Background: Differences between the features of primary cancer and matched metastatic cancer have recently drawn attention in research. This study investigated the concordance in microsatellite instability (MSI) and mismatch repair (MMR) status between primary and corresponding metastatic colorectal cancer (CRC). Methods: Consecutive patients with metastatic CRC who had both primary and metastatic tumors diagnosed at our institution in January 2008 through December 2016 were identified. Immunohistochemistry was used to test the MMR status of both primary and matched metastatic tumors, and PCR analysis was performed to test MSI in patients with deficient MMR (dMMR) status. Results: A total of 369 patients were included. Of the 46 patients with MSI-high primary tumors, 37 (80.4%) also had MSI-high metastatic tumors, whereas 9 (19.6%) had microsatellite stable (MSS) metastatic tumors. A high concordance was found in patients with liver, lung, or distant lymph node metastases. Interestingly, the discrepancy was more likely to be limited to peritoneal (5/20) or ovarian (4/4) metastasis (chi-square test, P<.001). These organ-specific features were also found in the pooled analysis. Along with the change of MSI-high in primary cancer to MSS in metastatic cancer, lymphocyte infiltration decreased significantly (P=.008). However, the change did not influence survival; the median overall survival of MSI-high and MSS metastatic tumors was 21.3 and 21.6 months, respectively (P=.774). The discrepancy rate was 1.6% for patients with proficient MMR primary tumors. Conclusions: For patients with dMMR primary tumors, the concordance of MSI and MMR status in primary CRC and corresponding metastatic cancer is potentially organ-specific. High concordance is found in liver, lung, and distant lymph node metastases, whereas discrepancy is more likely to occur in peritoneal or ovarian metastasis. Rebiopsy to evaluate MSI-high/dMMR status might be needed during the course of anti–PD-1 therapy in cases of peritoneal or ovarian metastasis.
Wen-Zhuo He, Wan-Ming Hu, Fang Wang, Yu-Ming Rong, Lin Yang, Qian-Kun Xie, Yuan-Zhong Yang, Chang Jiang, Hui-Juan Qiu, Jia-Bin Lu, Bei Zhang, Pei-Rong Ding, Xiao-Jun Xia, Jian-Yong Shao, and Liang-Ping Xia
David E. Gerber, Thomas Y. Sheffield, M. Shaalan Beg, Erin L. Williams, Valerie L. Clark, Yang Xie, M.E. Blair Holbein, Celette Sugg Skinner, and Simon J. Craddock Lee
Background: During the COVID-19 public health emergency, the FDA and NIH altered clinical trial requirements to protect participants and manage study conduct. Given their detailed knowledge of research protocols and regular contact with patients, clinicians, and sponsors, clinical research professionals offer important perspectives on these changes. Methods: We developed and distributed an anonymous survey assessing COVID-19–related clinical trial adjustment experiences, perceptions, and recommendations to Clinical Research Office personnel at the Harold C. Simmons Comprehensive Cancer Center. Responses were compared using the Fisher exact test. Results: A total of 94 of 109 contacted research personnel (87%) responded. Among these individuals, 58% had >5 years’ professional experience in clinical research, and 56% had personal experience with a COVID-19–related change. Respondents perceived that these changes had a positive impact on patient safety; treatment efficacy; patient and staff experience; and communication with patients, investigators, and sponsors. More than 90% felt that positive changes should be continued after COVID-19. For remote consent, telehealth, therapy shipment, off-site diagnostics, and remote monitoring, individuals with personal experience with the specific change and individuals with >5 years’ professional experience were numerically more likely to recommend continuing the adjustment, and these differences were significant for telehealth (P=.04) and therapy shipment (P=.02). Conclusions: Clinical research professionals perceive that COVID-19–related clinical trial adjustments positively impact multiple aspects of study conduct. Those with greatest experience—both specific to COVID-19–related changes and more generally—are more likely to recommend that these adjustments continue in the future.