A Nationwide Prospective Clinical Trial on Active Surveillance in Patients With Non-intraabdominal Desmoid-type Fibromatosis: The GRAFITI Trial

OBJECTIVE

To assess tumor behavior and the efficacy of active surveillance (AS) in patients with desmoid-type fibromatosis (DTF).

SUMMARY OF BACKGROUND DATA

AS is recommended as initial management for DTF patients. Prospective data regarding the results of AS are lacking.

METHODS

In this multicenter prospective cohort study (NTR4714), adult patients with non-intraabdominal DTF were followed during an initial AS approach for 3 years. Tumor behavior was evaluated according to Response Evaluation Criteria in Solid Tumors. Cumulative incidence of the start of an active treatment and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Factors predictive for start of active treatment were assessed by Cox regression analyses.

RESULTS

A total of 105 patients started with AS. Median tumor size at baseline was 4.1cm (interquartile range 3.0-6.6). Fifty-seven patients had a T41A CTNNB1 mutation; 14 patients a S45F CTNNB1 mutation. At 3 years, cumulative incidence of the start of active treatment was 30% (95% confidence interval [CI] 21-39) and PFS was 58% (95% CI 49-69). Median time to start active treatment and PFS were not reached at a median follow-up of 33.7 months. During AS, 32% of patients had stable disease, 28% regressed, and 40% demonstrated initial progression. Larger tumor size (≥5 cm; hazard ratio = 2.38 [95% CI 1.15-4.90]) and S45F mutation (hazard ratio = 6.24 [95% CI 1.92-20.30]) were associated with the start of active treatment.

CONCLUSIONS

The majority DTF patients undergoing AS do not need an active treatment and experience stable or regressive disease, even after initial progression. Knowledge about the natural behavior of DTF will help to tailor the follow-up schedule to the individual patient.

Tailored Beta-catenin mutational approach in extra-abdominal sporadic desmoid tumor patients without therapeutic intervention

Background

The efficacy of the classical treatment modalities surgery and radiotherapy in the treatment of aggressive fibromatosis is presently disputed and there is a shift towards a more conservative approach. The aim of the present study is to objectify tumor growth in patients with extra-abdominal or abdominal wall aggressive fibromatosis, while adhering to a “watchful waiting” policy. Other objectives are to investigate quality of life and to identify factors associated with tumor growth, in particular the relation with the presence of a CTNNB1-gene mutation in the tumor.

Design and methods

GRAFITI is a nationwide, multicenter, prospective registration trial. All patients with extra-abdominal or abdominal wall aggressive fibromatosis are eligible for inclusion in the study. Main exclusion criteria are: history of familiar adenomatous polyposis, severe pain, functional impairment, life/limb threating situations in case of progressive disease. Patients included in the study will be treated with a watchful waiting policy during a period of 5 years. Imaging studies with ultrasound and magnetic resonance imaging scan will be performed during follow-up to monitor possible growth: the first years every 3 months, the second year twice and the yearly. In addition patients will be asked to complete a quality of life questionnaire on specific follow-up moments. The primary endpoint is the rate of progression per year, defined by the Response Evaluation Criteria In Solid Tumors (RECIST). Secondary endpoints are quality of life and the rate of influence on tumor progression for several factors, such as CTNNB1-mutations, age and localization.

Discussion

This study will provide insight in tumor behavior, the effect on quality of life and clinicopathological factors predictive of tumor progression.

Trial registration

The GRAFITI trial is registered in the Netherlands National Trial Register (NTR), number 4714.

Time trends in the incidence and treatment of extra-abdominal and abdominal aggressive fibromatosis: a population-based study

BACKGROUND

Aggressive fibromatosis (AF) is a locally infiltrating soft-tissue tumor. In a population-based study in the Netherlands, we evaluated time trends for the incidence and treatment of AF.

METHODS

In PALGA: Dutch Pathology Registry, all patients diagnosed between 1993 and 2013 as having extra-abdominal or abdominal wall aggressive fibromatosis were identified and available pathology data of the patients were evaluated. Epidemiological and treatment-related factors were analyzed with χ (2)and regression analysis.

RESULTS

During the study period, 1134 patients were identified. The incidence increased from 2.10 to 5.36 per million people per year. Median age at the time of diagnosis increased annually by B 0.285 (P = 0.001). Female gender prevailed and increased over time [annual odds ratio (OR) 1.022; P = 0.058]. All anatomic localizations, but in particular truncal tumors, became more frequent. During the study period diagnostic histological biopsies were performed more often (annual OR 1.096; P < 0.001). The proportion of patients who underwent surgical treatment decreased (annual OR 0.928; P < 0.001). When resection was preceded by biopsy, 49.8 % of the patients had R0-resection versus 30.7 % in patients without biopsy (P < 0.001).

CONCLUSIONS

In this population-based study, an increasing incidence of extra-abdominal and abdominal-wall aggressive fibromatosis was observed. The workup of patients improved and a trend towards a nonsurgical treatment policy was observed.

Prognostic value of CTNNB1 gene mutation in primary sporadic aggressive fibromatosis

BACKGROUND

Aggressive fibromatosis (AF) comprises tumors with a varying biological behavior. Genetic tumor characteristics may be predictive of recurrence; hence, the prognostic value of three specific mutations on the CTNNB1 gene was evaluated in relation to known clinicopathologic risk factors in patients with primary, sporadic AF.

METHODS

In a multi-institutional retrospective cohort study of patients with primary extra-abdominal and abdominal wall AF who underwent surgical treatment, the original pathology specimens were reviewed for the presence of a T41A, S45F, and 45P mutations on the CTNNB1 gene. For these mutations, the risk of recurrence was analyzed by the Kaplan-Meier method with log-rank test. Univariable and multivariable Cox regression was performed to calculate hazard ratios.

RESULTS

A total of 101 patients were analyzed. During a median follow-up of 41 months, 17 recurrences were detected; the cumulative 5-year recurrence rate was 22.8 %. A specific CTNNB1 mutation was found in 76 patients, with the majority of patients having a T41A mutation (n = 49). CTNNB1 mutations were associated with the risk of recurrence: the presence of a S45F mutation was associated with a 5-year cumulative risk of recurrence of 63.8 % (P < 0.001). Multivariable analysis showed that young age and S45F mutation were independent risk factors (P = 0.011 and P < 0.001).

CONCLUSIONS

The presence of specific CTNNB1 mutations was predictive for recurrence in patients after surgical treatment for primary, sporadic extra-abdominal and abdominal AF. A S45F mutation increased the risk of recurrence significantly.