Spontaneous Regression of Metachronous Intra-Abdominal Desmoid Tumor in a Patient with Familial Adenomatous Polyposis.

Desmoid tumors are clonal fibroblastic neoplasms that arise in soft tissues. Patients with familial adenomatous polyposis (FAP) can develop intra-abdominal desmoid tumors. However, metachronous appearance of intra-abdominal desmoid tumor is rare, and its clinical course is not well known. Here, we report a case of spontaneous regression of metachronous intra-abdominal desmoid tumor in a 36-year-old man with FAP. The patient was diagnosed with FAP and underwent laparoscopic total colorectomy. Intra-abdominal desmoid tumor appeared 2 years later and progressed despite treatment with tamoxifen and sulindac. He received four cycles of combinatory therapy with dacarbazine and adriamycin, resulting in shrinkage and stabilization of the desmoid tumor even after cessation of chemotherapy. A new intra-abdominal desmoid tumor developed 2 years later at a different site from the first lesion and progressed from 65 mm to 70 mm in diameter within a month. The size of the first lesion, however, remained unchanged. We prepared for chemotherapy because the second lesion progressed, but follow-up computed tomography showed spontaneous shrinkage of the second lesion. The patient still has not needed additional therapy as of more than 4 years after the appearance of the second lesion. Immunohistochemical staining showed the presence of macrophages in the second lesion. Although metachronous intra-abdominal desmoid tumor is rare and management protocols have yet to be established, this case suggests that an active surveillance approach may be applicable under careful follow-up in asymptomatic patients.

Atezolizumab plus bevacizumab treatment for unresectable hepatocellular carcinoma progressing after molecular targeted therapy: A multicenter prospective observational study.

To evaluate the efficacy of atezolizumab plus bevacizumab treatment in patients with hepatocellular carcinoma (HCC) previously treated with molecular targeted agents (MTAs). Thirty-one patients treated with atezolizumab plus bevacizumab for unresectable HCC and previously treated with MTAs were enrolled in this study. The treatment lines ranged from second to sixth lines. The treatment effect on HCC differed from that during first-line treatment. The treatment effect was determined using the Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST. The treatment response was different for each MTA immediately prior to atezolizumab + bevacizumab treatment. Tumors treated with lenvatinib followed by atezolizumab + bevacizumab showed rapid growth for a short period of time followed by shrinkage. However, patients who received ramucirumab, sorafenib, and regorafenib did not show such changes. This was likely because of differences in the mechanism of action of the MTA administered immediately beforehand. The side-effect profile differed from that observed in the IMbrave150 phase 3 study of atezolizumab plus bevacizumab, which showed more adverse events related to hepatic reserve. Patients treated with the combination of atezolizumab and bevacizumab after lenvatinib therapy may experience rapid tumor growth and subsequent shrinkage.