Is It Possible to Identify Clinically Useful Prognostic Groups for Patients With Desmoid Tumors?
Authors: Yoshihiro Nishida, Satoshi Tsukushi, Hiroshi Urakawa, Eisuke Arai, Naoki Ishiguro
Journal: Journal of Clinical Oncology (2012)

TO THE EDITOR: In their recent article, Salas et al 1 report the results of a retrospective study of 426 patients with extra-abdominal desmoid tumors from 24 participating centers. To our knowledge, this is the largest such cohort ever reported. Three hundred seventy patients (86.9%) had surgical treatment initially; a wait-and-see policy was adopted for only 27 patients (6.3%). Patients who had non–lifethreatening tumors or who were at risk for mutilation were selected for the wait-and-see approach. Detailed characteristics of the patients in the wait-and-see group were not provided. Factors that had a significant impact on progression-free survival were age, tumor size, and tumor site in multivariate analysis. It can be understood that there are different prognostic subgroups of patients with desmoid tumors who could benefit from different therapeutic strategies. However, given that these factors are associated mainly with the results of surgical treatment (86.9% of patients) rather than the wait-and-see policy (6.3% of patients), it seems inappropriate to apply the factors extracted by the authors for the determination of the optimal treatment modality, particularly a wait-and-see policy. The constitutional host environment differed with respect to factors such as released growth factors 2 between tumors treated surgically, those treated with the wait-and-see approach, and possibly those treated medically. Therefore, factors determined by the cohort treated surgically are not applicable when another treatment modality is chosen. A previous study 3 revealed the results of a wait-and-see policy for patients with desmoid tumors. Fiore et al 3 retrospectively demonstrated that the 5-year progression-free survival in 83 such patients was 49.9%, in contrast to 58.6% in medically treated patients, with no statistical significance between the two groups. However, Fiore et al indicated that the characteristics of the patients in the wait-and-see group differed from those of the medical therapy group, suggesting that it is impossible from a retrospective series to extract patients who are suitable for a wait-and-see approach, conservative medical therapy, or surgical treatment. We have previously reported (prospectively) 22 consecutive patients with extra-abdominal desmoid tumors who were treated with meloxicam, a cyclooxygenase-2 selective inhibitor. 4 At the time of submission, the median period of meloxicam administration was 20 months (range, 3 to 66 months), and currently is 36 months (range, 3 to 81 months). Excluding the patients with unavailable evaluation information, the previous results were one patient with complete remission, seven with partial remission (PR), 11 patients with stable disease (SD), and one patient with progressive disease. The current results are one patient with complete remission, 10 patients with PR, seven patients with SD, and one patient with progressive disease, representing a slight improvement compared with the previous results. Salas et al 1 demonstrated that the location had a significant impact on prognosis. Limb tumors had a poor prognosis, which is consistent with the results reported by Balo et al. 5 However, these results were based mostly on treatment with surgery, surgery plus radiotherapy, or radiotherapy alone, and do not seem applicable to the cohort treated with a wait-and-see policy or conservative medical therapy. In fact, in our study, 4 seven of 22 patients had limb lesions, four of whom achieved PR and three of whom achieved SD with meloxicam, which is satisfactory compared with the results reported by Salas et al. These results (ours 4 and those of Salas et al 1 ) suggest that the different prognostic subgroups of patients with desmoid tumors should be determined independently and be recipients of different treatment modalities, whereas a prospective cohort study in which all patients receive identical treatment is required to extract the genuine prognostic factors in each treatment modality– dependent subgroup.