Unique ghost surface phonon polaritons in biaxially hyperbolic materials.

We predicted peculiar ghost surface phonon polaritons in biaxially hyperbolic materials, where the two hyperbolic principal axes lie in the plane of propagation. We took the biaxially-hyperbolic α-MoO3 as one example of the materials to numerically simulate the ghost surface phonon polaritons. We found three unique ghost surface polaritons to appear in three enclosed wavenumber-frequency regions, respectively. These ghost surface phonon polaritons have different features from the surface phonon polaritons found previously, i.e., they are some hybrid-polarization surface waves composed of two coherent evanescent branch-waves in the α-MoO3 crystal. The interference of branch-waves leads to that their Poynting vector and electromagnetic fields both exhibit the oscillation-attenuation behavior along the surface normal, or a series of rapidly attenuated fringes. We found that the in-plane hyperbolic anisotropy and low-symmetric geometry of surface are the two necessary conditions for the existence of these ghost surface polaritons.

Unique surface polaritons and their transitions in metamaterials.

We investigated surface polaritons in a metamaterial composed of polar-crystal layers and antiferromagnetic layers. In a specific geometry, two surface polaritons were predicted, which are a unique ghost surface polariton (GSP) and surface hybrid-polarization polariton (SHP). The two surface polaritons occupy different segments of one smooth dispersion curve and are magnetically tunable. An external magnetic field along the antiferromagnetic easy axis can bring about the switch or transition between the two surface polaritons and meanwhile performs the necessary condition for the existence of two surface polaritons. In the metamaterial, either surface polariton consists of two branch waves. The branch waves of the GSP are coherent and have the same amplitude and different phases, but those of the SHP are not coherent and have different amplitudes and phases. The main characteristic of the GSP is that its fields oscillate and attenuate with the distance away from the metamaterial surface and exhibit interferent fringes on the plane normal to the surface.

Spin angular momentum and nonreciprocity of ghost surface polariton in antiferromagnets.

We investigated the spin angular momentum (SAM) and nonreciprocity of ghost surface polariton (GSP) at the surface of an antiferromagnet (AF) in the normal geometry, where the AF easy axis and external field (H0) both are normal to the AF surface. We found that the dispersion equation is invariant when the inversions of wavevector and external magnetic field, k→-k and H0→-H0, are taken. However, its polarization and SAM are nonreciprocal. The SAM is vertical to the propagation direction of GSP, and consists of two components. We analytically found that the in-plane component is locked to H0, or it is changed in sign due to the inversion of H0. The out-plane one is locked to k since it is changed in sign as the inversion of k is taken. Either component contains an electric part and a magnetic part. Above the AF surface, the two electric parts form the left-handed triplet with the wavevector k, but the two magnetic parts form the right-handed triplet with k. In the AF, the chirality of the SAM changes with the distance from the surface. The SAM is very large on or near the surface and it may be very interesting for the manipulation of micron and nano particles on the AF surface. These are obviously different from the relevant features of conventional surface polaritons. The SAM also is field-tunable.

Large spatial shifts of reflective beam at the surface of graphene/hBN metamaterials.

We theoretically studied the Goos-Hänchen (GH) and Imbert-Fedorov (IF) shifts of reflective beam at the surface of graphene/hBN metamaterials. The results show that the GH-shift is significantly enhanced and also possesses the large reflectivity when the light beam is incident at the critical angle near the Brewster angle. We found that the IF-shift is the largest when the reflective beam is a special polarized-beam or the reflective coefficients satisfy the conditions |rs | = |rp | and φs - φp = 2jπ (j is an integer). By changing the chemical potential, filling ratio and tilted angle, the position and width of frequency windows obtaining the maximum values of shifts can be effectively adjusted. The large and tunable GH- and IF-shifts with the higher reflectivity provide an alternative scheme to develop new nano-optical devices.

Spin-splitting in a reflective beam off an antiferromagnetic surface.

A linearly-polarized radiation can be considered as the superposition of two circularly-polarized components with the same propagating direction and opposite spins. We investigated the splitting between the two spin-components in the reflective beam off the antiferromagnetic surface. The gyromagnetism and surface impedance mismatch cause the difference between the spatial shifts of the two spin-components, i.e., the spin-splitting. We analytically achieved the in- and out-plane shift-expressions of either spin-component for two typical linearly-polarized incident beams (i.e., the p- and s-incidences). In the case of no gyromagnetism, we obtained very simple shift-expressions, which indicate a key role played by the gyromagnetism or the surface impedance-mismatch in spin-splitting. Based on a FeF2 crystal, the spin-splitting distance was calculated. The spin-splitting distance is much longer for the p-incidence than the s-incidence, and meanwhile the in-plane splitting distance is much larger than the out-plane one. The gyromagnetism plays a key role for the in-plane spin-splitting and the surface impedance-mismatch is a crucial factor for the out-plane spin-splitting distance. The results are useful for the manipulation of infrared radiations and infrared optical detection.

Survival landscape of different tumor regression grades and pathologic complete response in rectal cancer after neoadjuvant therapy based on reconstructed individual patient data.

BACKGROUND: Neoadjuvant therapy can lead to different tumor regression grades (TRG) in rectal cancer after neoadjuvant therapy. The purposes of this study are to investigate the relationships among TRG, pathologic complete response (pCR) and long-term survival, on the basis of reconstructed individual patient data (IPD). METHODS: The PubMed, Embase, Ovid and Cochrane CENTRAL databases were searched. The primary endpoint was to evaluate the survival landscape of different TRGs after neoadjuvant therapy and the secondary endpoint was to evaluate the associations between pCR and survival. IPD were reconstructed with Kaplan-Meier curves. RESULTS: The 10-year overall survival (OS) and 5-year disease-free survival (DFS) were clearly higher in the pCR group than in the non-pCR (npCR) group (80.5% vs. 48.3, 90.1% vs. 69.8%). Furthermore, the OS and DFS increased with improvement in tumor regression after neoadjuvant therapy. According to the IPD, the pCR group had longer OS (HR = 0.240, 95% CI = 0.177-0.325, p < 0.001) and DFS (HR = 0.274, 95% CI = 0.205-0.367, p < 0.001) than the npCR group. Better tumor regression was associated with better survival outcomes (p < 0.005). Direct calculation of published HR values yielded similar results. CONCLUSIONS: Our results indicate a positive relationship between better tumor regressions and improved survival benefits among the npCR group and patients with rectal cancer achieving pCR had much longer OS and DFS than patients achieving npCR, presenting a survival landscape of different TRGs and pCR in rectal cancer after neoadjuvant therapy.

Protein acetylation in mitochondria plays critical functions in the pathogenesis of fatty liver disease.

BACKGROUND: Fatty liver is a high incidence of perinatal disease in dairy cows caused by negative energy balance, which seriously threatens the postpartum health and milk production. It has been reported that lysine acetylation plays an important role in substance and energy metabolism. Predictably, most metabolic processes in the liver, as a vital metabolic organ, are subjected to acetylation. Comparative acetylome study were used to quantify the hepatic tissues from the severe fatty liver group and normal group. Combined with bioinformatics analysis, this study provides new insights for the role of acetylation modification in fatty liver disease of dairy cows. RESULTS: We identified 1841 differential acetylation sites on 665 proteins. Among of them, 1072 sites on 393 proteins were quantified. Functional enrichment analysis shows that higher acetylated proteins are significantly enriched in energy metabolic pathways, while lower acetylated proteins are significantly enriched in pathways related to immune response, such as drug metabolism and cancer. Among significantly acetylated proteins, many mitochondrial proteins were identified to be interacting with multiple proteins and involving in lipid metabolism. Furthermore, this study identified potential important proteins, such as HADHA, ACAT1, and EHHADH, which may be important regulatory factors through modification of acetylation in the development of fatty liver disease in dairy cows and possible therapeutic targets for NAFLD in human beings. CONCLUSION: This study provided a comprehensive acetylome profile of fatty liver of dairy cows, and revealed important biological pathways associated with protein acetylation occurred in mitochondria, which were involved in the regulation of the pathogenesis of fatty liver disease. Furthermore, potential important proteins, such as HADHA, ACAT1, EHHADH, were predicted to be essential regulators during the pathogenesis of fatty liver disease. The work would contribute to the understanding the pathogenesis of NAFLD, and inspire in the development of new therapeutic strategies for NAFLD.

Goos-Hänchen and Imbert-Fedorov shifts on hyperbolic crystals.

We investigated Goos-Hänchen (GH) and Imbert-Fedorov (IF) shifts on a uniaxial hyperbolic crystal, where a circularly-polarized beam was incident on the crystal from the free space. The GH- and IF-shifts were analytically obtained and numerically calculated for the hexagonal boron nitride. Our results demonstrate that the GH- and IF-shift spectra are complicated and completely different in and out the hyperbolic frequency-bands (the reststrahlen bands in the infrared region). At the critical or Brewster angle, concisely analytical expressions of GH-shift was found, which explicitly state the optical-loss dependence of GH-shift at these special angles. We found the GH-shifts are very large at the critical and Brewster angles. It is very necessary to know these effects since hyperbolic materials are usually applied in the nano- and micro-optics or technology fields.

Unusual spin and angular momentum of Dyakonov waves at the hyperbolic-material surface.

Three Dyakonov-like polaritons (DLPs) exist at the interface between a hyperbolic material (HM) and a covering medium (CM). Each DLP is a hybridized-polarization surface polariton composed of two evanescent waves on both sides of the interface. We investigated their spin and angular momentum. We analytically found that any DLP carries two spins producing mutually orthogonal spin angular-momentum (SAM) components. The spins and angular-momentum have different features on both sides of the interface, and further differences among the three DLPs are very obvious. For the interface structure formed by hexagonal boron nitride (hBN) and air, the SAM mainly distributes in the air for DLP-I, the SAM is approximately transverse to the propagating direction for DLP-II, and it is surprisingly large in the hBN for DLP-III and can reach several ten times that in the usual situation. There is the spin-k locking for every DLP, but the spin-k locking is different for different DLPs. These properties do not exist for traditional surface polaritons or ordinary evanescent waves. The above unique results can support some potential applications in the fields of nano- and micro-photonics, optoelectronics and mechanics, as well as relevant technologies.

Efficacy and safety of low dose Mycophenolate mofetil treatment for immunoglobulin G4-related disease: a randomized clinical trial.

Objectives: This randomized, controlled clinical trial aims to compare the efficacy and safety of glucocorticoid combined with MMF and glucocorticoid monotherapy for patients with IgG4-related disease. Methods: Sixty-nine patients newly diagnosed with IgG4-related disease were randomly divided into two groups (35 patients in Group I and 34 patients in Group II). Patients in Group I received glucocorticoid monotherapy (0.6-0.8 mg/(kg·day) and tapered gradually); patients in Group II received glucocorticoid combined with MMF therapy (1-1.5 g/day). All the patients were followed up at 1, 3, 6 and 12 months. The primary endpoint was response rate in 12 months and the secondary endpoints were relapse, remission rate and adverse reactions. Results: Group I and Group II shared almost the same efficacy at the 1 month treatment, but during the follow-up, the complete response rate in Group II was much higher than that in Group I at different time points, and the cumulative relapse rate during 1 year of therapy was much higher in Group I than that in Group II (40.00 vs 20.59%). The remission rate was lower in Group I (51.42 vs 76.47%). Relapses were more likely to happen in lung, lacrimal gland, salivary gland, paranasal sinus and kidney. MMF could reduce relapse, especially organs recurrence. No serious adverse reactions occurred in the two groups. Conclusion: Combination treatment with glucocorticoid and MMF was more effective than the monotherapy, and the relapse of IgG4-related disease might be associated with the elevated levels of serum IgG4 and the low glucocorticoid maintenance dose. Trial registration: ClinicalTrials.gov, www.clinicaltrials.gov, NCT02458196.

Extraordinary reflection and refraction from natural hyperbolic materials.

The reflection and refraction were theoretically investigated for a linearly-polarized wave incident upon the surface of a naturally hyperbolic material. We proposed that this material is uniaxial and possesses two hyperbolic-frequency bands (HB-I and HB-II), whose optical axis is arbitrarily pointed. We paid our attention to reflective and refractive features in the HBs and predicted some extraordinary phenomena. The double reflection was found, where the reflective wave contains a transverse electric branch and a transverse magnetic branch with different amplitudes and phases. The asymmetry of reflection exists and the reflective coefficient abnormally decreases as the incident angle is enlarged. The double refraction inside the material means two refractive branches (the o-wave and e-wave). For the e-wave, there is a special frequency point (SP) in either HB, depending on the orientation of the optical axis. The e-wave and reflective wave exhibit completely different behaviors on the two sides of the SP. The e-wave is a normal refractive wave on the left side of the SP, but it is an evanescent wave on the right side. Its energy-flux seriously deviates from the incident plane and is highly condensed at the inner surface near the SP. It is more interesting that the energy-flux density of the e-wave in the HB-II can even be much larger than that of the incident wave and is opposite in direction on the two sides of the SP, which means an evident radiation-switching effect. The o-wave is a normal refractive wave in the HB-I, but it is an evanescent wave in the HB-II. The above results and conclusions were obtained from the hexagonal boron nitride (hBN). These unique properties may be very useful in optical or optoelectronic technology.

Clinical evidence of prevention strategies for capecitabine-induced hand-foot syndrome.

Hand-foot syndrome (HFS) is the most common adverse effect of capecitabine-containing chemotherapy. The purpose of this study was to assess the efficacies of various prevention and treatment strategies for capecitabine-induced HFS. Searches of the PubMed and Embase databases were performed to identify relevant studies. The risk ratio (RR) with the corresponding 95% confidence interval (CI) was used as an effect measure to evaluate the efficacies of these prevention and treatment strategies. Publication bias was evaluated using Begg's and Egger's tests. Overall and subgroup analyses were conducted. All statistical analyses were conducted with Stata software version 12.0. Seventeen eligible studies were included. Our results indicated that celecoxib was significantly associated with a lower incidence of grade ≥2 capecitabine-induced HFS without heterogeneity (RR = 0.43, 95% CI = 0.23-0.81, I2  = 0.0%). However, pyridoxine and topical urea/lactic acid were not effective toward preventing capecitabine-induced grade 1, 2, 3, ≥1 or ≥2 HFS. Moreover, pyridoxine was not effective in treating capecitabine-induced HFS. Similar results were obtained by subgroup analysis. Our results indicate that celecoxib has potential prophylactic efficacy for capecitabine-induced HFS. However, pyridoxine and topical urea/lactic acid are not associated with a decrease in the incidence of capecitabine-induced HFS.

Impact of timing of adjuvant chemotherapy on survival in stage III colon cancer: a population-based study.

BACKGROUND: There is no consensus regarding the optimal time to initiate adjuvant chemotherapy after surgery for stage III colon cancer, and the relevant postoperative complications that cause delays in adjuvant chemotherapy are unknown. METHODS: Eligible patients aged ≥66 years who were diagnosed with stage III colon cancer from 1992 to 2008 were identified using the linked Surveillance, Epidemiology, and End Results-Medicare database. Kaplan-Meier analysis and a Cox proportional hazards model were utilized to evaluate the impact of the timing of adjuvant chemotherapy on overall survival (OS). RESULTS: A total of 18,491 patients were included. Delayed adjuvant chemotherapy was associated with worse OS (9-12 weeks: hazard ratio [HR] = 1.222, 95% confidence interval [CI] = 1.063-1.405; 13-16 weeks: HR = 1.252, 95% CI = 1.041-1.505; ≥ 17 weeks: HR = 1.969, 95% CI = 1.663-2.331). The efficacies of adjuvant chemotherapy within 5-8 weeks and ≤4 weeks were similar (HR = 1.045, 95% CI = 0.921-1.185). Compared with the non-chemotherapy group, chemotherapy initiated at ≥21 weeks did not significantly improve OS (HR = 0.882, 95% CI = 0.763-1.018). Patients with postoperative complications, particularly cardiac arrest, ostomy infection, shock, and septicemia, had a significantly higher risk of a 4- to 11-week delay in adjuvant chemotherapy (p < 0.05). CONCLUSIONS: Adjuvant chemotherapy initiated within 8 weeks was acceptable for patients with stage III colon cancer. Delayed adjuvant chemotherapy after 8 weeks was significantly associated with worse OS. However, adjuvant chemotherapy might still be useful even with a delay of approximately 5 months. Moreover, postoperative complications were significantly associated with delayed adjuvant chemotherapy.

Generation of Elliptically Polarized Terahertz Waves from Antiferromagnetic Sandwiched Structure.

The generation of elliptically polarized electromagnetic wave of an antiferromagnetic (AF)/dielectric sandwiched structure in the terahertz range is studied. The frequency and external magnetic field can change the AF optical response, resulting in the generation of elliptical polarization. An especially useful geometry with high levels of the generation of elliptical polarization is found in the case where an incident electromagnetic wave perpendicularly illuminates the sandwiched structure, the AF anisotropy axis is vertical to the wave-vector and the external magnetic field is pointed along the wave-vector. In numerical calculations, the AF layer is FeF2 and the dielectric layers are ZnF2. Although the effect originates from the AF layer, it can be also influenced by the sandwiched structure. We found that the ZnF2/FeF2/ZnF2 structure possesses optimal rotation of the principal axis and ellipticity, which can reach up to about thrice that of a single FeF2 layer.

Meta-analysis of the laparoscopic versus open colorectal surgery within fast track surgery.

BACKGROUND: Laparoscopic methods and fast-track surgery (FTS) can enhance recovery and reduce postoperative hospital stay. However, whether laparoscopic surgery can provide short-term benefits within FTS is controversial. Thus, we conducted a meta-analysis of published studies to evaluate the effect of laparoscopic colorectal surgery within FTS. METHODS: We searched PubMed, EMBASE, Cochrane Library, and Ovid databases for eligible studies. Endpoints were duration of postoperative hospital stay, time to first bowel movement, total postoperative complication rate, readmission rate, mortality within 30 days after surgery, and conversation rate of laparoscopic surgery. RESULTS: Four randomized controlled trials and six clinical controlled trials (1510 patients) were eligible for analyses. Duration of postoperative hospital stay (weighted mean difference, -1.65 days; p < 0.001), time to first bowel movement (-1.13 days; p < 0.001), total postoperative complication rate (risk ratio [RR], 0.65; p < 0.001), readmission rate (0.46; p < 0.001), and mortality (0.45; p < 0.001) were significantly reduced in the laparoscopic surgery group. Overall conversion rate of laparoscopic surgery was 11.1%. Subgroup analyses based on each FT element demonstrated that studies without the element "prevention of hypothermia," "no bowel preparation," or "no routine use of drains" did not show significant differences between two groups with regard to duration of postoperative hospital stay or total prevalence of postoperative complications. CONCLUSION: Within FTS, laparoscopic methods can significantly shorten postoperative hospital stay, accelerate postoperative recovery, and enhance safety in colorectal surgery. The FT elements "prevention of hypothermia," "no bowel preparation," and "no routine use of drains" may play important parts in the combined effect of these two methods.

A dose-response meta-analysis reveals an association between vitamin B12 and colorectal cancer risk.

OBJECTIVE: The current meta-analysis evaluated the association between vitamin B12 intake and blood vitamin B12 level and colorectal cancer (CRC) risk. DESIGN: The PubMed and EMBASE databases were searched. A dose-response analysis was performed with generalized least squares regression, with the relative risk (RR) and 95 % CI as effect values. SETTING: The meta-analysis included seventeen studies. SUBJECTS: A total of 10 601 patients. RESULTS: The non-linear dose-response relationship between total vitamin B12 intake and CRC risk was insignificant (P=0·690), but the relationship between dietary vitamin B12 intake and CRC risk was significant (P<0·001). Every 4·5 µg/d increment in total and dietary vitamin B12 intake was inversely associated with CRC risk (total intake: RR=0·963; 95 % CI 0·928, 0·999; dietary intake: RR=0·914; 95 % CI 0·856, 0·977). The inverse association between vitamin B12 intake and CRC risk was also significant when vitamin B12 intake was over a dosage threshold, enhancing the non-linear relationship. The non-linear dose-response relationship between blood vitamin B12 level and CRC risk was insignificant (P=0·219). There was an insignificant association between every 150 pmol/l increment in blood vitamin B12 level and CRC risk (RR=1·023; 95 % CI 0·881, 1·187). CONCLUSIONS: Our meta-analysis indicates that evidence supports the use of vitamin B12 for cancer prevention, especially among populations with high-dose vitamin B12 intake, and that the association between CRC risk and total vitamin B12 intake is stronger than between CRC risk and dietary vitamin B12 intake only.

Aspirin and nonsteroidal anti-inflammatory drugs after but not before diagnosis are associated with improved breast cancer survival: a meta-analysis.

PURPOSE: The association between nonsteroidal anti-inflammatory drugs (NSAIDs) and breast cancer survival is still controversial. The aim of our meta-analysis was to assess the survival benefit of NSAIDs. METHODS: A literature search was conducted in PubMed and EMBASE (to September 2014). A meta-analysis was performed with hazard ratios (HRs) and 95% confidence intervals (CIs) as the effect measures. Subgroup analyses were based on time of NSAID use (before and after diagnosis), medication type (aspirin and other nonaspirin NSAIDs), and study design (cohort and case-control studies). RESULTS: There were 16 eligible studies. Use of NSAIDs after diagnosis was significantly inversely associated with relapse/metastasis (HR 0.69, 95% CI 0.59-0.80) and tended toward potentially protective effects on all-cause mortality, although significance was not reached (HR 0.79, 95% CI 0.61-1.02). In cohort studies, the association between post-diagnostic use of NSAIDs and breast cancer survival was stronger with reduced heterogeneity (breast-cancer-specific mortality: HR 0.65, 95% CI 0.48-0.89, I(2) = 65.3%; all-cause mortality: HR 0.73, 95% CI 0.57-0.92, I(2) = 83.2%; relapse/metastasis: HR 0.73, 95% CI 0.61-0.86, I(2) = 48.3%). Aspirin use after diagnosis was significantly associated with breast-cancer-specific mortality (HR 0.69, 95% CI 0.50-0.96) and relapse/metastasis (HR 0.75, 95% CI 0.56-1.00), and tended toward a protective effect on all-cause mortality, although significance was not reached (HR 0.79, 95% CI 0.60-1.03). Including cohort studies only, we obtained similar results and post-diagnostic use of aspirin was significantly associated with all-cause mortality (HR 0.72, 95% CI 0.56-0.93). CONCLUSIONS: NSAIDs and aspirin after but not before diagnosis were associated with improved breast cancer survival, including breast-cancer-specific mortality, all-cause mortality, and relapse/metastasis.

Laparoscopic resection with natural orifice specimen extraction versus conventional laparoscopy for colorectal disease: a meta-analysis.

PURPOSE: We wished to determine the effects of laparoscopic resection using natural orifice specimen extraction (NOSE) for patients with colorectal disease through a meta-analysis. METHODS: A study search was undertaken in PubMed, EMBASE, and Cochrane databases for eligible studies until December 2014. Duration of hospital stay, operation time, time to first flatus, pain score, cosmetic result, postoperative complications, and disease-free survival (DFS) were the main endpoints. The results were analyzed using RevMan v5.3. RESULTS: Nine clinical studies involving 837 patients were included for final analyses. Laparoscopic resection with NOSE had a shorter duration of hospital stay (weighted mean difference (WMD) = -0.62 days, 95 % confidence interval (CI) [-0.95, -0.28], p < 0.01) and time to first flatus (WMD = -0.59 days, 95 % CI [-0.78, -0.41], p < 0.01), less postoperative pain (WMD = -1.43, 95 % CI [-1.95, -0.90], p < 0.01), and postoperative complications (odds ratio (OR) = 0.51, 95 % CI [0.36, 0.74], p < 0.01) with better cosmetic result (WMD = 1.37, 95 % CI [0.59, 2.14], p < 0.01). However, the operation time was significantly longer in the NOSE group (WMD = 20.97 min, 95 % CI [4.33, 37.62], p = 0.01). No significant difference was observed in DFS (hazard ratio (HR) = 0.88, 95 % CI [0.49, 1.57], p = 0.67). CONCLUSION: Our meta-analysis supported the notion that laparoscopic resection with NOSE for colorectal disease can significantly reduce the duration of hospital stay, accelerate postoperative recovery with better cosmetic results, and in particular, result in less postoperative pain and fewer complications.

Fast-track surgery versus traditional perioperative care in laparoscopic colorectal cancer surgery: a meta-analysis.

BACKGROUND: Both laparoscopic and fast-track surgery (FTS) have shown some advantages in colorectal surgery. However, the effectiveness of using both methods together is unclear. We performed this meta-analysis to compare the effects of FTS with those of traditional perioperative care in laparoscopic colorectal cancer surgery. METHODS: We searched the PubMed, EMBASE, Cochrane Library, and Ovid databases for eligible studies until April 2014. The main end points were the duration of the postoperative hospital stay, time to first flatus after surgery, time of first bowel movement, total postoperative complication rate, readmission rate, and mortality. RESULTS: Five randomized controlled trials and 5 clinical controlled trials with 1,317 patients were eligible for analysis. The duration of the postoperative hospital stay (weighted mean difference [WMD], -1.64 days; 95% confidence interval [CI], -2.25 to -1.03; p < 0.001), time to first flatus (WMD, -0.40 day; 95% CI, -0.77 to -0.04; p = 0.03), time of first bowel movement (WMD, -0.98 day; 95% CI, -1.45 to -0.52; p < 0.001), and total postoperative complication rate (risk ratio [RR], 0.67; 95% CI, 0.56-0.80; p < 0.001) were significantly reduced in the FTS group. No significant differences were noted in the readmission rate (RR, 0.64; 95% CI, 0.41-1.01; p = 0.06) or mortality (RR, 1.55; 95% CI, 0.42-5.71; p = 0.51). CONCLUSION: Among patients undergoing laparoscopic colorectal cancer surgery, FTS is associated with a significantly shorter postoperative hospital stay, more rapid postoperative recovery, and, notably, greater safety than is expected from traditional care.

Which is the best postoperative chemotherapy regimen in patients with rectal cancer after neoadjuvant therapy?

BACKGROUND: There is no general agreement about whether patients who have already received neoadjuvant chemoradiotherapy need further postoperative chemotherapy based on 5-fluorouracil(5-FU) or 5-FU plus oxaliplatin. METHODS: Medicare beneficiaries from 1992 to 2008 with Union for International Cancer Control ypStages I to III primary carcinoma of the rectum who underwent 5-FU-based neoadjuvant chemoradiotherapy and surgery for curative intent were identified through the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. A Cox proportional hazards model and propensity score-matched techniques were used to evaluate the effect of treatment on survival. RESULTS: For patients with resected rectal cancer who have already received 5-FU-based neoadjuvant chemoradiotherapy, postoperative 5-FU-based chemotherapy did not prolong cancer-specific survival (CSS) in ypStage I (P = 0.960) and ypStage II (P = 0.134); however, it significantly improved the CSS in ypStage III (hazard ratio = 1.547, 95% CI = 1.101-2.173, P = 0.012). No significant differences in survival between the 5-FU group and oxaliplatin group were observed. CONCLUSIONS: For patients with resected rectal cancer who have already received 5-FU-based neoadjuvant chemoradiotherapy, postoperative 5-FU-based chemotherapy prolongs the CSS of groups in ypStage III. Adding oxaliplatin to fluoropyrimidines in the postoperative chemotherapy did not improve the CSS for patients who received neoadjuvant chemoradiotherapy.