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Introduction: We aimed to identify the role of radiotherapy (RT) in the treatment of thymic carcinoma as well as the optimal RT target volume. Materials and Methods: This single-institution retrospective study included 116 patients diagnosed with thymic carcinoma between November 2006 and December 2021 who received multimodal treatment including RT with or without surgery or chemotherapy. Seventy-nine patients (68.1%) were treated with postoperative RT, 17 patients (14.7%) with preoperative RT, 11 patients (9.5%) with definitive RT, and nine patients (7.8%) with palliative RT. The target volume was defined as the tumor bed or gross tumor with margin, and selective irradiation of the regional nodal area was performed when involved. Results: With a median follow-up of 37.0 (range, 6.7–174.3) months, the 5-year overall survival (OS), progression-free survival, and local recurrence-free survival rates were 75.2%, 47.7% and 94.7%, respectively. The 5-year OS was 51.9% in patients with unresectable disease. Overall, 53 recurrences were observed, of which distant metastasis was the most common pattern of failure (n = 32, 60.4%) after RT. No isolated infield or marginal failures were observed. Thirty patients (25.8%) who had lymph node metastases at the initial diagnosis had regional nodal areas irradiated. There was no lymph node failure inside the RT field. A tumor dimension of ≥5.7 cm (hazard ratio [HR] 3.01; 95% confidence interval [CI] 1.25–7.26; p = 0.030) and postoperative RT (HR 0.20; 95% CI 0.08–0.52; p = 0.001) were independently associated with OS. Intensity-modulated-RT-treated patients developed less overall toxicity (p < 0.001) and esophagitis (p < 0.021) than three-dimensional-conformal-RT-treated patients. Conclusions: A high local control rate was achieved with RT in the primary tumor sites and involved lymph node area in the treatment of thymic carcinoma. A target volume confined to the tumor bed or gross tumor plus margin with the involved lymph node stations seems reasonable. The advanced RT techniques with intensity-modulated RT have led to reduced RT-related toxicity.

Background The benefits of mediastinal lymph node dissection (MLND) in colorectal cancer‐related pulmonary metastasectomy (PM) have been poorly reported. This study aimed to determine whether MLND affects survival in patients undergoing PM and to identify the prognostic factors for survival. Methods We retrospectively reviewed 275 patients who had undergone colorectal cancer‐related PM from January 2010 to December 2016. MLND was defined as the resection of at least six mediastinal lymph node stations according to the International Association for the Study of Lung Cancer criteria (N1, ≥3 stations; N2, ≥3 stations). The propensity score matching method was used to reduce bias. Results Thirty‐three (12%) patients underwent MLND, and 13 (4.7%) patients had mediastinal lymph node involvement. This study showed no difference in 5‐year overall survival (no MLND, 52.7% vs. MLND, 53.5%; p = 0.81). On multivariable analysis, negative prognostic factors for overall survival were preoperative carcinoembryonic antigen (CEA) level (p

To assess the effect of local ablative therapy (LAT) on overall survival in patients with lung metastases from colorectal cancer (CRC) compared with patients treated with systemic therapy.CRC affects approximately 1.4 million individuals worldwide every year. The lungs are commonly affected by CRC, and there is no treatment standard for a secondary lung metastasis from CRC.This longitudinal, retrospective cohort study (2010-2018) quantified the pulmonary and extrapulmonary tumor burden of 1143 patients by retrospectively reviewing computed tomography images captured at diagnosis. A comprehensive multidisciplinary approach informed how and when surgery and/or stereotactic body radiotherapy was administered.Among 1143 patients, 473 patients (41%) received LAT, with surgery first (n = 421) or stereotactic ablative radiation therapy first (n = 52) either at the time of diagnosis (n = 288), within 1 year (n = 132), or after 1 year (n = 53). LAT was repeated in 158 patients (33.4%, 384 total sessions) when new lung metastases were detected. The 5- and 10-year survival rates for patients treated with LAT (71.2% and 64.0%, respectively) were significantly higher than those of patients treated with systemic therapy alone (14.2% and 10.0%, respectively; P0.001). The overall survival of patients who received LAT intervention increased as the total tumor burden decreased.A high long-term survival rate was achievable in a significant portion of patients with lung metastasis from CRC by the timely administrations of LAT to standard systemic therapy. The tumor burden and LAT feasibility should be included in a discussion during the follow-up period.

We aimed to measure the validity of the International Association for the Study of Lung Cancer (IASLC) grading system in Korean patients and propose a modification for an increase of its predictability, especially in grade 2 patients.From 2012 to 2017, histopathologic characteristics of 1358 patients with invasive pulmonary adenocarcinoma (stage I-III) from two institutions were retrospectively reviewed and re-classified according to the IASLC grading system. Considering the amount of the lepidic proportion, the validity of the revised model (Lepidic-10), derived from the training cohort (hospital A), was measured using the validation cohort (hospital B). Its predictability was compared to that of the IASLC system.Of the 1358 patients, 259 had a recurrence, and 189 died during follow-up. The Harrell's concordance index and area under the curve of the IASLC system were 0.685 and 0.699 for recurrence-free survival (RFS) and 0.669 and 0.679 for death, respectively. From the training cohort, the IASLC grade 2 patients were divided into grades 2a and 2b (Lepidic-10 model) with a 10 % lepidic pattern. This new model further distinguished patients in both institutions that had better performance than the IASLC grading (Hospital A, p 0.001 for RFS and death; Hospital B, p = 0.0215 for RFS, p = 0.0429 for death).The IASLC grading system was easily applicable; its clinical use in predicting the prognosis of Korean patients with pulmonary adenocarcinoma was validated. Furthermore, the introduction of the lepidic proportion as an additional criterion to differentiate grade 2 patients improved its predictability.

Purpose This multi-center, retrospective study was conducted to evaluate the long-term survival in patients who underwent surgical resection for small cell lung cancer (SCLC) and to identify the benefit of adjuvant therapy following surgery.Materials and Methods The data of 213 patients who underwent surgical resection for SCLC at four institutions were retrospectively reviewed. Patients who received neoadjuvant therapy or an incomplete resection were excluded.Results The mean patient age was 65.29±8.93 years, and 184 patients (86.4%) were male. Lobectomies and pneumonectomies were performed in 173 patients (81.2%), and 198 (93%) underwent systematic mediastinal lymph node dissections. Overall, 170 patients (79.8%) underwent adjuvant chemotherapy, 42 (19.7%) underwent radiotherapy to the mediastinum, and 23 (10.8%) underwent prophylactic cranial irradiation. The median follow-up period was 31.08 months (interquartile range, 13.79 to 64.52 months). The 5-year overall survival (OS) and disease-free survival were 53.4% and 46.9%, respectively. The 5-year OS significantly improved after adjuvant chemotherapy in all patients (57.4% vs. 40.3%, p=0.007), and the survival benefit of adjuvant chemotherapy was significant in patients with negative node pathology (70.8% vs. 39.7%, p=0.004). Adjuvant radiotherapy did not affect the 5-year OS (54.6% vs. 48.5%, p=0.458). Age (hazard ratio [HR], 1.032; p=0.017), node metastasis (HR, 2.190; p < 0.001), and adjuvant chemotherapy (HR, 0.558; p=0.019) were associated with OS.Conclusion Adjuvant chemotherapy after surgical resection in patients with SCLC improved the OS, though adjuvant radiotherapy to the mediastinum did not improve the survival or decrease the locoregional recurrence rate.

Skeletonizing en bloc esophagectomy (SEBE) involves the removal of the esophagus en bloc with locoregional soft tissues and lymph nodes, including the thoracic duct (TD); however, its oncologic benefits remain unclear. We evaluated the impact of SEBE on oncologic outcomes in patients with esophageal squamous cell carcinoma.Patients undergoing McKeown esophagectomy without neoadjuvant therapy between 2013 and 2019 were evaluated. Outcomes after SEBE were compared with those after conventional esophagectomy (CE) using propensity score-matched analysis.Overall, 232 patients were identified, including 133 patients with SEBE and 99 patients with CE. Lymph node metastasis along the TD was identified in 7.5% (10/133) of the SEBE group, and the incidence was closely related with the tumor invasion depth (2.2% in pT1 and 19.0% in pT2-3). Based on the propensity score, 180 patients (90 pairs) were analyzed. Tumor recurrence was identified in 24.4% and 12.2% of CE and SEBE cases, respectively (p = 0.036). The observed difference was due to the higher incidence of locoregional recurrence in CE (10.5% vs. 2.2%; p = 0.024), while the incidence of systemic recurrence was similar (18.6% vs. 12.2%; p = 0.240). The 5-year disease-free survival rate was 83.6% and 62.4% in the SEBE and CE groups, respectively (p = 0.022). Multivariate analysis revealed that SEBE could significantly reduce the risk of recurrence or death in patients with pT2-3 tumors (hazard ratio 0.173, 95% confidence interval 0.048-0.628; p = 0.008).SEBE could identify and eradicate lymphatic metastasis along the TD and positively impact disease-free survival, particularly in patients with pT2-3 tumors.

Introduction The International Association for the Study of Lung Cancer recently proposed a new N descriptor by combining the location of metastatic lymph nodes (LNs), nN (single-station versus multiple-station), and absence versus presence of skip metastasis as pN1a, pN1b, pN2a1, pN2a2 and pN2b. This study aimed to evaluate the discriminatory ability and prognostic performance of the proposed N descriptor in a large independent NSCLC cohort. Methods We analyzed 1228 patients who underwent major pulmonary resection for pathological N1 or N2 NSCLC between 2004 and 2014. Survival analysis using the Cox proportional hazard model was performed to assess the prognostic significance of the N descriptor. Results From 2004 to 2014, a total of 7437 patients were operated on for NSCLC. Patients pathologically confirmed as having N1 (n = 732) or N2 (n = 496) disease after surgery were included. The median total number of dissected LNs was 24 (range 10–83), and the median number of involved LNs was 2 (range 1–40). The 5-year overall survival rates were 62.6%, 57.0%, 64.7%, 48.4%, and 42.8% for stages N1a, N1b, N2a1, N2a2, and N2b, respectively. Analysis of overall and recurrence-free survival revealed that N2a1 is not sufficiently distinguished from N1a and N1b. In terms of overall survival, N1b is not sufficiently distinguished from N2a2. Conclusion On the basis of the N descriptor proposed by the International Association for the Study of Lung Cancer, some of the prognostic implications of the five groups overlapped. It would be better to classify similar prognostic groups into three or four groups to divide the group. A large-scale prospective study is needed to validate these N descriptors.

Background Lung cancer has a poor prognosis; the number of long-term survivors (LTSs) is small compared with that of other cancers. Few studies have focused on late recurrence in LTSs with lung cancer. The purpose of this study was to analyze the risk factors for survival and late recurrence in LTSs after disease-free period of 5 years. Methods A retrospective analysis of patients with a disease-free survival of at least 5 years after surgical resection for non-small cell lung cancer (NSCLC) between January 1998 and December 2012 was conducted. Patients who underwent neo-adjuvant therapy, had an incomplete resection, or had advanced stage (stages IIIb and IV) cancer were excluded. Results A total of 1,254 (53.2%) of 2,357 patients were enrolled. Of these, 759 (60.5%) were men, and the mean patient age was 61.9±10.1 (range, 10-87 years) years. Pathologic N0 (997 patients, 79.5%) and stage I (860 patients, 68.6%) were the dominant stages. Late recurrence occurred in 22 patients (1.8%) 5 years postoperatively. On multivariate analysis, male sex, older age, node-positive status, and late recurrence were found to be independent risk factors for overall survival (OS), while a node-positive status was the only independent risk factor for disease-free survival [hazard ratio (HR) =3.824; P=0.002; 95% confidence interval (CI): 1.658-8.821]. Conclusions The nodal stage at the time of surgical resection was found to be an independent risk factor for both OS and disease-free survival 5 years after initial treatment in patients with completely resected NSCLC.

Simple Summary The efficacy of the local consolidative therapy in lung cancer has been reported previously, however, those studies described the utility of the radiation therapy rather than of surgery. Furthermore, those studies included either no or few patients with oncogene-driven NSCLC, which has distinct biological properties and treatment options. Surgery is the most reliable method of tumor removal that allows detailed examinations of resected tissue, such as comprehensive genetic analysis. This retrospective study for the first time reports the operative outcomes and the benefit of cytoreductive surgery in TKI-treated cases of oncogene-driven locally advanced or metastatic NSCLC in parallel with the genetic analysis of the tumor. Abstract Most patients with oncogene-driven advanced non-small cell lung cancer (NSCLC) demonstrate recurrence because of the developing targeted therapy resistance. In this retrospective study, we assessed the efficacy of surgical local consolidative treatment by analyzing the operative outcomes and genetic data in 44 patients who underwent pulmonary resection for stage IIIB/C–IV NSCLC after targeted therapy. The initial mutations were in the EGFR (n = 32), ALK (n = 11), and ROS1 (n = 1) genes. The median interval from the initiation of tyrosine kinase inhibitor (TKI) therapy immediately before the surgery to the actual operation was 9.8 months. Operative mortality was absent. Four patients showed complete remission. The median follow-up period after TKI therapy initiation was 23.1 months. The Kaplan–Meier survival analysis showed that the 2-year failure-free survival and overall survival rates from the initiation of TKI were 70.8% and 95.0%, respectively. During the follow-up period, two patients died and 15 suffered from disease progression. Among the 32 patients with EGFR mutations, 12 showed additional mutations, and targeted agents were replaced in nine patients after the operation. We conclude that pulmonary resection for advanced NSCLC after targeted therapy is feasible, and the surgical specimens could be used for planning further targeted therapy.

In this study, we report a novel function of FCN3 (Ficolin 3), a secreted lectin capable of activating the complement pathway, as a tumor suppressor of lung adenocarcinoma (LUAD). First, the expression of FCN3 was strongly down-regulated in cancer tissues compared to matched normal lung tissues, and down-regulation of FCN3 was shown to be significantly correlated with increased mortality among LUAD patients. Interestingly, while ectopic expression of FCN3 led to cell cycle arrest and apoptosis in A549 and H23 cells derived from LUAD, the secreted form of the protein had no effect on the cells. Rather, we found evidence indicating that activation of the unfolded protein response from endoplasmic reticulum (ER) stress is induced by ectopic expression of FCN3. Consistently, inhibition of ER stress response led to enhanced survival of the LUAD cells. Of note, the fibrinogen domain, which is not secreted, turned out to be both necessary and sufficient for induction of apoptosis when localized to ER, consistent with our proposed mechanism. Collectively, our data indicate that FCN3 is a tumor suppressor gene functioning through induction of ER stress.

Summary Exome and transcriptome analyses of clinically homogeneous early-stage never-smoker female patients with lung adenocarcinoma were performed to understand tumor-T cell interactions and immune escape points. Using our novel gene panels of eight functional categories in the cancer-immunity cycle, three distinct subgroups were identified in this immune checkpoint blockade-refractory cohort by defective gene expression in two major domains, i.e., type I interferon production/signaling pathway and antigen-presenting machinery. Our approach could play a critical role in understanding immune evasion mechanisms, developing a method for effective selection of rare immune checkpoint blockade responders, and finding new treatment strategies., Graphical Abstract, Highlights • GMM-based clustering of cancer-immune gene expression helps to find LUAD classifiers • Classifiers are found in the earlier-phased cancer-immunity cycle • Classifiers include ubiquitination, Ag-presenting machinery, and type I IFN signaling • Tumor-intrinsic classifiers strongly influence the outcome of cancer immunity, Immunology; Cancer Systems Biology; Genomics

In this study, we describe a novel function of TNNC1 (Troponin C1, Slow Skeletal and Cardiac Type), a component of actin-bound troponin, as a tumor suppressor of lung adenocarcinoma (LUAD). First, the expression of TNNC1 was strongly down-regulated in cancer tissues compared to matched normal lung tissues, and down-regulation of TNNC1 was shown to be strongly correlated with increased mortality among LUAD patients. Interestingly, TNNC1 expression was enhanced by suppression of KRAS, and ectopic expression of TNNC1 in turn inhibited KRAS G12D-mediated anchorage independent growth of NIH3T3 cells. Consistently, activation of KRAS pathway in LUAD patients was shown to be strongly correlated with down-regulation of TNNC1. In addition, ectopic expression of TNNC1 inhibited colony formation of multiple LUAD cell lines and induced DNA damage, cell cycle arrest and ultimately apoptosis. We further examined potential correlations between expression levels of TNNC1 and various clinical parameters and found that low-level expression is significantly associated with invasiveness of the tumor. Indeed, RNA interference-mediated down-regulation of TNNC1 led to significant enhancement of invasiveness in vitro. Collectively, our data indicate that TNNC1 has a novel function as a tumor suppressor and is targeted for down-regulation by KRAS pathway during the carcinogenesis of LUAD.

Objectives Understanding the timing and pattern of cancer recurrence is essential to explain the causes of treatment failure. We investigated the recurrence pattern and rate over time in patients with completely resected N1-stage II lung adenocarcinoma. Materials and methods We retrospectively reviewed the medical records of 333 patients who underwent complete surgical resection for N1-stage II lung adenocarcinoma. Results The median recurrence-free survival (RFS) was 38.8 months and the 5-year RFS rate was 39.6%. Left-sided tumors, large tumor size, and lymph node (LN) ratio higher than 0.15 were significantly correlated with a worse RFS, whereas female sex, direct LN involvement, and adjuvant chemotherapy were significantly correlated with a better RFS. Among the 182 patients who experienced recurrences, 46 (25.3%) had only loco-regional recurrences and 136 (74.7%) had distant metastases. The organs most commonly involved in initial recurrence were the lungs (n = 89, 48.9%), followed by bone (n = 41, 22.5%) and the brain (n = 38, 20.9%). The recurrence hazard curve for the entire study population demonstrated a similarly shaped and sized initial and second peak at 15 and 23 months, and a third smaller peak during the fourth year. The recurrence hazard curve of patients who received adjuvant chemotherapy exhibited a more delayed and smaller first peak than those who did not receive adjuvant chemotherapy. The patients treated with adjuvant chemotherapy had a lower rate of distant metastasis (p = 0.037); adjuvant chemotherapy had no effect on brain metastasis (p = 0.640). Conclusion In the present cohort, the hazard curves suggested that bone and brain recurrences exhibited an earlier first peak, while lung recurrences presented later. Adjuvant chemotherapy not only reduced the recurrence hazard but also delayed the recurrence and altered the pattern of recurrence. However, these results need to be confirmed in a prospective study.

Background: The progress of mild ischemic mitral regurgitation (MR) after isolated coronary artery bypass is not clear. We aimed to determine the proportion of patients with mild ischemic MR undergoing isolated coronary artery bypass grafting (CABG) presenting with regression of or persistent MR one year after CABG and to identify the significantly different echocardiographic variables between regressing and persistent MR. Methods: Sixty-three patients with preoperative mild ischemic MR were categorized into an MR-regression or an MR-persistence group one year after isolated CABG. The echocardiographic indices, indicating mitral leaflet configuration and remodeling of the left ventricle (LV), were measured before and one year after the surgery. Results: One year after CABG, MR regressed in 60% (38/63) and persisted in 40% (25/63) of the patients. The left ventricular diameter, volume, and sphericity and anteroposterior diameter of the mitral annulus improved only in the MR-regression group, while the ejection fraction improved in both groups (47.7% ± 12.4% from 40.1% ± 11.3%, P < .001 in the regression group and 43.2% ± 14.0% from 39.3% ± 11.6%, P = .035 in the persistence group). A >15% decrease in the LV end-systolic volume was noted more frequently in the MR-regression group (60.5% versus 30%, P = .027). The leaflet angle did not show asymmetry or significant changes in both groups. Conclusions: Isolated CABG improved mild MR in most patients with mild ischemic MR. These patients showed greater reverse remodeling after revascularization than the patients with persistent MR after isolated CABG. Additional tests, which can predict LV reverse remodeling, are needed to predict persistent MR.

In patients with locally advanced (N2) non-small cell lung cancer (NSCLC), surgery alone results in dismal prognosis despite of its localized presentation by definition (1). As most locally advanced lung cancers are large and centrally located, extensive resection is expected for complete tumor removal. The incidence of postoperative complications is generally high, and functional impairments are often encountered after extensive surgery.

Tracheal agenesis is an extremely rare and typically lethal congenital disorder. Approximately 150 cases have been described since 1900, and very few cases of survival have been reported. We describe tracheal reconstruction with external esophageal stenting in a patient with Floyd’s type II tracheal agenesis. Neither long-term survival nor survival without mechanical ventilation for even a single day has previously been reported in patients with Floyd’s type II tracheal agenesis. The infant in the present case survived for almost a year and breathed without a ventilator for approximately 50 days after airway reconstruction using external supportive stents.

Amyloid deposits in the heart are not exceptional in systemic amyloidosis. The clinical manifestations of cardiac amyloidosis may include restrictive cardiomyopathy, characterized by progressive diastolic and eventually systolic bi-ventricular dysfunction; arrhythmia; and conduction defects. To the best of our knowledge, no previous cases of isolated tricuspid regurgitation as the initial manifestation of cardiac amyloidosis have been reported. We describe a rare case of cardiac amyloidosis that initially presented with severe tricuspid regurgitation in a 42-year-old woman who was successfully treated with tricuspid valve replacement. Unusual surgical findings prompted additional evaluation that established a diagnosis of plasma cell myeloma.

Background: Patients on dialysis undergoing surgery belong to a high-risk group. Only a few studies have evaluated the outcome of major thoracic surgical procedures in dialysis patients. We evaluated the outcomes of pulmonary resection for non-small cell lung cancer (NSCLC) in patients on hemodialysis (HD). Methods: Between 2008 and 2013, seven patients on HD underwent pulmonary resection for NSCLC at our institution. We retrospectively reviewed their surgical outcomes and prognoses. Results: The median duration of HD before surgery was 55.0 months. Five patients underwent lobectomy and two patients underwent wedge resection. Postoperative morbidity occurred in three patients, including pulmonary edema combined with pneumonia, cerebral infarction, and delirium. There were no instances of in-hospital mortality, although one patient died of intracranial bleeding 15 days after discharge. During follow-up, three patients (one patient with pathologic stage IIB NSCLC and two patients with pathologic stage IIIA NSCLC) experienced recurrence and died as a result of the progression of the cancer, while the remaining three patients (with pathologic stage I NSCLC) are alive with no evidence of disease. Conclusion: Surgery for NSCLC in HD patients can be performed with acceptable perioperative morbidity. Good medium-term survival in patients with pathologic stage I NSCLC can also be expected. Pulmonary resection seems to be the proper treatment option for dialysis patients with stage I NSCLC.

Introduction We investigated the timing and patterns of recurrence after the treatment of stage IIIA (N2) non-small cell lung cancer via neoadjuvant concurrent chemoradiotherapy followed by surgery. Materials and methods An institutional database was reviewed retrospectively between 1997 and 2013 (N = 570). Eligible patients had pathologically proven N2 disease, and they completed the planned trimodality therapy with curative intent. The hazard rate function and competing risk analysis were used to evaluate the recurrence dynamics. Results Among the included patients, 76% had single station N2 involvement and 95% had complete resection. The 5-year overall and recurrence-free survival rates were 47% and 29%, respectively. Of the 290 patients who experienced recurrence, 25 (8.4%) experienced loco-regional recurrence, whereas 238 (80.4%) had distant metastases. The hazard rate function for overall recurrence revealed a peak at approximately 8 months after surgery and a marked decline after 2 years. The peak recurrence frequency of distant metastasis differed at each site, with isolated brain metastases exhibiting the earliest peak (6 months) and a narrow recurrence interval (15 months). A histological comparison revealed a higher recurrence hazard rate for adenocarcinoma than for squamous cell carcinoma but similar pattern of recurrences. Patients with complete responses had a lower cumulative incidence rate of recurrence but a slightly earlier peak of recurrence. Nodal responses to induction therapy demonstrated that patents with ypN0 had the lowest recurrence risk, whereas patients with ypN1 and ypN2 had similar hazard rates and cumulative incidence rates of recurrence. Conclusions The dynamics of recurrence after trimodality therapy is organ-specific and varies according to pathologic factors. Our finding provides information on selection patients with risk of recurrence and timing of surveillance study.

Congenital pericardial defects (CPDs) are infrequent anomalies that are usually asymptomatic and are discovered incidentally during unrelated interventions. Here we report the case of a CPD with herniation of an enlarged left atrial appendage identified during total thoracoscopic ablation (TTA) for persistent atrial fibrillation (AF). The persistent AF was successfully treated with a hybrid procedure, in which TTA was followed by an electrophysiological study.

A case of a fistula running from the pulmonary vein to the esophagus after a staged hybrid procedure combining total thoracoscopic ablation and percutaneous radiofrequency catheter ablation has not been reported previously. We describe such a case in a 37-year-old man who was successfully treated by surgery.

A rapid response to corticosteroid treatment and a generally favourable outcome are characteristic features of BOOP (Bronchiolitis obliterans organizing pneumonia). However, with increasing experience of the clinical spectrum of this disease, it is now recognized that some patients are refractory to steroid, which is associated with a poor prognosis. Here, two cases of BOOP initially treated with predinisone and antibiotics without effects, but subsequently responded to secondary cyclosporine treatment, are reported. (Tuberc Respir Dis 2005; 59: 315-320)