational DE exposure and the risk of head and neck cancer (HNC), including cancer of the oral cavity, pharynx and larynx. We included cohort studies mentioned in the Monograph of the International Agency for Research on Cancer, 2014, on DE. Forest plots of relative risk (RR) were constructed for HNC overall and its anatomical subtypes. A random-effects model was used to address heterogeneity between studies. Fifteen articles were included after removing duplicates and irrelevant reports. The summary RR for DE exposure was 1.08 [95% confidence interval (CI) = 1.01-1.17, P heterogeneity = <0.001] for HNC overall, 0.98 (95% CI = 0.87-1.11) for oral cavity, 1.05 (95% CI = 0.77-1.43) for pharyngeal, 1.15 (95% CI = 0.96-1.38) for oral cavity and pharyngeal combined, and 1.13 (95% CI = 1.03-1.24) for laryngeal cancer. There were elevated RRs for incidence studies of HNC (RR = 1.13; 95% CI = 1.05-1.22, P = 0.001), European studies (RR = 1.13; 95% CI = 1.05-1.23, P = 0.001), and female studies (RR = 1.77; 95% CI = 1.31-2.39, P = 0.003). Our study suggested an association between occupational DE exposure and the risk of HNC, particularly laryngeal cancer. Although residual confounding cannot be ruled out, our results support the importance of controlling occupational DE exposure.

Occupational exposure to diesel exhausts and liver and pancreatic cancers: a systematic review and meta-analysis.

BACKGROUND: Diesel exhaust (DE) is human carcinogen with sufficient evidence only for lung cancer. Systematic evidence on other cancer types is scarce, thus we aimed to systematically review current literature on the association between occupational DE exposure and risk of liver and pancreatic cancers. METHODS: We performed a systematic literature review to identify cohort studies on occupational DE exposure and risk of cancers other than lung. We computed pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for liver and pancreatic cancers using DerSimonian and Laird random-effects model. RESULTS: Fifteen studies reporting results on pancreatic cancer and fourteen on liver cancer were included. We found a weakly increased risk of pancreatic cancer in workers exposed to DE (RR: 1.07, 95% CI: 1.00, 1.14), mainly driven by results on incidence (RR: 1.11, 95% CI: 1.02, 1.22). As for liver cancer, results were suggestive of a positive association (RR: 1.09; 95% CI: 0.99, 1.19), although a significant estimate was present in studies published before 2000 (RR: 1.41; 95% CI: 1.09, 1.82). We found no compelling evidence of publication bias. CONCLUSIONS: Our findings suggest an association between occupational DE exposure and liver and pancreatic cancer. Further studies with detailed exposure assessment, environmental monitoring data, and appropriate control for confounders are warranted.

Occupational-related exposure to diesel exhaust and risk of leukemia: systematic review and meta-analysis of cohort studies.

PURPOSE: Diesel exhaust (DE) is an established lung carcinogen. The association with leukemia is not well established. We conducted a systematic review and meta-analysis of cohort studies to determine the association between occupational DE exposure and risk of leukemia. METHODS: A systematic literature review was performed to identify all cohort studies on occupational exposure to DE and associated risk of leukemia. STROBE guidelines and PECOS criteria were followed. Meta-analyses with fixed effects (and random-effects model in cases of high heterogeneity) were performed to calculate summary relative risks (RR) and 95% confidence intervals (CI), including subgroup analyses by outcome (mortality or incidence), sex, geographic region, industry type, and study quality. Study quality was assessed using the the Joanna Briggs Institute (JBI) critical appraisal checklist for cohort studies. RESULTS: Of the 30 studies retained, 20 (8 from North America, 12 from Europe) reported a total of 33 estimates of the risk of leukemia. Overall, the relative risk (RR) of leukemia was 1.01 (95% CI = 0.97-1.05, I2 = 21.2%, n = 33); corresponding results for leukemia incidence and mortality were RR = 1.02 (95% CI = 0.98-1.06, I2 = 27.9%, n = 19) and RR = 0.91 (95% CI = 0.81-1.02, I2 = 0.0%, n = 15), respectively. The main results were confirmed in analyses by sex and geographic area. A statistically significant association was detected for miners (RR = 1.58, 95% CI = 1.15-2.15, I2 = 77.0%, n = 2) but not for other occupational groups. Publication bias was not detected (p = 0.7). CONCLUSION: Our results did not indicate an association between occupational DE exposure and leukemia, with the possible exception of miners. Residual confounding cannot be excluded.

Decrease of visits and hospital admissions for cancer patients during the COVID-19 pandemic. A systematic review and meta-analysis.

Background: During the COVID-19 pandemic, many nonurgent oncologic services were postponed. The aim of the present study was to estimate the impact of the pandemic on visits and hospital admissions for cancer patients worldwide. Methods: In our systematic review and meta-analysis, databases such as Pubmed, Proquest, and Scopus were searched comprehensively for articles published between January 1, 2020, and December 12, 2021. We included articles reporting data comparing the number of visits and hospital admissions for oncologic patients performed before and during the pandemic. Two pairs of independent reviewers extracted data from the selected studies. The weighted average of the percentage change was calculated and compared between pandemic and pre-pandemic periods. Stratified analysis was performed by geographic area, time interval, and study setting. Findings: We found a mean relative change throughout January-October 2020 of -37.8% (95% CI -42.6; -32.9) and -26.3% (95% CI -31.4; -21.1) compared to pre-pandemic periods for oncologic visits and hospital admission, respectively. The temporal trend showed a U-shaped curve with nadir in April for cancer visits and in May 2020 for hospital admissions. All geographic areas showed a similar pattern and the same was observed when stratifying the studies as clinic-based and population-based. Interpretation: Our results showed a decrease in the number of visits and hospital admission during the January-October 2020 period after the outbreak of the COVID-19 pandemic. The postponement or cancellation of these oncologic services may negatively affect the patient's outcome and the future burden of disease. Supplementary Information: The online version contains supplementary material available at 10.1007/s10389-023-01857-w.

Occupational Cancers among Employed Women: A Narrative Review.

The facts that occupational cancer in women is under-investigated, with few in-depth analyses are well known. In recent decades the workforce has changed, with an increasing number of women employed. Therefore, the inclusion of women in occupational cancer studies has become more urgent and feasible than in the past decades. The difficulties to evaluate occupational causes of female gynecologic tumors in most past cohorts and the potential variation in outcome responses between men and women must be taken into consideration. This narrative review discusses women's occupational cancer as a current area of research, focusing on three groups of workers characterized by peculiar exposure to occupational carcinogens and where women are often employed: beauticians and hairdressers; farmers; and healthcare workers. We discuss the most relevant cancers in each working category, with a particular focus on female breast cancer. In the three industries reviewed in detail, there are some risk factors which may affect primarily women, inducing breast cancer and cervical cancer, as well as risk factors that are carcinogenic in both genders, but whose effects are less well known in women.

Decrease of cancer diagnosis during COVID-19 pandemic: a systematic review and meta-analysis.

Many health services, including cancer care, have been affected by the COVID-19 epidemic. This study aimed at providing a systematic review of the impact of the epidemic on cancer diagnostic tests and diagnosis worldwide. In our systematic review and meta-analysis, databases such as Pubmed, Proquest and Scopus were searched comprehensively for articles published between January 1st, 2020 and December 12th, 2021. Observational studies and articles that reported data from single clinics and population registries comparing the number of cancer diagnostic tests and/or diagnosis performed before and during the pandemic, were included. Two pairs of independent reviewers extracted data from the selected studies. The weighted average of the percentage variation was calculated and compared between pandemic and pre-pandemic periods. Stratified analysis was performed by geographic area, time interval and study setting. The review was registered on PROSPERO (ID: CRD42022314314). The review comprised 61 articles, whose results referred to the period January-October 2020. We found an overall decrease of - 37.3% for diagnostic tests and - 27.0% for cancer diagnosis during the pandemic. For both outcomes we identified a U-shaped temporal trend, with an almost complete recovery for the number of cancer diagnosis after May 2020. We also analyzed differences by geographic area and screening setting. We provided a summary estimate of the decrease in cancer diagnosis and diagnostic tests, during the first phase of the COVID-19 pandemic. The delay in cancer diagnosis could lead to an increase in the number of avoidable cancer deaths. Further research is needed to assess the impact of the pandemic measures on cancer treatment and mortality.

Association between trends of mortality and incidence, survival and stage at diagnosis for six digestive and respiratory cancers in United States (2009-2013).

BACKGROUND: A decrease in cancer mortality has been reported in the USA, possibly due to decreased incidence, downstaging and improved survival. The aim of the present study is to estimate the contribution of these factors on the trend in cancer mortality. METHODS: Data on incidence, mortality, stage at diagnosis, and overall and stage-specific survival for six common digestive and respiratory cancers (esophagus, stomach, colorectal, liver, pancreas and lung) during 2009-2013 in the USA from the surveillance, epidemiology and end results (SEER) program, was analyzed using generalized linear models separately among men and women. RESULTS: Our study showed a decrease in mortality for esophageal (-0.09/100 000/year and -0.03/100 000/year), stomach (-0.11/100 000/year and -0.05/100 000/year), colorectal (-0.45/100 000/year and -0.29/100 000/year) and lung cancer (-1.89/100 000/year in men and -0.78/100 000/year in women) in men and women, respectively: for all of them, except lung cancer in women, there was a decrease in the incidence of comparable or greater magnitude; stage distribution and survival also contributed to the decrease in mortality for lung and colorectal cancer. Mortality from pancreatic cancer was stable: an increase in incidence was counterbalanced by an improvement in survival. Mortality from liver cancer increased, driven by an increase in mortality that was not offset by favorable trends in stage distribution and survival. CONCLUSIONS: Trends in mortality were primarily affected by changes in incidence; an increase in the proportion of local stage at diagnosis and improved survival, although evident for some cancers, played a lesser role in mortality trends.

The role of chance in cancer causation.

In the last years, the discussion about the role of chance in the causation of cancer has generated much scientific and public debate. The concept that chance, or "bad luck", as responsible for a majority of the variation of cancer incidence, may be misleading, possibly causing an underestimation of the role played by known risk factors. In this commentary we discuss how host and external factors interact with chance in cancer causation in different ways, and provide examples of situations where chance appears to play only a minor role on cancer onset.

Global Association of COVID-19 Pandemic Measures with Cancer Treatment: A Systematic Review and Meta-Analysis.

IMPORTANCE: The COVID-19 pandemic has put a serious strain on health services, including cancer treatment. OBJECTIVE: This study aimed to investigate the changes in cancer treatment worldwide during the first phase of the SARS-CoV-2 outbreak. DATA SOURCES: Pubmed, Proquest, and Scopus databases were searched comprehensively for articles published between 1 January 2020 and 12 December 2021, in order to perform a systematic review and meta-analysis conducted following the PRISMA statement. STUDY SELECTION: Studies and articles that reported data on the number of or variation in cancer treatments between the pandemic and pre-pandemic periods, comprising oncological surgery, radiotherapy, and systemic therapies, were included. DATA EXTRACTION AND SYNTHESIS: Data were extracted from two pairs of independent reviewers. The weighted average of the percentage variation was calculated between the two periods to assess the change in the number of cancer treatments performed during the pandemic. Stratified analyses were performed by type of treatment, geographic area, time period, study setting, and type of cancer. RESULTS: Among the 47 articles retained, we found an overall reduction of -18.7% (95% CI, -24.1 to -13.3) in the total number of cancer treatments administered during the COVID-19 pandemic compared to the previous periods. Surgical treatment had a larger decrease compared to medical treatment (-33.9% versus -12.6%). For all three types of treatments, we identified a U-shaped temporal trend during the entire period January-October 2020. Significant decreases were also identified for different types of cancer, in particular for skin cancer (-34.7% [95% CI, -46.8 to -22.5]) and for all geographic areas, in particular, Asia (-42.1% [95% CI, -49.6 to -34.7]). CONCLUSIONS AND RELEVANCE: The interruption, delay, and modifications to cancer treatment due to the COVID-19 pandemic are expected to alter the quality of care and patient outcomes.

Role of Occupation in Shaping Cancer Disparities.

Cancer occurrence is characterized globally by profound socioeconomic differences. Occupation is a fundamental component of socioeconomic status. In this review, we discuss the role of occupation as a determinant of cancer disparities. First, we address the issue of participation in cancer screening programs based on income, health insurance, occupational status and job title. Second, we review the role of occupation in contributing to disparities by acting as a mediator between cancer and (i) education and (ii) race/ethnicity. Lastly, we analyze data from a multicenter case-control study of lung cancer to calculate the mediating role of occupational exposure to diesel exhaust, silica and welding fumes in the association between education and lung cancer. By addressing the complex paths from occupation to cancer inequalities from multiple points of view, we provide evidence that occupational-related characteristics, such as income, health insurance, unemployment and hazardous exposures impinge on cancer control and outcomes. The increasing awareness of these aspects is fundamental and should lead to public health interventions to avoid inequalities rising from occupational factors.

Global Association of COVID-19 Pandemic Measures With Cancer Screening: A Systematic Review and Meta-analysis.

Importance: Public health services, including cancer screening tests, have been affected by the onset of the COVID-19 epidemic. Objective: To investigate the pandemic's association with cancer screening worldwide. Data Sources: In this systematic review and meta-analysis, databases such as PubMed, ProQuest, and Scopus were searched comprehensively for articles published between January 1, 2020, and December 12, 2021. Study Selection: Observational studies and articles that reported data from cancer registries that compared the number of screening tests performed before and during the pandemic for breast, cervical, and colorectal cancer were included. Data Extraction and Synthesis: Two pairs of independent reviewers extracted data from the selected studies. The weighted average of the percentage variation was calculated between the 2 periods to assess the change in the number of cancer screening tests performed during the pandemic. Stratified analysis was performed by geographic area, period, and type of setting. The systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Main Outcomes and Measures: The main outcome was the weighted average percentage variation in the number of screening tests performed between January and October 2020 compared with the previous period. Results: The review comprised 39 publications. There was an overall decrease of -46.7% (95% CI, -55.5% to -37.8%) for breast cancer screening, -44.9% (95% CI, -53.8% to -36.1%) for colorectal cancer screening, and -51.8% (95% CI, -64.7% to -38.9%) for cervical cancer screening during the pandemic. For all 3 cancers, a U-shaped temporal trend was identified; for colorectal cancer, a significant decrease was still apparent after May 2020 (in June to October, the decrease was -23.4% [95% CI, -44.4% to -2.4%]). Differences by geographic area and screening setting were also identified. Conclusions and Relevance: A summary estimate of the downscaling of cancer screening tests since the onset of the COVID-19 pandemic is provided in this systematic review and meta-analysis. This could be associated with an increase in the number of avoidable cancer deaths. Effective interventions are required to restore the capacity of screening services to the prepandemic level.

Inverse Association between Dietary Iron Intake and Gastric Cancer: A Pooled Analysis of Case-Control Studies of the Stop Consortium.

Background: Inconsistent findings have been reported regarding the relationship between dietary iron intake and the risk of gastric cancer (GC). Methods: We pooled data from 11 case-control studies from the Stomach Cancer Pooling (StoP) Project. Total dietary iron intake was derived from food frequency questionnaires combined with national nutritional tables. We derived the odds ratios (ORs) and 95% confidence intervals (CIs) for quartiles of dietary iron through multivariable unconditional logistic regression models. Secondary analyses stratified by sex, smoking status, caloric intake, anatomical subsite and histological type were performed. Results: Among 4658 cases and 12247 controls, dietary iron intake was inversely associated with GC (per quartile OR 0.88; 95% CI: 0.83-0.93). Results were similar between cardia (OR = 0.85, 95% CI = 0.77-0.94) and non-cardia GC (OR = 0.87, 95% CI = 0.81-0.94), and for diffuse (OR = 0.79, 95% CI = 0.69-0.89) and intestinal type (OR = 0.88, 95% CI = 0.79-0.98). Iron intake exerted an independent effect from that of smoking and salt intake. Additional adjustment by meat and fruit/vegetable intake did not alter the results. Conclusions: Dietary iron is inversely related to GC, with no difference by subsite or histological type. While the results should be interpreted with caution, they provide evidence against a direct effect of iron in gastric carcinogenesis.

Effect of cancer on outcome of COVID-19 patients: a systematic review and meta-analysis of studies of unvaccinated patients.

Background: Since the beginning of the SARS-CoV-2 pandemic, cancer patients affected by COVID-19 have been reported to experience poor prognosis; however, a detailed quantification of the effect of cancer on outcome of unvaccinated COVID-19 patients has not been performed. Methods: To carry out a systematic review of the studies comparing the outcome of unvaccinated COVID-19 patients with and without cancer, a search string was devised which was used to identify relevant publications in PubMed up to December 31, 2020. We selected three outcomes: mortality, access to ICU, and COVID-19 severity or hospitalization. We considered results for all cancers combined as well as for specific cancers. We conducted random-effects meta-analyses of the results, overall and after stratification by region. We also performed sensitivity analyses according to quality score and assessed publication bias. Results: For all cancer combined, the pooled odds ratio (OR) for mortality was 2.32 (95% confidence interval [CI] 1.82-2.94, I2 for heterogeneity 90.1%, 24 studies), that for ICU admission was 2.39 (95% CI 1.90-3.02, I2 0.0%, 5 studies), that for disease severity or hospitalization was 2.08 (95% CI 1.60-2.72, I2 92.1%, 15 studies). The pooled mortality OR for hematologic neoplasms was 2.14 (95% CI 1.87-2.44, I2 20.8%, 8 studies). Data were insufficient to perform a meta-analysis for other cancers. In the mortality meta-analysis for all cancers, the pooled OR was higher for studies conducted in Asia than studies conducted in Europe or North America. There was no evidence of publication bias. Conclusions: Our meta-analysis indicates a twofold increased risk of adverse outcomes (mortality, ICU admission, and severity of COVID-19) in unvaccinated COVID-19 patients with cancer compared to COVID-19 patients without cancer. These results should be compared with studies conducted in vaccinated patients; nonetheless, they argue for special effort to prevent SARS-CoV-2 infection in patients with cancer. Funding: No external funding was obtained.

Correction to: Prognostic Role of Blood Eosinophil Count in Patients with Sorafenib-Treated Hepatocellular Carcinoma.

An Online First version of this article was made available online at https://link.springer.com/article/10.1007/s11523-020-00757-3 on 12 October 2020. Errors were subsequently identified in the article, and the following corrections should be noted.

Prognostic Role of Blood Eosinophil Count in Patients with Sorafenib-Treated Hepatocellular Carcinoma.

BACKGROUND: Inflammation is a long-established hallmark of liver fibrosis and carcinogenesis. Eosinophils are emerging as crucial components of the inflammatory process influencing cancer development. The role of blood eosinophils in patients with hepatocellular carcinoma receiving systemic treatment is an unexplored field. OBJECTIVE: The objective of this study was to analyse the prognostic role of the baseline eosinophil count in patients with sorafenib-treated hepatocellular carcinoma. PATIENTS AND METHODS: A training cohort of 92 patients with advanced- or intermediate-stage sorafenib-treated hepatocellular carcinoma and two validation cohorts of 65 and 180 patients were analysed. Overall survival and progression-free survival in relation to baseline eosinophil counts were estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed. RESULTS: A negative prognostic impact of low baseline eosinophil counts (< 50*109/L) was demonstrated in all cohorts (training cohort: hazard ratio = 50.1, 95% confidence interval 11.6-216.5, p < 0.0001 for low vs high eosinophil counts; first validation cohort: hazard ratio = 4.55, 95% confidence interval 1.24-16.65, p = 0.022; second validation cohort: hazard ratio = 3.21, 95% confidence interval 1.83-5.64, p < 0.0001). Moreover, low eosinophil counts had a negative prognostic role in patients progressing on or intolerant to sorafenib who received second-line regorafenib, but not capecitabine or best supportive care. CONCLUSIONS: Our analysis identified baseline blood eosinophil counts as a new prognostic factor in patients with sorafenib-treated hepatocellular carcinoma. Concerning second-line therapies, eosinophil counts were associated with survival outcomes only in regorafenib-treated patients, suggesting a possible predictive role in this setting.