Towards a theoretical determination of the geographical probability distribution of meteoroid impacts on Earth

Tunguska and Chelyabinsk impact events occurred inside a geographical area of only 3.4\% of the Earth's surface. Although two events hardly constitute a statistically significant demonstration of a geographical pattern of impacts, their spatial coincidence is at least tantalizing. To understand if this concurrence reflects an underlying geographical and/or temporal pattern, we must aim at predicting the spatio-temporal distribution of meteoroid impacts on Earth. For this purpose we designed, implemented and tested a novel numerical technique, the "Gravitational Ray Tracing" (GRT) designed to compute the relative impact probability (RIP) on the surface of any planet. GRT is inspired by the so-called ray-casting techniques used to render realistic images of complex 3D scenes. In this paper we describe the method and the results of testing it at the time of large impact events. Our findings suggest a non-trivial pattern of impact probabilities at any given time on Earth. Locations at $60-90\deg$ from the apex are more prone to impacts, especially at midnight. Counterintuitively, sites close to apex direction have the lowest RIP, while in the antapex RIP are slightly larger than average. We present here preliminary maps of RIP at the time of Tunguska and Chelyabinsk events and found no evidence of a spatial or temporal pattern, suggesting that their coincidence was fortuitous. We apply the GRT method to compute theoretical RIP at the location and time of 394 large fireballs. Although the predicted spatio-temporal impact distribution matches marginally the observed events, we successfully predict their impact speed distribution.Comment: 16 pages, 11 figures. Accepted for publication in MNRA

Liver cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

BACKGROUND: Worldwide, liver cancer is a leading cause of death for both men and women. The number of Americans who are diagnosed with and die of liver cancer has been rising slowly each year. Using data from the CONCORD-2 study, this study examined population-based survival by state, race, and stage at diagnosis. METHODS: Data from 37 statewide registries, which covered 81% of the US population, for patients diagnosed during 2001-2009 were analyzed. Survival up to 5 years was adjusted for background mortality (net survival) with state- and race-specific life tables, and it was age-standardized with the International Cancer Survival Standard weights. RESULTS: Liver cancer was diagnosed overall more often at the localized stage, with blacks being more often diagnosed at distant and regional stages than whites. 5-year net survival was 12.2% in 2001-2003 and 14.8% in 2004-2009. Whites had higher survival than blacks in both calendar periods (11.7% vs 9.1% and 14.3% vs 11.4%, respectively). During 2004-2009, 5-year survival was 25.7% for localized-stage disease, 9.5% for regional-stage disease, and 3.5% for distant-stage disease. CONCLUSIONS: Some progress has occurred in survival for patients with liver cancer, but 5-year survival remains low, even for those diagnosed at the localized stage. Efforts directed at controlling well-established risk factors such as hepatitis B may have the greatest impact on reducing the burden of liver cancer in the United States. Cancer 2017;123:5059-78. Published 2017. This article is a U.S. Government work and is in the public domain in the USA

Stomach cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

BACKGROUND: Stomach cancer was a leading cause of cancer-related deaths early in the 20th century and has steadily declined over the last century in the United States. Although incidence and death rates are now low, stomach cancer remains an important cause of morbidity and mortality in black, Asian and Pacific Islander, and American Indian/Alaska Native populations. METHODS: Data from the CONCORD-2 study were used to analyze stomach cancer survival among males and females aged 15 to 99 years who were diagnosed in 37 states covering 80% of the US population. Survival analyses were corrected for background mortality using state-specific and race-specific (white and black) life tables and age-standardized using the International Cancer Survival Standard weights. Net survival is presented up to 5 years after diagnosis by race (all, black, and white) for 2001 through 2003 and 2004 through 2009 to account for changes in collecting Surveillance, Epidemiology, and End Results Summary Stage 2000 data from 2004. RESULTS: Almost one-third of stomach cancers were diagnosed at a distant stage among both whites and blacks. Age-standardized 5-year net survival increased between 2001 to 2003 and 2004 to 2009 (26.1% and 29%, respectively), and no differences were observed by race. The 1-year, 3-year, and 5-year survival estimates were 53.1%, 33.8%, and 29%, respectively. Survival improved in most states. Survival by stage was 64% (local), 28.2% (regional), and 5.3% (distant). CONCLUSIONS: The current results indicate high fatality for stomach cancer, especially soon after diagnosis. Although improvements in stomach cancer survival were observed, survival remained relatively low for both blacks and whites. Primary prevention through the control of well-established risk factors would be expected to have the greatest impact on further reducing deaths from stomach cancer. Cancer 2017;123:4994-5013. Published 2017. This article is a U.S. Government work and is in the public domain in the USA

Lung cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

BACKGROUND: Results from the second CONCORD study (CONCORD-2) indicated that 5-year net survival for lung cancer was low (range, 10%-20%) between 1995 and 2009 in most countries, including the United States, which was at the higher end of this range. METHODS: Data from CONCORD-2 were used to analyze net survival among patients with lung cancer (aged 15-99 years) who were diagnosed in 37 states covering 80% of the US population. Survival was corrected for background mortality using state-specific and race-specific life tables and age-standardized using International Cancer Survival Standard weights. Net survival was estimated for patients diagnosed between 2001 and 2003 and between 2004 and 2009 at 1, 3, and 5 years after diagnosis by race (all races, black, and white); Surveillance, Epidemiology, and End Results Summary Stage 2000; and US state. RESULTS: Five-year net survival increased from 16.4% (95% confidence interval, 16.3%-16.5%) for patients diagnosed 2001-2003 to 19.0% (18.8%-19.1%) for those diagnosed 2004-2009, with increases in most states and among both blacks and whites. Between 2004 and 2009, 5-year survival was lower among blacks (14.9%) than among whites (19.4%) and ranged by state from 14.5% to 25.2%. CONCLUSIONS: Lung cancer survival improved slightly between the periods 2001-2003 and 2004-2009 but was still low, with variation between states, and persistently lower survival among blacks than whites. Efforts to control well established risk factors would be expected to have the greatest impact on reducing the burden of lung cancer, and efforts to ensure that all patients receive timely and appropriate treatment should reduce the differences in survival by race and state. Cancer 2017;123:5079-99. Published 2017. This article is a U.S. Government work and is in the public domain in the USA

Cervical cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

BACKGROUND: Overall, cervical cancer survival in the United States has been reported to be among the highest in the world, despite slight decreases over the last decade. Objective of the current study was to describe cervical cancer survival trends among US women and examine differences by race and stage. METHODS: This study used data from the CONCORD-2 study to compare survival among women (aged 15-99 years) diagnosed in 37 states covering 80% of the US population. Survival was adjusted for background mortality (net survival) with state- and race-specific life tables and was age-standardized with the International Cancer Survival Standard weights. Five-year survival was compared by race (all races, blacks, and whites). Two time periods, 2001-2003 and 2004-2009, were considered because of changes in how the staging variable was collected. RESULTS: From 2001 to 2009, 90,620 women were diagnosed with invasive cervical cancer. The proportion of cancers diagnosed at a regional or distant stage increased over time in most states. Overall, the 5-year survival was 63.5% in 2001-2003 and 62.8% in 2004-2009. The survival was lower for black women versus white women in both calendar periods and in most states; black women had a higher proportion of distant-stage cancers. CONCLUSIONS: The stability of the overall survival over time and the persistent differences in survival between white and black women in all US states suggest that there is a need for targeted interventions and improved access to screening, timely treatment, and follow-up care, especially among black women. Cancer 2017;123:5119-37. Published 2017. This article is a U.S. Government work and is in the public domain in the USA

Higher incidence of clear cell adenocarcinoma of the cervix and vagina among women born between 1947 and 1971 in the United States

Although the association between in utero exposure to diethylstilbestrol (DES) and clear cell adenocarcinoma of the cervix and vagina (CCA) was first reported among young women, subsequent case reports and cohort studies suggest that an elevated risk for CCA may persist with age. Data from the National Program of Cancer Registries (NPCR) and the Surveillance, Epidemiology and End Results (SEER) Program were used to construct indirect standardized incidence ratios (SIR) comparing CCA risk among women born during the exposure period 1947 through 1971, when DES was prescribed to pregnant women, to the relevant time period for nonexposed women born before or after DES exposure period. CCA incidence among the women born before the DES exposure period (ages 30–54 at diagnosis of CAA) or after the DES exposure period (ages 15–29 at diagnosis) were used to calculate the expected rates for women born during the DES exposure period. Among women aged 15–29 years, CCA risk increased with age and peaked in the 25–29 year age group, but the risk estimates were unstable (SIR = 6.06; 95% CI: 0.97, −251.07, SEER data). Among women aged 40–54 years, CCA risk was greatest in the 40–44 year age group (SIR = 4.55; 95% CI: 1.11, 40.19, SEER data and SIR = 3.94; 95% CI: 1.06, 33.01, NPCR/SEER data) and remained significantly elevated throughout this age group in the combined data set. Risk was not elevated among women aged 30–39 years. The observed risk of CCA, if causally related to DES exposure, reflects a persistent health impact from in utero exposure that is widespread in the general population. When assessing a woman’s cancer risks, whether her mother took DES while pregnant may still be a relevant aspect of the medical history for women born during the period of DES use in pregnancy

Pancreatic cancer survival trends in the US from 2001 to 2014: a CONCORD-3 study

Background Survival from pancreatic cancer is low worldwide. In the US, the 5-year relative survival has been slightly higher for women, whites and younger patients than for their counterparts, and differences in age and stage at diagnosis may contribute to this pattern. We aimed to examine trends in survival by race, stage, age and sex for adults (15-99 years) diagnosed with pancreatic cancer in the US. Methods This population-based study included 399,427 adults registered with pancreatic cancer in 41 US state cancer registries during 2001-2014, with follow-up to December 31, 2014. We estimated age-specific and age-standardized net survival at 1 and 5 years. Results Overall, 12.3% of patients were blacks, and 84.2% were whites. About 9.5% of patients were diagnosed with localized disease, but 50.5% were diagnosed at an advanced stage; slightly more among blacks, mainly among men. No substantial changes were seen over time (2001-2003, 2004-2008, 2009-2014). In general, 1-year net survival was higher in whites than in blacks (26.1% vs. 22.1% during 2001-2003, 35.1% vs. 31.4% during 2009-2014). This difference was particularly evident among patients with localized disease (49.6% in whites vs. 44.6% in blacks during 2001-2003, 60.1% vs. 55.3% during 2009-2014). The survival gap between blacks and whites with localized disease was persistent at 5 years after diagnosis, and it widened over time (from 24.0% vs. 21.3% during 2001-2003 to 39.7% vs. 31.0% during 2009-2014). The survival gap was wider among men than among women. Conclusions gaps in 1-and 5-year survival between blacks and whites were persistent throughout 2001-2014, especially for patients diagnosed with a localized tumor, for which surgery is currently the only treatment modality with the potential for cure

Colorectal cancer survival in the USA and Europe: a CONCORD high-resolution study.

OBJECTIVES: To assess the extent to which stage at diagnosis and adherence to treatment guidelines may explain the persistent differences in colorectal cancer survival between the USA and Europe. DESIGN: A high-resolution study using detailed clinical data on Dukes' stage, diagnostic procedures, treatment and follow-up, collected directly from medical records by trained abstractors under a single protocol, with standardised quality control and central statistical analysis. SETTING AND PARTICIPANTS: 21 population-based registries in seven US states and nine European countries provided data for random samples comprising 12 523 adults (15-99 years) diagnosed with colorectal cancer during 1996-1998. OUTCOME MEASURES: Logistic regression models were used to compare adherence to 'standard care' in the USA and Europe. Net survival and excess risk of death were estimated with flexible parametric models. RESULTS: The proportion of Dukes' A and B tumours was similar in the USA and Europe, while that of Dukes' C was more frequent in the USA (38% vs 21%) and of Dukes' D more frequent in Europe (22% vs 10%). Resection with curative intent was more frequent in the USA (85% vs 75%). Elderly patients (75-99 years) were 70-90% less likely to receive radiotherapy and chemotherapy. Age-standardised 5-year net survival was similar in the USA (58%) and Northern and Western Europe (54-56%) and lowest in Eastern Europe (42%). The mean excess hazard up to 5 years after diagnosis was highest in Eastern Europe, especially among elderly patients and those with Dukes' D tumours. CONCLUSIONS: The wide differences in colorectal cancer survival between Europe and the USA in the late 1990s are probably attributable to earlier stage and more extensive use of surgery and adjuvant treatment in the USA. Elderly patients with colorectal cancer received surgery, chemotherapy or radiotherapy less often than younger patients, despite evidence that they could also have benefited

Trends in short-term survival from distant-stage cutaneous melanoma in the United States, 2001-2013 (CONCORD-3).

BACKGROUND: Survival from metastatic cutaneous melanoma is substantially lower than for localized disease. Treatments for metastatic melanoma have been limited, but remarkable clinical improvements have been reported in clinical trials in the last decade. We described the characteristics of US patients diagnosed with cutaneous melanoma during 2001-2013 and assessed trends in short-term survival for distant-stage disease. METHODS: Trends in 1-year net survival were estimated using the Pohar Perme estimator, controlling for background mortality with life tables of all-cause mortality rates by county of residence, single year of age, sex, and race for each year 2001-2013. We fitted a flexible parametric survival model on the log-hazard scale to estimate the effect of race on the hazard of death because of melanoma and estimated 1-year net survival by race. RESULTS: Only 4.4% of the 425 915 melanomas were diagnosed at a distant stage, cases diagnosed at a distant stage are more commonly men, older patients, and African Americans. Age-standardized, 1-year net survival for distant-stage disease was stable at approximately 43% during 2001-2010. From 2010 onward, survival improved rapidly, reaching 58.9% (95% confidence interval = 56.6% to 61.2%) for patients diagnosed in 2013. Younger patients experienced the largest improvement. Survival for distant-stage disease increased in both Blacks and Whites but was consistently lower in Blacks. CONCLUSIONS: One-year survival for distant-stage melanoma improved during 2001-2013, particularly in younger patients and those diagnosed since 2010. This improvement may be a consequence of the introduction of immune-checkpoint-inhibitors and other targeted treatments for metastatic and unresectable disease. Persistent survival inequalities exist between Blacks and Whites, suggesting differential access to treatment