Male Esophageal Cancer Research Articles

Progression of precancerous lesions of esophageal squamous cell carcinomas in a high-risk, rural Chinese population.

This study investigated the natural history of esophageal squamous cell carcinoma (ESCC) in rural Chinese. We sought to help provide more data to support ESCC screenings. This study was based on an existing Screening Program in Feicheng, China. Esophageal precancerous lesions were identified in 1753 cases, diagnosed from esophageal cancer screenings from 2006 to 2016. We followed up with them through endoscopic screening until October 1, 2017. Pathology results from various grades of precancerous lesions were recorded and the annual transition probabilities and incidence density of ESCC were calculated. As of October 1, 2017, a total of 4055.8 person-years has been observed. The ESCC incidence density of mild, moderate, and severe dysplasia (SD) was 0.17, 0.79, and 1.77 per 100 person-years, respectively. The median follow-up time of mild, moderate, and SD was 3.5, 2.3, and 2.2 years, respectively. The annual transition probability of mild, moderate, and SD to the next pathological level was 0.025, 0.038, and 0.016, respectively. The ESCC incidence density of males was 2.6 times higher than females (0.58 vs. 0.22), and the older age group (56-69 age group) had a ESCC incidence density 1.2 times higher than the younger group (40-55 age group) (0.45 vs. 0.39). The higher the grade of precancerous lesions, the higher the incidence density of ESCC. Screening of esophageal cancer in males and the elderly should be strengthened. It is recommended to reinforce follow-up management for untreated patients with SD/carcinoma in situ. For patients with mild and moderate dysplasia in high-risk rural Chinese populations, endoscopic follow-up intervals can be appropriately adjusted to once every 2 years.

Changing trend of incidence and mortality of esophageal cancer during 2010-2016 in Henan Province, China

Objective: To estimate the incidence and mortality of esophageal cancer in 2016 and their changing trend during 2010-2016 according to the cancer registration data in Henan province. Methods: The data quality including completeness, validity, and reliability of local registries which submitted the cancer registration data of 2016 were assessed according to the criteria of Guideline on Cancer Registration in China and IARC/IACR. Esophageal cancer cases (ICD10: C15) were extracted from the database, and the incidence and mortality stratified by gender, age, and areas (urban/rural) were calculated, the incidence and mortality of provincial cancer were estimated combined with provincial population data. China's 2000 census population and Segi's population were used to calculate the age-standardized rate. Joinpoint model was used to estimate the changing trend of age standardized incidence and mortality along with the calendar year. Results: Approximately 40.10 thousand new esophageal cancer cases were diagnosed in Henan in 2016, accounting for 13.46% of all new cancer cases, and it ranked the third among cancer of all sites. The crude incidence of esophageal cancer was 37.21/100 000 with an age-standardized incidence rate by China standard population (ASIRC) of 26.74/100 000 and an age-standardized incidence rate by world standard population (ASIRW) of 27.12/100 000. The incidence of esophageal cancer in males was higher than that in females, with the ASIRC of 34.53/100 000 and 19.19/100 000, respectively. It was higher in rural areas than that in urban areas, with the ASIRC of 28.13/100 000 and 20.90/100 000, respectively. About 29.30 thousand deaths of esophageal cancer in Henan in 2016, accounting for 15.61% of all cancer deaths in Henan, which ranked the third among cancer of all sites. The crude mortality rate was 27.14/100 000 with an age-standardized mortality rate by China standard population (ASMRC) of 18.74/100 000 and an age-standardized mortality rate by world standard population (ASMRW) of 18.78/100 000. The mortality in males was higher than that in females, with the ASMRC of 24.78/100 000 and 13.12/100 000, respectively. It was also higher in rural areas than that in urban areas, with the ASMRC of 19.48/100 000 and 15.73/100 000, respectively. The ASIRC and ASMRC were declining with annual percent change (APC) of 3.12% (APC=-3.12%; 95%CI: -5.30%, -0.90%; P=0.015) and 2.47% (APC=-2.47%; 95%CI: -4.70%, -0.20%; P=0.039) during 2010-2016. However, the significant declining trend was only observed in rural areas in Henan, and the changing trend was same between males and females. Conclusions: The incidence and mortality of esophageal cancer are declining since 2010, however, the disease burden remains large in Henan. Therefore, comprehensive prevention and control efforts should be strengthened according to its epidemic characteristics and risk factors.

Abstract P110: Neandertal introgressions contribute to upper aero-digestive tract tumor patient survival and identify patients who may benefit from STING agonist treatment

Abstract Background: Admixture of archaic (Neandertal and Denisova) and ancestral genes enhanced natural immunity during out of Africa migrations and modulates modern susceptibility to autoimmunity and cancer. We investigated a series of functional interactions between archaic and ancestral STING1 and TLR genes to identify vulnerabilities that could be addressed by STING agonist therapy. Methods: Gene variants from 10,389 cancer patients (pts) were obtained from TCGA. Archaic sequences were accessed using UCSD genome browser 410. Linkage disequilibrium was investigated using LDlink v5.0. Patient 1 was treated within NCT04144140. Results: STING1 variants were overrepresented in gastroesophageal cancer pts. V48V (rs7447927-C>G) with GWAS of lower rate of Asian esophageal cancer was in linkage disequilibrium with the reference alleles of the partially active HAQ and REF variants, and with rs13153461, present in Neandertal sequences. STING1 rs7447927-G was also associated with HLA A*24:02 (p<0.001), A*02:06 (p=0.01), and A*31:01 (p=0.02), of Neandertal origin. We then investigated a potential epistasis between STING1 rs7447927-G and TLR variants associated with decreased H. pylori prevalence: Neandertal-like TLR10 I775V (rs4129009) and ancestral TLR6 S249P (rs5743810). No independent prognosis was identified in 32 TCGA legacy studies; however, in upper aerodigestive (oral cavity, oropharynx, esophageal, gastric, biliary tract) tumor pts who carried reference/heterozygous TLR6 S249P and/or reference TLR10 I775, Neandertal-associated STING1 rs7447927-G zygosity was a strong predictor of survival. Hazards ratio for rs7447927-GG vs GC (4.8 vs 2.7 yrs. median survival), and GG vs CC (4.8 vs 1.8 yrs.) were respectively 0.71 and 0.53, N=713, p=0.0003. Patient 1 was a 75 yr.-old male esophageal cancer pt with GERD, Barrett’s esophagus and TLR6 S249/STING1 rs7447927-GC, who was progressing from anti-PD1 and chemotherapy and received 75 microg intra-tumoral injections of the STING agonist E7766. Non treatment-related grade 2 events of anemia and hyponatremia, serum IFNbeta and IP10 levels induction, 20% tumor size reduction including abscopal effects, and 6.3 months PFS benefit were observed. Conclusion: Genotyping of STING1, TLR6-10 variants could contribute to identify pts who may benefit from E7766 treatment. Citation Format: Antonio Gualberto, Tenghui Chen, Catherine Scholz, Jason Luke. Neandertal introgressions contribute to upper aero-digestive tract tumor patient survival and identify patients who may benefit from STING agonist treatment [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P110.

Analysis of incidence and mortality of esophageal cancer in China, 2015

Objective: To estimate the incidence and mortality rates of esophageal cancer in China in 2015. Methods: Based on the data quality review and assessment, the esophageal cancer data from 368 cancer registries in 31 provinces (autonomous regions and municipalities) in China were included in this study. According to the national population data in 2015, the nationwide incidence and mortality of the esophageal cancer were estimated. Chinese standard population in 2000 and world Segi's population were used to calculate the age-standardized (ASR) incidence and mortality rates (ASR China and world, respectively). Results: The 368 cancer registries covered a total of 309 553 499 populations in China, accounting for 22.52% of the national population. There were 245 651 new esophageal cancer cases estimated in China in 2015, with a crude incidence rate of 17.87/100 000. The ASR China and ASR world were 11.14/100 000 and 11.28/100 000, respectively. The estimated number of esophageal cancer death was 188 044 in China in 2015, with a crude mortality rate of 13.68/100 000; The ASR China and ASR world mortality rates were 8.33/100 000 and 8.36/100 000, respectively. The ASR China incidence and mortality of esophageal cancer in males were higher in males (16.50/100 000 and 12.66/100 000) than those in females (5.92/100 000 and 4.17/100 000), and they were higher in rural areas (15.95/1100 000 and 11.67/100 000) than those in urban areas (7.59/100 000 and 5.87/100 000). Conclusion: The incidence and mortality of esophageal cancer in China are higher than the global average. The disparity of the incidence and mortality rates of esophageal cancer significantly differed in genders and areas.

Do male esophageal cancer patients have impaired sexual function after esophagectomy? A self-reported outcomes study.

Sexual function is a significant part of patients' quality of life, which is another important aspect of cancer. This study assessed and compared the sexual function of male esophageal cancer patients to that of age-matched normal controls through postoperative follow-up surveys. The study included 105 male esophageal cancer patients aged 38-81years who underwent a curative-intent esophagectomy between April 2012 and May 2014. This observational study included sociodemographic and clinicopathological characteristics and responses to sexual function questionnaires International Index of Erectile Function (IIEF) at 6 and 12months after surgery. An age-matched normal control group was recruited. Non-parametric tests were used when appropriate. The median patient age was 59years. The factors significantly associated with sexual dysfunction on the 6-month survey included older age, and postoperative complications. At 12months after surgery, older age was significantly associated with poorer sexual function. The sexual function scores significantly increased from 6 to 12months after surgery (P<0.05); there was no difference in the patients' 12-month sexual function scores and those of the normal controls (P>0.05). Notably, compared to older patients (age ≥60years), the younger (age <60years) patients reported a significantly better sexual function scores (P<0.05). Age, and postoperative complications were the factors significantly associated with sexual function. Impaired sexual function after primary treatment can be recovered in male esophageal cancer patients; younger patients may regain sexual function better than their older counterparts.

Geographic spatial pattern of digestive system cancers in Yiwu city

To analyze the geographic spatial patterns and risk areas of main digestive system cancers in Yiwu city. Newly diagnosed cases of esophageal, gastric and colorectal cancer during 2010-2014 were obtained from Yiwu Center for Disease Control and Prevention (CDC). The household registration population data in 2013 were obtained from public security bureau. Hierarchy clustering and partitioning regionalization method was used to generate geographic units. Global Moran's I was used to evaluate whether cancer incidence was significantly clustered in space, Anselin Local Moran's I was used to identify statistically significant hot spots, cold spots, and spatial outliers, and Spatial Scan Statistics was implemented to analyze the relative risk of cancers in different areas. The 5-year average incidence of esophageal, gastric and colorectal cancers were 9.99/100 000, 34.01/100 000 and 31.46/100 000, respectively. Males showed significantly higher incidence than females. The incidence was heterogeneous throughout the study area. Spatial Scan analysis revealed that southern Yiwu presented a significantly higher male esophageal cancer (RR=1.78) and gastric cancer (RR=1.87) risk. The central area of Yiwu showed a significantly lower female esophageal cancer risk (RR=0.00) and male stomach cancer risk (RR=0.63) and the northern Yiwu exhibited a significantly lower female colorectal cancer risk (RR=0.48). The incidence of main digestive tract cancers shows a heterogeneous distribution in Yiwu city.

ERCP for Septic Cholangitis Through a Peg Tube, a Life-Saving Procedure Using an Alternative Access Route to Approach the Biliary Tree When the Regular ERCP Fails

Acute cholangitis, is a product of bile stasis and infection of the biliary tract. Diagnostic and therapeutic role of the Endoscopic retrograde cholangiopancreatography (ERCP) has a critical role in the management. Anatomical variation following Roux-en-Y gastric bypass or people who had esophageal obstructions tend to make the early intervention by the ERCP a challenge. We report a case of septic cholangitis in a patient whom the ERCP was achived through a peg tube. Case report: 75-year-old male esophageal cancer & gastrostomy tube for malnutrition presented to the local hospital with fevers. Initial evaluation showed feature of sepsis with a fever, leukopenia, elevation in the liver enzymes & total bilirubin 1.2 and lactic acid 3.2. Ct scan showed a stone in the common bile duct & blood cultures showed Enterobacter cloacae. The patient started on ceftriaxone & transferred to our tertiary center for therapeutic intervention. The patient had a MRCP that demonstrates a 1.3 cm obstructive distal common bile duct stone for which the patient underwent an attempt with ERCP that shortly aborted given partially obstructing esophageal mass. After changing to a small pediatric endoscope, the scope was able to be pass the mass but the procedure terminated due to scope malfunction. Another route to access the biliray system was found; the peg tube was removed after an anchoring system was placed. Following the placement of the anchors an Axio stent was placed & a balloon dilitation was performed inside the stent up to 15 mm in size. Following dilitation an ERCP scope was placed and the papilla was accessed and sphincterotomy was made and stone was removed. After the stone removal, the stent was removed and a peg tube was replaced and the patient tolerated the procedure without any complication & discharged on stable condition. Discussion: ERCP is the treatment of choice in establishing biliary drainage in acute cholangitis. In the setting of anatomical variation, the success rate dramatically dropped below 70% when compare it to the traditional ERCP 90-95%. The literature showed that the success rate is higher using surgically created route through the stomach as a mature gastrostomy, trans-gastric or laproscopic- assisted port are all well tolerated. In patient with limited access for the traditional ERCP, alternative routes can allow the gastroenterologist to drain the blockage; such intervention can improve the mortality & morbidty.

Patterns and trends in esophageal cancer mortality and incidence in Europe (1980–2011) and predictions to 2015

Over the last few decades, esophageal cancer incidence and mortality trends varied substantially across Europe, with important differences between sexes and the two main histological subtypes, squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). To monitor recent esophageal cancer mortality trends and to compute short-term predictions in the European Union (EU) and selected European countries, we analyzed data provided by the World Health Organization (WHO) for 1980-2011. We also analyzed incidence trends and relative weights of ESCC and EAC across Europe using data from Cancer Incidence in Five Continents. Long-term decreasing trends were observed for male esophageal cancer mortality in several southern and western European countries, whereas in central Europe mortality increased until the mid-1990s and started to stabilize or decline over the last years. In some eastern and northern countries, the rates were still increasing. Mortality among European women remained comparatively low and showed stable or decreasing trends in most countries. Between 2000-2004 and 2005-2009, esophageal cancer mortality declined by 7% (from 5.34 to 4.99/100 000) in EU men, and by 3% (from 1.12 to 1.09/100 000) in EU women. Predictions to 2015 show persistent declines in mortality rates for men in the EU overall, and stable rates for EU women, with rates for 2015 of 4.5/100 000 men (about 22 300 deaths) and 1.1/100 000 women (about 7400 deaths). In northern Europe, EAC is now the predominant histological type among men, while for European women ESCC is more common and corresponding rates are still increasing in several countries. The observed trends reflect the variations in alcohol drinking, tobacco smoking and overweight across European countries.

278 Mortality patterns in a cohort of 70,000 workers with blood lead measurements

ObjectivesTo determine whether adult lead exposure is associated with cause-specific mortality in a cohort with measured blood leadsMethodsWe studied 70,000 US adults from 11 states with blood lead levels measured...

Obviously Increasing Incidence Trend for Males but Stable Pathological Proportions for Both Genders: Esophageal Cancer in Zhongshan of China from 1970-2007

To analyze esophageal cancer incidence and pathological data of Zhongshan in China in 1970- 2007, and to provide scientific information for its prevention and control. From Zhongshan Cancer Registry esophageal cancer incident and pathological data were obtained. Pathological proportions and trends were calculated and analyzed. Although there was a continuously and obviously increasing trend for male incidence rates in 1970-2007 in Zhongshan, squamous cell carcinoma (SCC) and adenocarcinoma (AD) incident proportions during 1990-2007 remained relatively stable. Moreover, SCC was the major pathological type, accounting for 70.6 percent of all new cases, while AD were relatively few and accounted for only 2.66 percent throughout the period. The male esophageal cancer incident pattern in Zhongshan in 1970- 2007 was quite different from most other domestic areas. The data suggest that etiological analysis should be enhanced for improved control in Zhongshan.

Second cancer after radiotherapy, 1981–2007

Background and purposeToday, there is growing concern about radiotherapy induced secondary malignancies. We analysed the incidence and dose dependence of second cancer. Material and methodsThe study includes 12,000 one-year survivors of radiotherapy, treated between 1981 and 2007. For risk estimates a public databank on cancer in Germany served as reference. Contralateral second breast cancer, second oesophageal and colorectal cancer were analysed with retrospective dosimetry. GI-tract data were used for risk modelling. ResultsThe incidence rate of second cancers (493 cases) was ∼1% per year. Contralateral breast cancer was the most frequent entity (relative risk RR=2.8). The scatter-dose gradient (2–3Gy) across the contralateral breast did not cause a detectable risk gradient. There was an increased risk for second head and neck cancer (RR=5.1) and for male oesophageal cancer (RR=5.8). For both entities, dose response modelling with case-control data predicted maximum curves with peak induction at 1–5Gy and positive excess absolute risk values at high doses. ConclusionsA survey of second cancer after radiotherapy requires follow-up over decades. Preliminary dose response modelling albeit with low case numbers suggests an increased risk from multiportal techniques. To improve risk assessment, prospective out-of-field dosimetry and long-term multicentre data collection are recommended.

The changing epidemiology of upper gastrointestinal cancers in Israel: clinical and screening implications

Western countries and now developing countries have noted a decreasing incidence of upper gastrointestinal (UGI) (esophageal and gastric) cancers, but increasing distal esophageal adenocarcinoma and a shift to fundal-sited gastric cancer. We examined these trends in Israeli Jewish and non-Jewish populations, drawing conclusions on the need to promote prevention and/or screening. Israel Cancer Registry UGI cancer data were computed by ethnicity, immigration after 1990, sex, sites and histology, examining age-standardized rates (ASR)/10 for 2000-2005 and incidence trends during 1980-2005. In Jews, male esophageal cancer incidence has increased (P<0.01) and is highest in European-American-born males (ASR/10, 1.98), but decreasing in the upper two-thirds of esophagus so that in men 89% now occur in the lower one-third. In both sexes this was associated with decreasing squamous cell carcinoma (P<0.01) but increased adenocarcinoma to cause 72.6% of esophageal cancers in men. Gastric cancer incidence is highest in European-American-born males (ASR/10, 11.75); there is a decreasing incidence in both sexes (P<0.01) and gastric site trends are stable. In non-Jews, esophageal cancer incidence is three times higher in men (ASR/10, 0.82); they are only squamous cell cancers and incidence trends are stable. Gastric cancer incidence is twice as high in men (ASR/10, 8.45) and gastric site trends are stable. UGI cancer incidence in Jews and non-Jews, men and women, is low as compared with most developing countries. The important findings are the low but prominent incidence of distal esophageal and gastric adenocarcinoma in male immigrants. This requires attention to possible preventive measures in at-risk groups.

A Dosimetric Comparison of Intensity Modulated Radiotherapy versus Three-dimensional Conformal Radiotherapy for Esophageal Carcinoma

A Dosimetric Comparison of Intensity Modulated Radiotherapy versus Three-dimensional Conformal Radiotherapy for Esophageal Carcinoma

Occupational exposures and risk of oesophageal cancer by histological type: a case–control study in eastern Spain

Objective: To explore the relationship between occupations and specific occupational exposures and oesophageal cancer (OC) by histological type. Methods: A multicentre hospital-based case–control study was conducted in two Mediterranean provinces...

Pipe smoking and cancers of the upper digestive tract

Pipe smoking has been related to the risk of cancers of the upper digestive and respiratory tract, but quantification of the risk for exclusive pipe smokers is still limited. To analyse the association between exclusive pipe smoking and cancers of the upper digestive tract, we used data from a series of case-control studies conducted in Italy and Switzerland between 1984 and 1999. After excluding cigarette and cigar smokers, 41 male oral and pharyngeal cancer cases, 52 male oesophageal cancer cases and 1,032 male controls were included in the present analysis. Odds ratios (OR) of cancers were estimated by the mean of unconditional multivariate logistic regression, including terms for age, study centre, education, body mass index, and alcohol drinking. Compared to never smokers, exclusive pipe smokers had an OR of 8.7 [95% confidence intervals (CI): 4.0-18.9] of all upper digestive tract cancers. The OR was 12.6 for oral and pharyngeal and 7.2 for oesophageal cancer. Pipe smokers who were also heavy alcohol drinkers had an OR of 38.8 (95% CI: 13.6-110.9) as compared to never smokers and light drinkers. Thus, pipe smoking and heavy alcohol drinking appears to interact at least on a multiplicative model.

Smoking and mortality from esophageal cancer in China: A large case‐control study of 19,734 male esophageal cancer deaths and 104,846 living spouse controls

An innovative population-based case-control study was conducted in a national mortality survey to assess the hazards of tobacco use on esophageal cancer among Chinese men. Cases were 19,734 males aged 35 years or older, who died of esophageal cancer during 1986-1988. Controls were 104,846 male living spouses of the same age when their wife died (of any cause) during the same period in the same county or city. The absolute esophageal cancer death rates were higher in smokers than those in nonsmokers in all geographical groups. The relative risks for esophageal cancer were 1.88 (95% CI: 1.73-2.05) and 1.39 (95% CI: 1.28-1.50) in urban and rural men, respectively, after adjustment for other relevant covariates including age group (5 years) and locality. When the calculation was restricted to men aged 35-69, the risk ratios for current cigarette smokers increased significantly with increasing number of cigarettes smoked daily and duration of smoking. Tobacco use, in any form, is an important risk factor for esophageal cancer in Chinese men. Selecting living spouses as controls is a unique and useful approach in the design of case-control studies of cigarette smoking.

Mortality Predictions for Esophageal, Stomach, and Pancreatic Cancer, Ireland, Up to 2015

An analysis was undertaken to predict numbers of esophageal, stomach, and pancreatic cancer deaths and their World age standardized mortality rates (WASMRs) per 100,000 person years (100,000 PY-1) in Ireland for the years 2005, 2010 and 2015. Linear and log-linear Poisson regression models were applied to 1950-2002 Irish cancer mortality data. By 2015, esophageal cancer WASMR for males is expected to rise to 9.1 100,000 PY-1, but for females to fall to 2.3 100,000 PY-1. In women under 65 yr, the WASMR is expected to decline to 0.8 100,000 PY-1 but to increase to 3.6 100,000 PY-1 in men. The stomach cancer WASMR for males is predicted to decrease to 5.3 100,000 PY-1 and for females to 2.9 100,000 PY-1. In males under 65 yr, the WASMR is predicted to fall to 1.7 100,000 PY-1 and to 1.0 100,000 PY-1 in women. The male WASMR for pancreatic cancer is predicted to decrease to 5.9 100,000 PY-1 and to 4.7 100,000 PY-1 in women. In men under 65 yr, the WASMR is predicted to drop to 1.7 100,000 PY-1 and to fall in women to 1.2 100,000 PY-1. Apart from male esophageal cancer, the findings would indicate that declines in Irish WASMRs for these three cancer types are expected to occur by 2015.

Mutagenic drinking water and risk of male esophageal cancer: a population-based case-control study.

Drinking mutagenic downstream water from the Huangpu River was hypothesized to have increased the risk for male esophageal cancer in Shanghai, China. The authors conducted a population-based case-control study of a total of 71 esophageal cancer deaths and 1,122 controls collected during a 5-year follow-up period, 1984-1988, from four male cohorts born before January 1, 1944, living in four communities consuming water with different mutagenicities in the Shanghai area. The controls represented a 1% random sample of the defined living cohorts selected at the end of each of the 5 years of follow-up. Logistic regression showed an odds ratio of 2.77 (95% confidence interval: 1.52, 5.03) for drinking mutagenic downstream water from the river versus drinking nonmutagenic upstream water after controlling for possible confounders including age, disease history (hepatitis, cirrhosis, schistosomiasis, digestive tract ulcer), hazardous occupational history, pesticide exposure, lifestyle factors (cigarette smoking, tea intake, and alcohol intake), dietary habits (intake of pickled vegetables, maize, peanuts, and cured meat), education, poverty, urban environment, and water chlorination.

Trends in cancer mortality of the digestive tract in Belgrade, Yugoslavia, 1975-1989.

During the period of 1975-1989, in the Belgrade population increasing mortality trends were established for colon and rectal cancer, cancer of the pancreas and gallbladder and bile ducts cancer, for both sexes, and for esophageal cancer in males. Stomach and liver cancer mortality decreased in females. In males, stomach cancer mortality after a prolonged steady decrease suddenly rose in the years 1988 and 1989. Mortality rates series for esophageal cancer in females and for liver cancer in males did not fit any usual trend function.

Geographic variation in cancer incidence in the USSR: Estimating the proportion of avoidable cancer

Background. The Soviet Union offers a unique frame in which to study geographic variation in cancer incidence because of its uniform registration system of all newly diagnosed cancer cases throughout its 15 republics and 162 oblasts (administrative units). Variation in cancer rates is stronger when examined by oblasts than it is when examined by republics. In 1986, the age-standardized all-site cancer incidence rate for both sexes, in the Soviet republic having the highest overall rate (Russian Soviet Federative Socialist Republic for males, Lithuania for females) was about twice that of the Soviet republic with the lowest all-site cancer rate (Georgia). Within Soviet oblasts (data are from 1979), the ratio of the highest to the lowest rates was about 4 for all sites, 144 for male oesophageal cancer, and 303 for female oesophageal cancer. The excess incidence in the entire USSR compared with the republic having the lowest all-site incidence rate was 59% for males and 49% for females. Conclusion. Although the observed differences between republics or between oblasts are partially due to uneven quality of data recording or to statistical variability related to population sizes, there is a strong geographic variation of cancer incidence rates in the USSR that suggests a potentially important role of environmental factors in cancer etiology.