Risk of second primary neoplasm and mortality in childhood cancer survivors based on a national registry database

Late mortality among 5-year survivors of childhood cancer: A systematic review and meta-analysis

BACKGROUND

Childhood cancer survivors are at increased risk of late mortality (death ≥5 years after diagnosis) from cancer recurrence and treatment-related late effects. The authors conducted a systematic review and meta-analysis to provide comprehensive estimates of late mortality risk among survivors internationally and to investigate differences in risk across world regions.

METHODS

Health sciences databases were searched for cohort studies comprised of 5-year childhood cancer survivors in which the risk of mortality was evaluated across multiple cancer types. Eligible studies assessed all-cause mortality risk in survivors relative to the general population using the standardized mortality ratio (SMR). The absolute excess risk (AER) was assessed as a secondary measure to examine excess deaths. Cause-specific mortality risk was also assessed, if reported. SMRs from nonoverlapping cohorts were combined in subgroup meta-analysis, and the effect of world region was tested in univariate meta-regression.

RESULTS

Nineteen studies were included, and cohort sizes ranged from 314 to 77,423 survivors. Throughout survivorship, SMRs for all-cause mortality generally declined, whereas AERs increased after 15-20 years from diagnosis in several cohorts. All-cause SMRs were significantly lower overall in North American studies than in European studies (relative SMR, 0.63; 95% confidence interval, 0.49-0.80). SMRs for subsequent malignant neoplasms and for cardiovascular, respiratory, and external causes did not vary significantly between world regions.

CONCLUSIONS

The current findings suggest that late mortality risk may differ significantly between world regions, but these conclusions are based on a limited number of studies with considerable heterogeneity. Reasons for regional differences remain unclear but may be better elucidated through future analyses of individual-level data.

Treating secondary malignant neoplasms: A burden of childhood cancer survivors

Each year approximately 35,000 children and adolescents are diagnosed with cancer in Europe. Five-year survival rates have improved and now reach 80% in most European countries, thanks to a combination of chemotherapy, radiotherapy, and surgery. To date, there are more than 44,000 Italians still living several years after being diagnosed with cancer in developmental age. The risk of premature morbidity and mortality for cancer survivors is well known and documented. Approximately 60% of survivors of cancer in childhood and adolescence have at least one chronic health condition in later life, and more than one in four develop severe or life-threatening disorders. Among the various long-term iatrogenic sequelae of cancer treatments, the most worrisome are second malignant neoplasms. We reported on our mono-institutional experiences of screening and treating secondary breast cancer, secondary thyroid cancer and secondary osteosarcoma. Recommendations on the surveillance needed for cancer survivors because of the risk of late effects of their disease or its treatment suggest that discussing the potential problems early on can be crucial to a patient's future health. These considerations and our consolidated experience strengthen our conviction that survivors of cancer in childhood and adolescence who develop second malignant neoplasms should be treated at highly-specialized centers. Multidisciplinary care requires close communications and high levels of up-to-date professional expertise. This challenging area of health care is also changing rapidly because cancer survivorship is a work in progress, but we cannot wait for definitive conclusions on many aspects because this will take decades, especially for pediatric patients.

The Burden of Late Effects and Related Risk Factors in Adolescent and Young Adult Cancer Survivors: A Scoping Review

Simple Summary

It is unclear what the risk of negative health outcomes is after cancer during adolescence and young adulthood. We conducted a review to understand the risk of second cancers, chronic conditions, and death in adolescent and young adult (AYA) cancer survivors and found factors that increase the risk. In total, 652 studies were identified, of which 106 were included in the review: 23 for second cancers, 34 for chronic conditions, and 54 for deaths. The number of included studies increased over time, from four studies in 2010 to 17 in 2020. The studies found that AYA cancer survivors are at an increased risk of second cancers, chronic conditions, and deaths. In particular, the following factors increased risk: radiation exposure for second cancers; younger attained age and earlier calendar period of diagnosis for chronic conditions; and non-Hispanic Black or Hispanic, low socioeconomic status, and earlier calendar period of diagnosis for deaths.

Abstract

Risk factors associated with late effects in survivors of adolescent and young adult (AYA) cancer are poorly understood. We conducted a systematic scoping review to identify cohort studies published in English from 2010–2020 that included: (1) cancer survivors who were AYAs (age 15–39 years) at diagnosis and (2) outcomes of subsequent malignant neoplasms (SMNs), chronic conditions, and/or late mortality (>5 years postdiagnosis). There were 652 abstracts identified and, ultimately, 106 unique studies were included, of which 23, 34, and 54 studies related to the risk of SMNs, chronic conditions, and mortality, respectively. Studies investigating late effects among survivors of any primary cancer reported that AYA cancer survivors were at higher risk of SMN, chronic conditions, and all-cause mortality compared to controls. There was an indication that the following factors increased risk: radiation exposure (n = 3) for SMNs; younger attained age (n = 4) and earlier calendar period of diagnosis (n = 3) for chronic conditions; and non-Hispanic Black or Hispanic (n = 5), low socioeconomic status (n = 3), and earlier calendar period of diagnosis (n = 4) for late mortality. More studies including the full AYA age spectrum, treatment data, and results stratified by age, sex, and cancer type are needed to advance knowledge about late effects in AYA cancer survivors.

Risk of a second cancer in Canadians diagnosed with a first cancer in childhood or adolescence

BACKGROUND

Second cancers are an adverse outcome experienced by childhood cancer survivors. We quantify the risk and correlates of a second cancer in Canadians diagnosed with a first cancer prior to age 20 years.

METHODS

Using death-linked Canadian Cancer Registry data, a population-based cohort diagnosed with a first cancer between 1992 and 2014, prior to age 20 years, were followed for occurrence of a second cancer to the end of 2014. We estimate standardized incidence ratios (SIR), absolute excess risks (AER), cumulative probabilities, and hazard ratios (HR).

FINDINGS

22,635 people contributed 204,309•1 person-years of follow-up. Overall risk of a second cancer was 6•5 (95% CI: 5•8-7•1) times greater than expected resulting in an AER of 16•5 (14•4-18•5) cancers per 10,000 person-years and a 4•8% (3•8%-6•0%) cumulative probability of a second cancer at 22•6 years of follow-up. SIRs decreased with increasing age at diagnosis and time since diagnosis; were larger in more recent calendar periods of diagnosis; and varied by type of first cancer. Large SIRs in the first year after diagnosis and in those diagnosed in 2010-2014 were partly associated with changing registry practices. For the whole cohort, factors associated with the hazard of a second cancer included: being female vs. male [HR = 1•439 (95%CI: 1•179-1•760)]; being diagnosed in 2005-2014 vs. 1992-2004 [2•084 (1•598-2•719)]; having synchronous first cancers [4•814 (2•042-9•509)]; and being diagnosed with certain types of cancer. Factors varied, however, by type of first cancer.

INTERPRETATION

Risks of a second cancer are not equally distributed and can be impacted by changes in registry practice and the methods used to define second cancers.