Gastroenterology Report: Risk factor analysis for recurrence of routine colorectal adenomas and serrated polyps

Colorectal cancer (CRC) ranks third in cancer incidence and is the second leading cause of cancer-related death globally, with 1.
8 million new cases and 881,000 deaths in 2018
.
Polyps are known to be considered precancerous
.
According to the classification of the World Health Organization (WHO), polyps can be divided into four types: adenomas, serrated polyps (SP), inflammatory polyps, and hamartomas
.
About two-thirds of CRC cases are thought to develop through the adenoma-carcinoma sequence
.
The remaining one-third of CRC cases may originate from the pathway
of the serrated polyp.
To be sure, both of these carcinogenic pathways suggest that the occurrence of CRC is a gradual process
.
Removal of polyps during CRC screening can help reduce morbidity and mortality
in CRC.
Therefore, colonoscopic polypectomy and surveillance are important
for the prevention of colorectal cancer.
It is worth noting that the recurrence rate of polyps is as high as 20%-50%.

Previous studies have noted risk factors for polyp recurrence and have shown that age and male sex are risk factors
for polyp recurrence.
Overall, while there is consensus on the carcinogenic factors of colorectal polyps, the factors that contribute to polyp recurrence remain uncertain
.
This study aims to identify risk factors and subtypes
for recurrence of colorectal polyps based on the characteristics of the patient and polyps.

A total of 1165 patients diagnosed with conventional adenoma or SP in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2019 were included in this study, including 668 cases of conventional adenoma, 385 cases of SP, and 112 cases
of adenoma and SP.
Build a nomogram based on risk factors and use the calibration chart to evaluate performance
.

The results of the study showed that during a median follow-up of 24 months, recurrent polyps
were observed in 531 (45.
6%) cases.
Male men, age ≥ 50 years, body mass index (BMI) ≥ 24 kg/m2, greater than three numbers of polyps, smoking, alcohol consumption, family history of polyps, and family history of CRC are independent risk factors for
polyp recurrence.
The Norme plot developed with these parameters has a Harrell c index of 0.
69, and the calibration plot shows good agreement
between the actual polyp recursion and the recursion probability predicted by the Nomo plot.
In the subtype analysis, the risk factors for recurrence of conventional adenomas were the same as for all polyps, while smoking, alcohol consumption, family history of polyps, and family history of CRC were not risk factors
for recurrence of SP.

This study confirms that there are several independent risk factors for colorectal polyp recurrence, and it was found that some of them may increase the risk of adenoma recurrence but not the risk of SP recurrence, including smoking, alcohol consumption, and a family history of polyps/CRC, which may help us understand the different etiology and biology
between conventional adenomas and SP.

Original source:

Zengjie Chi.
et al.
Risk factors for recurrence of colorectal conventional adenoma and serrated polyp.
Gastroenterology Report.
2022.