Cause of death among patients with colorectal cancer: a population-based study in the United States

Abstract

CRC (Colorectal cancer) is one of the most common causes of death worldwide and in the US (United States). In this study, we aim to perform a population-based analysis on the cause of death among patients with CRC in the US. A total of 834,510 CRC patients diagnosed between 1975 and 2016 in the US were selected from the SEER (Surveillance, Epidemiology, and End Results) program. Causes of death among CRC patients were characterized and SMRs (standardized mortality ratios) of death from non-cancer causes were calculated. Among all CRC patients included in this study, a total of 531,507 deaths were recorded, of which 51.3% were due to CRC, 10.3% were due to other cancers, and 38.4% were due to non-cancer causes. Recently, there has been a relative decrease in index-cancer deaths and an increase in non-cancer causes among CRC patients. The mortality risk from non-cancer rises with accumulating age and longer follow-up time. Cardiovascular diseases are the most prevalent non-cancer causes, accounting for 20.3% of all deaths among CRC patients. Compared with the general population, the mortality rate of non-cancer deaths among CRC patients is doubled (SMR, 2.02; 95% confidence interval, 2.01-2.03).

Keywords: cancer survivorship; cause of death; colorectal cancer; epidemiology; surveillance.

Figure 1

Cause of death among patients diagnosed with CRC in SEER 9 registries by calendar year of death. (A) Cause of death among patients with CRC by year of death; (B) cause of death among patients with cancer of cecum by year of death; (C) cause of death among patients with appendicular cancer by year of death; (D) cause of death among patients with cancer of ascending colon by year of death; (E) cause of death among patients with cancer of hepatic flexure by year of death; (F) cause of death among patients with cancer of transverse colon by year of death; (G) cause of death among patients with cancer of splenic flexure by year of death; (H) cause of death among patients with cancer of descending colon by year of death; (I) cause of death among patients with cancer of sigmoid colon by year of death; (J) cause of death among patients with cancer of large intestine, NOS by year of death; (K) cause of death among patients with cancer of rectosigmoid junction by year of death; (L) cause of death among patients with cancer of rectum by year of death.

Figure 2

Cause of death among patients diagnosed with CRC in SEER 18 registries by age at diagnosis. (A) Number of deaths from different causes by age at diagnosis. (B) Percentage of deaths from different causes by age at diagnosis.

Figure 3

SMRs of non-cancer deaths among patients diagnosed with CRC in SEER 18 registries by age at diagnosis. (A) SMRs of all non-cancer deaths by age; (B) SMRs of infectious diseases by age; (C) SMRs of cardiovascular diseases by age; (D) SMRs of respiratory diseases by age; (E) SMRs of renal diseases by age; (F) SMRs of external injuries by age; (G) SMRs of cardiovascular diseases by age; (H) SMRs of other non-cancer deaths by age.

Figure 4

Cause of death among patients diagnosed with CRC in SEER 18 registries by follow-up time from diagnosis. (A) Cause of death among patients with CRC by time from diagnosis; (B) cause of death among patients with cancer of cecum by time from diagnosis; (C) cause of death among patients with appendicular cancer by time from diagnosis; (D) cause of death among patients with cancer of ascending colon by time from diagnosis; (E) cause of death among patients with cancer of hepatic flexure by time from diagnosis; (F) cause of death among patients with cancer of transverse colon by time from diagnosis; (G) cause of death among patients with cancer of splenic flexure by time from diagnosis; (H) cause of death among patients with cancer of descending colon by time from diagnosis; (I) cause of death among patients with cancer of sigmoid colon by time from diagnosis; (J) cause of death among patients with cancer of large intestine, NOS by time from diagnosis; (K) cause of death among patients with cancer of rectosigmoid junction by time from diagnosis; (L) cause of death among patients with cancer of rectum by time from diagnosis.

Figure 5

Flow chart of case inclusion and exclusion criteria in this study.