ASPO Abstracts
Gestational growth and risk of young-onset colorectal cancer
Category: Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2021
Abstract Body:
Purpose of the study: To estimate the effect of gestational growth on risk of colorectal cancer (CRC), a cancer
that is now increasing in young adults.
Methods: The Child Health and Development Studies is a population-based cohort of women receiving
prenatal care between June 1959 and September 1966, with deliveries through June 1967 (n=18,751 live
births excluding neonatal deaths among 14,507 mothers). We examined four measures of gestational growth
and risk of CRC in adult offspring: 1) maternal obesity, body mass index at the first prenatal visit; 2) total
gestational weight gain, the difference between the last pre-delivery weight and weight at the first prenatal visit;
3) rate of early gestational weight gain, pounds gained per week through 32 weeks' gestation; and 4) birth
weight, assessed with standardized scales at delivery (<2,000g vs. 2,000-3,999g vs. ≥4,000g). Incident cases
of CRC in offspring were ascertained through 2018 by linkage with the California Cancer Registry. We used
Cox proportional hazards models to estimate adjusted hazard ratios (aHR), with follow-up accrued from birth
through CRC diagnosis, death, or last contact. We also examined effect modification of total weight gain by
rate of early weight gain by including a statistical interaction term in the adjusted model.
Results: We identified 68 incident cases of CRC in offspring. Cases were diagnosed at ages 23 – 56 years
(median age 50 years). Maternal obesity increased risk of CRC in offspring (overweight: aHR 2.21, 95% CI
1.25, 3.94; obese: aHR 2.45, 95% CI 1.08, 5.55). Rate of early weight gain modified the effect of total weight
gain (p for interaction=0.01), suggesting discordant growth from early to late gestation increased risk of CRC in
offspring (aHR: 5.20, 95% CI 1.51, 17.86). There was an elevated but not statistically significant risk
associated with high (≥4,000g) birth weight (aHR 1.95, 95% CI 0.86, 4.38).
Conclusions: Our results provide compelling evidence that events in utero may contribute to increasing
incidence rates of CRC in young adults – more than 50 years after birth. Maternal obesity more than doubled
risk of CRC in offspring. Gestational weight gain trajectories, which may be markers of fetal and placental
development, similarly increased risk.
Keywords: colorectal cancer; obesity; early life; pregnancy