Neoplasms in the Navy, 1998-2000: A Descriptive Analysis of the Physical Evaluation Board Database

Military Medicine, Sep 2004 by Ajene, Anuli, Bohnker, Bruce, Malakooti, Mark A, Riegodedios, Asha, Sack, David M

Records with diagnoses for neoplasms (International Classification of Diseases, Ninth Revision, Clinical Modification, codes 140-239) contained in the U.S. Navy Physical Evaluation Board database for 1998 to 2000 were identified (n = 427 cases, 342 malignant and 85 benign). The four most common sites of occurrence were other and unspecified sites (27%), lymphatic and hematopoietic tissues (22%), benign neoplasms (20%), and genitourinary organs (12%). Crude overall cancer rates were 37.7 cases per 100,000 male subjects and 55.4 cases per 100,000 female subjects. Overall, Hodgkin's disease was the most common diagnosis, with a rate of 3.3 cases per 100,000 population. It also had the highest rate among male subjects, with 3.5 cases per 100,000 male subjects of all ages and 4.2 cases per 100,000 men more than 40 years of age. For women, breast cancer had the highest rate of 8.5 cases per 100,000 subjects. These values are consistent with or lower than the published reports of U.S. Navy and national rates. Ongoing surveillance of malignancies among Navy personnel is an important part of force health protection.

Introduction

Neoplasms that occur among active duty personnel in the Navy remain of interest, in part because of the associated attrition and disability. In addition, classification of these neoplasms provides a basis for screening and prevention programs. This analysis characterizes neoplasms in the U.S. Navy using a subset of data from the Physical Evaluation Board (PEB), as well as determining whether cancer rates in the Navy have increased with time and whether the Navy rates differ from those for the civilian population. The PEB is the Department of the Navy disability evaluation system, which identifies career-ending illnesses.1

There is longstanding interest in evaluating malignancies among active duty Navy personnel. A number of authors from the Naval Health Research Center in San Diego, California, have published reports on this topic2"6 using data from a variety of sources, including hospitalization records and inpatient medical data files maintained by the Naval Health Research Center. In addition, national cancer surveillance is maintained by the National Cancer Institute and its Surveillance, Epidemiology, and End Results (seeR) program. case ascertainment for the seeR program began on January 1, 1973, in the states of Connecticut, Iowa, New Mexico, Utah, and Hawaii and the metropolitan areas of Detroit and San Francisco-Oakland. The seeR program currently collects and publishes cancer incidence and survival data from 11 population-based cancer registries and three supplemental registries covering approximately 14% of the U.S. population. Expansion registries increase the coverage to approximately 26%. Information on more than 3 million in situ and invasive cancer cases is included in the seeR database, and approximately 170,000 new cases within the seeR catchment areas are accessioned each year.7

Data Collection and Analysis

This study analyzed data from the U.S. Navy PEB process for 1998-2000 provided by the Navy Medical Information Management Center (Bethesda, MD). The staff of the Navy Environmental Health Center previously published a summary analysis of that dataset.8 This article focuses on records containing the diagnoses for neoplasms, which were identified with International Classification of Diseases (ICD-9), Ninth Revision, Clinical Modification, codes of 140 to 239.9 This classification includes 73 malignant site-specific groupings and 20 benign site-specific groupings.

For analytical purposes, records were classified according to the listed diagnosis and were classified into large categories on the basis of the ICD-9 grouping of neoplasms, known as site. Diagnoses were stratified according to age and gender. Incidence rates are reported per 100,000 active duty Navy personnel and were calculated according to site as well as specific type of neoplasm. Three-year average rates are reported for the entire duration of the study. Denominators were obtained from enrollment data for active duty Navy personnel in 1998-2000. These data are available from the Army Medical Surveillance Activity through the Defense Medical Epidemiology Database.10 Data analysis was conducted with SPSS, Version 10.0.11

Results

During the study period, 427 cases of neoplasms were identified. Eighty percent of the neoplasms were malignant and 20% were benign. Notably, only 26% of the benign cases (22 of 85 cases) represented the only diagnosis being evaluated by the PEB. The population included 82% male subjects; enlisted personnel represented the majority (81%). The average age was 36 years, with a range of 19 to 69 years. However, the numbers of individuals in each age group were similar; 28%, 33%, and 38% of the total population were in the age groups of less than 30, 30 to 39, and 40 years and older, respectively. The average length of service was 146 months (12 years), with a range of 2 to 406 months (33 years). Population characteristics and mean ages are presented in Table I. Tables II and III present the overall rates of select neoplasms according to age, gender, site, and type. Table IV presents the rates of benign and malignant neoplasms and Table V presents the denominator data.