Abstract The implementation of a laparoscope-holding robot in minimally invasive surgery enhances the efficiency and safety of the operation. However, the extra robot control task can increase the cognitive load on surgeons. A suitable interface may simplify the control task and reduce the surgeon load. Foot interfaces are commonly used for commanding laparoscope-holding robots, with two control strategies available: decoupled control permits only one Cartesian axis actuation, known as decoupled commands; hybrid control allows for both decoupled commands and multiple axes actuation, known as coupled commands. This paper aims to determine the optimal control strategy for foot interfaces by investigating two common assumptions in the literature: 1. Decoupled control is believed to result in better predictability of the final laparoscopic view orientation, and 2. Hybrid control has the efficiency advantage in laparoscope control. Our user study with 11 experienced and trainee surgeons shows that decoupled control has better predictability than hybrid control, while both approaches are equally efficient. In addition, using two surgery-like tasks in a simulator, users' choice of decoupled and coupled commands is analysed based on their level of surgical experience and the nature of the movement. Results show that trainee surgeons tend to issue more commands than the more experienced participants. Single decoupled commands were frequently used in small view adjustments, while a mixture of coupled and decoupled commands was preferred in larger view adjustments. A guideline for foot interface control strategy selection is provided.

BackgroundThe role of adjuvant chemotherapy in stage II colon cancer continues to be debated. The presence of circulating tumor DNA (ctDNA) after surgery predicts very poor recurrence-free survival, whereas its absence predicts a low risk of recurrence. The benefit of adjuvant chemotherapy for ctDNA-positive patients is not well understood.MethodsWe conducted a trial to assess whether a ctDNA-guided approach could reduce the use of adjuvant chemotherapy without compromising recurrence risk. Patients with stage II colon cancer were randomly assigned in a 2:1 ratio to have treatment decisions guided by either ctDNA results or standard clinicopathological features. For ctDNA-guided management, a ctDNA-positive result at 4 or 7 weeks after surgery prompted oxaliplatin-based or fluoropyrimidine chemotherapy. Patients who were ctDNA-negative were not treated. The primary efficacy end point was recurrence-free survival at 2 years. A key secondary end point was adjuvant chemotherapy use.ResultsOf the 455 patients who underwent randomization, 302 were assigned to ctDNA-guided management and 153 to standard management. The median follow-up was 37 months. A lower percentage of patients in the ctDNA-guided group than in the standard-management group received adjuvant chemotherapy (15% vs. 28%; relative risk, 1.82; 95% confidence interval [CI], 1.25 to 2.65). In the evaluation of 2-year recurrence-free survival, ctDNA-guided management was noninferior to standard management (93.5% and 92.4%, respectively; absolute difference, 1.1 percentage points; 95% CI, −4.1 to 6.2 [noninferiority margin, −8.5 percentage points]). Three-year recurrence-free survival was 86.4% among ctDNA-positive patients who received adjuvant chemotherapy and 92.5% among ctDNA-negative patients who did not.ConclusionsA ctDNA-guided approach to the treatment of stage II colon cancer reduced adjuvant chemotherapy use without compromising recurrence-free survival. (Supported by the Australian National Health and Medical Research Council and others; DYNAMIC Australian New Zealand Clinical Trials Registry number, ACTRN12615000381583.)

Cardiac dextroposition, as opposed to dextrocardia, is an acquired horizontal displacement of heart to the right hemithorax with normal alignment of the major axis of the heart, caused by disease processes that either pull or push the heart to the right.1 Although dextrocardia can pose technical challenges when interventional treatments are required in such cases, dextroposition can be even more challenging given the distortion of normal anatomical relationships and the uncertainty of the accurate location and borders of the cardiac structures caused by the shift and rotation effected by the pathologic process.

Phosphoinositide kinases (PIKs) are a group of lipid kinases that are important upstream activators of various significant signaling pathways. Hyperactivation of the PI3K/AKT/mTOR pathways—either via mutations or genomic amplification—confers key oncogenic activity, essential for the development and progression of several solid tumors. Alterations in the PIK3CA gene are associated with poor prognosis of solid malignancies. Although the literature reports contradictory prognostic values of PIK3CA in aggressive cancers, most of the available data highlight the important role of PIK3CA mutation in mediating tumorigenesis via increased signaling of the PI3K/AKT/mTOR survival pathway. Several inhibitors of PI3K/AKT/mTOR pathways are investigated as potential therapeutic options in solid malignancies. This article reviews the role of PIK3CA mutations and inhibitors of PI3K/AKT/mTOR pathways in major cancer types and examines its association with clinicopathological parameters and prognosis.

Occupational exposures are an important determinant of respiratory health. International estimates note that about 15% of adult-onset asthma, 15% of chronic obstructive pulmonary disease and 10-30% of lung cancer may be attributable to hazardous occupational exposures. One-quarter of working asthmatics either have had their asthma caused by work or adversely affected by workplace conditions. Recently, cases of historical occupational lung diseases have been noted to occur with new exposures, such as cases of silicosis in workers fabricating kitchen benchtops from artificial stone products. Identification of an occupational cause of a lung disease can be difficult and requires maintaining a high index of suspicion. When an occupational lung disease is identified, this may facilitate a cure and help to protect coworkers. Currently, very little information is collected regarding actual cases of occupational lung diseases in Australia. Most assumptions about many occupational lung diseases are based on extrapolation from overseas data. This lack of information is a major impediment to development of targeted interventions and timely identification of new hazardous exposures. All employers, governments and health care providers in Australia have a responsibility to ensure that the highest possible standards are in place to protect workers' respiratory health.

Introduction . The association of Paneth cells with colorectal neoplasms has been demonstrated in several studies and case reports. T he frequency of Paneth cell-containing adenomas ranges from 0.2 to 39% in the various published studies. Although adenomas with Paneth cells have already been recognized before, there are no studies in the Philippines, that have been done to evaluate their clinicopathologic features. This study was performed to evaluate the clinicopathologic features of Paneth cell-containing adenomas and their association with adenoma burden. Methodology . A total of 326 colorectal adenomas from 133 patients diagnosed consecutively from April 2013 to June 2013 at St. Luke’s Medical Center, Quezon City, Philippines, were reviewed. These were checked for the presence of Paneth cells within the adenomatous crypts. The differences in gender and location were analyzed using one tail z-test, while the association of Paneth-cell containing adenomas with adenoma burden was analyzed using univariate odds ratio at 95% confidence interval. Results. The frequency of Paneth cell-containing adenomas in this study of 326 adenomas is 15% (50 of 326 adenomas). There was no statistical significance in the occurrence of the lesion between male and female patients (32% vs. 15%; p =0.2041). There was also no statistical difference in their occurrence in the proximal and distal colon (18% vs. 14%; p =0.1723). The odds of having multiple adenomas for patients with Paneth cell-containing adenomas are 3.16 times higher than those patients without Paneth cell-containing adenomas (15 patients with one adenoma, 23 patients with more than one adenoma; p=0.0037). Conclusion . This study has demonstrated the increased odds of harboring multiple adenomas in patients with Paneth-cell containing adenomas. This may be attributed in part to the fact that there have been recent studies revolving around Paneth cells that have shown that an established pathway of colorectal tumorigenesis, the APC/Wnt/ β - catenin pathway, regulates differentiation towards this cell lineage.

BackgroundCetuximab-induced hypomagnesemia has been associated with improved clinical outcomes in advanced colorectal cancer (CRC). We explored this relationship from a randomized clinical trial of cetuximab plus best supportive care (BSC) versus BSC alone in patients with pretreated advanced CRC. Patients and methodsDay 28 hypomagnesemia grade (0 versus ≥1) and percent reduction (<20% versus ≥20%) of Mg from baseline was correlated with outcome. ResultsThe median percentage Mg reduction at day 28 was 10% (-42.4% to 63.0%) for cetuximab (N = 260) versus 0% (-21.1% to 25%) for BSC (N = 251) [P < 0.0001]. Grade ≥1 hypomagnesemia and ≥20% reduction from baseline at day 28 were associated with worse overall survival (OS) [hazard ratio, HR 1.61 (95% CI 1.12–2.33), P = 0.01 and 2.08 (95% CI 1.32–3.29), P = 0.002, respectively] in multivariate analysis including grade of rash (0–1 versus 2+). Dyspnea (grade ≥3) was more common in patients with ≥20% versus < 20% Mg reduction (68% versus 45%; P = 0.02) and grade 3/4 anorexia were higher in patients with grade ≥1 hypomagnesemia (81% versus 63%; P = 0.02). ConclusionsIn contrast to prior reports, cetuximab-induced hypomagnesemia was associated with poor OS, even after adjustment for grade of rash.