Ji Hyung Hong
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Ji Hyung Hong has a total of 147 co-authors. Here are the top co-authors by number of shared publications:
- Yoon Ho Ko
Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
7 shared publications - Ji Hoon Kim
Department of Surgery, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Incheon 21431, Republic of Korea
4 shared publications - Hye Sung Won
Division of Medical Oncology, Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
3 shared publications - Keunsoo Kang
Department of Microbiology, College of Science and Technology, Dankook University, Cheonan, South Korea
3 shared publications - Myungsoo Kim
Department of Radiation Oncology, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
3 shared publications - Sang Hoon Chun
Division of Oncology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
3 shared publications
Latest Publications
- Open Access
- 15 January 2026
- Published by Korean Cancer Association in Cancer Research and Treatment
- Vol. 58 (1) , 198-207
The Impact of Obesity on Treatment Outcomes in Patients with Hormone Receptor–Positive HER2-Negative Metastatic Breast Cancer Receiving CDK 4/6 Inhibitors
PurposeGuidelines from the aromatase inhibitor era for early breast cancer (EBC) treatment recommend maintaining a body mass index (BMI) below 25. In the current era of cyclin-dependent kinase (CDK) 4/6 inhibitors, now standard in metastatic breast cancer (MBC), limited data exist on treatment outcomes in obese patients. This study investigates how adiposity affects the treatment outcome of CDK 4/6 inhibitors in patients with hormone receptor–positive, human epidermal growth factor receptor 2–negative MBC.Materials and MethodsWe searched PubMed, MEDLINE, and Embase databases, assessing efficacy outcomes such as progression-free survival (PFS) based on obesity markers, including BMI and visceral adipose tissue (VAT) index.ResultsTwelve studies were reviewed, with seven studies and 1,812 patients included in a pooled meta-analysis. Among patients with BMI ≥ 25, modest improvement in PFS was observed, with a pooled hazard ratio (HR) of 0.944 (95% confidence interval [CI], 0.909 to 0.980; p=0.003). Besides, add-on analysis using VAT to define obesity revealed a notable PFS improvement, with a pooled HR of 0.452 (95% CI, 0.256 to 0.798; p=0.006).ConclusionWhile BMI-defined obesity showed slight PFS improvement with CDK 4/6 inhibitors and endocrine therapy, using VAT to define obesity revealed significant PFS gains. This highlights the need for further research on biomarker to clarify the role of adiposity in MBC, which may differ from its impact in EBC.
- 15 January 2026
- Published by Korean Cancer Association in Cancer Research and Treatment
- Vol. 58 (1) , 198-207
Open AccessThe Impact of Obesity on Treatment Outcomes in Patients with Hormone Receptor–Positive HER2-Negative Metastatic Breast Cancer Receiving CDK 4/6 Inhibitors
PurposeGuidelines from the aromatase inhibitor era for early breast cancer (EBC) treatment recommend maintaining a body mass index (BMI) below 25. In the current era of cyclin-dependent kinase (CDK) 4/6 inhibitors, now standard in metastatic breast cancer (MBC), limited data exist on treatment outcomes in obese patients. This study investigates how adiposity affects the treatment outcome of CDK 4/6 inhibitors in patients with hormone receptor–positive, human epidermal growth factor receptor 2–negative MBC.Materials and MethodsWe searched PubMed, MEDLINE, and Embase databases, assessing efficacy outcomes such as progression-free survival (PFS) based on obesity markers, including BMI and visceral adipose tissue (VAT) index.ResultsTwelve studies were reviewed, with seven studies and 1,812 patients included in a pooled meta-analysis. Among patients with BMI ≥ 25, modest improvement in PFS was observed, with a pooled hazard ratio (HR) of 0.944 (95% confidence interval [CI], 0.909 to 0.980; p=0.003). Besides, add-on analysis using VAT to define obesity revealed a notable PFS improvement, with a pooled HR of 0.452 (95% CI, 0.256 to 0.798; p=0.006).ConclusionWhile BMI-defined obesity showed slight PFS improvement with CDK 4/6 inhibitors and endocrine therapy, using VAT to define obesity revealed significant PFS gains. This highlights the need for further research on biomarker to clarify the role of adiposity in MBC, which may differ from its impact in EBC.
- Open Access
- 1 January 2026
- Published by XMLink in Journal of Breast Cancer
- Vol. 29 (4) , 313-323
Meeting Highlights: The 11th Korean Breast Cancer Society Consensus Conference on Axillary Management in Early Breast Cancer
Bae SJ, et al. J Breast Cancer. 2026 Aug;29(4):313-323. https://doi.org/10.4048/jbc.2026.0144
- 1 January 2026
- Published by XMLink in Journal of Breast Cancer
- Vol. 29 (4) , 313-323
Open AccessMeeting Highlights: The 11th Korean Breast Cancer Society Consensus Conference on Axillary Management in Early Breast Cancer
Bae SJ, et al. J Breast Cancer. 2026 Aug;29(4):313-323. https://doi.org/10.4048/jbc.2026.0144
- Open Access
- 23 October 2024
- Published by Springer Nature in International Urology and Nephrology
- Vol. 57 (3) , 715-722
Increased risk of genitourinary cancer in kidney transplant recipients: a large-scale national cohort study and its clinical implications
Purpose To investigate the risk of genitourinary (GU) cancer in kidney transplant recipients (KTRs) compared to that in the general population, focusing on potential risk factors and clinical implications. Methods Using a national cohort of approximately 360,000 individuals, including 31,542 KTRs, we conducted a retrospective analysis of the data from 2007 to 2018. Propensity score matching was used to compare KTRs with a healthy population, adjusting for age, sex, diabetes, hypertension, and hypercholesterolemia. Results We identified a significantly increased risk of GU cancers, particularly bladder and kidney cancers, in KTRs. Multivariate analysis revealed a higher risk of GU cancer associated with kidney transplantation [hazard ratio (HR) 2.133, 95% confidence interval (CI) 1.641–2.772] and hypercholesterolemia (HR 1.725, 95% CI 1.227–2.425), with older age and male sex also being significant risk factors. Conversely, no significant increase in prostate cancer risk was observed in KTRs compared to the general population. Conclusion This national cohort-based study indicated an increased risk of GU cancer in KTRs, underscoring the need for targeted cancer surveillance and pre- and post-transplant counseling. These findings provide valuable insights for the development of cancer surveillance programs for KTRs and highlight the necessity for further research in this field.
- 23 October 2024
- Published by Springer Nature in International Urology and Nephrology
- Vol. 57 (3) , 715-722
Open AccessIncreased risk of genitourinary cancer in kidney transplant recipients: a large-scale national cohort study and its clinical implications
Purpose To investigate the risk of genitourinary (GU) cancer in kidney transplant recipients (KTRs) compared to that in the general population, focusing on potential risk factors and clinical implications. Methods Using a national cohort of approximately 360,000 individuals, including 31,542 KTRs, we conducted a retrospective analysis of the data from 2007 to 2018. Propensity score matching was used to compare KTRs with a healthy population, adjusting for age, sex, diabetes, hypertension, and hypercholesterolemia. Results We identified a significantly increased risk of GU cancers, particularly bladder and kidney cancers, in KTRs. Multivariate analysis revealed a higher risk of GU cancer associated with kidney transplantation [hazard ratio (HR) 2.133, 95% confidence interval (CI) 1.641–2.772] and hypercholesterolemia (HR 1.725, 95% CI 1.227–2.425), with older age and male sex also being significant risk factors. Conversely, no significant increase in prostate cancer risk was observed in KTRs compared to the general population. Conclusion This national cohort-based study indicated an increased risk of GU cancer in KTRs, underscoring the need for targeted cancer surveillance and pre- and post-transplant counseling. These findings provide valuable insights for the development of cancer surveillance programs for KTRs and highlight the necessity for further research in this field.
- Open Access
- 29 April 2024
- Published by The Korean Association of Hepato-Biliary-Pancreatic Surgery in Annals of Hepato-Biliary-Pancreatic Surgery
- Vol. 28 (2) , 161-202
Practice guidelines for managing extrahepatic biliary tract cancers
Hyung Sun Kim, Mee Joo Kang, Jingu Kang, Kyubo Kim, Bohyun Kim, Seong-Hun Kim, Soo Jin Kim, Yong-Il Kim, Joo Young Kim, Jin Sil Kim, Haeryoung Kim, Hyo Jung Kim, Ji Hae Nahm, Won Suk Park, Eunkyu Park, Joo Kyung Park, Jin Myung Park, Byeong Jun Song, Yong Chan Shin, Keun Soo Ahn, Sang Myung Woo, Jeong Il Yu, Changhoon Yoo, Kyoungbun Lee, Dong Ho Lee, Myung Ah Lee, Seung Eun Lee, Ik Jae Lee, Huisong Lee, Jung Ho Im, Kee-Taek Jang, Hye Young Jang, Sun-Young Jun, Hong Jae Chon, Min Kyu Jung, Yong Eun Chung, Jae Uk Chong, Eunae Cho, Eui Kyu Chie, Sae Byeol Choi, Seo-Yeon Choi, Seong Ji Choi, Joon Young Choi, Hye-Jeong Choi, Seung-Mo Hong, Ji Hyung Hong, Tae Ho Hong, Shin Hye Hwang, In Gyu Hwang, Joon Seong Park. Ann Hepatobiliary Pancreat Surg 2024;28:161-202. https://doi.org/10.14701/ahbps.23-170
- 29 April 2024
- Published by The Korean Association of Hepato-Biliary-Pancreatic Surgery in Annals of Hepato-Biliary-Pancreatic Surgery
- Vol. 28 (2) , 161-202
Open AccessPractice guidelines for managing extrahepatic biliary tract cancers
Hyung Sun Kim, Mee Joo Kang, Jingu Kang, Kyubo Kim, Bohyun Kim, Seong-Hun Kim, Soo Jin Kim, Yong-Il Kim, Joo Young Kim, Jin Sil Kim, Haeryoung Kim, Hyo Jung Kim, Ji Hae Nahm, Won Suk Park, Eunkyu Park, Joo Kyung Park, Jin Myung Park, Byeong Jun Song, Yong Chan Shin, Keun Soo Ahn, Sang Myung Woo, Jeong Il Yu, Changhoon Yoo, Kyoungbun Lee, Dong Ho Lee, Myung Ah Lee, Seung Eun Lee, Ik Jae Lee, Huisong Lee, Jung Ho Im, Kee-Taek Jang, Hye Young Jang, Sun-Young Jun, Hong Jae Chon, Min Kyu Jung, Yong Eun Chung, Jae Uk Chong, Eunae Cho, Eui Kyu Chie, Sae Byeol Choi, Seo-Yeon Choi, Seong Ji Choi, Joon Young Choi, Hye-Jeong Choi, Seung-Mo Hong, Ji Hyung Hong, Tae Ho Hong, Shin Hye Hwang, In Gyu Hwang, Joon Seong Park. Ann Hepatobiliary Pancreat Surg 2024;28:161-202. https://doi.org/10.14701/ahbps.23-170
- Open Access
- 1 August 2023
- Published by The Korean Society of Anesthesiologists in Korean Journal of Anesthesiology
- Vol. 76 (4) , 336-347
Effect of total intravenous versus inhalation anesthesia on long-term oncological outcomes in patients undergoing curative resection for early-stage non-small cell lung cancer: a retrospective cohort study
Background: Propofol-based total intravenous anesthesia (TIVA) improves long-term outcomes after cancer surgery compared with inhalation anesthesia. However, its effect on patients undergoing non-small cell lung cancer (NSCLC) surgery remains unclear. We aimed to compare the oncological outcomes of TIVA and inhalation anesthesia after curative resection of early-stage NSCLC. Methods: We analyzed the medical records of patients diagnosed with stage I or II NSCLC who underwent curative resection at a tertiary university hospital between January 2010 and December 2017. The primary outcomes were recurrence-free survival (RFS) and overall survival (OS) according to anesthesia type.Results: We included 1,508 patients with stage I/II NSCLC. The patients were divided into the TIVA (n = 980) and Inhalation (n = 528) groups. The two groups were well-balanced in terms of baseline clinical characteristics. The TIVA group demonstrated significantly improved RFS (7.7 years, 95% CI [7.37, 8.02]) compared with the Inhalation group (6.8 years, 95% CI [6.30, 7.22], P = 0.003). Similarly, TIVA was superior to inhalation agents with respect to OS (median OS; 8.4 years, 95% CI [8.08, 8.69] vs. 7.3 years, 95% CI [6.81, 7.71]; P < 0.001). Multivariable Cox regression analysis revealed that TIVA was an independent prognostic factor related to recurrence (hazard ratio [HR]: 1.24, 95% CI [1.04, 1.47], P = 0.014) and OS (HR: 1.39, 95% CI [1.12, 1.72], P = 0.002).Conclusions: Propofol-based TIVA was associated with better RFS and OS than inhalation anesthesia in patients with stage I/II NSCLC who underwent curative resection.
- 1 August 2023
- Published by The Korean Society of Anesthesiologists in Korean Journal of Anesthesiology
- Vol. 76 (4) , 336-347
Open AccessEffect of total intravenous versus inhalation anesthesia on long-term oncological outcomes in patients undergoing curative resection for early-stage non-small cell lung cancer: a retrospective cohort study
Background: Propofol-based total intravenous anesthesia (TIVA) improves long-term outcomes after cancer surgery compared with inhalation anesthesia. However, its effect on patients undergoing non-small cell lung cancer (NSCLC) surgery remains unclear. We aimed to compare the oncological outcomes of TIVA and inhalation anesthesia after curative resection of early-stage NSCLC. Methods: We analyzed the medical records of patients diagnosed with stage I or II NSCLC who underwent curative resection at a tertiary university hospital between January 2010 and December 2017. The primary outcomes were recurrence-free survival (RFS) and overall survival (OS) according to anesthesia type.Results: We included 1,508 patients with stage I/II NSCLC. The patients were divided into the TIVA (n = 980) and Inhalation (n = 528) groups. The two groups were well-balanced in terms of baseline clinical characteristics. The TIVA group demonstrated significantly improved RFS (7.7 years, 95% CI [7.37, 8.02]) compared with the Inhalation group (6.8 years, 95% CI [6.30, 7.22], P = 0.003). Similarly, TIVA was superior to inhalation agents with respect to OS (median OS; 8.4 years, 95% CI [8.08, 8.69] vs. 7.3 years, 95% CI [6.81, 7.71]; P < 0.001). Multivariable Cox regression analysis revealed that TIVA was an independent prognostic factor related to recurrence (hazard ratio [HR]: 1.24, 95% CI [1.04, 1.47], P = 0.014) and OS (HR: 1.39, 95% CI [1.12, 1.72], P = 0.002).Conclusions: Propofol-based TIVA was associated with better RFS and OS than inhalation anesthesia in patients with stage I/II NSCLC who underwent curative resection.
- Open Access
- 10 February 2023
- Published by Korean Medical Association in Journal of the Korean Medical Association
- Vol. 66 (2) , 92-104
Managing the adverse effects of cytotoxic chemotherapy at the level of primary healthcare
Background: Despite the increased incidence of cancer, more effective cancer drugs are being developed and cancer patient survival expectancy has been prolonged. Here, we discuss the contribution of primary healthcare clinics to managing the side effects of cytotoxic chemotherapy and provide a compilation of what is currently being used in this field.Current Concepts: Loperamide is recommended for active use when diarrhea occurs. In severe cases, octreotide can help control diarrhea by reducing small bowel fluid secretion. Mouthwash mixed with salt and sodium bicarbonate is helpful for controlling mucositis, and transdermal fentanyl patches can be used for severe pain. Limited evidence suggests that pilocarpine may be helpful for xerostomia. Neurokinin-1 receptor antagonists, serotonin receptor antagonists, glucocorticoids, metoclopramide, and olanzapine are used for nausea and vomiting. Opioid-related constipation can be relieved without counteracting the analgesic effect of opioids via peripherally acting μ-opioid receptor antagonists. Granulocyte colony-stimulating factor is recommended to treat neutropenic fever. In cases with neutropenia but no fever, the decision to use it should be based on the patient’s condition. Minoxidil can be used for hair loss, and scalp cooling can also be considered, but its practical applications are limited. Topical steroid ointments are used to treat hand-foot syndrome. Selective serotonin re uptake inhibitors are recommended for depression in cancer patients because they have little interaction with other drugs and are well tolerated.Discussion and Conclusion: Due to an increased cancer patient management burden and limited medical resources, primary healthcare practitioners should know these management strategies for cancer patients receiving cytotoxic chemotherapy.
- 10 February 2023
- Published by Korean Medical Association in Journal of the Korean Medical Association
- Vol. 66 (2) , 92-104
Open AccessManaging the adverse effects of cytotoxic chemotherapy at the level of primary healthcare
Background: Despite the increased incidence of cancer, more effective cancer drugs are being developed and cancer patient survival expectancy has been prolonged. Here, we discuss the contribution of primary healthcare clinics to managing the side effects of cytotoxic chemotherapy and provide a compilation of what is currently being used in this field.Current Concepts: Loperamide is recommended for active use when diarrhea occurs. In severe cases, octreotide can help control diarrhea by reducing small bowel fluid secretion. Mouthwash mixed with salt and sodium bicarbonate is helpful for controlling mucositis, and transdermal fentanyl patches can be used for severe pain. Limited evidence suggests that pilocarpine may be helpful for xerostomia. Neurokinin-1 receptor antagonists, serotonin receptor antagonists, glucocorticoids, metoclopramide, and olanzapine are used for nausea and vomiting. Opioid-related constipation can be relieved without counteracting the analgesic effect of opioids via peripherally acting μ-opioid receptor antagonists. Granulocyte colony-stimulating factor is recommended to treat neutropenic fever. In cases with neutropenia but no fever, the decision to use it should be based on the patient’s condition. Minoxidil can be used for hair loss, and scalp cooling can also be considered, but its practical applications are limited. Topical steroid ointments are used to treat hand-foot syndrome. Selective serotonin re uptake inhibitors are recommended for depression in cancer patients because they have little interaction with other drugs and are well tolerated.Discussion and Conclusion: Due to an increased cancer patient management burden and limited medical resources, primary healthcare practitioners should know these management strategies for cancer patients receiving cytotoxic chemotherapy.
- Open Access
- 1 January 2023
- Published by XMLink in Journal of Gastric Cancer
- Vol. 23 (2) , 315-327
A Randomized Phase III Study of Patients With Advanced Gastric Adenocarcinoma Without Progression After Six Cycles of XELOX (Capecitabine Plus Oxaliplatin) Followed by Capecitabine Maintenance or Clinical Observation
Lee GJ, et al. J Gastric Cancer. 2023 Mar;23:e16. https://doi.org/10.5230/jgc.2023.23.e16
- 1 January 2023
- Published by XMLink in Journal of Gastric Cancer
- Vol. 23 (2) , 315-327
Open AccessA Randomized Phase III Study of Patients With Advanced Gastric Adenocarcinoma Without Progression After Six Cycles of XELOX (Capecitabine Plus Oxaliplatin) Followed by Capecitabine Maintenance or Clinical Observation
Lee GJ, et al. J Gastric Cancer. 2023 Mar;23:e16. https://doi.org/10.5230/jgc.2023.23.e16
- Open Access
MicroRNA-769-3p Acts as a Prognostic Factor in Oral Squamous Cell Cancer by Modulating Stromal Genes
MiR-769-3p expression is suppressed in the stromal subtype of head and neck squamous cell carcinoma (HNSCC); however, its role in stromal HNSCC has not been fully elucidated. To investigate the biological relevance of miR-769-3p in the stromal phenotype, we established oral squamous cell cancer (OSCC) cell lines, namely CAL27, HSC3, and YD8, overexpressing miR-769-3p. miR-769-3p expression was positively and negatively correlated with interferon-gamma-related genes and MYC target gene sets, respectively. miR-769-3p decreased OSCC cell migration and invasion as well as mesenchymal marker expression and increased epithelial marker expression. Moreover, miR-769-3p enhanced OSCC cell sensitivity to 5-fluorouracil. High miR-769-3p expression was associated with good prognosis of HNSCC patients. Collectively, these results suggest that miR-769-3p suppression enhances stromal gene expression and promotes the epithelial-to-mesenchymal transition. Therefore, miR-769-3p may be a potential biomarker of the miRNA phenotype in OSCC patients.
Open AccessMicroRNA-769-3p Acts as a Prognostic Factor in Oral Squamous Cell Cancer by Modulating Stromal Genes
MiR-769-3p expression is suppressed in the stromal subtype of head and neck squamous cell carcinoma (HNSCC); however, its role in stromal HNSCC has not been fully elucidated. To investigate the biological relevance of miR-769-3p in the stromal phenotype, we established oral squamous cell cancer (OSCC) cell lines, namely CAL27, HSC3, and YD8, overexpressing miR-769-3p. miR-769-3p expression was positively and negatively correlated with interferon-gamma-related genes and MYC target gene sets, respectively. miR-769-3p decreased OSCC cell migration and invasion as well as mesenchymal marker expression and increased epithelial marker expression. Moreover, miR-769-3p enhanced OSCC cell sensitivity to 5-fluorouracil. High miR-769-3p expression was associated with good prognosis of HNSCC patients. Collectively, these results suggest that miR-769-3p suppression enhances stromal gene expression and promotes the epithelial-to-mesenchymal transition. Therefore, miR-769-3p may be a potential biomarker of the miRNA phenotype in OSCC patients.
- Open Access
Linear Tumor Regression of Rectal Cancer in Daily MRI during Preoperative Chemoradiotherapy: An Insight of Tumor Regression Velocity for Personalized Cancer Therapy
Objective: Neoadjuvant chemoradiotherapy (CCRT) is current standards of care for locally advanced rectal cancer. The precise and thorough investigation of a tumor during the full course of CCRT by means of daily MRI can provide an idea on real-time treatment sensitivity in addition to tumor biology. Tumor volumetry from daily MRI during CCRT may allow patient-driven treatment decisions. Material and Methods: Patients diagnosed with cT3-4 and/or cN+ rectal adenocarcinoma undergoing preoperative CCRT with capecitabine on the pelvis up to 50 Gy in 25 daily fractions from November 2018 to June 2019 were consecutively included. Rectal tumor volume was uniformly measured by a single physician (YKK) in daily 0.35T MRI obtained with MR-guided linear accelerator. Primary endpoint was to assess the pattern of tumor volume regression throughout the full course of CCRT using daily registration MRI. Secondary endpoint was to assess the effect of tumor regression velocity on disease-free survival (DFS). Tumor regression velocity (cc) per fraction of each patient was calculated using the simple regression analysis of tumor volumes from fraction 1 to fraction 25. Results: Twenty patients were included. Daily tumor volumetry demonstrated linear tumor regression during CCRT. The tumor regression velocity of all 20 patients was 2.40 cc per fraction (R2 = 0.93; p < 0.001). The median tumor regression velocity was 1.52 cc per fraction. Patients with tumor regression velocity ≥ 1.52 cc per fraction were grouped as rapid regressors (N = 9), and those with tumor regression velocity < 1.52 cc per fraction were grouped as slow regressors (N = 11). Rapid regressors had greater tumor regression velocity (4.58 cc per fraction) compared to that of slow regressors (0.78 cc per fraction) with statistical significance (p < 0.001). The mean DFS of rapid regressors was 36.8 months, numerically longer than the 31.9 months of slow regressors (p = 0.400) without statistical significance. Rapid regressors had numerically superior DFS rate compared to slow regressors without statistical significance. The 2-year DFS was 88.9% for rapid regressors and 72.7% for slow regressors, respectively (p = 0.400). Conclusion: This study is the first observation of linear tumor regression in daily MRI during the preoperative CCRT of locally advanced rectal cancer. Daily tumor regression velocity discriminated DFS, although without statistical significance. This study with a phenomenal approach is hypothesis-generating. Nevertheless, the potential of CCRT from therapeutics to a newer level, the “theranostics”, has been inceptively suggested. Further validation studies for the value of daily tumor volumetry on treatment decisions are warranted.
Open AccessLinear Tumor Regression of Rectal Cancer in Daily MRI during Preoperative Chemoradiotherapy: An Insight of Tumor Regression Velocity for Personalized Cancer Therapy
Objective: Neoadjuvant chemoradiotherapy (CCRT) is current standards of care for locally advanced rectal cancer. The precise and thorough investigation of a tumor during the full course of CCRT by means of daily MRI can provide an idea on real-time treatment sensitivity in addition to tumor biology. Tumor volumetry from daily MRI during CCRT may allow patient-driven treatment decisions. Material and Methods: Patients diagnosed with cT3-4 and/or cN+ rectal adenocarcinoma undergoing preoperative CCRT with capecitabine on the pelvis up to 50 Gy in 25 daily fractions from November 2018 to June 2019 were consecutively included. Rectal tumor volume was uniformly measured by a single physician (YKK) in daily 0.35T MRI obtained with MR-guided linear accelerator. Primary endpoint was to assess the pattern of tumor volume regression throughout the full course of CCRT using daily registration MRI. Secondary endpoint was to assess the effect of tumor regression velocity on disease-free survival (DFS). Tumor regression velocity (cc) per fraction of each patient was calculated using the simple regression analysis of tumor volumes from fraction 1 to fraction 25. Results: Twenty patients were included. Daily tumor volumetry demonstrated linear tumor regression during CCRT. The tumor regression velocity of all 20 patients was 2.40 cc per fraction (R2 = 0.93; p < 0.001). The median tumor regression velocity was 1.52 cc per fraction. Patients with tumor regression velocity ≥ 1.52 cc per fraction were grouped as rapid regressors (N = 9), and those with tumor regression velocity < 1.52 cc per fraction were grouped as slow regressors (N = 11). Rapid regressors had greater tumor regression velocity (4.58 cc per fraction) compared to that of slow regressors (0.78 cc per fraction) with statistical significance (p < 0.001). The mean DFS of rapid regressors was 36.8 months, numerically longer than the 31.9 months of slow regressors (p = 0.400) without statistical significance. Rapid regressors had numerically superior DFS rate compared to slow regressors without statistical significance. The 2-year DFS was 88.9% for rapid regressors and 72.7% for slow regressors, respectively (p = 0.400). Conclusion: This study is the first observation of linear tumor regression in daily MRI during the preoperative CCRT of locally advanced rectal cancer. Daily tumor regression velocity discriminated DFS, although without statistical significance. This study with a phenomenal approach is hypothesis-generating. Nevertheless, the potential of CCRT from therapeutics to a newer level, the “theranostics”, has been inceptively suggested. Further validation studies for the value of daily tumor volumetry on treatment decisions are warranted.