Factors that influence the further survival of patients who survive for five years after the diagnosis of cancer in childhood or adolescence

Cause-specific late mortality among 5-year survivors of childhood cancer: the Childhood Cancer Survivor Study

BACKGROUND

The proportion of pediatric and adolescent cancer patients surviving 5 years has increased during the past four decades. This growing population of survivors remains at risk for disease- and treatment-associated late mortality.

METHODS

A total of 20 483 five-year survivors of childhood and adolescent cancer diagnosed between January 1, 1970, and December 31, 1986, and enrolled in the Childhood Cancer Survivor Study (CCSS) were included in a National Death Index search for deaths occurring between January 1, 1979, and December 31, 2002. Treatment information was abstracted from primary medical records. Survival probabilities, standardized mortality ratios (SMRs), and absolute excess risks were calculated for overall and cause-specific deaths. Diagnosis- and sex-specific survival probabilities were estimated by the product-limit method. All statistical tests were two-sided.

RESULTS

Among the CCSS cohort, 2821 (13.8%) 5-year survivors had died by the end of the follow-up period. The cause of death was obtained for 2534 individuals, with 57.5% of deaths attributed to recurrent disease. Estimated probability of survival 30 years from diagnosis was 82%. When compared with the US population, the absolute excess risk of death from any cause was 7.36 deaths per 1000 person-years. The overall SMR was 8.4 (95% confidence interval [CI] = 8.0 to 8.7). Increases in cause-specific mortality were seen for deaths due to subsequent malignancy (SMR = 15.2, 95% CI = 13.9 to 16.6) and cardiac (SMR = 7.0, 95% CI = 5.9 to 8.2), pulmonary (SMR = 8.8, 95% CI = 6.8 to 11.2), and other medical (SMR = 2.6, 95% CI = 2.3 to 3.0) causes. At 20 years of follow-up (25 years after first cancer diagnosis), the death rate due to a subsequent malignancy exceeded that due to all other causes.

CONCLUSION

Our extended follow-up of 5-year survivors of pediatric and adolescent cancer indicates that excess mortality persists long after diagnosis. Continued observation is needed to further define lifetime risk and to determine the potential contribution of chronic health conditions and modifiable health behaviors.

Cause of mortality in 5-year survivors of childhood cancer

Survivors of childhood and adolescent cancer are at risk for long-term effects of disease and treatment. The Childhood Cancer Survivor Study assessed overall and cause-specific mortality in a retrospective cohort of 20,690 5-year survivors. Eligible subjects were individuals diagnosed with cancer (from 1970 to 1986) before the age of 21 who had survived 5 years from diagnosis. Underlying cause of death was obtained from death certificates and other sources, then and coded and categorized as recurrent disease, sequel of cancer treatment, or non-cancer-related. Age and sex standardized mortality ratios (SMRs) were calculated using United States population mortality data. The cohort demonstrated an 8.2-fold excess in overall mortality (95% confidence interval, 7.9 to 8.5). Recurrence of the original cancer was the leading cause of death among 5-year survivors, accounting for 57% of deaths. Statistically significant excess mortality rates were seen due to subsequent malignancies (SMR = 15.0), along with cardiac (SMR = 6.9), and pulmonary (SMR = 8.7). There was no increase seen for automotive accidents (SMR = 1.0), other accidents (SMR = 1.3), or suicide (SMR = 1.0). While recurrent disease remains a major contributor to late mortality in 5-year survivors of childhood cancer, significant excesses in mortality risk associated with treatment-related complications exist up to 25 years after the initial cancer diagnosis.

Mortality among 5-year survivors of cancer diagnosed during childhood or adolescence in British Columbia, Canada

BACKGROUND

Ongoing monitoring of late mortality among survivors of a childhood or adolescent cancer is essential to appropriately evaluate risk in more recent cohorts and with longer follow-up. We examined overall and cause-specific mortality in a population-based cohort of 2,354 individuals diagnosed with a cancer or tumor prior to 20 years of age between 1970 and 1995 in British Columbia (BC), Canada who survived at least 5 years.

PROCEDURE

Late deaths in a survivor cohort ascertained from the BC Cancer Registry were identified using death registrations. Standardized mortality ratios, absolute excess risk of death, and cumulative risk of death were determined. Demographic, temporal, and disease-related factors in risk of late mortality were also assessed.

RESULTS

After 24,491 person-years of follow-up, there were 181 deaths, 139 of which were cancer related. Excess risk of late mortality among survivors was 7 deaths per 1,000 person-years at risk (AER = 6.6). Standardized mortality ratio (SMR) was ninefold higher relative to the underlying BC population (SMR = 9.1, 95% CI, 7.8-10.5), and was greatest for those with a recurrence within 5 years of diagnosis, and for those diagnosed with acute lymphoblastic leukemia and nervous system tumors. Absolute excess risk of late death was significantly higher for males and for those diagnosed prior to 1980, but did not vary according to age at diagnosis. Relative mortality was significantly increased due to cancer-related causes of death (SMR = 81.7, 95% CI, 68.6-95.8), as well as circulatory (SMR = 9.7, 95% CI, 4.2-19.1) and respiratory (SMR = 16.8, 95% CI, 4.6-43.0) diseases.

CONCLUSIONS

In this population-based cohort with long follow-up, there continues to be excess late mortality among childhood and adolescent cancer survivors due to both cancer and non-cancer causes, even among more recently diagnosed survivors.

Adverse Late Effects of Childhood Cancer and Its Treatment on Health and Performance

More than 12,000 newly diagnosed cases of cancer occur each year in the United States among children ages 20 years or younger, and the current 5-year survival rate is near 80%. An estimated 228,000 among adults 47 years or younger and currently living in the United States had a diagnosis of cancer during childhood or adolescence. Here, we review long-term adverse effects of childhood cancer and its treatment with an emphasis on physical performance and health. We also briefly review existing guidelines that may be used to develop appropriate exercise and diet interventions for childhood cancer survivors. We suggest that there is a need for development of evidence-based, risk-based guidelines and interventions for health promotion among long-term childhood cancer survivors, particularly for those whose physical activity limitations interfere with chances for optimizing their bodies' potential in today's society.

Mortality experiences among 15+ year survivors of childhood and adolescent cancers

BACKGROUND

Studies of childhood and adolescent cancer survivorship have tended to focus on limited survival intervals (e.g., 5 and 10 years). Our report evaluates gender-specific overall mortality, as well as mortality by age group, and by cause, among 15+ year survivors of cancer diagnosed during childhood or adolescence.

PROCEDURE

This was a retrospective cohort study of 565 15+ year childhood cancer survivors from Roswell Park Cancer Institute's Long-Term Follow-Up Project. Sex- and age-specific person-years at risk were accumulated and applied to age-specific mortality rates for New York State, excluding New York City. Standardized mortality ratios (SMRs), and 95% confidence intervals, were calculated and compared to mortality risks of the general population.

RESULTS

Second malignancy was the leading cause of death among male and female survivors (15/38 deaths, 39%). Excess overall mortality was noted among both males (SMR = 284) and females (SMR = 371). Significant mortality excesses were seen in both genders for deaths due to primary malignant neoplasms and secondary malignancies, as well as cardiac deaths among males. Excess mortality was noted across most age strata. In the scenario of no cancer relapse, overall mortality in both genders did not differ significantly from the general population.

CONCLUSIONS

Long-term survivors of childhood and adolescent cancers continue to demonstrate significant excess mortality. However, overall mortality among 15+ year survivors without a relapse appears to be comparable to the general population. The leading cause of death among 15+ year survivors is second malignancy in this study, which represents a novel and important finding in terms of long-term follow-up.

Health-related quality of life in young survivors of childhood cancer using the Minneapolis-Manchester Quality of Life-Youth Form

OBJECTIVE

To assess the health-related quality of life (HRQL) of 8- to 12-year-old children undergoing therapy for cancer or childhood-cancer survivors by using the Minneapolis-Manchester Quality of Life-Youth Form (MMQL-YF), a comprehensive, multidimensional self-report instrument with demonstrable reliability and validity.

DESIGN, SETTING, AND PATIENTS

The MMQL-YF consists of 32 items comprising 4 scales: physical functioning, psychologic functioning, physical symptoms, and outlook on life. Scoring on the MMQL ranges from 1 to 5; 5 indicates maximal HRQL. An overall quality-of-life (QOL) score is also computed. By using a cross-sectional study design, the MMQL-YF was administered to 90 off-therapy cancer survivors, 72 children with cancer undergoing active therapy, and 481 healthy children without a history of cancer or other chronic disease.

RESULTS

Compared with healthy controls, children actively undergoing cancer treatment report low overall QOL, physical functioning, and outlook-on-life scores. However, off-therapy survivors report a superior overall QOL, compared with age-matched healthy controls.

CONCLUSIONS

Young survivors of childhood cancer report a favorable HRQL relative to healthy controls. These results are reassuring, suggesting that this group of survivors may have been too young to encounter some of the negative psychosocial impacts of cancer and its treatment.

Prediction of health behaviors in pediatric cancer survivors

BACKGROUND

It is important to understand the factors that motivate survivors of childhood cancer to engage in healthy behaviors. This is because of their susceptibility to adverse late effects from their malignancy and its treatment. We specifically examined sociodemographic and health perception variables as predictors of health-protective behaviors in pediatric cancer survivors.

PROCEDURE

Forty-six patients, ages 10--18 years, who were previously treated for cancer and were 1--4 years off-therapy, were assessed using a battery of testing instruments.

RESULTS

Preadolescent and adolescent cancer survivors reported moderately frequent practice of a variety of health-protective behaviors. The prevalence of risky health behaviors, as indicated by alcohol and tobacco use, was low. Regression analyses indicated that the practice of health-protective behaviors was best predicted by patient's age and socioeconomic status (SES); younger adolescents and patients from higher SES more frequently engaged in healthy behaviors. Health perception variables were not significantly related to health-protective behaviors. This was true despite findings that survivors perceived themselves to be vulnerable to health problems, identified a need to protect their health, and perceived their health outcomes to be largely determined by their own behaviors.

CONCLUSIONS

Sociodemographic factors should be kept in mind when designing interventions to promote continuing good health for young cancer survivors. Also to be included is the assessment of specific health risks secondary to the cancer therapies given. Risk counseling that recognizes and builds on these variables will be most effective in helping this patient population observe sound health habits.

Late mortality experience in five-year survivors of childhood and adolescent cancer: the Childhood Cancer Survivor Study

PURPOSE

Survivors of childhood and adolescent cancer are at risk for long-term effects of disease and treatment. The Childhood Cancer Survivor Study assessed overall and cause-specific mortality in a retrospective cohort of 20,227 5-year survivors.

PATIENTS AND METHODS

Eligible subjects were individuals diagnosed with cancer (from 1970 to 1986) before the age of 21 who had survived 5 years from diagnosis. Underlying cause of death was obtained from death certificates and other sources and coded and categorized as recurrent disease, sequelae of cancer treatment, or non-cancer-related. Age and sex standardized mortality ratios (SMRs) were calculated using United States population mortality data.

RESULTS

The cohort, including 208,947 person-years of follow-up, demonstrated a 10.8-fold excess in overall mortality (95% confidence interval, 10.3 to 11.3). Risk of death was statistically significantly higher in females (SMR = 18.2), individuals diagnosed with cancer before the age of 5 years (SMR = 14.0), and those with an initial diagnosis of leukemia (SMR = 15.5) or CNS tumor (SMR = 15.7). Recurrence of the original cancer was the leading cause of death among 5-year survivors, accounting for 67% of deaths. Statistically significant excess mortality rates were seen due to subsequent malignancies (SMR = 19.4), along with cardiac (SMR = 8.2), pulmonary (SMR = 9.2), and other causes (SMR = 3.3). Treatment-related associations were present for subsequent cancer mortality (radiation, alkylating agents, epipodophyllotoxins), cardiac mortality (chest irradiation, bleomycin), and other deaths (radiation, anthracyclines). No excess mortality was observed for external causes (SMR = 0.8).

CONCLUSION

While recurrent disease remains a major contributor to late mortality in 5-year survivors of childhood cancer, significant excesses in mortality risk associated with treatment-related complications exist up to 25 years after the initial cancer diagnosis.

Feasibility of implementing health promotion interventions to improve health-related quality of life

Survivors of childhood cancer are a growing and vulnerable population. Cure rates for pediatric cancers now exceed 60% and, by the year 2000, an estimated 1 of every 1,000 young adults will be a cancer survivor. Because this population is at increased risk for late medical and neoplastic complications that impact adversely on health-related quality of life, it is important to investigate methods to promote risk reduction by motivating survivors to practice health-promoting behaviors. With this background, we initiated a prospective, randomized, controlled feasibility study in which survivors attending a long-term follow-up clinic were randomized to receive standard care or standard care plus an educational intervention. Our objectives were to determine if the intervention would improve the survivors' knowledge about their cancer treatment and risks of late effects and increase their practice of health-protective behaviors. Since July 1995, 272 of 318 families (86%) approached about the study agreed to participate. Of these, 266 are evaluable for assessment of baseline knowledge and health behaviors. Demographic features, baseline knowledge, health perceptions and health behaviors did not differ among randomized groups. Assessment of the intervention's efficacy at changing health behaviors of survivors randomized to the intervention group will be available when the 1-year follow-up evaluations are completed for the study cohort. Our preliminary experience with this pilot study supports the feasibility of educational intervention research in a specialty clinic dedicated to monitoring long-term childhood cancer survivors. Int. J. Cancer Suppl. 12:138-142, 1999.

Cancer and cardiac mortality among 15-year survivors of cancer diagnosed during childhood or adolescence

PURPOSE

To evaluate the impact of cardiac disease and second malignant neoplasms on late mortality rate and to identify risk factors for late mortality among 15-year survivors of cancer diagnosed during childhood or adolescence.

PATIENTS AND METHODS

Gender-specific all-cause and cause-specific (cardiac disease, cancer) standardized mortality ratios were calculated. Kaplan-Meier survival estimates and Cox regression analyses were performed to determine the relationship of several demographic and treatment variables to survival.

RESULTS

Patients who survived for 15 years after diagnosis had excess subsequent all-cause, cancer (second malignant neoplasms only), and cardiac mortality rates. No decrease in the late mortality rate by treatment era (1960 to 1970, 1971 to 1984) was identified. Risk factors for males included disease recurrence during the first 15 years after diagnosis, treatment with doxorubicin, and the diagnosis of Hodgkin's disease. Those for females included treatment with radiation therapy, treatment with an alkylating agent, and disease recurrence during the first 15 years after diagnosis. Cox regression analysis demonstrated that only an initial duration of remission of less than 15 years (P <.01) and treatment with doxorubicin (P =.08) were significantly associated with shorter survival time for males. No variable was significantly associated with shorter survival time for females in Cox regression analysis.

CONCLUSION

Fifteen-year survivors of childhood cancer have excess mortality. More effective treatments must be developed to reduce this excess risk. Fifteen-year relapse-free survivors did not have excess mortality. This group will require continued observation to determine whether excess mortality will become apparent as more events occur.

Long-term survival and late deaths after allogeneic bone marrow transplantation. Late Effects Working Committee of the International Bone Marrow Transplant Registry

BACKGROUND AND METHODS

It is uncertain whether mortality rates among patients who have undergone bone marrow transplantation return to the level of the mortality rates of the general population. We analyzed the characteristics of 6691 patients listed in the International Bone Marrow Transplant Registry. All the patients were free of their original disease two years after allogeneic bone marrow transplantation. Mortality rates in this cohort were compared with those of an age-, sex-, and nationality-matched general population. Cox proportional-hazards regression was used to identify risk factors for death more than two years after transplantation (late death).

RESULTS

Among patients who were free of disease two years after transplantation, the probability of living for five more years was 89 percent (95 percent confidence interval, 88 to 90 percent). Among patients who underwent transplantation for aplastic anemia, the risk of death by the sixth year after transplantation did not differ significantly from that of a normal population. Mortality remained significantly higher than normal throughout the study among patients who underwent transplantation for acute lymphoblastic leukemia or chronic myelogenous leukemia and through the ninth year among those who underwent transplantation for acute myelogenous leukemia. Recurrent leukemia was the chief cause of death among patients who received a transplant for leukemia, whereas chronic graft-versus-host disease was the chief cause among those who received a transplant for aplastic anemia. Advanced, long-standing disease before transplantation and active chronic graft-versus-host disease were important risk factors for late death.

CONCLUSIONS

In patients who receive an allogeneic bone marrow transplant as treatment for acute myelogenous or lymphoblastic leukemia, chronic myelogenous leukemia, or aplastic anemia and who are free of their original disease two years later, the disease is probably cured. However, for many years after transplantation, the mortality among these patients is higher than that in a normal population.