Colorectal Cancer with Ovarian Metastasis After Panitumumab and FOLFOX4: A Case Report

BACKGROUND Colorectal cancer is now one of the most common malignancies worldwide. Systemic treatment options for metastatic colorectal cancer (mCRC) are unsatisfactory, and the disease recurs despite the use of multiple drug combinations. Patients with mCRC and left-sided KRAS/NRAS/BRAF wild-type tumors may benefit from epidermal growth factor receptor (EGFR) inhibitors such as cetuximab or panitumumab in combination with chemotherapy. This report describes the case of a 67-year-old woman with advanced wild-type (WT) KRAS sigmoid colon adenocarcinoma in remission following treatment with panitumumab-FOLFOX4, presenting with ovarian metastases. CASE REPORT We present the case of a 67-year-old woman who was diagnosed with sigmoid colon cancer with metastasis to the periaortic lymph nodes. Due to the wild-type tumor subtype, targeted treatment with panitumumab and FOLFOX4 chemotherapy was implemented. Upon the third follow-up evaluating the effectiveness of therapy, complete remission (CR) was confirmed. During a routine follow-up at the gynecologist, a gynecologic ultrasound performed showed a questionable left adnexal mass, suspicious for primary ovarian cancer. Histopathological examination revealed metastatic adenocarcinoma of the colon. Imaging studies confirmed significant cancer progression. The chemotherapy regimen was changed to FOLFIRI. Imaging studies evaluating the effectiveness of therapy were performed every 3 months, confirming disease stabilization. The patient is still alive and continues to receive systemic therapy. CONCLUSIONS This case report supports previous studies, reports, and clinical trial data showing that treatment with panitumumab-FOLFOX4 can lead to a response in patients with advanced colonic adenocarcinoma and shows the importance of patient selection using molecular diagnostics, including KRAS mutation testing.