Overweight-to-Obese Trajectory in Adulthood May Raise Ovarian Cancer Risk

Individuals who were overweight and later became obese in adulthood may have a higher ovarian cancer risk, according to a study published in Cancer Epidemiology.1

Within the ovarian cancer space, there are currently no effective population-based screening methods that reduce mortality, and treatment success is limited. Because of this, the researchers emphasized the need to prioritize the identification of ovarian cancer risk factors to inform primary prevention strategies.

Ovarian cancer is one of 13 cancers considered to be obesity-related, as evidence shows that the absence of excess body fat reduces someone’s risk.2 Additionally, one study found a 6% increase in ovarian cancer risk for each 5-unit increase in body mass index (BMI), a measure of body fat.3

While past studies have linked excess body fat in older adulthood to ovarian cancer, the researchers noted that the influence of changes in body fat over time is unclear.1 To address this gap, they conducted a study to examine the association between adulthood trajectories of BMI and ovarian cancer.

Individuals who transition from overweight to obese during adulthood may face a higher ovarian cancer risk, highlighting the importance of tracking body fat changes. | Image Credit: Vitalii Vodolazskyi - stock.adobe.com

In their population-based case-control study, the researchers used a group-based trajectory approach to identify BMI trajectories among the study population from age 20 to 70 years. Using unconditional logistic regression, they estimated adjusted ORs (AORs) and 95% CIs for the associations between the estimated BMI trajectories and ovarian cancer.

Eligible participants included female Canadian citizens of the greater Montreal area aged between 18 and 79 years who could communicate in French or English. Based on these criteria, the researchers prospectively identified incident cases of primary borderline or invasive cancer of the ovary, fallopian tubes, or peritoneum in 7 hospitals between 2011 and 2016. Of 741 cases identified, 498 eligible cases participated.

Potential population controls from the same regions as the cases were identified using the Quebec electoral lists and selected with frequency-matching to cases on 5-year age categories. Of the 2125 controls initially identified, 1634 were eligible, and 908 (56%) agreed to participate.

The mean (SD) age of cases and controls was 59.5 (9.9) and 60.4 (9.9), respectively. The researchers highlighted that more cases than controls had a family history of breast and ovarian cancer (23.4% vs 19.4%). Similarly, more cases had high body fat during childhood (23.4%) than controls (18.4%).

The researchers identified 3 distinct BMI trajectory groups across the course of the cases' adult lives. The normal-stable trajectory (63.2% of the sample) was characterized by a BMI below 25 kg/m2 from ages 20 to 70. In contrast, the normal-to-overweight trajectory (31%) showed BMI progressing from below 25 kg/m2 to between 25 and 30 kg/m2 between ages 30 and 40, then leveling off in later years.

Lastly, the overweight-to-obese trajectory (6.8%) had a steep linear BMI increase from age 20 to 70, beginning in the overweight range and progressing to above 30 kg/m2 between ages 20 and 30. A sensitivity analysis among controls only revealed the same 3 BMI trajectory groups, with similar sample proportions.

Compared with participants on the normal-stable trajectory, those on the normal-to-overweight trajectory did not show a significant difference in ovarian cancer risk (AOR, 0.89; 95% CI, 0.69-1.16).

However, participants on the overweight-to-obese trajectory had a 45% increase in the overall odds of ovarian cancer (AOR, 1.45; 95% CI, 0.87-2.43) compared with those on the normal-stable trajectory. They were also found to have an increased risk of both borderline (AOR, 1.52; 95% CI, 0.64-3.60) and invasive (AOR, 1.45; 95% CI, 0.83-2.52) ovarian cancers.

The researchers acknowledged their study’s limitations, including that misclassification was possible since adult BMI was calculated based on self-reported height and weight. Despite their limitations, they expressed confidence in their findings and suggested areas for further research.

“Our results suggest that the consideration of body fatness over the lifetime may be important in understanding its role in ovarian cancer risk,” the authors concluded. “Future life course epidemiology studies with larger samples are needed.”

References

1. L'Espérance K, Madathil S, Ritonja JA, et al. Trajectories of body fatness in adulthood and the risk of ovarian cancer. Cancer Epidemiol. doi:10.1016/j.canep.2025.102814
2. Lauby-Secretan B, Scoccianti C, Loomis D, et al. Body fatness and cancer—viewpoint of the IARC Working Group. N Engl J Med. 2016;375(8):794-798. doi:10.1056/NEJMsr1606602
3. Body fatness and weight gain and the risk of cancer. World Cancer Research Fund. 2018. Accessed April 22, 2025. https://www.wcrf.org/wp-content/uploads/2024/10/Body-fatness-and-weight-gain_0.pdf