Unrelated Death After Colorectal Cancer Screening: Implications for Improving Colonoscopy Referrals

Results

During the study period, 4,879 veterans (96.9% male) underwent at least 1 colonoscopy for screening or surveillance by 1 of the 2 providers. A total of 306 persons (6.3%) were aged > 80 years. The indication for surveillance colonoscopies included IBD in 78 (1.6%) veterans 2 of whom were women. The mean (SD) follow-up period between the index colonoscopy and study closure or death was 7.4 years (1.7). During the study time, 1,439 persons underwent a repeat examination for surveillance. The percentage of veterans with at least 1 additional colonoscopy after the index test was significantly higher in patients with known IBD compared with those without IBD (78.2% vs 28.7%; P < .01).

Between the index colonoscopy and August 2018, 974 patients (20.0%) died (Figure). The mean (SD) time between the colonoscopy and recorded year of death was 4.4 years (4.1). The fraction of women in the cohort that died (n = 18) was lower compared with 132 for the group of persons still alive (1.8% vs 3.4%; P < .05). The fraction of veterans with IBD who died by August 2018 did not differ from that of patients with IBD in the cohort of individuals who survived (19.2% vs 20.0%; P = .87). The cohort of veterans who died before study closure included 107 persons who were aged > 80 years at the time of their index colonoscopy, which is significantly more than in the cohort of persons still alive (11.0% vs 5.1%; P < .01).

Cause of Death

In 209 of the 974 (21.5%) veteran deaths a cause was recorded. Malignancies accounted for 88 of the deaths (42.1%), and CRCs were responsible for 14 (6.7%) deaths (Table 2). In 8 of these patients, the cancer had been identified at an advanced stage, not allowing for curative therapy. One patient had been asked to return for a repeat test as residual fecal matter did not allow proper visualization. He died 1 year later due to complications of sepsis after colonic perforation caused by a proximal colon cancer. Five patients underwent surgery with curative intent but suffered recurrences. In addition to malignancies, advanced diseases, such as cardiovascular, bronchopulmonary illnesses, and infections, were other commonly listed causes of death.

We also abstracted comorbidities that were known at the time of death or the most recent encounter within the VHA system. Hypertension was most commonly listed (549) followed by a current or prior diagnosis of malignancies (355) and diabetes mellitus (DM) (Table 3). Prostate cancer was the most commonly diagnosed malignancy (80), 17 of whom had a second malignancy. CRC accounted for 54 of the malignancies, 1 of which developed in a patient with long-standing ulcerative colitis, 2 were a manifestation of a known hereditary cancer syndrome (Lynch syndrome), and the remaining 51 cases were various cancers without known predisposition. The diagnosis of CRC was made during the study period in 29 veterans. In the remaining 25 patients, the colonoscopy was performed as a surveillance examination after previous surgery for CRC.