Estimating the prevalence of cancer in the United States

Cancer Prevalence in the Elderly

Aims and Background

To describe the cancer prevalence in elderly Italian people and analyze the differences, if any, with the prevalence among younger subjects.

Methods & Study Design

The cancer prevalence among elderly patients (65 years and over), the three age classes encompassing elderly age (65-74 years, 75-84 years, 85 years and over) and younger patients (0-64 years) was computed using the PREVAL method on the basis of the incident cases over the period 1976-1992 followed up to 31 December 1992 (prevalence reference date). Data were collected by 11 Italian cancer registries.

Results

The observed prevalence figures for all cancers (except skin epitheliomas), both sexes combined and considering the whole elderly group, were 1,090 and 3,601 cases per 100,000 one and five years since diagnosis, respectively; the prevalence increased up to the 75-84 age group and showed a slight decrease after age 85. With regard to specific cancer sites, in men bladder and prostate had the highest prevalence 5 years from diagnosis (more than 800 cases per 100,000), followed by colon and lung (about 500 cases per 100,000) stomach and rectum (about 300 cases per 100,000); in women breast cancer ranked first (more than 1,000 cases per 100,000), followed by colon (about 350 cases per 100,000), corpus uteri, stomach and rectum cancers (between 150 and 200 cases per 100,000). For all malignancies and the two sexes combined the prevalence figures were about six times higher in the older than in the younger age group.

Conclusions

These figures confirm the important role of aging in determining the increase in cancer prevalence. The resulting prevalence figures clearly indicate the cancer burden placed on health care services; moreover, the figures will probably increase in the next decades due to a possible improvement in survival and to the dramatic aging of the population, assuming a stable trend for incidence rates. This picture will represent a major challenge for politicians and those dealing with health care planning and social policies in general, especially in the light of the reduction of the available financial resources and the specific features of medical and social needs in the elderly.

Cancer Prevalence in Italian Cancer Registry Areas: The Itapreval Study

Aim

To present data on cancer prevalence for the areas covered by Italian cancer registries, by using a standardized set of data collection and elaboration criteria, and a single method of data analysis.

Subjects and Methods

Data on over 250,000 patients with cancer, diagnosed between 1978 and 1992, from 11 Italian cancer registries covering about 12% of the Italian population were collected, validated and analyzed according to the unified protocol of the ITAPREVAL project. The method implemented in the PREVAL computer program was used to provide prevalence estimates for the period covered by cancer registration. The total prevalence for each registry and for the pool of all registries was then estimated by correcting for incomplete observations due to the period in which the registration was not yet activated. All prevalence estimates were for 1992.

Results

Prevalence figures are presented by cancer site, age, sex, years from diagnosis and registry area. For all malignancies combined, total prevalence ranged from 1,350 per 100,000 inhabitants in Ragusa to 3,650 per 100,000 inhabitants in Romagna, the ratio between these two extremes being 2.7. For the pool of the areas covered by registration cancer prevalence was 3,100 per 100,000 females and 2,250 per 100,000 males. About a third of the total female cases and about half the male cases were diagnosed in the previous five years. Among those aged over 75 years, total prevalence was higher for males than for females: 11,300 versus 8,900 per 100,000 respectively.

Conclusions

This is the first large-scale estimate of the burden of cancer in Italy. It is also one of the first studies in the world which was aimed to study cancer prevalence in detail. These data are necessary for predicting health service needs and help in the evaluation of differences in health service demand by sex, age and Italian regions.

The Prevalence of Cancer: A Review of the Available Data

Aims and Background

Cancer prevalence in a population, defined as the proportion – or the number – of people who were diagnosed with a cancer during their lives and are still alive at a given date, is a crucial indicator for heath care planning and resource allocation. Long-term population-based cancer registries (CR) are the appropriate tools to produce prevalence figures, which, however, are scarcely available. This paper contains a review up to 1999 of the published data world-wide (reports and articles) on cancer prevalence: including measured and estimated figures.

Materials and Methods

Data on cancer prevalence from CRs are available for the Nordic countries, Connecticut, and Italy. In addition, electronic data are available for the European Union (EU). Data for the Nordic countries were first published in the mid-seventies, reporting the prevalence for 1970. The first data from Connecticut were available 10 years later. Estimates for all EU countries were published by the International Agency for Research on Cancer (IARC) in 1997. In Italy, observed and estimated data on the prevalence of respiratory and digestive tract cancer and breast cancer have been published during the nineties, followed by a systematic analysis for all cancers in 1999. By using information obtained from CRs, cancer prevalence data were calculated directly (observed prevalence) by means of incidence and follow-up information on individual cancer patients, or indirectly (estimated prevalence) by means of mathematical models, which generally use epidemiological information at the aggregate level.

Results

Cancer prevalence for all cancers combined (proportions per 100,000 inhabitants) showed values of less than 700 in males and less than 800 in females in 1970 (Finland) to over 2,300 in males and over 3,000 in females in 1992 (Italian registries). With few exceptions, in each country and period considered the cancer sites contributing most to cancer prevalence are lung, colon-rectum, prostate and bladder in males, colon-rectum, breast, uterus (both cervix and corpus) and ovary in females. At present, comparison of measurements from different areas is difficult because there exists no standardized mode of presentation.

Conclusions

In spite of their being potentially useful for health care planning, prevalence data have been produced inconsistently and late by cancer registries, at least in comparison with the systematic availability of incidence and survival statistics. The available data can be compared only to a limited extent due to differences in completeness, in the choice of indicators, in the standard populations, and in the frequency of publication. It would be desirable that in the future data will be produced systematically, with a higher level of standardization compared to the past, and, most importantly, on the same geographic and administrative scale as health-care decision-making.

Impact of irradiation on the safety and quality of poultry and meat products: a review

For more than 100 years research on food irradiation has demonstrated that radiation will make food safer and improve the shelf life of irradiated foods. Using the current food safety technology, we may have reached the point of diminishing returns even though recent figures from the CDC show a significant drop in the number of foodborne illnesses. However, too many people continue to get sick and die from eating contaminated food. New and under utilized technologies such as food irradiation need to be re-examined to achieve new levels of safety for the food supply. Effects of irradiation on the safety and quality of meat and poultry are discussed. Irradiation control of the principle microbial pathogens including viruses, the differences among at-risk sub-populations, factors affecting the diminished rate of improvement in food safety and published D values for irradiating raw meat and poultry are presented. Currently permitted levels of irradiation are probably not sufficient to control pathogenic viruses. Typical gram-negative spoilage organisms are very sensitive to irradiation. Their destruction leads to a significant increase in the acceptable shelf life. In addition, the destruction of these normal spoilage organisms did not provide a competitive growth advantage for irradiation injured food pathogens. Another of the main focuses of this review is a detailed compilation of the effects of most of the food additives that have been proposed to minimize the negative quality effect of irradiation. Most of the antimicrobials and antioxidants used singly or in combination produced an increased lethality of irradiation and a decrease in oxidation by-products. Combinations of dosage, temperature, dietary and direct additives, storage temperature and packaging atmosphere can produce meats that the average consumer will find indistinguishable from non-irradiated meats. A discussion of the production of unique radiological by-products is also included.

Prostate cancer: epidemiology and risk factors

After years of rapid increase, the incidence of prostate cancer has begun to decline in certain areas in the USA. Although these temporal trends are consistent with the impact of screening, it still remains to be shown that early detection programmes and screening will result in a reduced mortality rate from this disease. A positive family history of prostate cancer has been established as an important risk factor, and recent research supports and points to the existence of a subgroup of prostate cancer families with a hereditary form of the disease. Diet is another well-known risk factor. Recently, it has become evident that nutritional factors might both prevent the progression of prostate cancer or induce it.

The discovery of a new potential anticancer drug: a case history

DNA minor groove binders (MGB) represent a class of anticancer agents whose DNA sequence specificity was hypothesized to lead to high selectivity of action. Tallimustine (TAM), a benzoyl nitrogen mustard derivative of distamycin A (DST), showed excellent antitumor activity in preclinical tests, but also a severe myelotoxicity. Novel nitrogen mustard, nitrogen half-mustard and sulfur mustard derivatives of DST showing excellent activity were recently identified and SAR reported. In particular nitrogen half-mustard and sulfur mustard derivatives, as one-arm alkylating agents, represent interesting structural novelties. A further new class of cytotoxic anticancer agents is that of alpha-halogenoacrylamido derivatives of DST-like oligopeptides, which show an activity profile substantially improved in comparison to TAM. In particular brostallicin (PNU-166196), alpha-bromo-acrylamido tetra-pyrrole derivative ending with a guanidino moiety, showed high cytotoxic potency and myelotoxicity dramatically reduced in comparison to TAM and other MGB. Brostallicin binds to the minor groove but appears unreactive in classical in vitro DNA alkylation assays. About the apparent lack of DNA alkylation we speculated that an intracellular nucleophile, e.g. glutathione (GSH), could activate the reactivity of the compound leading to alkylation of DNA in vivo. Evidence of both covalent interaction of brostallicin with plasmidic DNA in the presence of GSH and of enhanced cytotoxicity in cancer cells characterized by high levels of GSH were obtained. Brostallicin was selected for clinical development and is now undergoing Phase II studies.

[Prevalence of cancer in the Guadalajara health area]

OBJECTIVE

To quantify the prevalence of cancerand its distribution in adults.

DESIGN

Descriptive study of point prevalence through research into primary and secondary sources.

SETTING

Primary care, Guadalajara Health Region. 133 539 people over 14 years old.

PARTICIPANTS

Patients previously diagnosed with cancer, who had a health card in the health area in June 1999.

MEASUREMENTS

Demographic and diagnostic details (location according to CIE-9, date and diagnostic method).

DATA SOURCES

primary care clinical records, cancer morbidity records and attendance orders. Overall crude and adjusted rates, in function of sex and age group, and specific to locations, were calculated. They were compared with data from other studies and data calculated for Spain on the basis of WHO information.

RESULTS

2717 tumours (2595 patients). Mean age, 68.2 (95% CI, 67.6-68.7); diagnostic age, 62.8 (95% CI, 62.1-63.5), in both cases higher in men (P<.01). Most common tumours: prostate, bladder, colon and lung (men); breast, colon, endometrium and ovaries (women). Crude prevalence: men, 2303.8/100 000; women, 1763.8. Adjusted to world population: 1394.2 and 1227.4/100 000, respectively (prevalence ratio, 1.14; 95% CI, 1.03-1.25). Truncated rate higher in women than in men (1638/100 000 against 1308). Five-year period with highest prevalence: 75-79 years old in men (8763.5/100 000) and 80-84 in women (4558.7/100 000).

CONCLUSIONS

Cancer prevalence in adults is slightly above 2%. Once adjusted for age, values are similar to other studies and as expected for our country. The most common tumours are in the digestive apparatus, breast and the genito-urinary system. The man/woman proportion is higher than that described in other studies.

Contrasts in cancer prevalence in Connecticut, Iowa, and Utah

BACKGROUND

Cancer prevalence--the proportion of a population with cancer, including those recently diagnosed, those in treatment, and survivors--is an important indicator of future health care requirements. Only limited information on cancer prevalence is available for the United States. In particular, comparative interstate studies are not available. In this study, we estimate and analyze the prevalence of seven major cancers in Connecticut, lowa, and Utah using the tried and tested PREVAL method applied to National Cancer Institute registry data.

METHODS

We analyzed data on 242,851 carcinomas of the stomach, colorectum, pancreas, breast, uterus (corpus), ovary, and non-Hodgkin lymphoma (NHL), diagnosed in white Americans from 1973 through 1992. Observed prevalence was estimated by applying the PREVAL method to incidence and life status data from the cancer registries. Complete prevalence was estimated by applying correction factors obtained by modeling incidence and survival rates.

RESULTS

The ratio of the highest to the lowest prevalence (as proportions) ranged from 1.69 for uterine carcinoma to 2.73 for stomach carcinoma, showing that marked differences in cancer prevalence exist within the United States. Utah had the lowest prevalence for each carcinoma. Connecticut and lowa had similar prevalence levels for carcinomas of the colorectum, pancreas, and ovary and for NHL. Breast carcinoma was the most prevalent, with 826 cases per 100,000 of population in Utah, 1518 per 100,000 in lowa, and 1619 per 100,000 in Connecticut. Cancer survival did not differ greatly among the three registry populations. The major determinants of prevalence differences were incidence and the population age distribution.

CONCLUSIONS

PREVAL provides reliable estimates of the numbers of living people in a population who have had a cancer diagnosis. Prevalence depends on incidence and survival and on the age structure of population. All these factors have changed markedly in recent years and will continue to do so in the future. Cancer prevalence should be monitored over time to evaluate changes by area, sex, age, and cancer site. The prevalence figures presented are directly comparable with those from European cancer registries.

Measuring cancer prevalence in Europe: the EUROPREVAL project

Cancer prevalence is the proportion of individuals in a population who at some stage during their lifetime have been diagnosed with cancer, irrespective of the date of diagnosis. Cancer prevalence statistics have generally been provided by a limited number of well established cancer registries that have been in existence for several decades. The advent of systematic follow-up of life status of incident cases and the availability of new statistical methodologies, now makes it possible for registries established during the 1970s or 1980s to provide prevalence data. The main problems encountered in the estimation of prevalence are the inclusion of: (i) cases lost to follow-up; (ii) cases known only from their death certificate; (iii) cases diagnosed before the start of registration; and (iv) the treatment of multiple tumours and migrations. The main aim of this paper was to review these problems and discuss, through the experience gained with EUROPREVAL, how they can be overcome. A method is presented for the calculation of prevalence of all cancers combined in the populations covered by the 45 cancer registries participating in EUROPREVAL. Prevalence of cancer is estimated to be 2% on average, with the highest values (3%) in Sweden and the lowest in Eastern Europe, with a minimum of approximately 1% in Poland.

Lessons learnt about early prostate cancer from large scale databases: population-based pearls of wisdom

Prostate cancer is one of most common solid tumors in men and poses some of the most difficult problems in clinical research. Although many clinical research hypotheses in this condition have been explored using single center cases series and multi-center clinical trials, the results of these studies have often been equivocal, leaving many questions unanswered. Recently, investigators have utilized large, administrative datasets for prostate cancer research. These databases tend to include large numbers of patients from different geographic regions increasing their generalizability and statistical power. The goal of this report is to review lessons learnt about early prostate cancer using these data sources. In particular, we focus on the application of large, population-based datasets to address issues concerning the natural history of prostate cancer, the impact of race on outcomes in prostate cancer and the effectiveness of various treatments for localized disease. Information gathered from large, administrative databases will be helpful when counseling patients regarding their treatments options for localized prostate cancer and in identifying future directions for prostate cancer research.

Increasing 'active prevalence' of cancer in Western Australia and its implications for health services

OBJECTIVE

To measure the active and total prevalence of cancer in Western Australia from 1990-98 and to examine trends in utilisation of hospital services by prevalent cancer patients.

METHOD

Longitudinal analysis of linked cancer registrations, hospital separations and death registrations in Western Australia in 1990-98 using a population-based record linkage system.

RESULTS

There was an estimated total of 53,450 patients ever-diagnosed with cancer in Western Australia at 30 June 1998 (29.7 per 1,000 population), an increase of 51% since mid-1990 (21.9/1,000). Patients with active disease accounted for 25% of the total prevalence, and the active prevalence of cancer increased from 5.1/1,000 in 1990 to 7.4/1,000 in 1998. In patients with active cancer, hospital admission rates for procedures other than chemotherapy and radiotherapy were stable or declining, but admission rates for chemotherapy and radiotherapy increased. The annual average cumulative length of stay decreased.

CONCLUSIONS AND IMPLICATIONS

There has been a rapid increase in the number of prevalent patients requiring health care services for cancer during the 1990s. Most of the increase is due to improved survival, population growth and ageing. Further strain on Australian health care expenditure seems inevitable.

Conditional median survival of patients with advanced carcinoma: surveillance, epidemiology, and end results data

BACKGROUND

Conditional survival is clinically useful, particularly for patients with malignant disease who have a poor prognosis. However, there are no published data on the conditional median survival of patients with advanced carcinoma on a population basis.

METHODS

Data on 217,573 patients with breast, colorectal, lung, or prostate carcinoma who were newly diagnosed with distant disease between 1973 and 1995 and who were followed through the end of 1997 were extracted from the Surveillance, Epidemiology, and End Results (SEER) data base of the National Cancer Institute. The Kaplan-Meier method was employed to estimate conditional median survival and 95% confidence intervals at 0-5 years after the initial diagnosis.

RESULTS

The conditional median survival increased as time elapsed after the initial diagnosis. The increase was slowest and almost leveled off among patients with prostate carcinoma. The median survival of patients with breast carcinoma increased relatively linearly with time, i.e., 5-6 months per year. Conversely, there was a rapid increase in the conditional median survival according to the amount of time since diagnosis for patients with lung and colorectal carcinoma. The trend was most pronounced for patients with colorectal carcinoma. At 5 years after the initial diagnosis, the remaining median survival was longest for patients with colorectal carcinoma, almost 6 years (71.5 months), followed by patients with lung carcinoma (52.5 months), breast carcinoma (42.5 months), and prostate carcinoma (34.5 months). Although race was a correlate with initial survival, gender and age had more impact on late conditional survival.

CONCLUSIONS

The conditional median survival provides useful and encouraging information for patients who survive with advanced disease and for healthcare professionals who treat these patients. However, the information should be used carefully, taking the limitations of these data into account.

Colorectal cancer prevalence in France

Cancer prevalence is a crucial indicator that allows the magnitude of the problem of colorectal cancer to be monitored. Population-based cancer registries with long-standing activity are the most appropriate tools for providing prevalence data. All colorectal cases registered between 1976 and 1995 in the Côte d'Or Cancer Registry have been considered in this study. Total prevalence (20 years) was the number of patients with a previously diagnosed colorectal cancer, alive on 31 December 1995. Cumulative recurrence rates up to 5 years after diagnosis were calculated and applied to the number of prevalent cases to estimate the number of recurrences by one-year intervals up to 5 years. The overall age-standardized prevalence rate was 170.8/100000, which yielded an estimated 185857 French people alive with a history of colorectal cancer. The 5-year prevalence rates were 149.4/100000, which represented 46.4% of prevalent cases. Five-year prevalence rates regularly increased with periods of diagnosis. These results represent useful indicators for monitoring the colorectal cancer problem and for health care planning.

Usefulness of strontium-89 for bone pain palliation in metastatic breast cancer patients

Most studies of prostate cancer have shown that strontium-89 chloride (89Sr) is effective in the palliation of metastatic bone pain, refractory to conventional analgesia. The aim of this study was to evaluate the usefulness of 89Sr for bone pain palliation in breast cancer patients. Forty women were treated with 148 MBq of 89Sr. Six patients were retreated, receiving two or more doses. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of 89Sr was evaluated at 3 months of treatment. The response was good in 60% of the patients and partial in 32%; there was no response in the remaining 8% (pre-treatment Karnofsky < or = 60). The duration of the response was 120+/-143 days. In the patients retreated, the response was good in 83% and partial in 17%, without significant differences compared with the first dose, but the pre-treatment Karnofsky and the duration of the efficacy were lower (P < 0.05). A transient and slight decrease of leukocyte and platelet counts after the first month of treatment with 59Sr was observed. In conclusion, breast cancer patients with metastatic bone pain can benefit from therapy with 89Sr. If necessary, the treatment may be repeated safely and with the same efficacy as is achieved after the first dose. A low functional performance status could be a cause of the lower effectiveness of 89Sr.

Cancer prevalence estimates based on tumour registry data in the Surveillance, Epidemiology, and End Results (SEER) Program

BACKGROUND

The Connecticut Tumor Registry (CTR) has collected cancer data for a sufficiently long period of time to capture essentially all prevalent cases of cancer, and to provide unbiased estimates of cancer prevalence. However, prevalence proportions estimated from Connecticut data may not be representative of the total US, particularly for racial/ethnic subgroups. The purpose of this study is to apply the modelling approach developed by Capocaccia and De Angelis to cancer data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute to obtain more representative US site-specific cancer prevalence proportion estimates for white and black patients.

METHODS

Incidence and relative survival were modelled and used to obtain estimated completeness indices of SEER prevalence proportions for all cancer sites combined, stomach, cervix uteri, skin melanomas, non-Hodgkin's lymphomas, lung and bronchus, colon/rectum, female breast, and prostate. For validation purposes, modelled completeness indices were computed for Connecticut and compared with empirical completeness indices (the ratio of Connecticut based prevalence proportion estimates using 1973-1993 data to 1940-1993 data). The SEER-based modelled completeness indices were used to adjust SEER prevalence proportion estimates for white and black patients.

RESULTS

Model validation showed that the adjusted SEER cancer prevalence proportions provided reasonably unbiased prevalence proportion estimates in general, although more complex modelling of the completeness indices is necessary for female cancers of the colon, melanoma, breast, cervix, and all cancers combined. The SEER-based cancer prevalence proportions are incomplete for most cancer sites, more so for women, whites, and at older ages. For all cancers combined, prevalence proportions tended to be higher for whites than blacks. For the site-specific cancers this was true for stomach, prostate, cervix uteri, and lung and bronchus (men only). For colon/rectal cancers the prevalence proportions were higher for blacks through ages 59 (men) and 64 (women), and then for the remaining ages they were higher for whites. Prevalence proportions were lowest for stomach cancer and highest for prostate and female breast cancers. Men experienced higher prevalence proportions than women for skin melanomas, non-Hodgkin's lymphomas, lung and bronchus, and colon/rectal cancers.

CONCLUSION

The modelling approach applied to SEER data generally provided reasonable estimates of cancer prevalence. These estimates are useful because they are more representative of cancer prevalence than previously obtained and reported in the US.

Resistance of cancer cells to immune recognition and killing

It is well recognized that, in order for a wound to heal, the fibrin clot must be eliminated by fibrinolytic enzymes. In certain instances, however, fibrin is ineffectively degraded or even not degraded. For example, in pregnancy, the placenta contains a layer of fibrin (Nitabuck's layer) which presents as 'self' to the immune system. Similar situations have been observed in many solid tumors. A hypothesis is presented according to which tumor cells can escape detection and attack by the immune system in most cancer patients. The tumor dons a 'coat' of the host's own protein on its cell surface. The coat is composed of fibrin and of a polymeric form of human serum albumin (HSA) which, by contrast to pure fibrin, is resistant to fibrinolytic degradation. Such a coated tumor appears as 'self' to the immune system, and thus is not detected as a tumor by the immune system (i.e. natural killer cells). When tumors are prepared for in vitro assays against drugs, they are routinely treated with proteolytic enzymes (e.g. pepsin, or chymotrypsin, etc.) which dissolve the protein coat, exposing the tumor cell surface to the drug. Thus, the in vivo existence of a coat on the tumor surface may explain why some drugs have little or no effect in vivo, while the same drugs are active in vitro.