Incidence of suicide among adolescent and young adult cancer patients: a population-based study

Abstract

Background: As the survival rates of cancer patients continue to increase, most cancer patients now die of non-cancer causes. Several studies have been showing elevated suicide rates among patients with cancer. However, no large-scale study has thoroughly assessed the risk of suicide among adolescent and young adult (AYA) patients with cancer. This study was conducted to characterize suicide mortality among AYA patients in the US and identify risk factors associated with a higher risk of suicide.

Methods: Patients aged 15-39 years were residents of the US served by the Surveillance, Epidemiology, and End Results (SEER) program, who were diagnosed with cancers from 1973 to 2015.

Results: We report that 981 of the 572,500 AYA patients with cancer committed suicide, for an age-, sex-, and race-adjusted suicide rate of 17.68/100,000 person-years. The rate of suicide was 14.33/100,000 person-years in the corresponding general population, giving a standardized mortality ratio (SMR) of 1.234 [95% confidence interval (CI) 1.159-1.313]. Higher suicide rates were associated with male sex, white race, unmarried state, distant tumor stage, and single primary tumor. AYA patients with otorhinolaryngologic, gonad, stomach, soft tissue, and nasopharyngeal cancer were at the greatest risk of suicide compared with those with other types of cancer. In older patients (≥ 40 years), the risk was highest in those with lung, stomach, oral cavity and pharynx, larynx, and bone malignancies. SMRs were highest in the first 5 years after diagnosis for most types of cancer.

Conclusion: AYA patients with cancer in the US have over 20% higher the incidence of suicide of the general population, and most suicides occurred in the first 5 years following diagnosis. Suicide rates vary among patients with cancers of different anatomic sites. Further examination of the psychological experience of these young patients with cancer, particularly that of those with certain types of cancer, is warranted.

Keywords: Adolescent and young adult (AYA); Cancer; Non-cancer cause of death; Suicide; Surveillance Epidemiology and End Results (SEER).

Fig. 1

Trends in suicide incidence over time. Despite the fluctuations, there was a trend of increase in the percentage of AYA patients who committed suicide in all deaths since the 1970s through 2015

Fig. 2

Distribution of suicides in cancer type among cancer patients as a function of age group. a The y-axis depicts the relative number of suicides compared to all cancer patients, and the x-axis depicts the age group at time of diagnosis. The colors depict the disease sites. For AYA patients, the plurality of suicides is seen in soft tissue cancer, and lymphoma. In contrast, among older adults (≥ 40 years old), the plurality of suicides occurs in patients with cancer of breast, lung and brounchs, and colorectum. b The y-axis depicts the absolute number of suicides and the x-axis depicts the age group at time of diagnosis. The colors depict the disease sites. The majority of suicide events are in patients diagnosed at an older age (≥ 40 years old), because most cancer patients are middle-aged and elderly