Colon cancer rates similar in patients with multiple serrated polyps, serrated polyposis syndrome

Last Updated: 2017-04-21

By Reuters Staff

NEW YORK (Reuters Health) - Colon cancer rates are similar in patients with multiple serrated polyps (MSP) and those with serrated polyposis syndrome (SPS), according to a new study from Spain.

Likewise, their first-degree relatives share a similarly elevated risk of developing the malignancy, researchers report in a paper online April 8 in Gastroenterology.

“These results confirm that a special surveillance strategy is needed for MSP patients and their relatives, probably similar to the strategy currently recommended for SPS patients,” conclude Dr. Rodrigo Jover from Hospital General Universitario de Alicante and colleagues.

SPS is a rare disease characterized by the presence of multiple serrated polyps. Diagnostic criteria for SPS from the World Health Organization (WHO) are: (I) five or more histologically diagnosed serrated lesions proximal to the sigmoid colon, of which two should be 10 mm in diameter or larger; (II) any number of serrated polyps proximal to the sigmoid colon in an individual who has a first-degree relative with SPS; or (III) more than 20 serrated polyps spread throughout the colon.

However, this definition is “arbitrary” and “somewhat restrictive,” and may lead to underdiagnosis of this disease, Dr. Jover and colleagues say. Many patients with MSP do not meet the criteria for SPS.

The researchers investigated whether patients with MSP not meeting WHO criteria for SPS and their close relatives have similar risks for CRC as those diagnosed with SPS.

They analyzed data from 53 patients who met the criteria for SPS and 145 patients with MSP who did not meet these criteria, but who had more than 10 polyps throughout the colon, of which more than 50% were serrated.

The researchers found that the prevalence of CRC was similar in patients with confirmed SPS (22.6%) and MSP (28.3%; odds ratio, 1.35; p=0.40). The standardized incidence ratios for CRC in patients with SPS and MSP were also not significantly different (SIR, 0.51 vs. 0.74; p=0.70).

The SIR for CRC also did not differ significantly between first-degree relatives of these groups (SIR, 3.28 for SPS 2.79 for MSP; p=0.50).

“The primary finding of this study is the identification of a group of patients with MSP who do not meet the WHO criteria for SPS, but who share with them a similar personal and familial risk of CRC,” say the authors.

“These results suggest that these patients should be treated with the same follow-up procedures as those proposed for patients with SPS, and possibly that the definition of SPS should be broadened to include this phenotype,” they conclude.

The study had no commercial funding and the authors have declared no conflicts of interest.

SOURCE: http://bit.ly/2ovDpLS

Gastroenterol 2017.