Blood in stool, abdominal pain could be early signs of colorectal cancer

Hematochezia and abdominal pain are strong indicators of colorectal cancer (CRC), with the likelihood of CRC increasing by up to six- and 54-fold in the presence of such symptoms, according to a meta-analysis.

Based on pooled data from 81 studies globally, which involved 24,908,126 CRC patients younger than 50 years, hematochezia and abdominal pain emerged as the most common presenting signs and symptoms, with a prevalence of 45 percent (95 percent confidence interval [CI], 40–50) and 40 percent (95 percent CI, 35–45), respectively. These were followed by altered bowel habits (prevalence, 27 percent, 95 percent CI, 22–33). [JAMA Netw Open 2024;7:e2413157]

Hematochezia was associated with between a 5.2- and 54.0-fold increase in the likelihood of early-onset CRC (EOCRC), whereas abdominal pain carried between a 1.3- and 6.0-fold increase. Other than these symptoms, anaemia also increased the likelihood of early-onset CRC by between 2.1- and 10.8-fold.

A typical delay of 4 to 6 months between the initial presentation of symptoms and the diagnosis of EOCRC  was observed.

Symptoms not to be ignored

“Globally and in the US, hematochezia, abdominal pain, and altered bowel habits were the three most common signs and symptoms. The fourth most common symptom differed based on geographic location—diarrhoea among US studies and loss of appetite in non-US studies,” the investigators said.

Abdominal pain is nonspecific and is associated with numerous gastrointestinal conditions. For Individuals presenting with this symptom, guidelines recommend imaging tests such as CT scans and ultrasounds, depending on the location of pain, but highlight the importance of considering other symptoms for a more accurate diagnosis. Performing colonoscopy for all adults younger than 45 years who are experiencing isolated abdominal pain may not be the most efficient approach, given the low diagnostic yield of the procedure and insufficient capacity to accommodate this group, particularly in the US, as the investigators pointed out. [Am Fam Physician 2008;77:971-978; N Z Med J 2013;126:36-44]

On the other hand, hematochezia is a frequently cited symptom among patients with CRC. Multiple guidelines recommend that a full colonoscopy be performed on individuals younger than 50 years who present with hematochezia. [BMC Gastroenterol 2011;11:65; Gastrointest Endosc 2014;79:875-885; Endoscopy 2009;41:227-233]

“A high index of suspicion for CRC in younger patients with hematochezia may be particularly useful to identify patients with high risk, given the high frequency and association with CRC… [Meanwhile,] abdominal pain could serve as a marker to prompt further patient-clinician discussion about additional medical history, which could help determine whether further diagnostic work-up is warranted,” according to the investigators.

Because nonspecific symptoms are frequently present at EOCRC diagnosis, medical professionals should be aware of the symptoms most associated with EOCRC to refine clinical practice pathways and minimize late EOCRC detection, they continued.

Workups

Overall, “EOCRC should be part of the initial differential diagnosis, and that a plan for follow-up should be in place, such as a 30- to 60-day follow-up visit to confirm whether the original working diagnosis was correct, the red flag sign or symptom has resolved, or to refer for colonoscopy to exclude EOCRC if these criteria are not met,” the investigators said.

If benign causes are suspected, red flag signs or symptoms either can be diagnostically confirmed or should resolve with initial treatment, they added. “When an alternative diagnosis is not confirmed or signs or symptoms fail to resolve, a colonoscopy to rule out EOCRC should be pursued.”