Prostate cancer (CaP) is the leading cancer among men of African descent in the USA, Caribbean, and Sub-Saharan Africa (SSA). The estimated number of CaP deaths in SSA during 2008 was more than five times that among African Americans and is expected to double in Africa by 2030. We summarize publicly available CaP data and collected data from the men of African descent and Carcinoma of the Prostate (MADCaP) Consortium and the African Caribbean Cancer Consortium (AC3) to evaluate CaP incidence and mortality in men of African descent worldwide. CaP incidence and mortality are highest in men of African descent in the USA and the Caribbean. Tumor stage and grade were highest in SSA. We report a higher proportion of T1 stage prostate tumors in countries with greater percent gross domestic product spent on health care and physicians per 100,000 persons. We also observed that regions with a higher proportion of advanced tumors reported lower mortality rates. This finding suggests that CaP is underdiagnosed and/or underreported in SSA men. Nonetheless, CaP incidence and mortality represent a significant public health problem in men of African descent around the world.
Tumor stage at diagnosis often varies by racial/ethnic group, possibly due to inequitable healthcare access. Within the Department of Defense (DoD) Military Health System, beneficiaries have equal healthcare access. This study aimed to determine if tumor stage differed between whites and blacks for breast, cervical, colorectal and prostate cancers, which have effective screening regimens, based on data from the DoD’s Automated Cancer Tumor Registry from 1990–2003.
Distributions of tumor stage (localized vs. non-localized) between whites and blacks in the military were compared stratified by sex, active duty status, and age at diagnosis. Logistic regression was used to further adjust for age, marital status, year of diagnosis, geographic region, military service branch and tumor grade. Distributions of tumor stage were then compared between the military and general populations.
Racial differences in the distribution of stage were significant only among non-active duty beneficiaries. After adjusting for covariates, earlier stages of breast cancer after age 49 and prostate cancer after age 64 were significantly more common among white than black non-active duty beneficiaries (p<0.05), although the absolute difference for prostate cancer was minimal. Racial differences in stage for cervical and colorectal cancers were not significant after adjustment. Compared to the general population, the racial differences in the military were similar or slightly attenuated.
Racial disparities in stage at diagnosis were apparent in the DoD’s equal access healthcare system among older non-active duty beneficiaries. Socioeconomic status, supplemental insurance, cultural beliefs and biological factors may be related to these results.
Increases in thyroid papillary carcinoma incidence rates have largely been attributed to heightened medical surveillance and improved diagnostics. We examined papillary carcinoma incidence in an equal-access healthcare system by demographics, which are related to incidence.
Incidence rates during 1990-2004 among white and black individuals aged 20-49 years in the military and the general U.S. population were compared using data from the Department of Defense’s Automated Central Tumor Registry and the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER-9) program.
Incidence was significantly higher in the military than in the general population among white women [incidence rate ratio (IRR)=1.42, 95% 95% confidence interval (CI)=1.25-1.61], black women (IRR=2.31, 95% CI=1.70-2.99), and black men (IRR=1.69, 95% CI=1.10-2.50). Among whites, differences between the two populations were confined to rates of localized tumors (women: IRR=1.73, 95% CI=1.47-2.00; men: IRR=1.51, 95% CI=1.30-1.75), which may partially be due to variation in staging classification. Among white women, rates were significantly higher in the military regardless of tumor size, and rates rose significantly over time both for tumors ≤2 cm (military: IRR=1.64, 95% CI=1.18-2.28; general population: IRR=1.55, 95% CI=1.45-1.66) and >2 cm (military: IRR=1.74, 95% CI=1.07-2.81; general population: IRR=1.48, 95% CI=1.27-1.72). Among white men, rates increased significantly only in the general population. Incidence also varied by military service branch.
Heightened medical surveillance does not appear to fully explain the differences between the two populations or the temporal increases in either population.
These findings suggest the importance of future research into thyroid cancer etiology.
Thyroid Neoplasms; Incidence; SEER Program; Military Personnel; United States/epidemiology
A prospective study of diet and cancer has not been conducted in India; consequently, little is known regarding follow-up rates or the completeness and accuracy of cancer case ascertainment.
We assessed follow-up in the India Health Study (IHS; 4,671 participants aged 35–69 residing in New Delhi, Mumbai, or Trivandrum). We evaluated the impact of medical care access and relocation, re-contacted the IHS participants to estimate follow-up rates, and conducted separate studies of cancer cases to evaluate registry coverage (604 cases in Trivandrum) and the accuracy of self- and proxy-reporting (1600 cases in New Delhi and Trivandrum).
Over 97% of people reported seeing a doctor and 85% had lived in their current residence for over six years. The 2-year follow-up rate was 91% for Trivandrum and 53% for New Delhi. No cancer cases were missed among public institutions participating in the surveillance program in Trivandrum during 2003–04; but there are likely to be unmatched cases (ranging from 5 to13% of total cases) from private hospitals in the Trivandrum registry, as there are no mandatory reporting requirements. Vital status was obtained for 36% of cancer cases in New Delhi as compared to 78% in Trivandrum after a period of 4 years.
A prospective cohort study of cancer may be feasible in some centers in India with active follow-up to supplement registry data. Inclusion of cancers diagnosed at private institutions, unique identifiers for individuals, and computerized medical information would likely improve cancer registries.
Cancer; end-point; follow-up; registry; prospective cohort; India
Previous research has noted higher cancer mortality rates and lower survival among males than females. However, systematic comparisons of these two metrics by sex has been limited.
We extracted U.S. vital rates and survival data from the Surveillance, Epidemiology and End Results Database for 36 cancers by sex and age for the period 1977–2006. We compared sex-specific mortality rates and male-to-female mortality rate ratios (MRRs). We also extracted case data which included age and date of diagnosis, sex, primary cancer site, tumor stage and grade, survival time, vital status, and cause of death. Relative cancer-specific hazard ratios (HRs) for death in the 5-year period following diagnosis were estimated with Cox proportional hazards models, adjusted for covariates.
For the vast majority of cancers, age-adjusted mortality rates were higher among males than females with the highest male-to-female MRR for lip (5.51), larynx (5.37), hypopharynx (4.47), esophagus (4.08) and urinary bladder (3.36). Cancer-specific survival was, for most cancers, worse for males than females, but such disparities were drastically less than corresponding MRRs; e.g., lip (HR = 0.93), larynx (1.09), hypopharynx (0.98), esophagus (1.05), and urinary bladder (0.83).
Male-to-female MRRs differed markedly while cancer survival disparities were much less pronounced. This suggests that sex-related cancer disparities are more strongly related to etiology than prognosis.
Future analytical studies should attempt to understand causes of observed sex disparities in cancer.
Sex; Male; Female; SEER program; Neoplasms; Mortality; Epidemiology
Objective. To evaluate oral cavity and pharynx cancer (OCPC) patterns by gender. Methods. We used Surveillance, Epidemiology, and End Results program data for 71,446 cases diagnosed during 1975–2008 to classify OCPC by anatomic subsite as potentially HPV-related or not, with oral tongue cancer considered a separate category. Results. Total OCPC rates among men were 2–4 times those among women. Among whites, total OCPC rates rose in the younger age groups due to substantial increases in successive birth cohorts for HPV-related cancers, more rapid among men than women, and oral tongue cancers, more rapid among women than men. Among blacks, total OCPC rates declined among cohorts born since 1930 reflecting the strong downward trends for HPV-unrelated sites. Among Hispanics and Asians, HPV-unrelated cancer rates generally declined, and oral tongue cancer rates appeared to be converging among young men and women. Conclusions. Decreases in total OCPC incidence reflect reductions in smoking and alcohol drinking. Rising HPV-related cancers among white men may reflect changing sexual practices. Reasons for the increasing young oral tongue cancer rates are unknown, but the narrowing of the gender differences provides a clue.
The increasing incidence of thyroid cancer in the United States is well documented. In this study, we assessed the incidence patterns by histologic type according to demographic and tumor characteristics to further our understanding of these cancers.
We used the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program for cases diagnosed during 1992–2006 to investigate patterns for the four major histologic types of thyroid cancer by gender, race/ethnicity, and age as well as registry, tumor stage, and size.
Among women, papillary thyroid cancer rates were highest among Asians (10.96 per 100,000 woman-years) and lowest among blacks (4.90 per 100,000 woman-years); follicular cancer rates did not vary substantially by race/ethnicity (p-values >0.05), medullary cancer rates were highest among Hispanics (0.21 per 100,000 woman-years) and whites (0.22 per 100,000 woman-years), and anaplastic rates were highest among Hispanics (0.17 per 100,000 woman-years). Among men, both papillary and follicular thyroid cancer rates were highest among whites (3.58 and 0.58 per 100,000 man-years, respectively), medullary cancer rates were highest among Hispanics (0.18 per 100,000 man-years), and anaplastic rates were highest among Asians (0.11 per 100,000 man-years). Racial/ethnic-specific rates did not vary notably across registries. In contrast to age-specific rates of papillary thyroid cancer that peaked in midlife (age 50), especially pronounced among women, rates for follicular, medullary, and anaplastic types continued to rise across virtually the entire age range, especially for anaplastic carcinomas. Female-to-male incidence rate ratios among whites decreased with age most steeply for the follicular type and least steeply for the medullary type; it was <1 until the very oldest ages for the anaplastic type.
We conclude that the similar age-specific patterns and lack of geographical variation across the SEER racial/ethnic groups indicate that detection effects cannot completely explain the observed thyroid cancer incidence patterns as variation in the amount or quality of healthcare provided has been shown to vary by SEER racial/ethnic groups, gender, and age. We find that the variations in age-specific patterns by gender and across histologic types are intriguing and recommend that future etiologic investigation focus on exogenous and endogenous exposures that are experienced similarly by racial/ethnic groups, more strongly among women, and distinctively by age.
The use of cellular telephones has grown explosively during the past two decades, and there are now more than 279 million wireless subscribers in the United States. If cellular phone use causes brain cancer, as some suggest, the potential public health implications could be considerable. One might expect the effects of such a prevalent exposure to be reflected in general population incidence rates, unless the induction period is very long or confined to very long-term users. To address this issue, we examined temporal trends in brain cancer incidence rates in the United States, using data collected by the Surveillance, Epidemiology, and End Results (SEER) Program. Log-linear models were used to estimate the annual percent change in rates among whites. With the exception of the 20–29-year age group, the trends for 1992–2006 were downward or flat. Among those aged 20–29 years, there was a statistically significant increasing trend between 1992 and 2006 among females but not among males. The recent trend in 20–29-year-old women was driven by a rising incidence of frontal lobe cancers. No increases were apparent for temporal or parietal lobe cancers, or cancers of the cerebellum, which involve the parts of the brain that would be more highly exposed to radiofrequency radiation from cellular phones. Frontal lobe cancer rates also rose among 20–29-year-old males, but the increase began earlier than among females and before cell phone use was highly prevalent. Overall, these incidence data do not provide support to the view that cellular phone use causes brain cancer.
brain cancer; cellular telephones; epidemiology; SEER
The etiology of cancers of the small intestine (SI) is largely unknown. To gain insight into these rare malignancies, we evaluated contemporaneous incidence and survival patterns.
Using SI cancer data from 12 population-based registries of the Surveillance, Epidemiology and End Results Program, we calculated age-adjusted and age-specific incidence rates (IRs), IR ratios (IRRs) and relative survival (RS) rates.
In total, 10,945 SI cancers (IR=2.10/100,000 person-years) were diagnosed during 1992-2006, including carcinomas (n=3,412, IR=0.66), neuroendocrine cancers (n=4,315, IR=0.83), sarcomas (n=1,084, IR=0.20), and lymphomas (n=2,023, IR=0.38). For all histologic groups, males had significantly higher IRs than females, and distinct age-specific gender patterns were limited to intermediate-/high-grade lymphomas. Neuroendocrine cancer rates varied significantly by race, with rates highest among Blacks and lowest among Asians/Pacific Islanders (APIs). Carcinoma IRs were highest among Blacks, sarcoma IRs were highest among APIs, and lymphoma IRs were highest among Whites. Age-specific IR patterns were similar across racial/ethnic groups. During 1992-2006 duodenal cancer IRs increased more markedly than those for other subsites. RS varied little by gender or race. Neuroendocrine cancers had the most favorable RS and carcinomas the least favorable. The greatest improvement in 5-year RS from 1992-1998 to 1999-2005 was observed for sarcomas and lymphomas.
Distinct SI cancer IR patterns according to histologic subtype suggest different underlying etiologies and/or disease biology, with susceptibility varying by gender, racial/ethnic groups, and subsite. Temporal patterns support a possible role for diagnostic bias of duodenal cancers.
Future epidemiologic studies of SI cancer should consider histologic subtype by gender, race/ethnicity, and subsite.
Small intestinal cancers; epidemiology; minority populations; incidence; survival
African American men have among the highest prostate cancer incidence rates in the world yet rates among their African counterparts are unclear. In this paper, we compared reported rates among black men of Sub-Saharan African descent using data from the International Agency for Research on Cancer (IARC) and the National Cancer Institute Surveillance, Epidemiology, and End Results Program for 1973–2007. Although population-based data in Africa are quite limited, the available data from IARC showed that rates among blacks were highest in the East (10.7–38.1 per 100,000 man-years, age-adjusted world standard) and lowest in the West (4.7–19.8). These rates were considerably lower than those of 80.0–195.3 observed among African Americans. Rates in Africa increased over time (1987–2002) and have been comparable to those for distant stage in African Americans. These patterns are likely due to differences between African and African American men in medical care access, screening, registry quality, genetic diversity, and Westernization. Incidence rates in Africa will likely continue to rise with improving economies and increasing Westernization, warranting the need for more high-quality population-based registration to monitor cancer incidence in Africa.
Primary cutaneous adenoid cystic carcinoma (PCACC) is a rare appendageal tumor of uncertain origin. Details on epidemiologic features of PCACC are sparse and largely based on clinical reports.
To develop an understanding of PCACC incidence, survival, and associated cancers using population-based data.
We utilized the Surveillance, Epidemiology and End Results program to calculate age-adjusted incidence rates (IRs), IR ratios, 95% confidence intervals, standardized incidence ratios (SIRs), and 5-year relative survival rates of PCACC diagnosed during 1976-2005.
In a population of 723,174,580 person-years, the overall PCACC IR was 0.23 per one million person-years (n=152), with similar IRs among males and females (IR=0.24). Most cases of PCACC presented at a localized stage and arose on the face/head/neck. Among 122 two-month survivors of PCACC and more than 2.4 million two-month cancer survivors, risk of associated cancers overall was not significantly increased (SIR=1.17 (n=24) and SIR=1.43 (n=16), respectively). However, PCACC was associated with significantly increased risks of subsequent lymphohematopoietic (n=6; SIR=3.70) and thyroid (n=2; SIR=15.25) cancers, whereas the converse associations were not observed. Five-year relative survival was excellent (96.1%; n=122) with more favorable survival noted for PCACC involving the face/head/neck than the trunk.
A pathologic review of reported cases was not undertaken.
PCACC is a rare appendageal tumor that affects males and females equally, primarily presents at localized stage, predominates in the face/head/neck, and is associated with favorable survival. Immunosuppression does not appear to contribute to the development of PCACC, and the observed associated cancer patterns will need to be confirmed in larger studies.
adenoid cystic carcinoma; skin cancer; epidemiology; incidence; survival; second primary cancers
While testicular cancer incidence rates have been widely reported in populations of Northern European ancestry, rates in other population have been less frequently examined. In a prior report, global testicular cancer incidence rates and trends for the years 1973–1997 were summarized. The current report extends these analyses with an additional 5 years of data from Cancer Incidence in Five Continents.
Age-standardized incidence rates over successive 5-year time periods were obtained for populations in the Americas, Asia, Europe, and Oceania.
In general, testicular cancer incidence remained highest in Northern European populations (8.0–9.0 per 100,000) and lowest in Asian and African populations (<1 per 100,000). One notable exception to this pattern, however, was the very high rate reported by the Valdivia, Chile registry (8.8 per 100,000). In many populations, incidence rates rose between 1973 and 2002, although the increases were strongest and most consistent among populations of European ancestry. In some European populations, such as those of Denmark and of Geneva, Switzerland, some plateauing of rates was evident in recent years. There was little evidence of increase and possible evidence of modest decline in rates in east Asian populations. In general, the trends by histology (seminoma, nonseminoma) were similar to one another.
Risk of testicular cancer remains high in Northern European populations and low in Asian and African populations. Reasons for increasing rates among Northern Europeans and more stable or declining rates among East Asians are unexplained, supporting the need for future etiologic studies.
testicular cancer; trends; seminoma; nonseminoma
We analyzed renal cell cancer incidence patterns in the United States and reviewed recent epidemiologic evidence with regard to environmental and host genetic determinants of renal cell cancer risk. Renal cell cancer incidence rates continued to rise among all racial/ethnic groups in the United States, across all age groups, and for all tumor sizes, with the most rapid increases for localized stage disease and small tumors. Recent cohort studies confirmed the association of smoking, excess body weight, and hypertension with an elevated risk of renal cell cancer, and suggested that these factors can be modified to reduce the risk. There is increasing evidence for an inverse association between renal cell cancer risk and physical activity and moderate intake of alcohol. Occupational exposure to TCE has been positively associated with renal cell cancer risk in several recent studies, but its link with somatic mutations of the VHL gene has not been confirmed. Studies of genetic polymorphisms in relation to renal cell cancer risk have produced mixed results, but genome-wide association studies with larger sample size and a more comprehensive approach are underway. Few epidemiologic studies have evaluated risk factors by subtypes of renal cell cancer defined by somatic mutations and other tumor markers.
renal cell cancer; incidence trends; cohort studies; smoking; obesity; hypertension; diet; occupation; genetic polymorphism; somatic mutation
Burkitt lymphoma (BL) is a unique B-cell non-Hodgkin lymphoma with three established clinical-epidemiological variants: endemic, sporadic, and AIDS-related BL shows characteristic dysregulation of MYC gene, but the causes of MYC dysregulation or BL arising at different ages are poorly understood. Therefore, we examined population-based BL incidence patterns in the United States to determine age-related risk. BL case and population data were obtained from the NCI’s Surveillance, Epidemiology, and End Results Databases (1973–2005). Standard cross-sectional, age-standardized, and age-specific incidence rates were stratified by sex and race and supplemented with age-period-cohort (APC) models. We analyzed 3058 BL cases diagnosed during 1,160,300,297 person-years of observation. Age-standardized incidence rates rose 6.8% per year (95% CI 4.5–9.1) for males and 7.1% (95% CI 3.2–11.1) for females during the study period. The rate among males was 3.2 times that among females, and among Whites 1.3 times that among Blacks. Male-to-female incidence rate ratios did not differ by race, but were 4.2 for pediatric (0–19 years), 4.1 for adult (20–59 years) and 2.0 for geriatric (≥ 60 years) BL. Cross-sectional age-specific rates showed two separate peaks among males and females, near ages 10 and 75 years, and a third peak near age 40 years among males. The tri/bimodal incidence pattern was present in sensitivity analyses excluding registries with many HIV/AIDS cases and in period-specific, cohort-specific analyses. To our knowledge tri/bimodal incidence patterns have not previously been reported for BL. Trimodal/bimodal BL suggests heterogeneity in etiology or biology of BL diagnosed at different ages in males and females.
Though incidence of colorectal cancer (CRC) in the US, has declined in recent years, rates remain higher in men than women and the male-to-female incidence rate ratio (MF IRR) increases progressively across the colon from the cecum to the rectum. Rates among races/ethnicities other than Whites or Blacks have not been frequently reported. To examine CRC rates by sex across anatomic subsite, age, and racial/ethnic groups, we used the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program for cases diagnosed among residents of 13 registries during 1992–2006. Incidence rates were expressed per 100,000 person-years and age-adjusted to the 2000 US Standard Population; MF IRR and 95% confidence intervals were also calculated. Among each racial/ethnic group, the MF IRR increased fairly monotonically from close to unity for cecal cancers to 1.81 (Hispanics) for rectal cancers. MF IRRs increased with age most rapidly for distal colon cancers from <1.0 at ages <50 years to 1.4–1.9 at older ages. The MF IRR for rectal cancers also rose with age from about 1.0 to 2.0. For proximal cancer, the MF IRR was consistently <1.5; among American Indian/Alaska Natives it was <1.0 across all ages. The MF IRRs for CRC vary markedly according to subsite and age but less by racial/ethnic group. These findings may partially reflect differences in screening experiences and access to medical care but also suggest that etiologic factors may be playing a role.
colorectal cancer; sex ratio; incidence; SEER program; epidemiology; neoplasms
After over two decades of increasing rates, kidney cancer incidence trends worldwide show signs of plateauing or decreases in recent years. In the United States, rates for renal cell cancer, the predominant form of kidney cancer in adults, continue to rise but mainly for early stage tumors. Incidence rates for renal pelvis cancer have declined, while kidney cancer mortality rates overall have leveled. These patterns are consistent with reports of incidental diagnosis and downward shift of tumor stage and size in clinical series. The changing prevalence of known risk factors for renal cell cancer, including cigarette smoking, obesity, and hypertension, may also be influencing the incidence trends, although their relative impact may differ in various populations,. Evidence is accumulating to suggest an etiologic role for physical activity, alcohol consumption, occupational exposure to trichloroethylene, and high parity among women, but causal conclusions are not yet supported. Genetic susceptibility and its interaction with environmental exposures are believed to influence renal cell cancer risk, but limited studies based on candidate gene approaches have not produced conclusive results. Large consortium efforts employing genome-wide scanning technology are underway, which hold promise for novel discoveries in renal carcinogenesis.
The risk factors and co-factors for sporadic childhood BL are unknown. We investigated demographic and age-specific characteristics of childhood BL (0–14 years) in the U.S.
BL age-standardized incidence rates (2000 U.S. standard population), were calculated using data obtained from 12 registries in the NCI’s Surveillance, Epidemiology, and End Results program for cases diagnosed from 1992 through 2005. Incidence rate ratios and 95% confidence intervals (95% CI) were calculated by gender, age-group, race, ethnicity, calendar-year period, and registry.
Of 296 cases identified, 56% were diagnosed in lymph nodes, 21% in abdominal organs, not including retroperitoneal lymph nodes, 14% were Burkitt cell leukemia, and 9% on face/head structures. The male-to-female case ratio was highest for facial/head tumors (25:1) and lowest for Burkitt cell leukemia (1.6:1). BL incidence rate was 2.5 (95% CI 2.3–2.8) cases per million person-years and was higher among boys than girls (3.9 vs. 1.1, p<0.001) and higher among Whites and Asians/Pacific Islanders than among Blacks (2.8 and 2.9 vs.1.2, respectively, p<0.001). By ethnicity, BL incidence was higher among non-Hispanic Whites than Hispanic Whites (3.2 vs. 2.0, p=0.002). Age-specific incidence rate for BL peaked by age 3–5 years (3.4 cases per million), then stabilized or declined with increasing age, but it did not vary with calendar-year or registry area.
Our results indicate that early childhood exposures, male-sex, and White race may be risk factors for sporadic childhood BL in the United States.
epidemiology; pediatric cancer; non-Hodgkin lymphoma; HIV/AIDS
Using data from the U.S. National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program, we analyzed stomach carcinoma incidence patterns by both histologic type and anatomic site.
We calculated age-adjusted (2000 U.S. standard) rates for 1978–2005 and for five time periods from 1978–1983 through 2001–2005 according to histologic type and anatomic site separately and jointly. We also analyzed rates by race, gender, and age group.
During 1978–2005, more than 54,000 stomach carcinoma cases were diagnosed among residents of the nine SEER areas. Total stomach carcinoma rates declined 34% from 1978–1983 to 2001–2005. By histologic type, intestinal rates decreased consistently while those for diffuse rose through 2000 and declined in recent years. By anatomic site, cardia rates increased during the earlier years and then decreased, while rates for all other sites declined. When considered jointly by histologic type and anatomic site, intestinal carcinoma rates decreased for all sites except the cardia; diffuse rates increased through 2000 and decreased in recent years for all sites except overlapping/non-specified sites Both diffuse and intestinal rates were lowest among whites, intermediate among blacks, and highest among the other, primarily Asian, races, with only modest gender differences for the diffuse type. In contrast, cardia carcinoma rates were highest among whites and were notably higher among males, especially whites among whom the male/female rate ratio was five.
Stomach carcinoma incidence patterns differ by histologic type, anatomic site, race, gender, and age, suggesting etiologic heterogeneity to be pursued in future research.
stomach cancer; intestinal type carcinoma; diffuse carcinoma; gastric cardia; incidence
The U.S. active-duty military population may differ from the U.S. general population in its exposure to cancer risk factors and access to medical care. Yet, it is not known if cancer incidence rates differ between these two populations. We therefore compared the incidence of four cancers common in U.S. adults (lung, colorectum, prostate, and breast cancers) and two cancers more common in U.S. young adults (testicular and cervical cancers) in the military and general populations. Data from the Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) nine cancer registries for the years 1990-2004 for persons aged 20-59 years were analyzed. Incidence rates were significantly lower in the military population for colorectal cancer in white men, lung cancer in white and black men and white women, and cervical cancer in black women. In contrast, incidence rates of breast and prostate cancers were significantly higher in the military among both whites and blacks. Incidence rates of testicular cancer did not differ between ACTUR and SEER. Although the numbers of diagnoses among military personnel were relatively small for temporal trend analysis, we found a more prominent increase in prostate cancer in ACTUR than in SEER. Overall, these results suggest that cancer patterns may differ between military and non-military populations. Further studies are needed to confirm these findings and explore contributing factors.
Active duty; cancer; incidence; military; SEER
Cancer epidemiology manuscripts often point out that cancer rates tend to be higher among males than females, yet rarely is this theme the subject of investigation.
We used the Surveillance, Epidemiology, and End Results (SEER) program data to compute age-adjusted (2000 US standard population) sex-specific incidence rates and male-to-female incidence rate ratios (IRR) for specific cancer sites and histologies for the period 1975-2004.
The ten cancers with the largest male-to-female IRR were Kaposi sarcoma (28.73), lip (7.16), larynx (5.17), mesothelioma (4.88), hypopharynx (4.13), urinary bladder (3.92), esophagus (3.49), tonsil (3.07), oropharynx (3.06) and other urinary organs (2.92). Only five cancers had a higher incidence in females compared to males: breast (0.01), peritoneum, omentum and mesentery (0.18), thyroid (0.39), gallbladder (0.57), and anus, anal canal and anorectum (0.81). Between 1975 and 2004, the largest consistent increases in male-to-female IRR were for cancers of the tonsil, oropharynx, skin excluding basal and squamous, and esophagus, while the largest consistent decreases in IRR were for cancers of the lip and lung and bronchus. Male-to-female IRRs varied considerably by age, the largest increases of which were for ages 40-59 years for tonsil cancer and hepatocellular carcinoma. The largest decreases in male-to-female IRR by age, meanwhile, were for ages 30-49 years for thyroid cancer, ages ≥70 years for esophageal squamous cell carcinoma, and ages ≥30 years for lung and bronchus cancer.
These observations emphasize the importance of sex in cancer etiopathogenesis and may suggest novel avenues of investigation.
Sex; Male; Female; SEER program; Neoplasms; Incidence; Epidemiology
Thyroid cancer incidence rates have increased worldwide for decades, although more for papillary carcinomas than other types and more for females than males. There are few known thyroid cancer risk factors except female gender, and the reasons for the increasing incidence and gender differences are unknown.
We used the National Cancer Institute’s Surveillance, Epidemiology, and End Results 9 Registries Database for cases diagnosed during 1976–2005 to develop etiological clues regarding gender-related differences in papillary thyroid cancer incidence. Standard descriptive epidemiology was supplemented with age-period-cohort (APC) models, simultaneously adjusted for age, calendar-period and birth-cohort effects.
The papillary thyroid cancer incidence rate among females was 2.6 times that among males (9.2 versus 3.6 per 100,000 person-years, respectively), with a widening gender gap over time. Age-specific rates were higher among women than men across all age groups, and the female-to-male rate ratio declined quite consistently from more than five at ages 20–24 to 3.4 at ages 35–44 and approached one at ages 80+. APC models for papillary thyroid cancers confirmed statistically different age-specific effects among women and men (p < .001 for the null hypothesis of no difference by gender), adjusted for calendar-period and birth-cohort effects.
Gender was an age-specific effect modifier for papillary thyroid cancer incidence. Future analytic studies attempting to identify the risk factors responsible for rising papillary thyroid cancer incidence should be designed with adequate power to assess this age-specific interaction among females and males.
Thyroid cancer incidence; age-period-cohort analysis; gender
Inflammatory breast carcinoma (IBC) appears to be a clinicopathologic entity distinct from noninflammatory locally advanced breast cancer (LABC). We examined incidence and survival trends for IBC in Surveillance, Epidemiology, and End Results (SEER) Program data with a case definition designed to capture many of its unique clinical and pathologic characteristics.
We analyzed breast cancer cases diagnosed in the SEER 9 Registries (n = 180 224), between 1988 and 2000. Breast cancer cases were categorized using SEER’s “ Extent of Disease” codes in combination with International Classification of Diseases for Oncology morphology code 8530/3 and classified as IBC (n = 3648), LABC (n = 3636), and non-T4 breast cancer (n = 172 940). We compared changes in incidence rates over 3-year intervals by breast cancer subtype and race using SEER*Stat. Survival differences by breast cancer subtype and race were assessed using Kaplan–Meier curves and log-rank statistics. All statistical tests were two-sided.
Between 1988 and 1990 and 1997 and 1999, IBC incidence rates (per 100 000 woman-years) increased from 2.0 to 2.5 (P<.001), whereas those for LABC declined (2.5 to 2.0, P = .0025), as did those for non-T4 breast cancer (108 to 101, P = .0084). IBC incidence rates were statistically significantly higher in black women (3.1) than in white women (2.2) during the study period (P<.001). Women diagnosed with IBC had statistically significantly poorer survival than women with either LABC or non-T4 breast cancer (log-rank test, P<.001). Median survival of women with IBC (2.9 years) was statistically significantly shorter than that of women with LABC (6.4 years; P<.0001) or non-T4 breast cancer (>10 years, P<.0001). Black women with IBC or LABC had poorer survival than white women with IBC or LABC, respectively (log-rank test, P<.001).
Throughout the 1990s, IBC incidence rose, and survival improved modestly. Substantial racial differences were noted in age at diagnosis, age-specific incidence rates, and survival outcomes.