Characterization in Effective Stimulation on the Magnitude, Gating, Frequency Dependence, and Hysteresis of INa Exerted by Picaridin (or Icaridin), a Known Insect Repellent

Picaridin (icaridin), a member of the piperidine chemical family, is a broad-spectrum arthropod repellent. Its actions have been largely thought to be due to its interaction with odorant receptor proteins. However, to our knowledge, to what extent the presence of picaridin can modify the magnitude, gating, and/or the strength of voltage-dependent hysteresis (Hys_(V)) of plasmalemmal ionic currents, such as, voltage-gated Na⁺ current [I_Na], has not been entirely explored. In GH₃ pituitary tumor cells, we demonstrated that with exposure to picaridin the transient (I_Na(T)) and late (I_Na(L)) components of voltage-gated Na⁺ current (I_Na) were differentially stimulated with effective EC₅₀’s of 32.7 and 2.8 μM, respectively. Upon cell exposure to it, the steady-state current versus voltage relationship I_Na(T) was shifted to more hyperpolarized potentials. Moreover, its presence caused a rightward shift in the midpoint for the steady-state inactivate curve of the current. The cumulative inhibition of I_Na(T) induced during repetitive stimuli became retarded during its exposure. The recovery time course from the I_Na block elicited, following the conditioning pulse stimulation, was satisfactorily fitted by two exponential processes. Moreover, the fast and slow time constants of recovery from the I_Na block by the same conditioning protocol were noticeably increased in the presence of picaridin. However, the fraction in fast or slow component of recovery time course was, respectively, increased or decreased with an increase in picaridin concentrations. The Hys_(V)’s strength of persistent I_Na (I_Na(P)), responding to triangular ramp voltage, was also enhanced during cell exposure to picaridin. The magnitude of resurgent I_Na (I_Na(R)) was raised in its presence. Picaritin-induced increases of I_Na(P) or I_Na(R) intrinsically in GH₃ cells could be attenuated by further addition of ranolazine. The predictions of molecular docking also disclosed that there are possible interactions of the picaridin molecule with the hNa_V1.7 channel. Taken literally, the stimulation of I_Na exerted by the exposure to picaridin is expected to exert impacts on the functional activities residing in electrically excitable cells.

PCDHB15 as a potential tumor suppressor and epigenetic biomarker for breast cancer

Breast cancer is among the most frequently diagnosed cancer types and the leading cause of cancer-related death in women. The mortality rate of patients with breast cancer is currently increasing, perhaps due to a lack of early screening tools. In the present study, using The Cancer Genome Atlas (TCGA) breast cancer dataset (n=883), it was determined that methylation of the protocadherin β15 (PCDHB15) promoter was higher in breast cancer samples than that in normal tissues. A negative association between promoter methylation and expression of PCDHB15 was observed in the TCGA dataset and breast cancer cell lines. In TCGA cohort, lower PCDHB15 expression was associated with shorter relapse-free survival times. Treatment with the DNA methyltransferase inhibitor restored PCDHB15 expression in a breast cancer cell line; however, overexpression of PCDHB15 was shown to suppress colony formation. PCDHB15 methylation detected in circulating cell-free DNA (cfDNA) isolated from serum samples was higher in patients with breast cancer (40.8%) compared with that in patients with benign tumors (22.4%). PCDHB15 methylation was not correlated with any clinical parameters. Taken together, PCDHB15 is a potential tumor suppressor in cases of breast cancer, which can be epigenetically silenced via promoter methylation. PCDHB15 methylation using cfDNA is a novel minimally invasive epigenetic biomarker for the diagnosis and prognosis of breast cancer.

Quantitation of Nitration, Chlorination, and Oxidation in Hemoglobin of Breast Cancer Patients by Nanoflow Liquid Chromatography Tandem Mass Spectrometry

Cells are continually exposed to endogenous reactive oxygen, nitrogen, and halogen species, causing damage to biomolecules. Among them, peroxynitrite and hypochlorous acid are not only oxidants but also biological nitrating and chlorinating agents, leading to the formation of 3-nitrotyrosine and 3-chlorotyrosine, respectively, in proteins. 3-Nitrotyrosine has been detected in vivo under several pathophysiological conditions, including breast cancer. Studies show that the concentrations of 3-nitrotyrosine in plasma proteins and platelets were significantly elevated in breast cancer patients. Compared to blood serum albumin, hemoglobin adducts represent biomonitoring of exposure with a longer lifetime. In this study, human hemoglobin was freshly isolated from blood and digested into peptides with trypsin, and the levels of protein adducts, including nitration, nitrosylation, and chlorination of tyrosine as well as oxidation of methionine residues, were simultaneously quantified by nanoflow liquid chromatography nanoelectrospray ionization tandem mass spectrometry (nanoLC-NSI/MS/MS) with selected reaction monitoring. The results demonstrated that the relative extents of nitration at α-Tyr-42 and β-Tyr-130, nitrosylation at α-Tyr-24, and chlorination at α-Tyr-24 and β-Tyr-130 are significantly higher in globin of 25 breast cancer patients compared to those in 25 healthy subjects (p < 0.05). In particular, nitration at α-Tyr-42 and chlorination at α-Tyr-24 showed the area under the receiver operating characteristic curve of >0.8. While the age of the subjects is correlated with the extents of some of these adducts, the body mass index does not have an effect on any of them. Starting with 1 drop of blood, our results indicated that this highly sensitive and specific nanoLC-NSI/MS/MS is useful in investigating the role of reactive nitrogen oxide species and reactive chlorine species in the etiology of breast cancer.

Sole adjuvant intraoperative breast radiotherapy in Taiwan: a single-center experience

Introduction

Intraoperative radiotherapy (IORT) is more convenient than standard whole breast external beam radiotherapy (EBRT) as a sole adjuvant radiotherapy for breast cancer. The impact of age on breast cancer course and treatment strategy is still under investigation, and the peak age for breast cancer in Taiwan is much younger than that in Western countries. We aimed to review the oncological outcomes of sole IORT compared with standard EBRT in a country with younger breast cancer patients.

Patients and methods

We reviewed patients with invasive breast cancer who received breast-conserving surgery (BCS) from September 2014 to December 2016. The clinicopathologic characteristics and oncological outcomes of eligible patients who received EBRT or IORT as sole adjuvant radiotherapy after BCS were collected and reviewed.

Results

A total of 170 patients were enrolled with a mean follow-up time of 3.53 ± 0.82 years. The risk of locoregional recurrence was 2.44% for EBRT versus 10.64% for IORT (p = 0.024). IORT was a significant risk factor of locoregional recurrence (p = 0.005). The hazard ratios (HRs) for locoregional recurrence in the IORT group compared with the EBRT group were significantly higher in non-suitable risk group patients (HR = 7.02, p = 0.009) and in patients under 50 years old (HR = 10.42, p = 0.011).

Conclusions

Locoregional recurrence was significantly higher in patients who received IORT than in those who underwent EBRT. IORT should not be used alone in patients under 50 years old who do not belong to a suitable group.

Gallium vacancies—common non-radiative defects in ternary GaAsP and quaternary GaNAsP nanowires

Nanowires (NWs) based on ternary GaAsP and quaternary GaNAsP alloys are considered as very promising materials for optoelectronic applications, including in multi-junction and intermediate band solar cells. The efficiency of such devices is expected to be largely controlled by grown-in defects. In this work we use the optically detected magnetic resonance (ODMR) technique combined with photoluminescence measurements to investigate the origin of point defects in Ga(N)AsP NWs grown by molecular beam epitaxy on Si substrates. We identify gallium vacancies, which act as non-radiative recombination centers, as common defects in ternary and quaternary Ga(N)AsP NWs. Furthermore, we show that the presence of N is not strictly necessary for, but promotes, the formation of gallium vacancies in these NWs.

Wave representation for asymmetric elliptic vortex beams generated from the astigmatic mode converter

An analytical wave representation is derived to express the asymmetric elliptic vortex beams generated by using an astigmatic mode converter to transform the asymmetric Hermite-Gaussian modes. The effect of the spatial asymmetry on the elliptic vortex beam can be straightforwardly considered in the analytical wave representation. A detailed comparison with experimental intensity patterns and phase structures is made. The good agreement between experimental results and theoretical analyses confirms the characterization and generation of the asymmetric elliptic vortex beams.

Composite metal substrate for thin film AlGaInP LED applications

The fabrication and feasibility assessment of n-side up, thin-epilayer, AlGaInP-based vertical light-emitting-diodes (LEDs; emitting area: 1 mm × 1 mm) with a copper-invar-copper-composite metal (CIC) substrate was obtained by wafer bonding and epilayer transferring technologies. The structure of CIC substrate is a top Cu layer of 20 μm, a middle Invar layer of 64 μm, and a bottom Cu layer of 20 μm. The invar layer consists of Fe and Ni at a ratio of 70% to 30%. The coefficient of thermal expansion for CIC is about 6.1 × 10^-6 /K, which is similar to that of the GaAs substrate (5.7 × 10^-6 /K) and AlGaInP epilayers. Due to the high thermal conductivity (160 W/m-K) of 104-μm-thick CIC, the high performances of the packaged LEDs are obtained. They present a low red shift phenomenon (from 623 to 642 nm for 100 mA to 1 A) and a high output power 212 mW at 800 mA. The CIC substrate can be extended to fabricate high-efficiency thin film LEDs with conventional vertical electrodes.

Exploring elliptical vortex beams with the spatial damping effect

A general integral formula is analytically derived to represent the wave function of elliptical vortex modes. The derived formula can be straightforwardly employed to take account of spatial damping to explore vortex structure. Spatial damping is found to cause the central degenerate singularity of the circular vortex mode to be split into several singularities with different topological charges. For the non-circular vortex beam, the influence of spatial damping on the distribution of singularities is not significant. Theoretical analyses are confirmed to agree very well with the experimental measurements.

Wild-type p53 upregulates an early onset breast cancer-associated gene GAS7 to suppress metastasis via GAS7-CYFIP1-mediated signaling pathway

The early onset breast cancer patients (age ≤ 40) often display higher incidence of axillary lymph node metastasis, and poorer five-year survival than the late-onset patients. To identify the genes and molecules associated with poor prognosis of early onset breast cancer, we examined gene expression profiles from paired breast normal/tumor tissues, and coupled with Gene Ontology and public data base analysis. Our data showed that the expression of GAS7b gene was lower in the early onset breast cancer patients as compared to the elder patients. We found that GAS7 was associated with CYFIP1 and WAVE2 complex to suppress breast cancer metastasis via blocking CYFIP1 and Rac1 protein interaction, actin polymerization, and β1-integrin/FAK/Src signaling. We further demonstrated that p53 directly regulated GAS7 gene expression, which was inversely correlated with p53 mutations in breast cancer specimens. Our study uncover a novel regulatory mechanism of p53 in early onset breast cancer progression through GAS7-CYFIP1-mediated signaling pathways.

Efficacy and toxicity of pegylated liposomal doxorubicin-based chemotherapy in early-stage breast cancer: a multicenter retrospective case-control study

AIM

PEGylated liposomal doxorubicin (PLD) has comparable efficacy and differing toxicity from conventional anthracyclines used to treat advanced breast cancer. This study compared disease-free survival and toxicity between PLD-based and conventional anthracycline-based regimens as adjuvant treatments for early-stage breast cancer.

METHODS

We analyzed disease-free survival (DFS) rates, and adverse events in 102 women with early-stage (I-IIIa) breast cancer who received adjuvant PLD-based chemotherapy from 2002 to 2008. Each patient was matched for age, stage at diagnosis, HER-2 expression and hormone therapy use to a patient treated with an epirubicin-based regimen. Fisher's exact and Pearson's chi-square tests were used for categorical data analysis. Kaplan-Meier analysis and Cox regression models were used to analyze DFS.

RESULTS

DFS at 5 years was 81.3% for PLD-based regimen and 82.3% for epirubicin-based regimen. This difference was not significant (p = 0.939). Stage IIIa disease was associated with a shorter DFS in univariate analysis (p = 0.048). In multivariate analysis that controlled for adjuvant treatment, age at diagnosis, stage, HER-2 expression, type of surgery and hormone and radiation therapy, stage IIIa disease (P = 0.023) and lack of hormone therapy (P = 0.024) were each independently associated with shorter DFS. Adverse events were evaluated, and with the exception of hand-foot syndrome, more grade 3 and 4 toxicities occurred in patients who received epirubicin-based regimens than in those given PLD-based regimens.

CONCLUSION

For patients with early-stage breast cancer who received PLD-based adjuvant chemotherapy, 5-year DFS was comparable and toxicity was acceptable, yet different from those of patients who received epirubicin-based regimens.

Promotion of metastasis of thyroid cancer cells via NRP-2-mediated induction

Tumor-node-metastasis is one of the leading causes of morbidity and mortality in thyroid cancer patients. Upregulation of vascular endothelial growth factor-C (VEGF-C) increases the migratory ability of thyroid cancer cells to lymph nodes. Expression of neuropilin-2 (NRP-2), the co-receptor of VEGF-C, has been reported to be correlated with lymph node metastasis in human thyroid cancer. The present study investigated the role of VEGF-C/NRP-2 signaling in the regulation of metastasis of two different types of human thyroid cancer cells. The results indicated that the VEGF-C/NRP-2 axis significantly promoted the metastatic activities of papillary thyroid carcinoma cells through the activation of the mitogen-activated protein kinase (MAPK) kinase (MEK)/extracellular signal-regulated kinase and p38 MAPK signaling cascades. However, neither MEK or p38 MAPK inhibitors produced significant inhibition of the migratory activity and invasiveness regulated by the VEGF-C/NRP-2 axis in follicular thyroid carcinoma cells. Finally, VEGF-C/NRP-2-mediated invasion and migration of thyroid cancer cells required the expression of NRP-2. The present results demonstrate that the promotion of metastasis by VEGF-C is mainly due to the upregulation of NRP-2 in thyroid cancer cells, and this metastatic activity regulated by the VEGF-C/NRP-2 axis provides further insight into the process of tumor metastasis.

Hinokitiol inhibits vasculogenic mimicry activity of breast cancer stem/progenitor cells through proteasome-mediated degradation of epidermal growth factor receptor

Hinokitiol, alternatively known as β-thujaplicin, is a tropolone-associated natural compound with antimicrobial, anti-inflammatory and antitumor activity. Breast cancer stem/progenitor cells (BCSCs) are a subpopulation of breast cancer cells associated with tumor initiation, chemoresistance and metastatic behavior, and may be enriched by mammosphere cultivation. Previous studies have demonstrated that BCSCs exhibit vasculogenic mimicry (VM) activity via the epidermal growth factor receptor (EGFR) signaling pathway. The present study investigated the anti-VM activity of hinokitiol in BCSCs. At a concentration below the half maximal inhibitory concentration, hinokitiol inhibited VM formation of mammosphere cells derived from two human breast cancer cell lines. Hinokitiol was additionally indicated to downregulate EGFR protein expression in mammosphere-forming BCSCs without affecting the expression of messenger RNA. The protein stability of EGFR in BCSCs was also decreased by hinokitiol. The EGFR protein expression and VM formation capability of hinokitiol-treated BCSCs were restored by co-treatment with MG132, a proteasome inhibitor. In conclusion, the present study indicated that hinokitiol may inhibit the VM activity of BCSCs through stimulating proteasome-mediated EGFR degradation. Hinokitiol may act as an anti-VM agent, and may be useful for the development of novel breast cancer therapeutic agents.

Pegylated Liposomal Doxorubicin as Adjuvant Therapy for Stage I-III Operable Breast Cancer

BACKGROUND

Conventional anthracyclines play an essential role for the treatment of breast cancer and have potent cytotoxic activity, but are associated with severe toxicity. In metastatic breast cancer, pegylated liposomal doxorubicin (PLD) is a formulation with efficacy similar to conventional doxorubicin but with reduced toxicity. This multicenter study evaluated the efficacy and safety of PLD-based adjuvant chemotherapy for women with stage I-III operable breast cancer.

PATIENTS AND METHODS

One hundred and eighty women with stage I-III breast cancer who received PLD-based adjuvant chemotherapy at six different Institutions in Taiwan from February 2002 to March 2008 were included and followed-up until April 2015. Treatment efficacy was determined by disease-free survival (DFS) rate and safety was evaluated by adverse events.

RESULTS

The 5- and 10-year DFS rates were 76.3 and 72.6%, respectively. Univariate analysis revealed that tumor size >5 cm (p=0.045; hazard ratio=3.31) and stage III (hazard ratio=3.54; p=0.019) were each associated with shorter DFS. Only stage III (hazard ratio=5.60; p=0.018) retained statistical significance with regard to DFS in the multivariate analysis. Grade 3/4 hematological toxicity was neutropenia (n=13; 7.2%). The women receiving PLD had low-grade 3 or 4 nausea/vomiting, mucositis, and alopecia. Grade 3 hand-foot syndrome occurred in three patients (1.7%).

CONCLUSION

PLD could be considered an effective and safe alternative to conventional anthracyclines in the treatment of stage I-III operable breast cancer.

Defect properties of ZnO nanowires revealed from an optically detected magnetic resonance study

Optically detected magnetic resonance (ODMR) complemented by photoluminescence measurements is used to evaluate optical and defect properties of ZnO nanowires (NWs) grown by rapid thermal chemical vapor deposition. By monitoring visible emissions, several grown-in defects are revealed and attributed to Zn vacancies, shallow (but not effective mass) donor and exchange-coupled pairs of Zn vacancies and Zn interstitials. It is also found that the intensity of the donor-related ODMR signals is substantially lower in the NWs compared with that in bulk ZnO. This may indicate that formation of native donors is suppressed in NWs, which is beneficial for achieving p-type conductivity.

Electrical and structural properties of antimony-doped p-type ZnO nanorods with self-corrugated surfaces

We report on p-type conductivity in antimony (Sb)-doped ZnO (ZnO:Sb) nanorods which have self-corrugated surfaces. The p-ZnO:Sb/n-ZnO nanorod diode shows good rectification characteristics, confirming that a p-n homojunction is formed in the ZnO nanorod diode. The low-temperature photoluminescence (PL) spectra of the ZnO:Sb nanorods reveal that the p-type conductivity in p-ZnO:Sb is related to the Sb(Zn)-2V(Zn) complex acceptors. Transmission electron microscopy (TEM) analysis of the ZnO:Sb nanorods also shows that the p-type conductivity is attributed to the Sb(Zn)-2V(Zn) complex acceptors which can be easily formed near the self-corrugated surface regions of ZnO:Sb nanorods. These results suggest that the Sb(Zn)-2V(Zn) complex acceptors are mainly responsible for the p-type conductivity in ZnO:Sb nanorods which have corrugated surfaces.

Evidence for coupling between exciton emissions and surface plasmon in Ni-coated ZnO nanowires

We show that coating ZnO nanowires (NWs) with a transition metal, such as Ni, can increase the efficiency of light emission at room temperature. Based on detailed structural and optical studies, this enhancement is attributed to energy transfer between near-band-edge emission in ZnO and surface plasmons in the Ni film which leads to an increased rate of the spontaneous emission. It is also shown that the Ni coating leads to an enhanced non-radiative recombination via surface states, which becomes increasingly important at low measurement temperatures and in annealed ZnO/Ni NWs.

Effects of a longitudinal magnetic field on spin injection and detection in InAs/GaAs quantum dot structures

Effects of a longitudinal magnetic field on optical spin injection and detection in InAs/GaAs quantum dot (QD) structures are investigated by optical orientation spectroscopy. An increase in the optical and spin polarization of the QDs is observed with increasing magnetic field in the range 0-2 T, and is attributed to suppression of exciton spin depolarization within the QDs that is promoted by the hyperfine interaction and anisotropic electron-hole exchange interaction. This leads to a corresponding enhancement in spin detection efficiency of the QDs by a factor of up to 2.5. At higher magnetic fields, when these spin depolarization processes are quenched, the electron spin polarization in anisotropic QD structures (such as double QDs that are preferably aligned along a specific crystallographic axis) still exhibits a rather strong field dependence under non-resonant excitation. In contrast, such a field dependence is practically absent in more 'isotropic' QD structures (e.g. single QDs). We attribute the observed effect to stronger electron spin relaxation in the spin injectors (i.e. wetting layer and GaAs barriers) of the lower-symmetry QD structures, which also explains the lower spin injection efficiency observed in these structures.

The Hanle effect and electron spin polarization in InAs/GaAs quantum dots up to room temperature

The Hanle effect in InAs/GaAs quantum dots (QDs) is studied under optical orientation as a function of temperature over the range of 150-300 K, with the aim of understanding the physical mechanism responsible for the observed sharp increase of electron spin polarization with increasing temperature. The deduced spin lifetime T(s) of positive trions in the QDs is found to be independent of temperature, and is also insensitive to excitation energy and density. It is argued that the measured T(s) is mainly determined by the longitudinal spin-flip time (T(1)) and the spin dephasing time (T(2)*) of the studied QD ensemble, of which both are temperature independent over the studied temperature range and the latter makes a larger contribution. The observed sharply rising QD spin polarization degree with increasing temperature, on the other hand, is shown to be induced by an increase in spin injection efficiency from the barrier/wetting layer and also by a moderate increase in spin detection efficiency of the QD.

Laparoscopic Roux-en-Y gastric bypass in a morbidly obese patient with renal transplant: a case report

Renal transplant is the only curative treatment for end-stage renal disease. As diabetes and obesity are the major causes of graft failure and post-transplant complication, it is important to manage obesity in patients with renal transplant. Herein, we report a case of a morbidly obese renal-transplant patient with poorly controlled diabetes who received bariatric surgery. A 34-year-old obese Taiwanese man with type 2 diabetes had end-stage renal disease that had progressed since 2008, when he had commenced hemodialysis (January 2008) and had a renal transplant (July 2008). Because of persistent obesity and poorly controlled diabetes, he received LRYGB at Chiayi Christian hospital on 18 August 2010. In the month that followed, he lost 10 kg. His serum creatinine decreased to 1.11 mg/dL (1.4 mg/dL, preoperative) and his hemoglobin A1c decreased to 8.5% (10.4%, preoperative). These results indicate that, in obese renal transplant patients, LRYGB may be employed to treat obesity, control diabetes and stabilize or improve the renal function.

Appendiceal hemorrhage -- an uncommon cause of lower gastrointestinal bleeding

Lower gastrointestinal bleeding is a common disease among elderly patients. The common sources of lower gastrointestinal bleeding include vascular disease, Crohn's disease, neoplasms, inflammatory bowel disease, hemorrhoids, and ischemic colitis. Lower gastrointestinal bleeding arising from the appendix is an extremely rare condition. We report a case of appendiceal hemorrhage in a young male. Diagnosis was made by multidetector computerized tomography during survey for hematochezia. The patient recovered well after appendectomy. The histological finding revealed focal erosion of appendix mucosa with bleeding.

Spin injection in lateral InAs quantum dot structures by optical orientation spectroscopy

Optical spin injection is studied in novel laterally-arranged self-assembled InAs/GaAs quantum dot structures, by using optical orientation measurements in combination with tunable laser spectroscopy. It is shown that spins of uncorrelated free carriers are better conserved during the spin injection than the spins of correlated electrons and holes in an exciton. This is attributed to efficient spin relaxation promoted by the electron-hole exchange interaction of the excitons. Our finding suggests that separate carrier injection, such as that employed in electrical spin injection devices, can be advantageous for spin conserving injection. It is also found that the spin injection efficiency decreases for free carriers with high momentum, due to the acceleration of spin relaxation processes.

Room-temperature defect-engineered spin filter based on a non-magnetic semiconductor

Generating, manipulating and detecting electron spin polarization and coherence at room temperature is at the heart of future spintronics and spin-based quantum information technology. Spin filtering, which is a key issue for spintronic applications, has been demonstrated by using ferromagnetic metals, diluted magnetic semiconductors, quantum point contacts, quantum dots, carbon nanotubes, multiferroics and so on. This filtering effect was so far restricted to a limited efficiency and primarily at low temperatures or under a magnetic field. Here, we provide direct and unambiguous experimental proof that an electron-spin-polarized defect, such as a Ga(i) self-interstitial in dilute nitride GaNAs, can effectively deplete conduction electrons with an opposite spin orientation and can thus turn the non-magnetic semiconductor into an efficient spin filter operating at room temperature and zero magnetic field. This work shows the potential of such defect-engineered, switchable spin filters as an attractive alternative to generate, amplify and detect electron spin polarization at room temperature without a magnetic material or external magnetic fields.

Optical configuration and color-representation range of a variable-pitch dot matrix holographic printer

The optical system configuration and design of a dot matrix holographic printer that can create image grating pixels of variable size, arbitrary pitch, and discretionary angle on a photoresist plate are presented. With the capability to vary spot size, grating orientation, and grating pitch on the fly, this newly developed holographic printer can apply a prespecified color at each specific viewing angle. Diffractive images with various visual effects and the wide color range that are possible by use of this system are examined in detail.

Primary uncommon malignant tumors of the esophagus: an analysis of 30 cases

BACKGROUND

Uncommon malignant tumors of the esophagus are defined as any histological type of malignant esophageal tumors other than the typical squamous cell carcinoma. Their biological characteristics remain obscure because of their rarity. Thus, this is a retrospective review of patients here with uncommon esophageal cancers in an attempt to evaluate their prognostic factors and proper therapeutic modalities.

METHODS

Among 1,674 patients with esophageal cancers, only 30 (1.8%) with uncommon esophageal cancers were collected between 1977 and 1992. The clinical parameters for evaluation consisted of age, sex, histological type, location, staging and a variety of therapeutic management techniques and their results.

RESULTS

Histologically, there were 10 adenocarcinomas, 7 small cell carcinomas, 6 adenosquamous carcinomas, 3 carcinosarcomas, 1 mucoepidermoid carcinoma, 1 adenoid cystic carcinoma, 1 fibrosarcoma, and 1 basal cell carcinoma. The mean age was 65.8 years, ranging from 46 to 85 years. Upon admission to hospital, the most common clinical symptoms included dysphagia, body weight loss and substernal pain. The tumor staging, according to TNM classification was evaluated as follows: Stage I: 13.3%, Stage II: 46.7%, Stage III: 16.9%, Stage IV: 23.3%. The middle third thoracic esophagus was the most common location of tumor occurrence. Overall one-year, two-year, and five-year survival rates were 39.3%, 21.4%, and 10.7% respectively. These results were as poor as those of squamous cell carcinoma. However, the patients with Stage I and Stage II tumors (mean, 23.8 months) had significantly better survivals than those with Stage III and Stage IV (mean, 3.9 months). Furthermore, if the tumor was resectable, the patients undergoing esophagectomy had much better one-year and two-year survival rates than those without esophagectomy (p < 0.01). In addition, patients with small cell carcinoma seemed to have worse treatment outcome than those with other histological types of tumors.

CONCLUSIONS

These results suggested that key factors contributing to prognosis included tumor staging as well as respectability. Thus, it is recommended that, with early detection and diagnosis, esophagectomy might be the treatment-of-choice in managing these uncommon esophageal malignancies. Adjuvant therapy including irradiation and chemotherapy may be helpful, particular for small cell carcinoma.