Int J Gastrointest Interv 2023; 12(3): 159-161
Published online July 31, 2023 https://doi.org/10.18528/ijgii230028
Copyright © International Journal of Gastrointestinal Intervention.
1Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
2Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
Correspondence to:*Department of Gastroenterology, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea.
E-mail address: firstname.lastname@example.org (S.W. Hong).
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Total regression without endoscopic treatment of colorectal adenoma is rare. We report the case of a 58-year-old male diagnosed with advanced gastric cancer and advanced colorectal adenoma. He received chemotherapy for gastric cancer and achieved regression of colorectal adenoma. To our knowledge, this is the first case of regression of colorectal adenoma.
Keywords: Adenoma, Neoadjuvant therapy, Neoplasms, Stomach neoplasms
Advanced colorectal adenoma (CRA) describes polyps with one of the following features: 1) size ≥ 10 mm, 2) villous component on histology, or 3) high-grade dysplasia.1 Approximately 75% of colorectal cancers (CRCs) arise from adenomatous polyps and are in the adenoma-carcinoma pathway, and the advanced adenoma is estimated to progress to CRCs at a rate of 1% per year.2,3 Therefore, these precancerous lesions or early-stage CRCs can be removed using appropriate endoscopic resection methods. With these treatment strategies, there have been few case reports of regression of advanced adenoma or early after immune checkpoint inhibitor (ICI)-based chemotherapy for other cancers. Herein, we report a case of regression of advanced adenoma or early after treating a patient with advanced gastric cancer (AGC).
A 58-year-old man without underlying disease underwent an esophagogastroduodenoscopy (EGD) at an outside hospital for cancer surveillance. The EGD showed an ulcerofungating mass on the upper third of the stomach, suggesting malignancy. He was referred for a diagnostic workup and cancer treatment. The laboratory results (complete blood count, liver function test, electrolyte levels, and serum creatinine measurements) were within the normal range. The EGD performed in our hospital revealed an approximately 4-cm ulcerofungating lesion on the posterior wall extending from high body to cardia. The pathologic diagnosis was moderately differentiated adenocarcinoma. A computed tomography (CT) scan of the abdomen and pelvis revealed known gastric cancer with suspected regional lymph node (LN) enlargement in the left gastric area. Positron emission tomography (PET)-CT showed AGC and regional LN metastasis in the left gastric area. The PET-CT scan showed a focal hypermetabolic lesion at the sigmoid colon. Colonoscopy revealed two polyps, one was located on the hepatic flexure, removed directly because that was a 4 mm-sized, benign-looking polyp. Finally, that polyp was reported as tubular adenoma with clear resection margin. And the other one was a 25-mm lesion compatible with the definition of a laterally spreading tumor (LST) with a nodular-mixed surface located in the rectosigmoid junction. The lesion showed a branch-like pit pattern on the white-light image, compatible with Kudo type IV.4 In the narrow-band image, the vascular pattern showed variable vessel caliber and irregular distribution. However, there was no obscure surface pattern (Fig. 1). The endoscopist suspected that the lesion was high-grade dysplasia or early CRC. She performed a biopsy and referred the patient to another specialist for
The informed consent was waived.
In this case, the advanced CRA totally regressed after treating the AGC with ICI plus platinum analog. ICI possibly affects the achievement of regression by an immune response, and platinum-based chemotherapy, which has been widely used for CRC chemotherapy, could also influence the regression of advanced adenoma.8 Interestingly, ICI with platinum-based chemotherapy could treat gastric cancer with simultaneous regression of CRA or early CRC. Considering the mechanism by which ICI binds with immune cells and enables T cells to attack tumor cells, we presumed that ICI contributes to CRA regression more than cytotoxic agents. However, no study has evaluated the pharmacologic effects of each drug for CRA. Further preclinical research is necessary to prove the mechanism and identify the precipitating factors for regression of adenoma.
Subsequent studies should obtain additional data, such as the density of tumor-infiltrating lymphocytes or microsatellite instability (MSI) status, to elucidate the immune response of regression of CRA or early CRC.9 Our pathologic review observed unusual edematous change with myxoid degeneration in the resected specimen, probably related to immune response. Unfortunately, we could not perform immunohistochemistry staining for related immune markers and MSI tests due to cost considerations.
In conclusion, this case report describes regression of advanced CRA after treatment of other malignancy with ICI plus platinum analog. Our results suggest that precancerous lesions, such as adenomas, could be regressed by ICI. To our knowledge, this is the first report of regression of advanced CRA in Korea.
No potential conflict of interest relevant to this article was reported.
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