IBD Medications Show No Link with Breast Cancer Recurrence

Medications for inflammatory bowel disease (IBD) appear to have no impact on risk of incident malignancies among patients with a history of breast cancer, according to investigators.

These findings diminish concerns that IBD therapy could theoretically reactivate dormant micrometastases, lead author Guillaume Le Cosquer, MD, of Toulouse University Hospital, Toulouse, France, and colleagues, reported.

“In patients with IBD, medical management of subjects with a history of breast cancer is a frequent and unresolved problem for clinicians,” the investigators wrote in Clinical Gastroenterology and Hepatology (2024 Nov. doi: 10.1016/j.cgh.2024.09.034).

Previous studies have reported that conventional immunosuppressants and biologics do not increase risk of incident cancer among IBD patients with a prior nondigestive malignancy; however, recent guidelines from the European Crohn’s and Colitis Organisation (ECCO) suggest that data are insufficient to make associated recommendations, prompting the present study.

“[T]he major strength of our work is that it is the first to focus on the most frequent cancer (breast cancer) in patients with IBD only, with the longest follow-up after breast cancer in patients with IBD ever published,” Dr. Le Cosquer and colleagues noted.

The dataset included 207 patients with IBD and a history of breast cancer, drawn from 7 tertiary centers across France. 

The index date was the time of breast cancer diagnosis, and patients were followed for a median of 71 months. The median time from cancer diagnosis to initiation of IBD treatment was 28 months. 

First-line post-cancer treatments included conventional immunosuppressants (19.3%), anti–tumor necrosis factor (anti-TNF) agents (19.8%), vedolizumab (7.2%), and ustekinumab (1.9%). Approximately half (51.6%) received no immunosuppressive therapy during follow-up.

Over the study period, 42 incident cancers were recorded (20.3%), among which 34 were breast cancer recurrences. Adjusted incidence rates per 1000 person-years were 10.2 (95% CI, 6.0–16.4) in the untreated group and 28.9 (95% CI, 11.6–59.6) in patients exposed to immunosuppressive or biologic therapies (P = .0519). Incident cancer–free survival did not differ significantly between treated and untreated groups (P = .4796).

On multivariable analysis, independent predictors of incident cancer included T4d stage (P = .036), triple-negative status (P = .016), and follow-up duration shorter than 71 months (P = .005).

“[I]mmunosuppressant and biologic use in selected patients with IBD with prior breast cancer does not seem to increase the risk of incident cancer,” the investigators wrote, noting that the main predictors of cancer recurrence were known poor prognostic features of breast cancer.

Dr. Le Cosquer and colleagues acknowledged a lack of prospective safety data for biologic therapies among patients with prior malignancy, as these individuals are often excluded from clinical trials. Still, they underscored alignment between their findings and earlier retrospective studies, including analyses from the SAPPHIRE registry and Medicare data, which also found no significant increase in breast cancer recurrence with anti-TNF agents or newer biologics such as vedolizumab and ustekinumab. 

“Our findings will help clinicians to make decisions in multidisciplinary meetings to start immunosuppressants or biologics in case of IBD flare-up in these patients,” they concluded.

The investigators disclosed relationships with AbbVie, Janssen, Takeda, and others.