Chidharla, Anusha

Objective: In this study, we evaluate the utility of ctDNA analysis in a large cohort of patients for whom ctDNA testing was ordered commercially with real-world application. Summary Background Data: Circulating tumor DNA (ctDNA) has emerged as a prognostic and predictive biomarker for assessing post-surgical molecular residual disease (MRD) and response to treatment. Methods: A real-world data analysis was performed using commercial ctDNA testing (SignateraTM) from patients (N=795, n=5,971 plasma samples) with stage I-III colon cancer treated at multiple US institutions. The association of ctDNA detection within the MRD window, during surveillance, and the impact of ACT was correlated with patient outcomes. Results: ctDNA-positive patients during the MRD window and surveillance showed significantly shorter DFS compared to ctDNA-negative patients (hazard ratio (HR): 9.85, P<0.0001; HR: 26.91, P<0.0001). Multivariate analysis of the MRD window revealed ctDNA-positivity as the most significant factor associated with inferior DFS (adjHR: 7.7, P<0.001). MRD-positive patients who received ACT showed improved DFS compared to patients observed post-surgery (adjHR: 6.1, FDR adj P=0.0007). No ACT benefit was observed in MRD-negative patients (adj HR: 1.20, FDR adj P=0.768). On evaluating ctDNA dynamics from MRD to surveillance, patients who remained ctDNA-positive or converted from negative to positive showed a significantly inferior DFS (HR: 34.40, P<0.0001; HR: 13.65, P<0.0001) compared to persistently ctDNA-negative patients. Conclusions: Postsurgical ctDNA detection is prognostic of relapse and potentially predictive of ACT benefit in patients with resectable colon cancer, which may enable personalized surveillance, intervention, and/or trial options, ultimately improving patient outcomes.

3623 Background: Minimal residual disease (MRD) assessment may effectively detect cure in patients with colorectal cancer (CRC). Emerging data have suggested that circulating tumor DNA (ctDNA) can be a reliable biomarker for MRD in patients. Recent studies have shown the ability to detect MRD using ctDNA assay to assess recurrence risk and patient selection for adjuvant chemotherapy. We performed a systematic review and metanalysis of post operative ctDNA in Stage I-IV (oligometastatic) CRC patients after curative intent resection with or without adjuvant chemotherapy. Methods: We searched PubMed/Medline, EMBASE, Web of Science, Cochrane Library, and Google from inception to February 3, 2022 using keywords related to colorectal cancer, ctDNA, and MRD. The search also includes paper and conference presentations. The search resulted in 427 studies after removing the duplicates. Data were extracted to perform a meta-analysis using RevMan 5.4. software. Subsequent subgroup analysis was performed for stages I-III and oligometastatic stage IV CRC patients. Results: After the initial abstract screening, 48 studies were identified. The final review led to the inclusion of 27 studies representing 3459 patients with evaluable ctDNA, with 623 having +ve post-surgery ctDNA levels. Seven studies had analyses of patients specifically with oligometastatic disease, the rest 20 studies subdivided within stages I-III. The pooled HR for RFS in post-surgical ctDNA +ve vs -ve patients in all stages was 7.16 (95% CI 6.12-8.36) p <0.00001. Subgroup analysis revealed pooled HR = 8.27 (95% CI 6.16-11.09) and 6.07 (95% CI 4.54-8.13) for stage I-III and IV CRC, respectively. Only 11 studies did analysis for post adjuvant chemotherapy patients based on ctDNA status. The pooled HR for RFS in post-adjuvant chemotherapy ctDNA +ve versus -ve patients in all stages was 12.40 (95% CI 9.24-16.64) p <0.00001. Subgroup analysis revealed pooled HR = 13.95 (95% CI 9.08-21.43) and 11.39 (95% CI 5.99-21.66) for stage I-III and IV CRC, respectively. Conclusions: This is the largest and most current meta-analysis done on ctDNA levels as MRD assessment in CRC. Our analysis emphasizes that post operative ctDNA is a strong prognostic marker of RFS. Based on our results ctDNA can be a significant and independent predictor of RFS. Several ctDNA-based randomized adjuvant trials are ongoing internationally to confirm the clinical utility of ctDNA in colorectal cancer. [Table: see text]

The use of social media continues to increase in health care and academia. Health care practice, particularly the oncologic field, is constantly changing because of new knowledge, evidence-based research, clinical trials, and government policies. Therefore, oncology trainees and professionals continue to strive to stay up-to-date with practice guidelines, research, and skills. Although social media as an educational and professional development tool is no longer completely new to medicine and has been embraced, it is still under-researched in terms of various outcomes. Social media plays several key roles in professional development and academic advancement. We reviewed the literature to evaluate how social media can be used for professional development and academic promotion of oncology professionals.