1522MO - Hormonal contraception and pregnancy and risk of progression or relapse in desmoid-type fibromatosis (DF)

Background

DF is a locally aggressive tumor with unpredictable course, but most relapses/progressions occur within 2 years. Some indirect arguments suggest that DF could be a hormone-dependent tumor, and that recent exposure to hormonal contraception or pregnancy could influence DF outcome.

Methods

ALTITUDES (NCT02867033) is a nationwide cohort of incident DF, diagnosed from January 2016 to February 2021 and confirmed by central pathological review (Penel, ASCO 2021). In the present study, we have selected women with childbearing age. The primary endpoint was event-free survival EFS (including progression during active surveillance -AS -or relapse after surgery -SUR-). We estimated EFS Kaplan-Meier curves, and modeled the risk in Cox models. We considered hormonal contraception or pregnancy within the 2 years before DF.

Results

We included 242 pts with a median age of 34.1 (range, 17.3-45.8). Abdominal wall is the most common tumor site (N=124, 51.5%). Pts were managed by AS (N=194) or SUR (N=48). Pregnancy occurred within 2 years before DF diagnosis, at the time of DF diagnosis and after DF diagnosis in 87 (36.0%), 12 (5.0%) and 24 cases (9.9%), respectively. Exposure to hormonal contraception within 2 years before diagnosis, at the time of diagnosis and after diagnosis concerned 107 (44.2%), 82 (33.9%) and 94 cases (38.8%). The median follow-up was 23.9 mo. (range, 0.4 to 59.7 mo.). The 2-year EFS rate was 74.5% (95%CI, 67.5-80.3%). We did not observe any association between pregnancy occurring within 2 years and EFS: 2-year EFS= 70.4% versus 76.9%, Hazard ratio=1.32 (0.77-2.28), p=0.31. We did not observe any association between exposure to hormonal contraception within 2 years and EFS: 2-year EFS= 78.5% versus 72.5%, Hazard ratio=0.84 (0.48-1.46), p=0.53. Results were stable in multivariate analysis. Subgroup analyses showed that effect of both pregnancy and hormonal contraception did not significantly differ according to primary site (abdominal wall versus other), age, tumor size and 1^st-line strategy (AS versus SUR) (all interaction tests, p>0.15).

Conclusions

Pregnancy and exposure to hormonal contraception within 24 months did not influence DF outcome.

Clinical trial identification

NCT02867033.

Editorial acknowledgement

Legal entity responsible for the study

Centre Oscar Lambret.

Funding

Ligue Nationale contre le Cancer, Fondation Institut Curie, InterSarc.

Disclosure

All authors have declared no conflicts of interest.