Descriptive epidemiology of selected olfactory tumors.

Olfactory tumors, especially olfactory neuroblastomas (ON) and carcinomas with neuroendocrine differentiation (CND), are extremely rare, and little descriptive epidemiologic information is available. The objective of this study was to more fully describe selected olfactory tumors using a large population-based cancer incidence database. The Surveillance, Epidemiology and End Results (SEER) 9 registries limited-use data were reviewed from 1973 to 2006 for selected nasal cavity (C30.0) and accessory sinus (C31.0-31.9) tumors. Frequencies, incidence rates, and relative survival rates were estimated using SEER*Stat, v6.5.2. The majority of cases were squamous cell carcinoma (SCC), while the incidence of ON was greater than CND. For ON, the incidence was highest in the 60-79 year age group, while for SCC, the incidence was highest in the 80+ year age group. For CND, the incidence leveled off in the oldest age groups. Survival rates were highest for ON (>70% alive at 5 years after diagnosis) and poorest for CND (44% alive at 5 years). Adjuvant radiation therapy did not improve survival over surgery alone in ON. In SCC, survival was worse in patients who received adjuvant radiation compared to patients who had surgery alone. Our analysis confirms some previously published information, and adds new information about the incidence and demographics of ON and CND. In addition, our analysis documents the lack of benefit of adjuvant radiation in ON. It is not feasible to conduct prospective trials in patients with these rare diseases, and the importance of registry data in learning about olfactory tumors is emphasized.

A case for the worldwide collection of primary benign brain tumors.

BACKGROUND: Incidence data on malignant tumors are reported by the International Agency for Research on Cancer, with 189,485 new malignant brain tumors globally in 2002. However, collection and reporting of benign brain tumors are not universal. The objective here is to encourage the collection of primary benign brain tumors worldwide. METHODS: Worldwide numbers of primary benign brain tumors were estimated through published articles and cancer registry reports presenting directly or indirectly reported benign incidence rates or frequencies for regions or countries. RESULTS: An estimated 186,678 benign brain tumors were diagnosed worldwide in 2002. The estimated numbers of benign brain tumors were higher in females than males (105,918 vs. 80,759). Since many countries do not report primary benign brain tumors, the incidence rate estimates vary significantly by region. CONCLUSIONS: This is the first survey to assess worldwide numbers of benign brain tumors. Under-reporting, non-standardized collection, lack of age-adjustment, and other causes of the varying incidence rates must be considered. However, the estimated number of benign brain tumors approximately equals, and could exceed, the number of malignant brain tumors globally. Registration of primary benign brain histologies in different geographical areas and ethnicities could provide clues to the underlying causes of these tumors.

Do children and adults differ in survival from medulloblastoma? A study from the SEER registry.

Studies investigating whether adults have diminished survival from medulloblastoma (MB) compared with children have yielded conflicting results. We sought to determine in a population-based registry whether adults and children with MB differ in survival, and to examine whether dissimilar use of chemotherapy might contribute to any disparity. 1,226 MB subjects were identified using the Surveillance Epidemiology and End Results (SEER-9) registry (1973-2002) and survival analysis performed. MB was defined strictly to exclude non-cerebellar primitive neuro-ectodermal tumors. Patients were stratified by age at diagnosis: <3 years (infants), 3-17 years (children) and >or=18 years (adults). Because the SEER-9 registry lacks treatment data, a subset of 142 patients were identified using the San Francisco-Oakland SEER registry (1988-2003) and additional analyses performed. There was no significant difference in survival between children and adults with MB in either the SEER-9 (P = 0.17) or SFO (P = 0.89) cohorts but infants fared worse compared to both children (P < 0.01) and adults (P < 0.01). In the SFO sample, children and adults who received chemotherapy plus radiation therapy (XRT) did not differ in survival. Among patients treated with XRT alone, children showed increased survival (P = 0.04) compared with adults. Children and adults with MB do not differ with respect to overall survival, yet infants fare significantly worse. For children and adults with MB treated with both XRT and chemotherapy, we could not demonstrate a survival difference. Similar outcomes between adult and childhood MB may justify inclusion of adults in pediatric cooperative trials for MB.

Gender affects survival for medulloblastoma only in older children and adults: a study from the Surveillance Epidemiology and End Results Registry.

BACKGROUND: Males have a higher incidence of medulloblastoma (MB) than females, but the effect of gender on survival is unclear. Studies have yielded conflicting results, possibly due to small sample sizes or differences in how researchers defined MB. We aimed to determine the effect of gender on survival in MB using a large data set and strict criteria for defining MB. PROCEDURE: A sample of 1,226 subjects (763 males and 463 females) was identified from 1973 to 2002, using the Surveillance Epidemiology and End Results (SEER-9) registry. MB was strictly defined to exclude non-cerebellar embryonal tumors (primitive neuro-ectodermal tumors). Because children <3 years of age are known to have worse survival, patients were stratified by age <3 years at diagnosis (95 males, 82 females) and >3 years (668 males, 381 females). RESULTS: Overall, there was no significant difference in survival between males and females (log rank P = 0.22). However, among subjects >3 years, females had significantly greater survival than males (log rank P = 0.02). In children <3 years, there was a non-significant trend toward poorer survival in females (median survival: males 27 months, females 13 months; log rank P = 0.24). This interaction between age group and gender was statistically significant (P = 0.03). CONCLUSION: Females with MB have a survival advantage only in subjects >3 years. In children <3 years, females may even have poorer outcome. The effect of gender on survival and incidence in MB warrants additional biologic investigation, and may differ in very young children with MB.

Medulloblastoma incidence has not changed over time: a CBTRUS study.

Earlier studies have reported changes in the incidence of medulloblastoma (MB) but have conflicted, likely because of small sample size or misclassification of MB with primitive neuroectodermal tumor (PNET). The incidence of MB and PNET from 1985 to 2002 was determined from the Central Brain Tumor Registry of the United States, a large population-based cancer registry, using strict histologic and site codes. No statistically significant change in MB incidence was observed over the last 2 decades, but there was an increase in MB and PNET combined.

Malignant pineal germ-cell tumors: an analysis of cases from three tumor registries.

The exact incidence of pineal germ-cell tumors is largely unknown. The tumors are rare, and the number of patients with these tumors, as reported in clinical series, has been limited. The goal of this study was to describe pineal germ-cell tumors in a large number of patients, using data from available brain tumor databases. Three different databases were used: Surveillance, Epidemiology, and End Results (SEER) database (1973-2001); Central Brain Tumor Registry of the United States (CBTRUS; 1997-2001); and National Cancer Data Base (NCDB; 1985-2003). Tumors were identified using the International Classification of Diseases for Oncology, third edition (ICD-O-3), site code C75.3, and categorized according to histology codes 9060-9085. Data were analyzed using SAS/STAT release 8.2, SEER*Stat version 5.2, and SPSS version 13.0 software. A total of 1,467 cases of malignant pineal germ-cell tumors were identified: 1,159 from NCDB, 196 from SEER, and 112 from CBTRUS. All three databases showed a male predominance for pineal germ-cell tumors (>90%), and >72% of patients were Caucasian. The peak number of cases occurred in the 10- to 14-year age group in the CBTRUS data and in the 15- to 19-year age group in the SEER and NCDB data, and declined significantly thereafter. The majority of tumors (73%-86%) were germinomas, and patients with germinomas had the highest survival rate (>79% at 5 years). Most patients were treated with surgical resection and radiation therapy or with radiation therapy alone. The number of patients included in this study exceeds that of any study published to date. The proportions of malignant pineal germ-cell tumors and intracranial germ-cell tumors are in range with previous studies. Survival rates for malignant pineal germ-cell tumors are lower than results from recent treatment trials for intracranial germ-cell tumors, and patients that received radiation therapy in the treatment plan either with surgery or alone survived the longest.

Time trends in oligodendroglial and astrocytic tumor incidence.

BACKGROUND: We hypothesized that the incidences of oligodendrogliomas, anaplastic oligodendrogliomas, and mixed gliomas have significantly increased from the early 1990 s forward, while the incidences of anaplastic and grade II astrocytic tumors have significantly decreased. METHODS: Data for the years 1973-2004 from the Surveillance, Epidemiology and End Results (SEER) public-use data and for 1985-2004 from six collaborating registries of the Central Brain Tumor Registry of the US (CBTRUS) were obtained. SEER*Stat was used to estimate age-adjusted incidence trends and annual percent change (APC) for selected histologies. Joinpoint regression was used to identify sharp changes in incidences occurring over time. RESULTS: Using CBTRUS data, the incidences (per 100,000 person-years) of oligodendrogliomas (APC = 4.7), mixed gliomas (APC = 3.9) and anaplastic oligodendrogliomas (APC = 12.5) have all increased over time, while the incidences of astrocytoma not otherwise specified (APC = -8.1) and fibrillary astrocytoma (APC = -2.1) have decreased. Restricting the analyses to later years (1992-2004) using SEER data shows the incidence of oligodendrogliomas leveling off (APC = 0.5), while joinpoint analyses demonstrate a decreasing trend after 1998. CONCLUSIONS: This study has demonstrated that increases in oligodendroglial tumor incidence correspond to decreases in astrocytic tumor incidence over the same time period. Minimizing misclassification of glial tumors will be essential for accurately assessing incidence, survival, and mortality rates, as well as for identifying homogeneous subgroups for epidemiologic and treatment studies.

Seasonal variation in incidence of pediatric medulloblastoma in the United States, 1995-2001.

BACKGROUND/AIMS: Brain tumors are the second most common pediatric malignancy. The literature suggests that one of the most common subtypes of malignant childhood brain tumor, medulloblastoma, has some seasonal variation in incidence by month of birth. METHODS: Data from cases in the Central Brain Tumor Registry of the United States, including primary brain tumor cases diagnosed in children (0-19 years) between the years 1995 and 2001 from 13 state cancer registries, were analyzed to determine whether there was seasonal variation. Analyses were performed using Edwards' test for sinusoidal variation, which uses case frequencies per month, and tests whether frequencies follow a sine function over 12 months. RESULTS: Seasonal variation in incidence by month of birth was highly statistically significant for medulloblastoma, not otherwise specified (NOS) (p = 0.016), with the peak occurring in October. Medulloblastoma, NOS also demonstrated seasonal variation in incidence by month of birth in children aged 5-19 (p = 0.041), especially females aged 5-19 (p = 0.034), with the peak in October. There were no significant results for brain tumors overall, or for the other most common pediatric tumor subtypes (pilocytic astrocytoma, other astrocytoma, and ependymoma). CONCLUSION: These preliminary results indicate seasonal variation unique to medulloblastoma incidence by month of birth and may provide evidence for an environmental exposure etiology, though further studies are needed to explore specific hypotheses.

Temporal trends in incidence of primary brain tumors in the United States, 1985-1999.

A number of reports have indicated an increasing incidence of primary brain tumors over the past few decades. The purpose of this study was to describe incidence rate trends in a population-based series of newly diagnosed primary nonmalignant and malignant brain and other CNS tumors, contributing five additional years to previously published incidence trends. Data for the years 1985 through 1999 from six collaborating state cancer registries of the Central Brain Tumor Registry of the United States were used to determine incidence trends in the broad age groups 0-19, 20-64, and >or=65 years, overall and for selected histologies. Multiplicative Poisson regression was used to express trends as average annual percent change (AAPC). Joinpoint regression was used to identify sharp changes in incidence occurring over this period. Overall, incidence increased modestly (AAPC, 1.1; 95% CI, 0.8-1.4). When brain lymphomas were excluded, this increase remained statistically significant. A sharp change in incidence of brain lymphomas from increasing to decreasing over time was identified. Specific histologies that were increasing included anaplastic astrocytomas in individuals aged >or=65 years, microscopically confirmed gliomas in both adult age groups, and microscopically confirmed glioma, not otherwise specified (NOS), in children. Increases that were not specific to any population subgroup were seen for oligodendrogliomas, ependymomas, meningiomas, and nerve sheath tumors. Decreases were noted for astrocytoma, NOS, nonmicroscopically confirmed gliomas, and pituitary tumors. Improvements in diagnosis and classification are likely reflected in the decreasing trends in unspecified glioma subgroups and the accompanying increasing trends in more specific glioma subgroups. However, increases in meningiomas and nerve sheath tumors deserve further attention.

Descriptive epidemiology of vestibular schwannomas.

Vestibular schwannomas, commonly termed acoustic neuromas, arise from the vestibular branch of the eighth cranial nerve (acoustic nerve) and are benign, slow-growing brain tumors that negatively impact patient quality of life. They are thought to account for the majority of intracranial nerve sheath tumors. To describe incidence rate patterns and trends of primary nerve sheath tumors of the brain/CNS and the subset of vestibular schwannomas in two population-based incidence registries, data were obtained from 11 Central Brain Tumor Registry of the United States (CBTRUS) collaborating state registries and the Los Angeles County Cancer Surveillance Program (LACCSP) (1975-1998). Average annual incidence rates were tabulated by age, gender, race, year, and region and were age-adjusted to the year 2000 U.S. standard population. Multiplicative Poisson regression models were used to compare trends in primary nerve sheath tumors of the brain/CNS overall and in subgroups, including vestibular schwannomas, controlling for age, gender, race, microscopic confirmation, and region. Joinpoint regression analysis was used to identify any sharp changes in incidence over time. The overall incidence of primary nerve sheath tumors of the brain/CNS was 1.1 per 100,000 person-years (CBTRUS, 1995-1999 and LACCSP, 1995-1998). The incidence of vestibular schwannomas was similar for both data sets: 0.6 per 100,000 person-years (CBTRUS, 1995-1999) and 0.8 per 100,000 person-years (LACCSP, 1995-1998). Moreover, the incidence of primary nerve sheath tumors of the brain/CNS overall (CBTRUS, 1985-1999 and LACCSP, 1975-1998) and of vestibular schwannomas (CBTRUS, 1992-1999 and LACCSP, 1992-1998) increased over time. However, the incidence of benign schwannomas in sites other than the acoustic nerve either decreased (CBTRUS, 1992-1999) or experienced no significant change (LACCSP, 1992-1998). While improvements in diagnosis and reporting may explain some of these trends, further consideration of potential etiologic factors may be warranted.

Descriptive epidemiology of central nervous system germ cell tumors: nonpineal analysis.

Central nervous system (CNS) germ cell tumors (GCT) have not been epidemiologically well described. Our study describes 2 population-based series of nonpineal CNS GCT. Data on all primary (malignant and nonmalignant) CNS (ICD-O-3 sites: C70.0-C72.9, C75.1-C75.3) GCT diagnosed between 2000 and 2004 from the Central Brain Tumor Registry of the United States (CBTRUS) and on all malignant GCT diagnosed between 1992 and 2005 from the Surveillance, Epidemiology, and End Results (SEER) were analyzed. Of 234 nonpineal GCT in CBTRUS, the most common site was brain, NOS (31.6%). Males had a greater frequency (59.7%) than females (40.3%). However, by age group, the male-to-female incidence rate ratio (IRR) differed: children (0-14 years) had an IRR of 1.1, young adults (15-29 years) an IRR of 2.3, and adults (aged 30+) an IRR of 1.0. For children and young adults, most tumors were malignant (86.8% and 89.0%, respectively), whereas for adults, more than half were nonmalignant (56.8%). Germinoma was the most frequent diagnosis (61.5%). In SEER, the frequency of malignant GCT in the CNS (2.5%) was greater than that in the mediastinum (2.1%). Of 408 malignant CNS GCT, 216 (52.9%) were nonpineal. The male-to-female IRR was 1.5. Overall relative survival for nonpineal CNS malignant GCT was 85.3% at 2 years, 77.3% at 5 years, and 67.6% at 10 years. Previous studies of GCT that have not stratified by site have suggested greater gender disparity. Nonpineal CNS GCT show no significant gender preference, yet have outcomes similar to pineal GCT.

Descriptive epidemiology of primary spinal cord tumors.

OBJECT: There is little population-based data available on primary spinal cord tumors. Many of the existing statistics are not current or were obtained from surgical series. Historically, population-based data were collected only for malignant tumors, and only recently have data begun to be collected on non-malignant tumors. The objective of this study was to estimate the incidence of both non-malignant and malignant primary spinal cord tumors and to estimate the survival rates for primary malignant spinal cord tumors. METHODS: Incidence of spinal cord tumors was estimated from cases diagnosed between 1998 and 2002 in 16 CBTRUS collaborating state cancer registries. Age-adjusted rates were generated using SAS (8.2) and standardized to the 2000 US standard population. SEER*Stat 6.1.4 software was used to estimate relative survival for malignant spinal cord tumors for cases diagnosed between 1975 and 2002 in nine SEER regions. CONCLUSIONS: Of the spinal cord tumors identified (CBTRUS; n = 3,226), 69% were non-malignant. The most common histologic types were meningiomas (29%), nerve sheath tumors (24%), and ependymomas (23%). The overall incidence of spinal cord tumors was 0.74 per 100,000 person-years, with an incidence of 0.77/100,000 in females and 0.70/100,000 in males. The incidence rate was lowest in children (0.26) and peaked in the 75-84 year age group (1.80). Rates were higher in non-Hispanic whites (0.79) than in Hispanics (0.61) or non-Hispanic blacks (0.45). The 1-, 5-, and 10-year survival rates following diagnosis of a primary malignant spinal cord tumor were 85%, 71%, and 64%, respectively (SEER; n = 1,220).

Average years of potential life lost in those who have died from brain and CNS tumors in the USA.

The aim of this study was to quantify the impact of all primary malignant and nonmalignant brain and central nervous system (CNS) tumors on mortality in the USA in terms of years of life lost, an indicator of premature mortality in the population. In this study, US mortality data for the year 2001 from the National Center for Health Statistics and life tables from the US Census Bureau were used. Person-years of potential life lost (PYPLL) and average years of potential life lost (AYPLL) were calculated for all deaths due to brain and CNS tumors as an underlying cause. 16,819 deaths due to brain and CNS tumors occurred in 2001, leading to a total loss of 357,483 person-years of life and an average loss of 21.3 years (AYPLL). Hispanic men and women had an AYPLL of 31.7 and 33.9 years, respectively, a figure substantially higher than other race and ethnicity categories. Malignant tumors led to an AYPLL of 25 years, which was significantly higher than the AYPLL of 19 years due to nonmalignant tumors. The relative impact of tumors arising in the various anatomical sites in the brain and CNS among adults and among children was not similar. The use of population survival indicators, such as PYPLL and AYPLL, will help better understanding of the effect of racial, ethnic, gender and age differences on the mortality due to malignant and nonmalignant brain and CNS tumors. Information on years of life lost, as well as mortality data, will be useful in focusing research priorities and resources in this field.