A successful rechallenge with cetuximab for a case with metastatic rectal cancer

　A 55-year-old man who had been diagnosed with rectal cancer with multiple liver metastases and lymph node metastases on colonoscopy and computed tomography (CT) was referred to Okayama University Hospital for treatment. Based on the diagnosis of non-curative rectal cancer, we planned to perform systematic chemotherapy after surgical resection. We performed a low anterior resection of a 36×35 mm upper rectal moderately differentiated adenocarcinoma with wil-type KRAS. After the resection, a FOLFIRI regimen with cetuximab was given as the first-line chemotherapy. Although metastatic lesions in the liver showed shrinkage, we decided to switch regimens because of intolerable adverse events. A modified FOLFOX6 regimen with bevacizumab was administered as the second-line treatment. There were no signs of disease progression until eight months later, when positron emission tomography (PET)/CT scans revealed that the new metastatic lesions appeared. As the third-line treatment, an irinotecan with cetuximab regimen was administered, leading to a good response for over 12 months. 　We experienced a successful rechallenge with cetuximab for a case with metastatic rectal cancer. For patients with wild-type KRAS colorectal cancer, rechallenge with cetuximab-based chemotherapy can be an effective therapeutic option

A case of metastatic cecal cancer with mutation in the BRAF oncogene and poor survival

　A 79-year-old woman visited a previous hospital with a complaint of general fatigue. The patient was diagnosed with cecal cancer with multiple liver metastases and lymph node metastases on colonoscopy, abdominal ultrasonography and CT scan, and was referred to our division for treatment. Based on the diagnosis of non-curative colonic cancer, we planned to perform systematic chemotherapy after local surgical treatment. We performed an ileocecal resection, and the specimen showed poorly differentiated adenocarcinoma with mutation in the BRAF oncogene. After the surgical treatment, the tumor grew rapidly and the patient died from cancer on the 19th postoperative day without having the opportunity to undergo chemotherapy. 　Multiple genetic and epigenetic alterations in oncogenes and tumor suppressor genes are involved in the process of colorectal carcinogenesis. Some of the alterations have been identified as predictive and prognostic biomarkers. A mutation in the BRAF oncogene was reported to be associated with a very unfavorable prognosis in colorectal cancers. Some of the cases with rapid progression are suggested to have the BRAF oncogene mutation. According to our experience, chemotherapy before surgical treatment might improve the prognosis of cases with the BRAF mutation

18F-Fluorodeoxyglucose Positron Emission Tomography Is Useful in the Evaluation of Prognosis in Retroperitoneal Sarcoma

Background: Retroperitoneal sarcomas are rare neoplasms that occur in the retroperitoneum. Complete surgical resection is the only effective treatment option. The prediction of prognosis by histological diagnosis has not yet been established. The purpose of this study was to identify the usefulness of [18-F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging for validating the prognosis of retroperitoneal sarcoma (RPS) established by histological diagnosis. Methods: We retrospectively reviewed 201 patients with RPS treated at the Osaka International Cancer Institute between 2010 and 2021. We extracted the clinical data, including standardized uptake values (SUVs), evaluated with FDG-PET, and statistically analyzed the data. Results: The median age of patients was 64 years (range, 31–85 years). A total of 101 (50.2%) patients were men, and 100 (49.8%) were women. Surgical resection was performed in 155 (77.1%) patients. On histological analysis, 75 (37.3%), 52 (25.9%), and 29 (14.4%) patients were diagnosed with dedifferentiated liposarcoma, well-differentiated liposarcoma, and leiomyosarcoma, respectively. The median survival time for patients with high maximum SUV (SUVmax) (≥4) or low SUVmax (<4) was 275.8 months and 79.5 months, respectively. Furthermore, among the patients with dedifferentiated liposarcoma, the overall survival rate for patients with high SUVmax (≥4) was significantly lower than that of those with low SUVmax (<4). Conclusions: The present study demonstrated that SUVmax calculated with FDG-PET was useful as a prognostic factor in RPS, especially in dedifferentiated liposarcoma and Grade2 RPS. To devise a treatment strategy for RPS, SUVmax during FDG-PET scan may be considered for clinical assessment