In the United States the incidence of and mortality from pancreatic cancer have increased over the past several decades but have tended to level off in recent years. The rates are higher in blacks than in whites and higher in males than in females. Mortality rates increase with age but there appears to be a decline in elderly blacks, possibly on an artifactual basis. There is a suggestion that rates are higher in Jews. No consistent differences by socioeconomic status or by geographic location within the United States have been identified. Both genetic and environmental factors may be playing significant roles in this disease. Cigarette smoking may be etiologically related, or at the very least, may help to identify a group of patients at increased risk of pancreatic cancer. However, the relative risk estimated for cigarette smoking is much lower than that found for cancer of the lung. The leveling off in incidence and mortality rates for pancreatic cancer in recent years also differs from the time trends observed for lung cancer. However, this could result from differences in site-specific carcinogens and from the fact that the lung is the first organ to be exposed to cigarette smoke in the highest concentrations and prior to the metabolism of any of its components. 
Dietary factors may have an important role in pancreatic cancer, but further research is needed to clarify this relationship. In particular, the possibility that dietary fats may be implicated and that vitamins or fiber may be protective in this disease remains to be explored. Finally, there is suggestive evidence that specific chemical exposures may be carcinogenic for the pancreas. Many of the data are from animal studies, and the findings from human studies are not entirely consistent.

Epidemiology of Pancreatic Cancer

Epidemiology of and Risk Factors for Pancreatic Cancer

The non-Hodgkin lymphomas (NHL) are a heterogeneous group of B-cell and T-cell neoplasms that arise primarily in the lymph nodes NHL incidence rates in the US doubled between about 1970 and 1990, and stabilized during the 1990s NHL accounts for approximately 34% of cancer deaths in the US Although some of the observed patterns in NHL have been related to HIV/AIDS, these conditions cannot fully explain the magnitude of the changes; neither do changes in classification systems nor improved diagnostic capabilities Studies of occupational and environmental exposures (eg, pesticides, solvents) have produced no consistent pattern of significant positive associations Inverse associations with ultraviolet radiation exposure and alcohol and fish intake, and positive associations with meat and saturated fat intake have been reported in several studies; additional studies are needed to confirm or refute these associations Family history of NHL or other hematolympho-proliferative cancers and personal history of several autoimmune disorders are associated with increased risk of NHL, but are not likely to account for a large proportion of cases HIV and other infectious agents, such as human herpesvirus 8 and Epstein-Barr, appear to be associated with differing types of NHL, such as some B-cell lymphomas Future epidemiologic studies should evaluate associations by NHL type, enhance exposure information collected, and elucidate factors that may identify susceptible (or resistant) subpopulations because of genetic, immunologic or other characteristics The extent to which the etiology of NHL types may differ is important to resolve in ongoing and future studies

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.22719

The non‐Hodgkin lymphomas: A review of the epidemiologic literature

Multiple myeloma, a neoplasm of plasma cells, accounts for approximately approximately 15% of lymphatohematopoietic cancers (LHC) and 2% of all cancers in the US. Incidence rates increase with age, particularly after age 40, and are higher in men, particularly African American men. The etiology is unknown with no established lifestyle, occupational or environmental risk factors. Although several factors have been implicated as potentially etiologic, findings are inconsistent. We reviewed epidemiologic studies that evaluated lifestyle, dietary, occupational and environmental factors; immune function, family history and genetic factors; and the hypothesized precursor, monoclonal gammopathies of undetermined significance (MGUS). Because multiple myeloma is an uncommon disease, etiologic assessments can be difficult because of small numbers of cases in occupational cohort studies, and few subjects reporting exposure to specific agents in case-control studies. Elevated risks have been reported consistently among persons with a positive family history of LHC. A few studies have reported a relationship between obesity and multiple myeloma, and this may be a promising area of research. Factors underlying higher incidence rates of multiple myeloma in African Americans are not understood. The progression from MGUS to multiple myeloma has been reported in several studies; however, there are no established risk factors for MGUS. To improve our understanding of the causes of multiple myeloma, future research efforts should seek the causes of MGUS. More research is also needed on the genetic factors of multiple myeloma, given the strong familial clustering of the disease.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.22718

Multiple myeloma: A review of the epidemiologic literature

With the hope that exposures responsible for colorectal cancer might be especially obvious among those in whom it develops early, 147 men with colorectal carcinomas first diagnosed between the ages of 25 and 44 years were compared to neighborhood controls. Physical activity on the job was protective for tumors located in the transverse and descending portions of the colon. Rectal cancer and to a lesser extent sigmoid cancers were associated with jobs in which dusts or fumes were inhaled, especially if those jobs were held for long periods in young adulthood. While risk for rectal cancer did not seem to be limited to any particular type of dust or fume, the excess risk was strongest for wood and metal dusts. Consumption of fruits and vegetables and a preference for whole grain breads were protective for colon but not rectal cancers, while consumption of deep fried foods and barbecued/smoked meats increased risk at specific subsites. Beef intake, alcohol consumption, and cigarette smoking appeared to play little or no role at any subsite.

https://cancerres.aacrjournals.org/content/canres/49/19/5459.full.pdf

A case-control study of occupational and dietary factors in colorectal cancer in young men by subsite.

This retrospective cohort study examines mortality and cancer incidence among 3,686 men and 75 women who were employed as chemists in 1959. During the period 1964 to 1977, the male chemists experienced lower overall mortality than other salaried employees of the chemical company (198 deaths observed, 241.0 expected, SMR = 82). Large deficits are seen in lung cancer and arteriosclerotic heart disease death. The chemist appear to be at slightly higher risk for death from malignancies of the colon (12 observed, 6.7 expected, SMR = 178) and from cerebrovascular disease (15 observed, 10.8 expected, SMR = 138). The low overall mortality resulted in a larger than expected proportion of deaths due to cancer. Fewer than expected cases were diagnosed of cancer of all sited combined (61 observed, 86.5 expected, SIR = 71) and of the lung (8 observed, 20.0 expected, SIR = 40). The incidence rates of melanoma and of cancer of the prostate are slightly higher than expected, relative to the Third National Cancer Survey and the experience of nonchemists, respectively. Among female chemists, deaths due to all causes and suicide occurred more frequently than expected. Possible explanations for the lack of anticipated excess risks and for the observed deficits are presented.

A retrospective cohort study of mortality and cancer incidence among chemist.

A group of 902 pattern and model makers were screened for colorectal cancer and polyps using a 60-cm flexible sigmoidoscope. Three recent mortality studies have found a significant excess of colorectal malignant neoplasms in this occupational group. Four adenocarcinomas, two carcinoids, and two cancers in situ were found. In addition, 150 (17%) of the individuals were found to have polyps. Among white males 40 to 70 years of age, the prevalence rate was found to be 23%. The prevalence of colorectal polyps among the pattern and model makers was compared with that of four previously studied asymptomatic populations who were also examined using a 60-cm flexible sigmoidoscope. Polyp rates were found to be significantly greater among pattern and model makers than among three of the four comparison populations. The odds ratios between these three populations and the study population ranged from 1.9 to 2.7 and closely approximate the ratios found in previous studies evaluating colon cancer in this occupational group.

Prevalence of colorectal polyps among Michigan pattern and model makers.

This retrospective cohort study examines disability among 3,686 men and 75 women who were employed as chemists in 1959 and who were followed through 1977. Overall, the chemists experienced fewer absences of eight or more consecutive days than expected on the basis of the experience of other salaried employees of the chemical company. Among the men, fewer claims than expected were observed for absences due to benign and unspecified neoplasia, heart disease, and peptic ulcer, and to diseases of the urinary system, bones and joints, and skin. Also, the chemist had lower than expected incidence rates of first myocardial infarction (90 observed, 149.8 expected). The deficits may be attributable to exposure misclassification or to confounding by smoking or socioeconomic status. A slight excess was seen of absences due to mental disorders.

A retrospective cohort study of disability among chemists.

The National Cancer Institute has contracted with Syracuse Research Corporation to produce monographs on the potential hazards of human exposure to approximately 70 chemicals used in the workplace. The monographs include detailed exposure data for specific job categories, as well as summaries of chemical and physical data, animal and human toxicological studies, short-term assays, and epidemiologic data. The information is useful for identifying suitable populations for epidemiologic research.

Shelia K. Hoar

Papers

A retrospective cohort study of mortality and cancer incidence among chemist.

Prevalence of colorectal polyps among Michigan pattern and model makers.

A retrospective cohort study of disability among chemists.

Monographs on human exposures to chemicals in the workplace.