Final analyses of the prospective controlled trial on the efficacy of uracil and tegafur/leucovorin as an adjuvant treatment for stage II colon cancer with risk factors for recurrence using propensity score-based methods (JFMC46-1201).

BACKGROUND: The efficacy of adjuvant chemotherapy for high-risk stage II colon cancer (CC) has not been well established. Using propensity score matching, we previously reported that the 3-year disease-free survival (DFS) rate was significantly higher in patients treated with uracil and tegafur plus leucovorin (UFT/LV) against surgery alone. We report the final results, including updated 5-year overall survival (OS) rates and risk factor analysis outcomes. METHODS: In total, 1902 high-risk stage II CC patients with T4, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, and/or < 12 dissected lymph nodes were enrolled in this prospective, non-randomized controlled study based on their self-selected treatment. Oral UFT/LV therapy was administered for six months after surgery. RESULTS: Of the 1880 eligible patients, 402 in Group A (surgery alone) and 804 in Group B (UFT/LV) were propensity score-matched. The 5-year DFS rate was significantly higher in Group B than in Group A (P = 0.0008). The 5-year OS rates were not significantly different between groups. The inverse probability of treatment weighting revealed significantly higher 5-year DFS (P = 0.0006) and 5-year OS (P = 0.0122) rates in group B than in group A. Multivariate analyses revealed that male sex, age ≥ 70 years, T4, < 12 dissected lymph nodes, and no adjuvant chemotherapy were significant risk factors for DFS and/or OS. CONCLUSION: The follow-up data from our prospective non-randomized controlled study revealed a considerable survival advantage in DFS offered by adjuvant chemotherapy with UFT/LV administered for six months over surgery alone in individuals with high-risk stage II CC. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180155 (date of registration: 25/02/2019), UMIN Clinical Trials Registry: UMIN000007783 (date of registration: 18/04/2012).

Evaluation of a Webinar for Pharmacists Learning Basic Clinical-Oncology during COVID-19 Pandemic in Japan.

It is essential for oncology pharmacists to update their knowledge, skills, and ethical attitudes. The Japanese Society of Pharmaceutical Oncology is an academic society for healthcare professionals involved in cancer treatment. It has conducted in-person seminars every year to cultivate the knowledge necessary for practicing advanced cancer medicine. Owing to the coronavirus disease (COVID-19) pandemic, the society was obligated to conduct a web-based seminar this year. A questionnaire survey was conducted before and after the webinar to explain how it works and to assess the learning attitudes of beginner and moderately skilled pharmacists in the field of oncology. Questionnaire surveys were conducted with the participants before and after watching the webinar. The questionnaires sought to determine participants' perspectives on the webinar and their knowledge of the seven modules. Of the 1756 webinar attendees, 1661 (94.6%) answered the pre-webinar survey and 1586 (90.3%) answered the post-webinar survey. Results indicate that the median post-webinar knowledge score was significantly higher than the median pre-webinar score (p < 0.001) in all modules. Principal component analysis of the degree of knowledge of seven modules revealed that the improved score group consisted of those from younger age groups, with less experience as pharmacists, non-society members, and those with less experience in past society seminars. Moreover, the web-based seminar provided a uniform learning effect throughout the country without distinguishing between urban and rural learners. The web-based educational program was an acceptable educational tool for Japanese oncology pharmacists.

Prospective observational study of the efficacy of oral uracil and tegafur plus leucovorin for stage II colon cancer with risk factors for recurrence using propensity score matching (JFMC46-1201).

BACKGROUND: The efficacy of adjuvant chemotherapy for high-risk stage II colon cancer (CC) has not been well established. We compared the effects of surgery with and without oral uracil and tegafur plus leucovorin (UFT/LV) in patients with high-risk stage II CC, adjusting for potential risk factors. METHODS: We enrolled patients with histologically confirmed stage II colon adenocarcinoma with at least one of the following conditions: T4 disease, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, or < 12 dissected lymph nodes. Patients chose to be non-randomized or randomized to undergo surgery alone (NR-Group S or R-Group S) or surgery followed by 6 months of UFT/LV (NR-Group U or R-Group U). The primary endpoint was disease-free survival (DFS) after adjusting for previously reported risk factors using propensity score matching (1:2) and inverse probability of treatment weighting (IPTW) in the non-randomized arm. RESULTS: Overall, 1,902 (98%) and 36 (2%) patients were enrolled in the non-randomized and randomized arms, respectively. There were too few patients in the randomized arm and these were therefore excluded from the analysis. Of the 1,902 patients, 402 in NR-Group S and 804 in NR-Group U were propensity score-matched. The 3-year DFS rate (95% confidence interval) was significantly higher in NR-Group U (80.9% [77.9%-83.4%]) than in NR-Group S (74.0% [69.3%-78.0%]) (hazard ratio, 0.64 [0.50-0.83]; P = 0.0006). The 3-year overall survival rate was not significantly different between NR-Group S and NR-Group U. Significantly higher 3-year DFS (P = 0.0013) and overall survival (P = 0.0315) rates were observed in NR-Group U compared with NR-Group S using IPTW. CONCLUSIONS: Adjuvant chemotherapy with UFT/LV showed a significant survival benefit over surgery alone in patients with high-risk stage II CC characterized by at least one of the following conditions: T4 disease, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, or < 12 dissected lymph nodes. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180155 (date of registration: 25/02/2019) (UMIN Clinical Trials Registry: UMIN000007783 , date of registration: 18/04/2012).

Evaluation of a web-based educational programme for pharmacists during the COVID-19 pandemic in Japan.

WHAT IS KNOWN AND OBJECTIVE: Continuing education is essential for pharmacists to acquire and maintain the knowledge, skills, and ethical attitudes necessary for clinical practice. However, with the emergence of COVID-19, the social circumstances and face-to-face learning environments have changed. The objectives of this study were to determine Japanese pharmacists' perception of a web-based educational programme in oncology, and assess changes in their understanding of pharmaceutical care in oncology before and after their participation in the webinar. METHODS: Questionnaire-based surveys were conducted for the participants of the web-based educational programme to determine their perspectives on the webinar, and their degree of comprehension of the five cancer types covered before and after watching the webinar. RESULTS AND DISCUSSION: Of the 1936 pharmacists taking the programme, all participated in the pre-webinar survey, and 1861 (96.1%) in the post-webinar survey. Compared with previous seminars that were held in the offline mode before the COVID-19 pandemic, 76.8% of respondents were significantly satisfied with the web-based educational programme. The median post-webinar comprehension scores in all modules were significantly higher than the median pre-webinar scores (p < 0.0001). A majority of the participants agreed that a web-based educational programme was satisfactory in acquiring knowledge. WHAT IS NEW AND CONCLUSION: This web-based educational programme was effective for Japanese pharmacists for postgraduate education in pharmaceutical care in oncology. To the best of our knowledge, our study is the first to report the effectiveness of a web-based educational programme for oncology pharmacists using a large population.

Laparoscopic cholecystectomy for a cholelithiasis patient with an aberrant biliary duct of B5: a case report.

BACKGROUND: An aberrant biliary duct of segment 5 (B5) is a rare anomaly of the biliary tract. All anatomical anomalies of the biliary tract are risk factors for bile duct injury during surgery. We report a case of cholelithiasis with an aberrant B5 that was detected during a detailed preoperative imaging examination and treated with laparoscopic cholecystectomy. CASE PRESENTATION: A 69-year-old woman was admitted to the emergency room of our hospital with abdominal pain. She was diagnosed with cholelithiasis, and an aberrant B5 branching off the hepatic duct was suggested during preoperative imaging. Laparoscopic cholecystectomy was performed at our surgical department. There were no intra- or postoperative complications, and the patient was discharged on the fourth day after surgery. CONCLUSIONS: Laparoscopic cholecystectomy can be safely performed without intra- or postoperative complications in patients with cholelithiasis and an aberrant B5 if it is accurately diagnosed preoperatively.

Pneumatosis Cystoides Intestinalis Secondary to Sunitinib Treatment for Gastrointestinal Stromal Tumor.

A 67-year-old man with liver and retroperitoneal metastases from a gastrointestinal stromal tumor arising in the jejunum had been administered oral sunitinib for 2 months. He presented to our department with right-sided lower abdominal pain. His general condition was good, with no high-grade fever, and the other vital signs were also stable. Contrast-enhanced computed tomography was promptly performed, and pneumatosis cystoides intestinalis (PCI) was detected in a wide area around the ileocecal lesion. There were no signs of acute abdomen requiring emergency surgery due to conditions such as intestinal perforation, ischemia, or obstruction. Sunitinib was discontinued and the patient was placed on nil orally with intravenous infusion. PCI resolved promptly and the patient was discharged on the 21st day after admission. PCI is a rare side effect of sunitinib with only 8 cases reported previously, which can complicate with acute abdomen or gastrointestinal perforation, in some cases. Thus, the early identification of sunitinib as the cause of PCI is important. Although PCI is a rare adverse effect of sunitinib, clinicians must be aware of it to promptly provide the correct diagnosis and treatment.

Capecitabine versus S-1 as adjuvant chemotherapy for patients with stage III colorectal cancer (JCOG0910): an open-label, non-inferiority, randomised, phase 3, multicentre trial.

BACKGROUND: Adjuvant chemotherapy with oral fluoropyrimidine alone after D3/D2 lymph node dissection improves disease-free survival and overall survival in patients with stage III colon cancer. Adjuvant S-1 has been shown to be non-inferior to uracil and tegafur plus leucovorin in terms of disease-free survival. This study aims to confirm the non-inferiority of S-1 compared with capecitabine as adjuvant treatment in patients with stage III colorectal cancer. METHODS: This study was an open-label, non-inferiority, randomised, phase 3, multicentre trial done in 56 Japanese centres to assess the non-inferiority of S-1 to capecitabine as adjuvant chemotherapy. Eligible patients were aged 20-80 years with stage III colorectal adenocarcinoma, as defined by the presence of an inferior margin of the primary tumour above the peritoneal reflection; R0 resection; and colectomy with D3 or D2 lymph node dissection. Patients were randomly assigned (1:1) to receive eight courses of capecitabine (1250 mg/m2 orally twice daily, days 1-14, every 21 days) or four courses of S-1 (40 mg/m2 orally twice daily, days 1-28, every 42 days). Randomisation was done via phone call, fax, or web-based systems to the Japan Clinical Oncology Group Data Center and used a minimisation method with a random component adjusted by institution, tumour location (colon vs rectosigmoid and upper rectum), number of positive lymph node metastases (≤3 vs ≥4), and surgical technique (conventional vs non-touch isolation). The primary endpoint was disease-free survival with a non-inferiority margin for the hazard ratio (HR) set at 1·24, analysed by intention to treat. This trial was registered with UMIN Clinical Trial Registry, number UMIN000003272. FINDINGS: Between March 1, 2010, and Aug 23, 2013, 1564 patients were randomly assigned to capecitabine (n=782) or S-1 (n=782), all of whom were included in the efficacy analysis; 777 patients in the capecitabine group and 768 in the S-1 group were included in the safety analysis. At the prespecified second interim analysis after final accrual, 258 (48%) of 535 required events were reported, and the Data and Safety Monitoring Committee recommended early publication because S-1 could not show non-inferiority compared with capecitabine for disease-free survival. With a median follow-up of 23·7 months (IQR 14·1-35·2), 3-year disease-free survival was 82·0% (95% CI 78·5-85·0) for the capecitabine group and 77·9% (74·1-81·1) for the S-1 group (HR 1·23, 99·05% CI 0·89-1·70; one-sided pnon-inferiority=0·46). The most frequent grade 3 or higher adverse events in the capecitabine group were hand-foot skin reactions (123 [16%] of 777 patients), and in the S-1 group were diarrhoea (64 [8%] of 768 patients) and neutropenia (61 [8%]). There was one (<1%) treatment-related death in each group. INTERPRETATION: Adjuvant capecitabine remains one of the standard treatments for stage III colorectal cancer in Japan; S-1 is not recommended. FUNDING: National Cancer Center and Ministry of Health, Labour and Welfare of Japan.

The Primary Result of Prospective Randomized Multicenter Trial of New Spray-Type Bio-absorbable Adhesion Barrier System (TCD-11091) Against Postoperative Adhesion Formation.

BACKGROUND: Postoperative adhesions are the major cause of postoperative complications including intestinal obstruction, infertility, and chronic pelvic pain. In order to reduce postoperative adhesions, Terumo Corporation (Tokyo, Japan) has developed an adhesion barrier system (TCD-11091) which is easy to use at the treatment site in various surgical procedures including laparoscopic surgeries. We conducted a prospective randomized single-blind study in patients who underwent laparotomy with ileostomy. METHODS AND RESULTS: One hundred twenty-six patients were randomly assigned to TCD-11091 group (n = 62) or non-treatment group (n = 62). Patient backgrounds were similar between the groups. At the time of ileostomy closure (the second-look surgery), the observation was performed on 55 in the TCD-11091 group and 43 in the control group. The incidence of adhesions observed at the second-look surgery was significantly lower in the TCD-11091 group (52.7 versus 90.7%; p < 0.001). For the secondary endpoints, the incidence of wide extent adhesions (grade 2 or higher) was significantly reduced (38.2 versus 79.1%; p < 0.001). Regarding the severity of adhesions, the incidence of grade 2 or higher adhesions was also significantly lower in the TCD-11091 group (47.3 versus 88.4%; p < 0.001). No differences in the incidence of adverse events were found between the TCD-11091 group and the non-treatment group (85.2 versus 75.4%; p = 0.225). CONCLUSIONS: Use of TCD-11091 was safe and associated with significantly lower incidence of adhesion and severity of adhesions compared with non-treatment procedure.

Preplanned safety analysis of the JFMC37-0801 trial: a randomized phase III study of six months versus twelve months of capecitabine as adjuvant chemotherapy for stage III colon cancer.

BACKGROUND: Six months of adjuvant chemotherapy is regarded as the standard of care for patients with stage III colon cancer. However, whether longer treatment can improve prognosis has not been fully investigated. We conducted a phase III study comparing 6 and 12 months of adjuvant capecitabine chemotherapy for stage III colon cancer, and report here the results of our preplanned safety analysis. METHODS: Patients aged 20-79 years with curatively resected stage III colon cancer were randomly assigned to receive 8 cycles (6 months) or 16 cycles (12 months) of capecitabine (2500 mg/m2/day on days 1-14 of each 21-day cycle). Treatment exposure and adverse events (AEs) were evaluated. RESULTS: A total of 1304 patients (642 and 636 in the 6-month and 12-month groups, respectively) were analyzed. The most common AE was hand-foot syndrome (HFS). HFS, leukocytopenia, neutropenia, and hyperbilirubinemia (any grade) occurred more frequently in the 12-month group than in the 6-month group. HFS was the only grade ≥3 AE to have a significantly higher incidence in the 12-month group (23 vs 17%, p = 0.011). The completion rate for 8 cycles was 72% in both groups, while that for 16 cycles was 46% in the 12-month group. HFS was the most common AE requiring dose reduction and treatment discontinuation. CONCLUSIONS: Twelve months of adjuvant capecitabine demonstrated a higher cumulative incidence of HFS compared to the standard 6-month treatment period, while toxicities after 12 months of capecitabine were clinically acceptable. TRIAL REGISTRATION: UMIN-CTR, UMIN000001367.

Treatment Rationale and Study Design for Clinical Trial on the Efficacy of UFT/LV for Stage II Colorectal Cancer With Risk Factors for Recurrence (JFMC46-1201).

BACKGROUND: The usefulness of adjuvant chemotherapy for stage II colon cancer has not been established. Meanwhile, the presence of stage II colon cancer with high-risk factors for recurrence has been reported. To our knowledge, no prospective study of adjuvant chemotherapy for stage II colon cancer with high-risk factors has been implemented to date. PATIENTS AND METHODS: This study is a prospective nonrandomized controlled study based on patients' selection of treatment option, including randomized therapeutic decision-making, to evaluate the usefulness of adjuvant chemotherapy with tegafur-uracil (UFT) with leucovorin (LV) for stage II colon cancer with high-risk factors for recurrence, compared with surgery alone. Five courses of UFT/LV therapy will be given as follows: UFT (300 mg/m(2)/d) with LV (75 mg/d) will be orally administered in 3 doses per day. Treatment will be received daily for 28 days, followed by a 7-day rest or will be received daily for 5 days, followed by a 2-day rest. For both regimens, 1 course will last 5 weeks, and 5 courses will be given. The primary end point is disease-free survival. A propensity score matching will be conducted based on 7 variables that represent risk factors to minimize selection bias in a comparison between the nonrandomized arms. For this nonrandomized comparison, a target sample size is set at 1200 (400 and 800 patients for the surgery alone and UFT/LV groups, respectively) and 1720 patients will be enrolled. In this study we aim to evaluate the therapeutic usefulness of adjuvant chemotherapy with UFT/LV for stage II colorectal cancer with risk factors for recurrence.

Open-label, randomized, comparative, phase III study on effects of reducing steroid use in combination with Palonosetron.

The purpose of this study is to compare the efficacy of a single administration of dexamethasone (DEX) on day 1 against DEX administration on days 1-3 in combination with palonosetron (PALO), a second-generation 5-HT3 receptor antagonist, for chemotherapy-induced nausea and vomiting (CINV) in non-anthracycline and cyclophosphamide (AC) moderately-emetogenic chemotherapy (MEC). This phase III trial was conducted with a multi-center, randomized, open-label, non-inferiority design. Patients who received non-AC MEC as an initial chemotherapy were randomly assigned to either a group administered PALO (0.75 mg, i.v.) and DEX (9.9 mg, i.v.) prior to chemotherapy (study treatment group), or a group administered additional DEX (8 mg, i.v. or p.o.) on days 2-3 (control group). The primary endpoint was complete response (CR) rate. The CR rate difference was estimated by logistic regression with allocation factors as covariates. The non-inferiority margin was set at -15% (study treatment group - control group). From April 2011 to March 2013, 305 patients who received non-AC MEC were randomly allocated to one of two study groups. Overall, the CR rate was 66.2% in the study treatment group (N = 151) and 63.6% in the control group (N = 154). PALO plus DEX day 1 was non-inferior to PALO plus DEX days 1-3 (difference, 2.5%; 95% confidence interval [CI]: -7.8%-12.8%; P-value for non-inferiority test = 0.0004). There were no differences between the two groups in terms of complete control rate (64.9 vs 61.7%) and total control rate (49.7% vs 47.4%). Anti-emetic DEX administration on days 2-3 may be eliminated when used in combination with PALO in patients receiving non-AC MEC.

[Long-Term Survival of a Patient with Colon Cancer with Peritoneal Dissemination].

This case involves a 76 year-old woman. A sigmoidectomy was performed for sigmoid colon cancer in August 2006. On histological examination, the cancer was shown to be tub2>tub1>por2, pSE, int, INF b, ly2, v0, pN0, p1 (Douglas), Stage Ⅳ. After surgery, 4 courses of FOLFOX and 8 courses of TS-1 plus CPT-11 were administered after UFT plus LV was performed. Because of suspected recurrence at the anastomotic site, a partial colectomy was performed in September 2010, and TS-1 was started after surgery. In March 2012, the carcinoembryonic antigen level had increased to 13.7 ng/mL. Irregular masses with spicula, 13×15 mm and 19×23 mm on the right and left sides, respectively, were observed on chest computed tomography, and lung metastasis was suspected. Left lower and partial right middle lobectomies were performed. After surgery, the tumor marker levels were normalized. Chemotherapy was not performed. Currently, at 2 years 8 months after resection of the lung metastases, no recurrence was observed. Long-term survival in cases of colon cancer with peritoneal dissemination is rare, but multidisciplinary treatment, including surgical treatment, showed the promising possibility of long-term survival.

Phenol-based endoscopic ultrasound-guided celiac plexus neurolysis for East Asian alcohol-intolerant upper gastrointestinal cancer patients: a pilot study.

AIM: To investigate the effectiveness of phenol for the relief of cancer pain by endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN). METHODS: Twenty-two patients referred to our hospital with cancer pain from August 2009 to July 2011 for EUS-CPN were enrolled in this study. Phenol was used for 6 patients with alcohol intolerance and ethanol was used for 16 patients without alcohol intolerance. The primary endpoint was the positive response rate (pain score decreased to ≤ 3) on postoperative day 7. Secondary endpoints included the time to onset of pain relief, duration of pain relief, and complication rates. RESULTS: There was no significant difference in the positive response rate on day 7. The rates were 83% and 69% in the phenol and ethanol groups, respectively. Regarding the time to onset of pain relief, in the phenol group, the median pre-treatment pain score was 5, whereas the post-treatment scores decreased to 1.5, 1.5, and 1.5 at 2, 8, and 24 h, respectively (P < 0.05). In the ethanol group, the median pre-treatment pain score was 5.5, whereas the post-treatment scores significantly decreased to 2.5, 2.5, and 2.5 at 2, 8, and 24 h, respectively (P < 0.01). There was no significant difference in the duration of pain relief between the phenol and ethanol groups. No significant difference was found in the rate of complications between the 2 groups; however, burning pain and inebriation occurred only in the ethanol group. CONCLUSION: Phenol had similar pain-relieving effects to ethanol in EUS-CPN. Comparing the incidences of inebriation and burning pain, phenol may be superior to ethanol in EUS-CPN procedures.

[Adjuvant chemotherapy with capecitabine for colon cancer - a case series].

We examined the treatment condition; adverse events, especially hand-foot syndrome (HFS); and prognosis in 65 patients with colon cancer who received adjuvant chemotherapy with capecitabine. The treatment completion rate was 75.4%; however, only 15.4% of patients completed treatment without dose reduction or treatment interruption. HFS occurred in 78.5% of all cases. The 3-year relapse-free survival rate was 73.8% for all cases, 80.8% for treatment-completed cases, and 51.1% for treatment-discontinued cases; however, there were no differences in relapse-free survival rates for cases that required dose reduction or treatment interruption. We conclude that adjuvant chemotherapy with capecitabine is effective in colon cancer and that completing treatment (even with dose reduction or dose interruption) improves prognosis.

[A case of an elderly patient with recurrent GIST, which was effectively treated with low-dose imatinib mesylate].

The recommended dose of imatinib for recurrent gastrointestinal stromal tumors (GIST) is 400mg/day. However, adverse effects limit the use of the standard dose in elderly patients. We report a case of an elderly patient with recurrent GIST, where long-term control of the disease was achieved with low-dose imatinib therapy. An 86-year-old man presenting with tarry stool was admitted to the hospital; upper GI endoscopy revealed a gastric submucosal tumor of the stomach at the posterior wall of the cardia. Partial gastrectomy was performed laparoscopically. The submucosal lesion was histopathologically diagnosed as malignant GIST. Administration of imatinib was initiated 17 months after surgery because of recurrence of GIST. The initial dose of imatinib was 400mg/day, which was later adjusted to 200mg or 300 mg/day because of adverse effects. Though imatinib was withdrawn several times due to strong side effects, the disease was well controlled for 6 years after surgery.

[A case report of goblet cell carcinoid tumor of the appendix].

Goblet cell carcinoid (GCC) tumor of the appendix is rare, and the prognosis is considered poor compared to classical carcinoid tumor. We present a case of a 60-year old woman who underwent appendectomy for acute appendicitis. Histopathological studies revealed a GCC tumor with submucosal invasion. Based on the malignancy of this tumor and the possible risk of regional lymph node metastases, we performed laparoscopic ileocecectomy with lymph node dissection. Histologically, no residual tumor or lymph node metastases were found. The patient remains well without any sign of recurrence.

[A case report of long-term survival in the patient with anorectal malignant melanoma].

Malignant melanoma of the anorectal region is rare, and the prognosis is considered to be poor. We present a case of long-term survival in a 56-year-old patient with primary malignant melanoma in the anorectal area, who complained of anal bleeding. Barium enema showed an elevated lesion in the anorectal region. Colonoscopy revealed a 3 cm sessile tumor with focal pigmentation, and a satellite nodule, 1 cm in diameter. Based on diagnosis of malignant melanoma by biopsy, abdominoperineal resection with lateral node dissection was performed. Pathologically the tumor remained in the mucosa, and no lymph node metastasis was found. This patient refused any adjuvant chemotherapy after the operation, and remains well without any sign of recurrence for seven years.

[Thymic basaloid carcinoma].

This is a case of a 72-year-old male whose chest computed tomography (CT) revealed a 2.0 x 1.6 cm anterior mediastinal solid tumor during follow-up of an abnormal shadow of the lung. The tumor increased its size during preoperative follow-up, and multilocular cyst was also observed. Radical thymectomy was performed, and histopathologically the tumor was diagnosed as thymic basaloid carcinoma. Thymic basaloid carcinoma is a rare tumor and is often associated with multilocular thymic cyst. There are only 32 cases reported both locally and internationally. Surgical resection is the general treatment for this disease. Adjuvant radiotherapy can be considered in cases of incomplete resection and invasive tumor. In our case, no recurrence of the tumor was noted 12 months post-operative. Generally, the malignancy of thymic basaloid carcinomas are regarded as low-grade compared with other thymic carcinomas, however, since mortality and recurrence have been reported, careful follow-up is required.