Table 1

Baseline characteristics of patients with SPS (n=296)

Demographic and clinical features
 Age at diagnosis SPS (years), mean±SD57.2±9.9
 Female, n (%)130 (43.9%)
 BMI*, mean±SD27.5±4.6
 Overweight/obesity (BMI ≥25), n (%)146 (69.5%)
 Smoking history, n (%)†207 (74.5%)
 First-degree relative with CRC, n (%)87 (29.4%)
 First-degree relative with SPS, n (%)13 (4.4%)
 WHO criteria‡, n (%)
  I79 (26.7%)
  III134 (45.3%)
  I+III83 (28%)
 Follow-up since SPS diagnosis (months), median (IQR)45 (26–79.7)
 Number of total colonoscopies, median (IQR)3 (2–4)
Cumulative number of serrated polyps (per patient)
 Serrated polyps, median (IQR)26 (18.2–40.7)
 Location, median (IQR)
  Proximal to splenic flexure7 (4–14)
  Descending colon3 (1–6)
  Rectosigmoid11 (5–23.5)
 Size, median (IQR)
 Serrated polyps ≥10 mm2 (0–4)
Histology, median (IQR)
 Serrated polyp subtypes
  Hyperplastic polyp17.5 (6–30.2)
  Sessile serrated adenoma/polyp3 (0–9)
  Traditional serrated adenoma0 (0–0)
 Serrated polyp with dysplasia§
  Any dysplasia0 (0–1)
  LGD0 (0–1)
  HGD0 (0–1)
Adenoma features
 Patients with ≥1 adenoma, n (%)238 (80.4%)
 Patients with ≥1 advanced adenoma¶, n (%)131 (44.2%)
 Number of adenomas (per patient), median (IQR)3 (1–6)
 Number of advanced adenomas¶ (per patient), median (IQR)0 (0–1)
  • *Referred to 210 patients with available information.

  • †Smoking history includes both active and former smokers (referred to 278 patients with available information).

  • WHO criteria: (I) patients who fulfil criterion I only; (III) patients who fulfil criterion III only; (I+III) patients who fulfil both I and III criteria.

  • §Regardless of the serrated polyp subtype.

  • ¶Advanced adenoma: ≥10 mm in diameter or with villous structure or with high-grade dysplasia.

  • BMI, body mass index; CRC, colorectal cancer; HGD, high-grade dysplasia; LGD, low-grade dysplasia; SPS, serrated polyposis syndrome.