Development and validation of a comorbidity index for predicting survival outcomes after allogeneic stem cell transplantation in adult patients with acute leukemia: a Korean nationwide cohort study

Background@#Allogeneic hematopoietic stem cell transplantation (alloSCT) is a potentially curative treatment option for acute leukemia. We aimed to identify the comorbidity factors affecting survival outcomes after alloSCT and develop a new comorbidity index tool for predicting overall survival (OS). @*Methods@#A Korean nationwide cohort of 3,809 adults with acute leukemia treated with alloSCT between January 2002 and December 2018 was analyzed as the development cohort.A retrospective cohort comprising 313 consecutive adults with acute leukemia who underwent alloSCT between January 2019 and April 2020 was analyzed as the validation cohort. @*Results@#In the development cohort, advanced age, male sex, and comorbidities such as previous non-hematologic malignancy, hypertension, and coronary or cerebral vascular disease were significantly related to poor OS. Subsequently, a new comorbidity scoring system was developed, and risk groups were created, which included the low-risk (score ≤0.17), intermediate-risk (0.17＜ score ≤0.4), high-risk (0.4＜ score ≤0.55), and very high-risk (score ＞0.55) groups. The 1-year OS rates were discriminatively estimated at 73.5%, 66.2%, 61.9%, and 50.9% in the low-risk, intermediate-risk, high-risk, and very high-risk groups in the development cohort, respectively (P ＜0.001). The developed scoring system yielded discriminatively different 1-year OS rates and 1-year incidence of non-relapse mortality according to the risk group (P =0.085 and P =0.018, respectively).Furthermore, the developed model showed an acceptable performance for predicting 1-year non-relapse mortality with an area under the curve of 0.715. @*Conclusion@#The newly developed predictive scoring system could be a simple and reliable tool helping clinicians to assess risk of alloSCT in adults with acute leukemia.

The clinical, laboratory, and radiologic improvement due to siltuximab treatment in idiopathic multicentric Castleman’s disease

Background/Aims@#Idiopathic multicentric Castleman disease (iMCD) comprises approximately 30% of all cases of Castleman disease. It is characterized by constitutional symptoms, enlarged lymph nodes at multiple anatomical sites, and laboratory test abnormalities, which are primarily related to the overproduction of interleukin 6 (IL-6). Siltuximab is a human-mouse chimeric immunoglobulin G1κ monoclonal antibody against human IL-6. In view of the limited treatment options for iMCD, this study aimed to evaluate the efficacy and safety of siltuximab in the management of this condition. @*Methods@#In this real-world retrospective study, we administered siltuximab to 15 patients with iMCD who previously received conventional chemotherapy and/or steroid pulse therapy. The median time to a durable symptomatic response was 22 days (range, 17 to 56). The serum hemoglobin and albumin levels and erythrocyte sedimentation rates significantly normalized after the first 3 months of siltuximab treatment. Lymph node involution, assessed using imaging, was relatively gradual, demonstrating a complete or partial response at 6 months. @*Results@#On an average, the improvements in clinical, laboratory, and radiologic parameters of iMCD in responders were observed after one, three, and eight cycles of siltuximab treatment, respectively. Siltuximab demonstrated a favorable safety profile, and prolonged treatment was well-tolerated. @*Conclusions@#Despite the small sample size of the present study, the results are encouraging and demonstrate the potential of siltuximab as the first-line treatment of iMCD. Further large multicenter studies are needed to evaluate the clinical outcomes and adverse events associated with siltuximab.

Treatment outcome and prognostic factors of Korean patients with chronic lymphocytic leukemia: a multicenter retrospective study

Background/Aims@#Compared with Western countries, chronic lymphocytic leukemia (CLL) rarely occurs in Asia and has different clinical characteristics. Thus, we aimed to evaluate the clinical characteristics, treatment outcomes, and prognostic significance of Korean patients with CLL. @*Methods@#We retrospectively analyzed 90 patients with CLL who had received chemotherapy at 6 centers in Korea between 2000 and 2012. @*Results@#Compared with Western patients with CLL, Korean patients with CLL express lambda (42.0%) and atypical markers such as CD22 and FMC7 (76.7% and 40.0%, respectively) more frequently. First-line chemotherapy regimens included chlorambucil (n = 43), fludarabine and cyclophosphamide (FC) (n = 20), fludarabine (n = 13), rituximab-FC (n = 4). The remaining patients were treated with other various regimens (n = 10). The 5-year overall survival (OS) and progression-free survival (PFS) rates were 79.3% and 28.1%, respectively. Multivariate analyses showed that hyperleukocytosis (≥ 100 × 103/μL), extranodal involvement, and the Binet C stage were significant negative prognostic factors for OS (hazard ratio [HR] 4.75, p = 0.039; HR 21.6, p = 0.002; and HR 4.35, p = 0.034, respectively). Cytogenetic abnormalities including complex karyotypes (≥ 3), del(11q), and del(17) had a significantly adverse impact on both OS and PFS (p < 0.001 and p = 0.010, respectively). @*Conclusions@#Initial hyperleukocytosis, extranodal involvement, complex karyotype, del(17) and del(11q) need to be considered in the risk stratification system for CLL.

Development and validation of a comorbidity index for predicting survival outcomes after allogeneic stem cell transplantation in adult patients with acute leukemia: a Korean nationwide cohort study

Background@#Allogeneic hematopoietic stem cell transplantation (alloSCT) is a potentially curative treatment option for acute leukemia. We aimed to identify the comorbidity factors affecting survival outcomes after alloSCT and develop a new comorbidity index tool for predicting overall survival (OS). @*Methods@#A Korean nationwide cohort of 3,809 adults with acute leukemia treated with alloSCT between January 2002 and December 2018 was analyzed as the development cohort.A retrospective cohort comprising 313 consecutive adults with acute leukemia who underwent alloSCT between January 2019 and April 2020 was analyzed as the validation cohort. @*Results@#In the development cohort, advanced age, male sex, and comorbidities such as previous non-hematologic malignancy, hypertension, and coronary or cerebral vascular disease were significantly related to poor OS. Subsequently, a new comorbidity scoring system was developed, and risk groups were created, which included the low-risk (score ≤0.17), intermediate-risk (0.17＜ score ≤0.4), high-risk (0.4＜ score ≤0.55), and very high-risk (score ＞0.55) groups. The 1-year OS rates were discriminatively estimated at 73.5%, 66.2%, 61.9%, and 50.9% in the low-risk, intermediate-risk, high-risk, and very high-risk groups in the development cohort, respectively (P ＜0.001). The developed scoring system yielded discriminatively different 1-year OS rates and 1-year incidence of non-relapse mortality according to the risk group (P =0.085 and P =0.018, respectively).Furthermore, the developed model showed an acceptable performance for predicting 1-year non-relapse mortality with an area under the curve of 0.715. @*Conclusion@#The newly developed predictive scoring system could be a simple and reliable tool helping clinicians to assess risk of alloSCT in adults with acute leukemia.

Clinical impact of anti-thymocyte globulin on survival and graft-versus-host disease in patients undergoing human leukocyte antigen mismatched allogeneic stem cell transplantation

Background/Aims@#Rabbit anti-thymocyte globulin (ATG) is usually incorporated in hematopoietic stem cell transplantation (HSCT) to reduce the incidence of graft-versus-host disease (GVHD). This study aimed to find optimal ATG doses in patients undergoing human leukocyte antigen (HLA)-mismatched allogeneic HSCT. @*Methods@#We retrospectively collected medical records from 352 consecutive patients with acute myeloid leukemia (n = 214), acute lymphoblastic leukemia (n = 62), or myelodysplastic syndrome (n = 76) in eight centers of Korea between 2005 and 2015. All patients received busulfan-based conditioning without total body irradiation (TBI) and received stem cells from HLA-mismatched donors. @*Results@#In the current study, 5-year overall survival rates of patients receiving low to medium doses of ATG (2.5 to 7.5 mg/kg) were higher than those receiving other doses of ATG (hazard ratio [HR], 0.528; 95% confidence interval [CI], 0.311 to 0.897; p = 0.018). The incidence rates of extensive chronic GVHD (ecGVHD) after administration of low to medium doses of ATG were lower than those after other doses of ATG (HR, 0.447; 95% CI, 0.224 ton 0.889; p = 0.022). @*Conclusions@#The low to medium doses of ATG may be associated with improving survival outcomes and reducing incidence of ecGVHD without enhancing the chances of relapse in patients with acute leukemia or myelodysplastic syndrome undergoing non-TBI-based HLA-mismatched allogeneic HSCT.

New agents in acute myeloid leukemia (AML)

Despite expanding knowledge in the molecular landscape of acute myeloid leukemia (AML) and an increasing understanding of leukemogenic pathways, little has changed in the treatment of AML in the last 40 years. Since introduction in the 1970s, combination chemotherapy consisting of anthracycline and cytarabine has been the mainstay of treatment, with major therapeutic advances based on improving supportive care rather than the introduction of novel therapeutics. Over the last decades, there have been extensive efforts to identify specific target mutations or pathways with the aim of improving clinical outcomes. Finally, after a prolonged wait, we are witnessing the next wave of AML treatment, characterized by a more “precise” and “personalized” understanding of the unique molecular or genetic mapping of individual patients. This new trend has since been further facilitated, with four new FDA approvals granted in 2017 in AML therapeutics. Currently, a total of eight targeted agents have been approved since 2017 (as of Jan. 2020). In this review, we will briefly discuss these newer agents in the context of their indication and the basis of their approval.

Predictive Role of Circulating Immune Cell Subtypes Early after Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acute Leukemia

BACKGROUND AND OBJECTIVES: Cells of innate immunity normally recover in the first weeks to months after allogenenic hematopoietic stem cell transplantation (allo-HSCT). Their relevance in terms of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect is largely unknown. The predictive role of early recovery in the immune cells on acute GVHD and GVL effect after allo-HSCT was investigated in patients with acute leukemia who achieved the first complete remission. METHODS: Peripheral blood samples were taken at the median of 14 days (range, 12~29 days) after allo-HSCT. A cohort including 119 samples and characteristics of patients were analyzed. Immune cell populations were identified by flow cytometry. RESULTS: The median age was 49.0 years (range, 21~69) at transplantation. Univariate analysis showed that age less than 40 years old, lower frequencies of CD8+ T cells, invariant natural killer T (iNKT) cells, monocytic myeloid derived suppressor cells (M-MDSCs) and higher frequency of immature MDSCs were associated with occurrence of grade III–IV acute GVHD. Multivariate analyses showed that iNKT cells (hazard ratio (HR), 0.453, 95% CI, 0.091~0.844, p=0.024) and M-MDSCs (HR, 0.271, 95% CI, 0.078~0.937, p=0.039) were independent factors. Combination of higher frequencies of both cell subsets was associated with lower incidence of grade III–IV acute GVHD, whereas patients with lower frequency of iNKT cells and higher frequency of M-MDSCs showed significant higher probability of relapse. CONCLUSIONS: iNKT cells and M-MDSCs could be relevant cell biomarkers for predicting acute GVHD and/or relapse in acute leukemia patients treated with allo-HSCT.

Enhanced polo-like kinase 1 expression in myelodysplastic syndromes

BACKGROUND: Cancer is characterized by uncontrolled cellular proliferation, and Polo-like kinase 1 (PLK1), a key regulator of the cell cycle, is overexpressed in many cancers, including acute leukemia and lymphoma. However, the dynamics of PLK1 transcription in myelodysplastic syndromes (MDS) are unknown. This study aimed to investigate the transcript dynamics of PLK1 and determine its role in the pathophysiology of MDS. METHODS: PLK1 mRNA obtained from the bone marrow samples of 67 patients with MDS, 16 patients with secondary acute myeloid leukemia (sAML), and 10 healthy controls were analyzed using quantitative real-time PCR and compared according to various clinical parameters. RESULTS: The median PLK1 expression levels differed slightly, but not significantly, between MDS and sAML patients [661.21 (range, 29.38–8,987.31) vs. 1,462.05 (32.22–5,734.09), respectively], but were significantly higher (P<0.001) than the levels in the healthy controls [19.0 (1.60–49.90)]. Further analyses of PLK1 levels according to the WHO classification of MDS, prognostic risk groups, karyotype risk groups, marrow blast percentage, and depth of cytopenia did not reveal any significant associations. In patients progressing to sAML, PLK1 expression levels differed significantly according to the presence or absence of resistance to hypomethylation treatment (2,470.58 vs. 415.98, P=0.03). CONCLUSION: PLK1 is upregulated in MDS patients; however, its role in the pathophysiology of MDS is unclear. Gene upregulation in cases with pharmacotherapeutic resistance warrants further investigation.

Comparison of quality of life and depression between hematopoietic stem cell transplantation survivors and their spouse caregivers

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is an exhausting process that impacts both the patient and caregiver. METHODS: This was a cross-sectional, HSCT survivor-spouse caregiver matching study to determine quality of life (QoL) and depression among HSCT survivors and their caregivers. QoL and depression were measured with the World Health Organization Quality of Life: Brief Version (26 items) and the 9-item Patient Health Questionnaire, respectively. Data from 97 married couples were analyzed. RESULTS: There were no significant differences in overall QoL and psychological, social, and environmental health between survivors and spouse caregivers (P=0.345, 0.424, 0.415, and 0.253); however, physical QoL was better in the spouse caregiver group (P=0.011). There was no difference in mean depression scale scores (5.3 vs. 5.1, P=0.812) or proportion of severe depression (15.6% vs. 13.7%, P=0.270) between the two groups. We found that family income had a significant impact on overall QoL and environmental health among spouse caregivers (P=0.013 and 0.023), and female gender, co-morbidities, and family income were the important factors associated with depression among spouse caregivers (P=0.007, 0.017 and 0.049). CONCLUSION: This study found that there were no significant differences in QoL or level of depression between HSCT survivors and their spouse caregivers. Family income, gender, and co-morbidities showed significant association with spouse caregiver distress.

Poor Prognostic Implication of ASXL1 Mutations in Korean Patients With Chronic Myelomonocytic Leukemia

BACKGROUND: Molecular genetic abnormalities are observed in over 90% of chronic myelomonocytic leukemia (CMML) cases. Recently, several studies have demonstrated the negative prognostic impact of ASXL1 mutations in CMML patients. We evaluated the prognostic impact of ASXL1 mutations and compared five CMML prognostic models in Korean patients with CMML. METHODS: We analyzed data from 36 of 57 patients diagnosed as having CMML from January 2000 to March 2016. ASXL1 mutation analysis was performed by direct sequencing, and the clinical and laboratory features of patients were compared according to ASXL1 mutation status. RESULTS: ASXL1 mutations were detected in 18 patients (50%). There were no significant differences between the clinical and laboratory characteristics of ASXL1-mutated (ASXL1+) CMML and ASXL1-nonmutated (ASXL1−) CMML patients (all P>0.05). During the median follow-up of 14 months (range, 0–111 months), the overall survival (OS) of ASXL1+ CMML patients was significantly inferior to that of ASXL1− CMML patients with a median survival of 11 months and 19 months, respectively (log-rank P=0.049). An evaluation of OS according to the prognostic models demonstrated inferior survival in patients with a higher risk category according to the Mayo molecular model (log-rank P=0.001); the other scoring systems did not demonstrate a significant association with survival. CONCLUSIONS: We demonstrated that ASXL1 mutations, occurring in half of the Korean CMML patients examined, were associated with inferior survival. ASXL1 mutation status needs to be determined for risk stratification in CMML.

Establishment and operation of a cooperative program to identify work-related acute myeloid leukemia in a general hospital

BACKGROUND@#The purpose of this report is to introduce the occupational cancer surveillance system, implemented in June 2018, and to share the results of our cooperative program.@*METHODS@#The cooperative program begins when the patient is diagnosed with acute myeloid leukemia (AML). Newly diagnosed AML patients are admitted to the internal medicine hematology department, then attending hematology physician requests a consultation from the occupational and environmental medicine (OEM) department. The OEM doctor next visits the hospitalized patient and interviews them to take their occupational history, and preliminarily evaluates the likelihood that the condition is associated with occupation. If the patient wants to apply for compensation through the Korea Workers' Compensation & Welfare Service, the patient was informed to visits the outpatient clinic of the OEM department and requests a ‘work-relatedness evaluation report’ for use in applying for compensation.@*RESULTS@#Among the 103 patients, who received an OEM departmental work history evaluation, 18 patients were considered to have a work-related incidence and 12 patients were registered in the Industrial Accident Compensation Insurance system.@*CONCLUSIONS@#The present report provides data on a sustainable model for identifying occupational disease in a general hospital setting, while also informing patients about their occupational rights.

First Case of Echinocandin-Resistant Candida albicans in Korea

No abstract available.

Chronic Myeloid Leukemia Relapsing as Isolated Extramedullary Disease Presenting as a Cardiac Mass / 대한내과학회지

Allogeneic hematopoietic stem cell transplantation is the only option for chemotherapy-refractory chronic myeloid leukemia (CML). Extramedullary relapse after transplantation is rare and usually accompanies marrow relapse. Generally, the prognosis of extramedullary relapse is poor. Here, we report a man with extramedullary relapsed CML after stem cell transplantation that presented as an isolated cardiac mass, which has shown an indolent course for more than 2 years, without evolving to medullary relapse during that period. This case implies that the CML clone might contribute to the development of quiescent extramedullary relapse with a benign course.

Myelodysplastic Syndrome (RAEB-II) Development 2 Months after Chemotherapy for a Primary Non-seminomatous Mediastinal Germ Cell Tumor / 대한내과학회지

Here, we report on a 20-year-old patient with a primary nonseminomatous mediastinal germ cell tumor (MGCT) who developed myelodysplastic syndrome (MDS) 2 months following chemotherapy with cisplatin, etoposide, ifosfamide, and paclitaxel. Bone marrow examinations revealed that the MDS was a refractory anemia with excess type II blasts and complex chromosomal abnormalities. With the onset of MDS occurring rapidly following chemotherapy, it is unlikely to have been caused by the therapy. We discuss the association between primary nonseminomatous MGCTs and hematological malignancies, including the possibility of a common clonal origin.

Clinical Significance of Non-neutropenic Fever in the Management of Diffuse Large B-Cell Lymphoma Patients Treated with Rituximab-CHOP: Comparison with Febrile Neutropenia and Risk Factor Analysis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard chemotherapy in diffuse large B-cell lymphoma (DLBCL) patients. Although febrile neutropenia (FN) is the major toxicity of this regimen, non-neutropenic fever (NNF) becomes an emerging issue. MATERIALS AND METHODS: We analyzed clinical features and outcomes of febrile complications from 397 patients with newly diagnosed DLBCL who were registered in the prospective cohort study. They had completed R-CHOP between September 2008 and January 2013. RESULTS: Thirty-nine patients (9.8%) had NNF whereas 160 patients (40.3%) had FN. Among them, 24 patients (6.0%) had both during their treatment. Compared to frequent occurrence of initial FN after the first cycle (> 50% of total events), more than 80% of NNF cases occurred after the third cycle. Interstitial pneumonitis comprised the highest proportion of NNF cases (54.8%), although the causative organism was not identified in the majority of cases. Thus, pathogen was identified in a limited number of patients (n=9), and Pneumocystis jiroveci pneumonia (PJP) was the most common. Considering that interstitial pneumonitis without documented pathogen could be clinically diagnosed with PJP, the overall rate of PJP including probable cases was 4.5% (18 cases from 397 patients). The NNF-related mortality rate was 10.3% (four deaths from 39 patients with NNF) while the FN-related mortality rate was only 1.3%. CONCLUSION: NNF was observed with incidence of 10% during R-CHOP treatment, and showed different clinical manifestations with respect to the time of initial episode and causes.

Intra-tumoral Metastatic Double Primary Carcinoma: Synchronous Metastatic Tumor in Lung from Breast and Thyroid Carcinoma / Journal of the Korean Cancer Association, 대한암학회지

Cases of phenotypic heterogeneity of cells within tumors have recently been reported. Here, we report on a patient with characteristic intra-tumor double primary metastases in the lung. This patient was a 40-year-old Korean woman who had been diagnosed with breast cancer (T1N0M0, estrogen receptor/progesterone receptor/HER2 +/+/+) and papillary thyroid cancer three years prior and underwent a complete surgical resection followed by appropriate adjuvant treatment with radiation, hormone, and radioactive iodine. She was recently admitted for newly developed pulmonary nodules. Metastasectomy through video-assisted thoracoscopic surgery revealed recurrent double primary cancer with two different components (metastatic ductal carcinomas from the breast and metastatic papillary carcinomas from the thyroid gland) in each pulmonary nodule in the right upper lobe and right middle lobe. To the best of our knowledge, this is the first report of simultaneous recurrent double metastasis in one organ from different primary origins.

Nomogram to Predict Treatment Outcome of Fluoropyrimidine/Platinum-Based Chemotherapy in Metastatic Esophageal Squamous Cell Carcinoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The degree of benefit from palliative chemotherapy differs widely among patients with metastatic esophageal squamous cell carcinoma (MESCC). The purpose of this study was to develop and validate a prognostic nomogram to predict survival and aid physicians and patients in the decision-making process regarding treatment options. MATERIALS AND METHODS: Clinicopathologic variables and treatment outcomes of 239 patients who were diagnosed with MESCC and received either fluorouracil/cisplatin (FP) or capecitabine/cisplatin (XP) as first-line chemotherapy were reviewed. A nomogram was developed as a prognostic scoring system incorporating significant clinical and laboratory variables based on a multivariate Cox proportional hazards regression model. An independent series of 61 MESCC patients treated with FP served as an independent data set for nomogram validation. RESULTS: No difference in response rate was observed between the FP group (44.8%) and the XP group (54.2%). Similarly, no significant differences in median progression-free survival and median overall survival were observed between regimen groups. Multivariate analysis showed that poor performance status (Eastern Cooperative Oncology Group [ECOG] status> or =2), weight loss (10% of the weight loss for 3 months), low albumin level (135) prognostic groups. The median survival for those with a favorable ECOG was 13.8 months (95% confidence interval [CI], 10.8 to 18.6 months), for intermediate 11.2 months (95% CI, 8.7 to 11.9 months), and for poor, 7.0 months (95% CI, 3.6 to 10.0 months). External validation of the nomogram in a different patient cohort yielded significantly similar findings. CONCLUSION: The nomogram described here predicts survival in MESCC patients and could serve as a guide for the use of FP/XP chemotherapy in MESCC patients.

A Case of Endovascular Stent Grafting for an Aortoesophageal Fistula / 대한내과학회지

An aortoesophageal fistula is a rare cause of upper gastrointestinal bleeding. The standard treatment of an aortoesophageal fistula is surgical, because conservative management results in very high mortality. Nevertheless, the mortality related to the surgical treatment ranges from 30 to 60%. Recently, endovascular stent grafting has become an alternative to open surgery in selected patients. We report an aortoesophageal fistula treated with endovascular stent grafting in an 84-year-old female with hematemesis and abdominal pain. Endoscopy showed a 5-cm pulsating esophageal mass with central ulceration and bleeding. Computed tomography (CT) of the abdomen revealed a descending thoracic aortic pseudoaneurysm. Being at high risk in open thoracic surgery, she underwent endovascular stenting. We suggest that endovascular stent grafting is an alternative treatment of aortoesophageal fistula, instead of open surgery, in selected patients.

Implications of Bone-Only Metastases in Breast Cancer: Favorable Preference with Excellent Outcomes of Hormone Receptor Positive Breast Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The aim of the current study was to determine the incidence, clinical presentation, and treatment outcomes of "bone-only metastases" in patients with breast cancer and to analyze the impact of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status on prognosis. MATERIALS AND METHODS: Between 1994 and 2007, of 968 patients with metastatic breast cancer who underwent palliative management at Samsung Medical Center, 565 (57%) relapsed with distant metastases. Of the 968, 146 (15%) had bone-only metastases during a median follow-up period of 75 months. Among the 146 patients with bone-only metastases, 122 (84%) were relapsed patients after curative surgery and 24 (26%) were initially metastatic cases. RESULTS: The median time from primary surgery to bone-only metastases of the 122 patients was 37 months (95% confidence interval [CI], 27 to 46 months). Bone-only metastases were more common in the HR-positive group than in the other subtypes (85% for HR+; 8.2% for HER2+; 6.8% for triple negative. Among all 146 patients, 75 (51%) were treated with hormone therapy. The median post-relapse progression-free survival was 15 months (95%CI, 13 to 17 months). The median overall survival was much longer in the HR+ patients than the HER2+ and triple negative breast cancer patients with marginal statistical significance (65 vs. 40 vs. 40 months, p=0.077). CONCLUSION: Breast cancer patients with "bone-only metastases" had excellent clinical outcomes. Further study is now warranted to reveal the underlying biology that regulates the behavior of this indolent tumor, as it should identify 'favorable tumor characteristics' in addition to 'favorable preferential metastatic site.'

Evidence-based healthcare and the need of conditional decision

The decision making for reimbursement has become more difficult than before because of the high cost innovative new technologies and limitation of healthcare resources. Evidence-based healthcare system has been introduced in Korea since 2007. Not infrequently, however, decision makers have been confronted with uncertainties caused by lack of information related to comparative effectiveness, real world outcomes, off-label drug use, combination therapy and cost-effectiveness. Under these circumstances, the decision making of whether or not to reimburse is inadequate because undesirable results may be induced. Managed entry agreement has been introduced globally. This kind of decision is conditional and linked with monitoring and following the results and adjusting the policy according to the results. Especially access with evidence development is a form of prospective data correction with conditional coverage in the case of existing uncertainties of effectiveness and safety. In Korea, there have been several examples including off-label drug use in oncologic drugs, new healthcare intervention and re-evaluation of existing drugs. Even though there has been some conflict and confusion because of inadequate systematization, it is strongly recommended to establish the conditional decision making system in Korea since this is a unique answer to manage the uncertainty in maintaining development of health science, keeping patients' right and using healthcare resources rationally.