Post-Progression Survival Highly Influences Overall Survival in Driver Gene Mutation/Translocation Negative or Unknown Type of Non-Small Cell Lung Cancer.

INTRODUCTION: In stage I-III non-small cell lung cancer (NSCLC), which is considered operable, surgical resection is the most efficacious treatment and is considered to provide a cure. However, after complete surgical resection, approximately 50% of patients with stage I-IIIA NSCLC experience recurrence and death. Once postoperative recurrence of NSCLC occurs, the prognosis is significantly poor, and the course of treatment after recurrence may influence overall survival (OS). Consequently, we investigated the relationship between relapse-free survival (RFS), post-progression survival (PPS), and OS in patients with postoperative recurrence of NSCLC with driver gene mutation/translocation negative or unknown status. METHODS: Between January 2007 and September 2019, 101 patients with driver gene mutation/translocation negative or unknown status of NSCLC who underwent complete resection and in whom recurrence occurred were analyzed. The associations between RFS, PPS, and OS were analyzed at the individual patient level. RESULTS: Linear regression and Spearman rank correlation analyses revealed that PPS was strongly associated with OS (r = 0.83, p < 0.0001, R2 = 0.71), whereas RFS was moderately correlated with OS (r = 0.65, p < 0.0001, R2 = 0.48). In the multivariate analysis, performance status at relapse, administration of immune checkpoint inhibitors, and radiotherapy for oligo-recurrences were significantly associated with PPS (p < 0.001). CONCLUSION: Current analysis of individual-level data of patients who underwent complete resection implied that PPS had a higher impact on OS than RFS in patients with postoperative recurrence of driver gene mutation/translocation negative or unknown status of NSCLC. Additionally, current perceptions indicate that treatment beyond progression after complete surgical resection might strongly affect OS.

Post-Progression Survival Is Strongly Associated with Overall Survival in Patients Exhibiting Postoperative Relapse of Non-Small-Cell Lung Cancer Harboring Sensitizing EGFR Mutations.

Background and Objective: Patients with advanced non-small-cell lung cancer (NSCLC) harboring sensitizing epidermal growth factor receptor (EGFR) mutations show a good response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). The subsequent treatments influence the evaluability of the efficacy of front-line therapy on overall survival (OS). Consequently, we evaluated the associations of relapse-free survival (RFS) and post-progression survival (PPS) with OS in patients who exhibited postoperative relapse of EGFR-mutated NSCLC. Materials and Methods: We analyzed the data of 35 patients with EGFR-mutated NSCLC who underwent complete resection between January 2007 and June 2019. The correlations of RFS and PPS with OS were evaluated at the individual patient level. Results: Linear regression and Spearman's rank correlation analyses demonstrated that the PPS highly correlated with OS (r = 0.91, p < 0.05, R2 = 0.85), whereas the RFS weakly associated with OS (r = 0.36, p < 0.05, R2 = 0.25). Age and performance status at relapse were significantly associated with PPS. Conclusion: Overall, PPS was more strongly and significantly associated with OS than RFS. These results suggest that the OS of our cohort may be affected by treatments, besides postoperative relapse. However, larger-scale prospective studies are needed to confirm these results.

Correlations of mRNA Levels among Efflux Transporters, Transcriptional Regulators, and Scaffold Proteins in Non-Small-Cell Lung Cancer.

Multidrug resistance (MDR) due to enhanced drug efflux activity of tumor cells can severely impact the efficacy of antitumor therapies. We recently showed that increased activity of the efflux transporter P-glycoprotein (P-gp) associated with activation of Snail transcriptional regulators may be mediated mainly by moesin in lung cancer cells. Here, we aimed to systematically evaluate the relationships among mRNA expression levels of efflux transporters (P-gp, breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 2 (MRP2)), scaffold proteins (ezrin (Ezr), radixin (Rdx), and moesin (Msn); ERM proteins), and SNAI family members (Snail, Slug, and Smac) in clinical lung cancer and noncancer samples. We found high correlations between relative (cancer/noncancer) mRNA expression levels of Snail and Msn, Msn and P-gp, Slug and MRP2, and Smuc and BCRP. These findings support our previous conclusion that Snail regulates P-gp activity via Msn and further suggest that Slug and Smuc may contribute to the functional regulation of MRP2 and BCRP, respectively, in lung cancer cells. This trial is registered with UMIN000023923.

High STMN1 Expression is Associated with Cancer Progression and Chemo-Resistance in Lung Squamous Cell Carcinoma.

BACKGROUND: Known as a microtubule-destabilizing protein, STMN1 (gene symbol: STMN1) regulates the dynamics of microtubules, cell cycle progress, and chemo-resistance against taxane agents. It is highly expressed in various human cancers and involved in cancer progression as well as poor prognosis. METHODS: Expression of STMN1 was examined by immunohistochemistry using FFPE tissue sections from 186 patients with lung squamous cell carcinoma (LSCC). Analysis of STMN1 suppression was performed for STMN1 small interfering RNA (siRNA)-transfected LSCC cell lines to determine the change in proliferation, invasive and apoptosis abilities, and paclitaxel sensitivity. RESULTS: The cytoplasmic STMN1 expression in LSCC was higher than in normal tissues. The high expression was significantly associated with vascular invasion (P = 0.0477) and poor prognosis. In addition, the proliferating and invasive abilities were decreased, and the apoptosis ability and paclitaxel sensitivity were increased in STMN1-suppressed LSCC cells compared with control cells. CONCLUSION: The results suggest that STMN1 is a prognostic factor that also is associated with caner progression and chemo-resistance. Therefore, STMN1 could be a predictor for poor prognosis and a potential therapeutic target in LSCC.

SIRT6 expression is associated with poor prognosis and chemosensitivity in patients with non-small cell lung cancer.

BACKGROUND: Despite advances in the development of various therapeutic agents, non-small cell lung cancer (NSCLC) is associated with a poor prognosis. To improve the prognosis of patients with NSCLC, new therapeutic targets for overcoming drug resistance are required. The process of autophagy is required to support the tumorigenesis and drug resistance of cancer cells. We investigated the clinical significance of SIRT6, a member of the NAD(+) -dependent deacetylase family, which regulates a variety of cancer-related processes, including autophagy. METHODS: Immunohistochemistry analysis of SIRT6 expression and localization in 98 NSCLC clinical specimens and in vitro analysis using SIRT6-knockout lung carcinoma cell lines were performed. RESULTS: Patients with high cytoplasmic expression and low nuclear expression of SIRT6 (n = 33) had more aggressive cancer, shorter overall survival, and shorter recurrence-free survival than did patients with different SIRT6 expression profiles (P < 0.05). In vitro analysis revealed that SIRT6 knockdown lung adenocarcinoma cell line improved paclitaxel sensitivity (P < 0.05) and reduced the expression levels of both nuclear factor kappaB and autophagy marker Beclin1. CONCLUSION: Our data demonstrated that SIRT6 expression in NSCLC could be a useful prognostic marker and that SIRT6 might represent a novel target gene for predicting sensitivity of chemotherapy in lung adenocarcinoma.

Course of postoperative relapse in non-small cell lung cancer is strongly associated with post-progression survival.

BACKGROUND: For early-stage non-small cell lung cancer (NSCLC), surgical resection is considered the most effective treatment strategy and curative treatment. Unfortunately, even after complete resection, almost half of all patients with stage I-IIIA NSCLC relapse and die. Although the possibility of a cure for postoperative recurrence of NSCLC is significantly low, the course of subsequent treatment can possibly affect overall survival (OS). Here, we examined the association of relapse-free survival (RFS) and post-progression survival (PPS) with OS in patients with postoperative recurrence of NSCLC. METHODS: We evaluated 128 patients with NSCLC who underwent complete resection between January 2007 and December 2018. The association between RFS and PPS on OS was examined at the patient level. RESULTS: Spearman's rank correlation and linear regression analyses revealed that PPS was strongly correlated with OS (r = 0.83, p < 0.05, R2  = 0.72), whereas RFS was weakly associated with OS (r = 0.56, p < 0.05, R2  = 0.37). Additionally, the performance status at relapse and administration of tyrosine kinase inhibitors were significantly correlated with PPS. CONCLUSIONS: PPS was significantly more strongly correlated with OS than was RFS in patients with postoperative recurrence of NSCLC. These results suggest that therapy following postoperative recurrence affects OS. Therefore, it is necessary to validate these promising results in a large prospective study.

Comprehensive expressional analysis of chemosensitivity-related markers in large cell neuroendocrine carcinoma of the lung.

OBJECTIVES: Various drug-sensitivity markers have been reported to be associated with tumor progression and chemotherapy resistance. Detailed expression profiles of sensitivity markers for cytotoxic chemotherapy in pulmonary large cell neuroendocrine carcinoma (LCNEC) remain unclear. Herein, we aimed to clarify the correlation between the expression of drug-sensitivity markers and clinicopathological features, prognostic impact, and status of tumor immunity in patients with LCNEC. METHODS: We retrospectively analyzed the correlation between clinicopathological features and the expression of drug-sensitivity-related markers, including vascular endothelial growth factor 2 (VEGFR2), thymidylate synthase (TS), tubulin beta 3 class III (TUBB3), topoisomerase I (Topo-I), and Topo-II in 92 surgically resected LCNEC samples. Furthermore, we examined the prognostic significance of expression of these and their correlation with the immune cell status. RESULTS: Overall, high expression of TS, TUBB3, VEGFR2, Topo-I, and Topo-II was detected in 50 (54%), 31 (34%), 23 (25%), 65 (71%), and 36 (39%) samples, respectively. Univariate and multivariate analyses revealed that advanced pathological T and N factors, positive lymphatic permeation, and Topo-II expression were independent unfavorable prognosticators for recurrence-free survival, and advanced pathological T and N factors, Topo-II positive expression, and TS positive expression were independent unfavorable prognosticators for overall survival. In terms of correlation with immune cell status, higher expression of VEGFR2 was closely linked to negative PD-L1 expression. CONCLUSIONS: These findings suggest that elevated Topo-II and TS expression may contribute to poor outcomes through protumoral biology in patients with LCNEC, and elevated VEGFR2 expression might negatively impact tumor immune reactions in LCNEC.

Metachronous bilateral breast metastases of a lung neuroendocrine tumor: A case report.

Breast metastases of primary lung neuroendocrine tumors are rarely reported. The current report presents the case of a 41-year old female with no history of smoking who initially underwent surgery for a breast fibroadenoma, during which a neuroendocrine tumor of the right lung was detected via chest X-ray. The patient underwent surgery for the tumor and developed right breast nodules after adjuvant chemotherapy. Histological and immunohistochemical examinations of biopsies from these nodules indicated breast metastasis of the primary lung neuroendocrine tumor. The patient underwent mastectomy of the right breast but subsequently developed metastases in the left breast, for which local radiotherapy was administered. The observed metachronous bilateral breast metastases indicated that the contralateral breast should be considered during an investigation of metastasis.

Moesin-Mediated P-Glycoprotein Activation During Snail-Induced Epithelial-Mesenchymal Transition in Lung Cancer Cells.

Epithelial-mesenchymal transition (EMT) plays a role in not only cancer metastasis, but also drug resistance, which is associated with increased levels of efflux transporters such as P-glycoprotein (P-gp). Here, we examined whether P-gp activation during Snail-induced EMT of lung cancer cells is mediated by ezrin, radixin, and moesin (ERM), which regulate transporter localization. HCC827 lung cancer cells overexpressing the transcription factor Snail showed increased Rhodamine123 efflux and increased paclitaxel resistance, reflecting increased P-gp activity. Concomitantly, the expression level of moesin, but not ezrin or radixin, was significantly increased. The increase of P-gp activity was suppressed by knockdown of moesin. Thus, the increase of P-gp activity associated with Snail-induced EMT may be mediated mainly by moesin in HCC827 cells. On the other hand, the Snail mRNA expression level was correlated with the expression level of each ERM in 4 non-small-cell lung cancer cell lines (HCC827, A549, H441, H1975) and in tumor tissues, but not normal tissues, of patients with lung cancer. These results suggest that P-gp activation during EMT is at least partially due to increased expression of moesin. Coadministration of moesin inhibitors with anticancer drugs might block P-gp-mediated drug efflux organ-specifically, improving treatment efficacy and minimizing side effects on other organs.

Immunohistochemical analysis of phosphorylated epidermal growth factor receptor might provide a surrogate marker of EGFR mutation.

PURPOSE: Overexpression of EGFR is found in several malignancies including lung cancers. Recently, EGFR mutation has been shown to correlate with responsiveness to tyrosine kinase inhibitors (TKI). Although antibodies against phophorylated EGFR have been used in vitro, phosphorylated EGFR has yet not been examined well in resected non-small cell lung cancers (NSCLCs). EXPERIMENTAL DESIGN: We studied the immunohistochemistry of anti-EGFR and phosphorylated EGFR in 97 resected NSCLCs, examined the relationship with EGFR mutation, and performed quantitative RT-PCR of the EGFR gene in the TaqMan assay. RESULT: EGFR mutation was seen in 27% of 97 NSCLCs and 37% of 70 adenocarcinomas. EGFR was stained in 60% of 97 NSCLCs. Phosphorylation of tyrosine 845 (pY845) and 1068 (pY1068) was positive in 49% and 48%, respectively. The observed correlation with EGFR mutation and pY845 or pY1068 was statistically significant (P=0.0001 for pY845, P<0.0001 for pY1068, chi square test), although phospho-EGFR status was not associated with a particular mutation type. pY1068-positive tumors also correlated with female, light smoker, and adenocarcinoma histology, but not with mRNA expression. Moreover, patients with pY1068-positive tumors showed prolonged survival (P=0.0093, log-rank test). CONCLUSION: It is possible that immunohistochemistry of phosphorylated EGFR can substitute for EGFR mutation analysis. Further investigation is necessary to determine whether phospho-EGFR immunohistochemistry predicts response to TKIs and survival benefit.

Long-term complete response in a patient with postoperative recurrent ALK-rearranged lung adenocarcinoma treated with crizotinib: A case report.

Anaplastic lymphoma kinase (ALK) gene rearrangements are identified in approximately 5% of patients with non-small cell lung cancer (NSCLC). Despite initial dramatic responses to ALK inhibitors, the majority of patients relapse within 1 year, owing to the development of resistance. Herein we present a case of variant type 2 ALK-rearranged lung adenocarcinoma recurrence with multiple lung metastasis that maintained complete response over 5 years with crizotinib, which is the first approved ALK inhibitor. The efficacy of crizotinib may vary among ALK fusion variants and thus, variant type may represent an important factor in guiding the treatment strategy for ALK-rearranged lung adenocarcinoma.

Fas/FasL signaling is critical for the survival of exhausted antigen-specific CD8+ T cells during tumor immune response.

Antigen (Ag)-specific activated CD8+ T cells are critical for tumor elimination but become exhausted, and thus, dysfunctional during immune response against the tumor due to chronic antigen stimulation. The signaling of immune checkpoint receptors is known to be a critical component in this exhaustion; however, the fate of these exhausted CD8+ T cells remains unclear. Therefore, to elucidate this, we followed the fate of Ag-specific CD8+ T cells by directly visualizing them using MHC class I tetramers coupled with ovoalubumin257-264 in C57BL/6 mice inoculated with EG.7. We found that the number of generated Ag-specific activated CD8+ T cells decreased via apoptosis during a prolonged tumor immune response. However, the number of Ag-specific CD8+ T cells was significantly higher in Fas ligand (FasL)-dysfunctional gld mice than in control mice, resulting in suppressed tumor growth. In contrast, the enforced expression of Bcl-2 failed to rescue apoptosis of the exhausted CD8+ T cells following EG.7 inoculation. These results suggest that Fas/FasL signaling is critical for the survival of exhausted CD8+ T cells during the tumor immune response.

Prognostic significance of PD-L1 expression and tumor infiltrating lymphocytes in large cell neuroendocrine carcinoma of lung.

OBJECTIVES: Since large cell neuroendocrine carcinoma (LCNEC) is a relatively rare histologic type of primary lung cancer, little is known about the immunological status of patients with LCNEC. We aimed to clarify the expression and prognostic impact of programmed cell death ligand 1 (PD-L1), CD8, CD4, and Forkhead box protein P3 (Foxp3) in LCNEC. METHODS: We retrospectively analyzed PD-L1, CD8, CD4, and Foxp3 expressions in 95 surgically resected LCNEC. PD-L1 positive staining was determined in tumors with more than 1% of tumor cells stained to any intensity, and CD8, CD4, and Foxp3 positivity was determined in tumors with more than 5% of lymphocytes stained. RESULTS: Positive expression of PD-L1, CD8, CD4, and Foxp3 was observed in 70 (74%), 52 (55%), 76 (80%), and 43 (45%) tumors, respectively. The expression of PD-L1 was significantly correlated with positive lymphatic permeation. Positive correlations were mutually observed among tumor infiltrating immune cells. Univariate and multivariate analyses showed that positive pleural invasion and Foxp3 negative expression were independent unfavorable prognostic factors for overall survival (OS). Advanced pathological stage, positive pleural invasion, CD4 negative expression in cancer stroma, and Foxp3 negative expression were identified as independent unfavorable prognostic factors for recurrence free survival (RFS). CONCLUSIONS: Foxp3 positive tumor infiltrating lymphocytes (TILs) were an independent favorable prognostic factor for both OS and RFS, whereas CD4 positive TILs were an independent significant unfavorable prognostic factor for RFS. The high frequency of PD-L1 expression could support the use of anti-programmed cell death 1 antibody in the treatment of LCNEC.

LKB1 gene mutations in Japanese lung cancer patients.

Mutation of the LKB1 gene (also known as STK11) is regarded as a cause of Peutz-Jeghers syndrome. In Caucasian patients, LKB1 somatic mutations occur in approximately one-third of lung adenocarcinomas. The aim of the present study was to examine the LKB1 gene in Japanese patients with lung cancer and to evaluate its clinical and pathological implications. We sequenced the LKB1 gene in 22 lung cancer cell lines and 100 Japanese patients with lung cancer (including 81 adenocarcinomas, 14 squamous cell carcinomas and five other histological types) who had undergone curative pulmonary resection. We also determined expression levels of the LKB1 gene by quantitative real-time reverse transcription-polymerase chain reaction and correlated these results with the clinical and pathological features of patients. Among the 22 cell lines, four had mutations and three of these were in adenocarcinoma cells. Of 100 primary lung cancers, only three had LKB1 gene mutations (3%). All of them were male smokers with adenocarcinomas. Hence, when confined to this subset of patients, the mutation frequency was 9% (3/33). No significant correlation was observed between the expression level of LKB1 and patient clinicopathological features. In conclusion, LKB1 gene mutations were relatively rare in Japanese patients with lung cancer compared with Caucasian patients. LKB1 gene mutations appear to be frequent in male, smoking patients of Caucasian origin, in contrast to EGFR or HER2 mutations that are frequent in non-smoking, female patients of Asian origin.

Intraductal papillary mucinous tumor of the pancreas associated with autosomal dominant polycystic kidney disease.

A 43-year-old male with a history of autosomal dominant polycystic kidney disease (ADPKD) was admitted to our center with severe abdominal pain and was diagnosed with acute pancreatitis. CT showed multiple cysts in the liver and both kidneys along with ADPKD and a cystic mass, 4 cm in diameter, in the pancreatic head. The main pancreatic duct was dilated to 1 cm in diameter. The patient was diagnosed with acute pancreatitis due to intraductal papillary mucinous tumor (IPMT), and pancreatoduodenectomy was performed. Histologic examination revealed a multiloculated cystic tumor filled with mucin in the head of the pancreas. Microscopically, the tumor was diagnosed as adenocarcinoma and was found to have invaded the main pancreatic duct. Although, in addition to our case, only seven cases with association between ADPKD and malignant neoplasms have been reported, five of these cases had neoplasms arising from the pancreas. Therefore, we suggest that some genetic interactions may exist between ADPKD and pancreatic carcinogenesis.

Video-Assisted Thoracoscopic Surgery after Preoperative CT-Guided Lipiodol Marking of Small or Impalpable Pulmonary Nodules.

PURPOSE: Small pulmonary lesions that include ground-glass attenuation have been increasingly discovered because of progressive imaging diagnostic technologies. Despite the detection of such small lesions, sometimes it is quite difficult to localize them because of their size or considerable depth from the visceral pleura. In the present study, we examined the usefulness of computed tomography-guided lipiodol marking for thoracoscopic resection of impalpable pulmonary nodules. METHODS: Fifty-six patients with an undiagnosed peripheral lesion(s) of the lung who had undergone preoperative computed tomography-guided lipiodol marking followed by video-assisted thoracoscopic surgery were studied. RESULTS: All of the nodules were successfully marked by computed tomography-guided lipiodol marking, and all except for one case were localized by means of intraoperative fluoroscopy as clear spots. With regard to complications, pneumothorax occurred in 21 patients (37.5%), and only one patient required transient drainage. Although hemorrhaging in the lung parenchyma and hemosputum occurred in nine patients (16.1%) and one patient (1.8%), respectively, no patients were in serious condition. No intra- or postoperative mortality or morbidity was observed. CONCLUSION: Preoperative computed tomography-guided lipiodol marking of small or impalpable pulmonary nodules is a safe and useful procedure for thoracoscopic resection of the lung.

Src kinase-associated phosphoprotein2 expression is associated with poor prognosis in non-small cell lung cancer.

BACKGROUND/AIM: Non-small cell lung cancer (NSCLC) is among the leading causes of cancer-related deaths worldwide. In certain human cancer types, Src is associated with cancer progression and refractory cancer. To improve the prognoses of NSCLC patients, we evaluated Src kinase-associated phosphoprotein 2 (SKAP2), a factor associated with integrin-stimulated cytoskeletal rearrangement, as a new therapeutic target. MATERIALS AND METHODS: We performed immunohistochemistry for SKAP2 in 99 NSCLC samples and evaluated the relationship between SKAP2 expression, clinicopathological factors and prognosis. RESULTS: Higher SKAP2 expression was detected in cancerous tissues and was predominantly expressed in the cytoplasm. Elevated SKAP2 expression levels were associated with poor prognosis (p=0.007) and shorter survival time after recurrence (p=0.035). High SKAP2 expression was an independent prognostic factor in NSCLC patients (p=0.027). CONCLUSION: High SKAP2 expression levels in NSCLC tissues could be a powerful biomarker of poor prognosis. Therefore, SKAP2 is a promising candidate molecular target for NSCLC treatment.

Single-incision laparoscopic surgery for a small-intestinal gastrointestinal stromal tumor: report of a case.

Our report concerns a 64-year-old man with a small-intestinal gastrointestinal stromal tumor (GIST), which was successfully treated with single-incision laparoscopic surgery (SILS). Small-bowel endoscopy detected a submucosal tumor located approximately 10 cm from the ligament of Treitz in the wall of the proximal jejunum. Contrast-enhanced computed tomography revealed a tumor (diameter, 4 cm) containing high- and low-density areas in the proximal jejunum. On 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET), the tumor demonstrated intense FDG uptake (maximum standard uptake value, 3.82), whereas it displayed high signal intensity on diffusion-weighted magnetic resonance images. No metastatic lesions were observed. The patient was diagnosed with a jejunal GIST. Wedge resection of the jejunum was performed using the SILS procedure. The tumor was histopathologically diagnosed as a low-grade malignant GIST. SILS is a useful resection technique for small-intestinal GIST.

FBXW7 mediates chemotherapeutic sensitivity and prognosis in NSCLCs.

UNLABELLED: Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide. To improve the prognosis of patients with NSCLCs, new and validated therapeutic targets are critically needed. In this study, we focused on F-box and WD repeat domain containing-7 (FBXW7), an E3 ubiquitin ligase, that regulates the degradation of MCL1, Myc, cyclin E, and TOP2A. Importantly, loss of FBXW7 was associated with increased sensitivity of tumors to a class I-specific histone deacetylase (HDAC) inhibitor, MS-275. Immunohistochemical analysis revealed increased expression of FBXW7 targets, MCL1 and TOP2A, in NSCLC tumors with low expression of FBXW7. Moreover, clinical specimens exhibiting low FBXW7 expression presented with more progressive cancer and significantly shorter cancer-specific survival than patients with high FBXW7 expression. Mechanistic study of NSCLC cell lines with silenced FBXW7 revealed enhanced MS-275 sensitivity and taxol resistance. Interestingly, taxol resistance was eliminated by MS-275 treatment, suggesting the potential of HDAC inhibitors for the treatment of aggressive taxol-resistant NSCLCs that lack FBXW7. IMPLICATIONS: FBXW7 status impacts chemosensitivity and is a prognostic marker in NSCLCs. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/early/2013/12/19/1541-7786.MCR-13-0341/F1.large.jpg.

Relapsed cervicomediastinal lymph node carcinoma with an unknown primary site treated with TS-1 alone: a case report.

BACKGROUND: Cervicomediastinal lymph node carcinoma with an unknown primary site is quite rare, and useful treatment of these diseases has not been established. We report here the case of a patient successfully treated with TS-1 alone after the relapse of cervicomediastinal lymph node carcinoma with an unknown primary site. CASE PRESENTATION: A 62-year-old man was referred to our hospital because of cervicomediastinal lymph node swelling and high serum levels of carbohydrate antigen 19-9 and carcinoembryonic antigen. Fluorodeoxyglucose-positron emission tomography/computed tomography revealed an accumulation of fluorodeoxyglucose in the left supraclavicular lymph nodes, mediastinal lymph nodes, and the pelvic cavity. Colonoscopy revealed rectal cancer, which was diagnosed by biopsy as a tubular adenocarcinoma. Because metastases from rectal cancer to the cervicomediastinal lymph nodes are rare, the patient underwent thoracoscopic mediastinal lymphadenectomy. A biopsy specimen from the paraaortic lymph nodes demonstrated papillary adenocarcinoma that was pathologically different from the rectal cancer; therefore, a diagnosis of mediastinal carcinoma with an unknown primary site was established. The patient underwent low anterior resection of the rectum for the rectal cancer, and no abdominal lymph node metastasis (pMP, N0/stage I) was found. Although radiotherapy was performed for the cervicomediastinal lymph nodes, the mediastinal carcinoma relapsed after 6 months. Because the patient desired oral chemotherapy on an outpatient basis, TS-1 was administered at a dosage of 80 mg/day for 2 weeks, followed by a 1-week rest. TS-1 treatment resulted in a decrease in the size of the cervicomediastinal lymph nodes, and the serum tumor marker levels decreased to normal after the fourth course. The patient continued TS-1 treatment without adverse events and is currently alive without recurrence or identification of the primary site at the 32nd month after TS-1 treatment. CONCLUSION: This is the first reported case of relapsed cervicomediastinal lymph node carcinoma with an unknown primary site treated by TS-1 alone. TS-1 treatment for the carcinoma with an unknown primary site may be useful in patients who are not candidates for systemic platinum-based chemotherapy.