Cancer Incidence in New Jersey
1992-1996

by

Betsy A. Kohler, MPH, CTR
Toshi Abe, MSW, CTR
Judith B. Klotz, DrPH

Christine Todd Whitman
Governor

Len Fishman
Commissioner of Health and Senior Services

New Jersey Department of Health and Senior Services
Office of Cancer Epidemiology
State Cancer Registry
PO Box 369
Trenton, NJ 08625-0369

ACKNOWLEDGMENTS

The following staff of the New Jersey State Cancer Registry and other Programs of the Office of Cancer Epidemiology were involved in the collection, quality assurance, and preparation of the data on incident cases of cancer in New Jersey:

Anne Marie Anepete, CTR

Helen Martin, CTR

Allen Barnes

Kevin Masterson,CTR

Pamela Beasley

Judy McDuffie

Priya Bhatia, MS

Patricia McGorry

Stasia Burger, MS, CTR

John Murphy

Thomas English, CTR

Barbara Pingitor

Lorraine Fernbach, CTR

Karen Robinson, CTR

Ruth Filipowicz

Lisa Roche, MPH, PhD

Joyce Foti

Antonio Savillo, MD, CTR

Maria Halama, MD, CTR

Celia Troisi, CTR

Margaret Hodnicki, RN, CTR

Susan Van Loon, RN, CTR

Catherine Karnicky

Rachel Weinstein, PhD

Joan Kay, CTR

Helen Weiss, RN, CTR

Henry Lewis, MPH

Homer Wilcox III

New Jersey hospitals, laboratories, physicians, dentists, and the states of Delaware, Florida, New York, and Pennsylvania reported cancer cases to the New Jersey State Cancer Registry.

TABLE OF CONTENTS

Introduction

This report presents statewide age-adjusted incidence rates for all cancers diagnosed among New Jersey residents during the period 1992-1996, incidence trends since 1979 for some types of cancer, and comparisons of state and national data for 1990- 1994. The data for 1996 should be considered preliminary.

The primary goal of this report is to provide 1992-1996 data to health planners and researchers. Data are provided statewide for four population subgroups, white males, white females, African American males and African American females. Rates are also provided for males and for females of all races combined.

Registry Overview

This publication is based on data reported to the New Jersey State Cancer Registry (NJSCR). The NJSCR was established by legislation (NJSA 26:2-104 et.seq.) as a population-based incidence registry and includes all cancer cases diagnosed among New Jersey residents since October 1, 1978. The NJSCR serves the entire State of New Jersey, with a population of approximately eight million people.

New Jersey regulations (NJAC 8:57-A) require the reporting of all newly diagnosed cancer cases to the Registry within three months of hospital discharge or six months of diagnosis (whichever is sooner). All primary malignant and in situ neoplasms are reportable to the NJSCR, except certain carcinomas of the skin. Additionally, beginning with 1995 diagnosis year, cancer in situ of the cervix is no longer reportable based on recommendations by a New Jersey panel of experts and the North American Association of Central Cancer Registries.Reports are filed by hospitals, diagnosing physicians, dentists, and independent clinical laboratories. In addition, reporting agreements are maintained with New York, Pennsylvania, Delaware, and Florida so that we may collect reports of cancer among New Jersey residents diagnosed with cancer in health care facilities outside the state. Legislation in 1996 strengthened the Registry by (1) requiring electronic reporting, (2) requiring abstracting by certified tumor registrars, and (3) establishing penalties for late or incomplete reporting.

The information collected by the NJSCR includes demographic characteristics of the patient, and medical information on each cancer (such as anatomic site, histologic type and summary stage of disease). Annual follow-up status (alive/dead) and, when the patient is deceased, the underlying cause of death are incorporated into the basic data set.

Data Summary

With the addition of 1996 data, the overall trends for total cancers and some specific types of cancer since 1992 can be seen more clearly; the rates for most types of cancer continue to decline. Notable exceptions are non-Hodgkin's lymphoma and malignant melanoma among some subgroups of the population. The patterns in New Jersey closely approximate those for the entire nation for 1990-1995 as recently published in the journal, Cancer (Wingo et al., 1998).

Data on patients diagnosed in earlier years continues to be received by the NJSCR, so that the statistics for diagnosis years before 1996 have continued to change slightly. For example, the 1995 rates for all cancers combined increased by 5.2 % for males and 5.0 % for females between the time the data for our previous report and the current report were analyzed. However, prompt electronic reporting to the NJSCR has been improving steadily since the 1996 legislation, and consequently the 1996 data are more complete than the 1995 data were a year ago. Based on recent changes in reporting trends, we estimate that the final 1996 rates will increase by less than 2% over the preliminary rates shown in this report, and that the overall trend in cancer incidence rates will continue to show a decrease for 1996.

New Jersey residents diagnosed in surrounding states in recent years may not yet have been reported to the NJSCR under reciprocal agreements. As other states tackle their backlogs, their reporting to us will improve. Extremely rare tumors, and tumors among children, are often diagnosed and treated outside New Jersey. Reports on these cases tend to be received later than those from New Jersey facilities.

In viewing the tables of this report, it should also be noted that the annual rates for relatively uncommon cancers tend to fluctuate more from year to year, due to the smaller number of cases, particularly in minority populations. It is important to look at overall trends in cancer, as illustrated in Figures 1 through 10 as well as individual years.

Cancer Rates in New Jersey 1992-1996 (Tables 1-6)

As of February 1998, 40,010 cases of invasive cancer diagnosed in 1996 among New Jersey residents had been reported to the NJSCR. During the period 1992-1996, 207,716 cases of cancer were diagnosed among New Jersey residents, 52% among males and 48% among females. Tables 1 through 6 display the total counts of newly diagnosed cases of cancer in New Jersey and the age- adjusted incidence rates by race and sex for the period 1992 through 1996. For each year, the age-adjusted rate per 100,000 population is given for 64 major and minor subsites and for all sites combined.For females, breast and cervix in-situ statistics are given but not included in the totals for all sites combined (as is standard practice for publication of cancer rates in the United States). In the paragraphs below, we note the most striking patterns indicated in Tables 1 through 6 according to gender and the largest racial subgroups.

All Males (Table 1): The overall cancer rate for all males in NJ continued to decline steadily by nearly 16% during the 1992- 1996 period or about 3% per year. In particular, cancers of the lung, digestive system (especially colon), prostate, and bladder declined during the period. Non-Hodgkin's lymphoma increased slightly in a trend similar to that for the U.S. as a whole (see Figure 7 and the discussion below). All Females (Table 2): The overall cancer rate for all females declined by about 6% during the 1992-1996 period or about 1% per year. Notably, breast cancer, the most common reportable cancer in women, declined. An increase of in situ breast cancers in conjunction with the decrease in invasive cancer incidence are indications of improved screening. Declines were also seen for cancers of the digestive system (e.g. colon), cervix, ovary and brain. Lung cancer remained fairly stable.

White Males (Table 3): For white males, the overall cancer rate declined steadily throughout the period by about 3% per year. The most common cancers in men, lung, colon, and prostate, all declined steadily. Declines were also seen in cancers of the oral cavity and the bladder. Malignant melanoma, the most serious type of skin cancer, and non-Hodgkin's lymphoma showed increasing rates over the last few years (similar to the trend for the US as a whole).

White Females (Table 4): For white females the overall cancer rate fell steadily throughout the period by about 1% per year. Cancers of the breast, bladder, colon, ovary, and brain showed steady declines. No trend was noticeable for lung cancer. As with all females combined, the increase of in situ breast cancers in conjunction with the decrease in invasive breast cancer incidence indicates improved screening.

African American Males (Table 5): For African American males, the overall cancer rate shows a declining trend at about 3% per year. Among the sites showing strongest declines are colon, lung, prostate, and esophageal cancers.

African American Females (Table 6): For African American females, the rates declined from 1992 to 1994, increased in 1995, and decreased in 1996. The data from 1992 to 1996 currently indicates about a 3% decline per year. Lower rates for 1996 in cancers of the breast and digestive system contributed to the overall decrease for that year. Declining trends from 1992 to 1996 can also be seen for cancer of the ovary and lymphocytic leukemia.

Trends for 1979-1996 in New Jersey for the most common cancers: lung, colon, breast, and prostate (Figures 1-6)

Lung Cancer: Figures 1 and 2 illustrate that lung cancer has been decreasing since the late 1980's among males, most notably among white males, while it has been increasing among females until the late 1980's. Changing smoking patterns are probably responsible for these trends.

Colon Cancer: Figures 3 and 4 illustrate that the colon cancer rates have been decreasing in recent years. Improved dietary habits may be responsible. Early detection can lead to improved treatment and survival.

Breast cancer among women: Figure 5 illustrates that rates of breast cancer appeared to peak in the late 1980's among white women and around 1992 for African American women. Since then, for both groups, the rates of breast cancer appear to be gradually declining.

Prostate cancer: Figure 6 illustrates that prostate cancer increased dramatically in the late 1980's and appears to have peaked for white males at about 1992 and for African American males a year or so later. These trends are probably due to the recent widespread use of screening techniques which detect prostate cancers at an earlier date than they otherwise would have been found.

Trends for 1979-1996 in New Jersey for cancers that are increasing: non-Hodgkin's lymphoma and malignant melanoma (Figures 7-10).

Non-Hodgkin's Lymphoma: Figures 7 and 8 illustrate that among males and females, this less common cancer has been increasing, particularly for African American males. Not all the reasons for this trend are known. However, it is believed that immune function deficits and infectious agents, including HIV infection, are related.

Malignant Melanoma: Figures 9 and 10 indicate that this serious skin cancer has been increasing during the last few years among white males although not among females. This disease remains rare among African Americans. The reasons for the increases are not clear but may be related to patterns of sun exposure, especially in early life. Malignant melanoma is often diagnosed in private physicians' offices and reporting for this cancer may not be as reliable as for other cancers. Recently the NJSCR has targeted reporting from physicians and laboratories to ensure complete reporting of this cancer.

Comparison Data for New Jersey vs the United States, 1990-1994 (Tables 7-8) These tables show the comparable rates for the three most common sites of cancer for men and women and for non-Hodgkin's lymphoma as well as for all cancer sites combined. Historically, New Jersey rates have been representative of the Northeast region, which tend to have higher cancer incidence rates than the U.S.

When comparing cancer data between areas or over time, it is important to compare rates that are adjusted or weighted to a common standard. In this report, and as general practice in this country, we have presented rates adjusted to the 1970 US Census standard population. Using this standard, and the SEER multiple primary rules, make it possible to compare age-adjusted rates in this publication to rates published by the North American Association of Central Cancer Registries (NAACCR) publication ACancer in North America.@ The most recent detailed data available from NAACCR is for the time period 1990-1994. Therefore, we have prepared comparison tables for major sites for this time period.

Among men, (Table 7) for all races combined total cancer rates were higher in New Jersey than the U.S. during 1990-1994. Cancers of the colon, lung, prostate, and non-Hodgkin's lymphoma were higher than for the total U.S. However, among white males, prostate cancer rates were lower than for the combined U.S. For African American males in NJ, rates were lower rates for lung cancer than for the U.S. as a whole.

Among women, (Table 8) for all races combined, New Jersey had higher rates than the U.S. during the period 1990-1994 for total cancer, colon, lung, breast, and non-Hodgkin's lymphoma. However, lung cancer incidence among African American women was slightly lower than for the U.S. as a whole.

Methods

Collection and Sources of Data

The data were taken from the February, 1998 analytic file and tabulated using the Health Information Retrieval System (HIRS), a statistical software package distributed by the Centers for Disease Control and Prevention (CDC). The 1992-1996 population figures are provided by the U.S. Bureau of the Census through the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute (NCI).

The New Jersey State Cancer Registry (NJSCR) follows guidelines and standard practices of the SEER Program in determining multiple primary cancers for an individual. Statistics for in situ cancers of the breast and cervix are presented, but not included in the statistics for cancers of all sites. Note that, beginning with diagnoses in 1995, in situ cancers of the cervix are no longer collected, in accordance with the recommendations of NAACCR.

An individual may develop more than one type of cancer within a given year, thus the number of cancer cases is greater than the number of cancer patients. Persons of unknown age and/or sex are excluded, as are out-of-state residents.Race-specific information is not shown for persons of non-white or non-African American races (including unknown race), but this information is included in the "all races" data.

Estimation of Completeness and Other Data Quality Indicators

The percentage completeness of cases received was estimated using incidence to mortality ratios for whites, standardized for age, sex, and cancer site. The data used to generate these ratios were the cancer incidence rates for all SEER registries combined and the U.S. mortality rates for 1990-1994. Using these standard formulae, it is possible for the estimation of completeness to be greater than 100%.For 1996,the completeness of case reporting was estimated as 100.6% for NJ white males and 98.5% for NJ white females. Cancers among children (age 0-14) tended to be reported somewhat later than those in adults because many are diagnosed in out-of-state facilities that are not subject directly to New Jersey regulations. These cases are reported later under mutual agreements with New York and Pennsylvania.

Other data quality indicators measured were:

Percent death certificate only cases: 3.2%
Percent of cases microscopically confirmed: 91.3%
Percent of unresolved duplicates: Less than 0.09%

Calculation of Rates

A cancer incidence rate is defined as the number of new cases of cancer detected during a specified time period in a specified population. These rates are most commonly expressed as cases per 100,000 person-years of observation. Cancer occurs at different rates in different age groups, and population subgroups defined by gender and race have different age distributions. Therefore, before a valid comparison can be made between rates, it is necessary not only to adjust the rates by age but also to standardize the rates to the age distribution of a standard population. In this report, the 1970 US Standard Population was used.

The first step in this procedure was to determine the age- specific rates. For each age-group for a given time interval (within each race-sex group, for the entire state), the following formula was applied:

formula

where:

ra = the age-specific rate for age-group a,
da = the number of events (cancer diagnoses) in the age-group during the time interval,
t = the length of the time interval (in years), and
Pa = average size of the population in the age-group during the time interval (mid- year population or average of mid-year population sizes).

The age-specific, race and sex specific population estimates for the state were provided by the SEER Program of NCI through an interagency agreement with the US Bureau of the Census. The age-specific rates are not shown in this report but are available from the NJSCR upon request.

In order to determine the age-adjusted and standardized rate, a weighted average of the age-specific rates was calculated, using the age distribution of the standard population to derive the age-specific weighting factors (Rothman, 1985). This is the technique of direct standardization, which uses the following formula:

formula

where:

R = the age-adjusted rate
ra = the age-specific rate for age-group a, and
Std.Pa = the size of the standard population in each age- group a.

While age adjustment and standardization facilitates the comparison of rates among different populations, there can be important age-specific differences in disease occurrence which are not apparent in comparisons of the age-adjusted rates (Breslow and Day, 1987).

References

  1. Breslow NE and Day NE. Statistical Methods in Cancer Research. Volume II - The Design and Analysis of Cohort Studies. New York: Oxford University Press. 1987.

  2. Chen V, Andrews P, Xiao W, Correa C, and Fontham E. Cancer Incidence in North America, 1990-1994. North American Association of Central Cancer Registries. Sacramento, CA. April 1998.

  3. Chiang CL. "Standard error of the age-adjusted death rate." Vital Statistics - Special Reports, Volume 47, Number 9. USDHEW, PHS, Washington, D.C. U.S. Government Printing Office. 1961.

  4. National Cancer Institute. Cancer Rates and Risks. Fourth edition, U.S. PublicHealth Service. 1996.

  5. Rothman K. Modern Epidemiology. U.S.A. Little, Brown, and Company. 1986.

  6. Wingo PA, Ries LAG, Rosenberg HM, Miller DS, and Edwards BK. Cancer Incidence andMortality, 1973-1995; A Report Card for the U.S. Cancer 82:1197-1207. March 15, 1998.


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