Protocol for the UK cohort study to investigate the prevention of parastomal hernia (the CIPHER study).

AIM: Abdominal surgery sometimes necessitates the creation of a stoma, which can cause future complications including parastomal hernia (PSH), an incisional hernia adjacent to and related to the stoma. PSH affects approximately 40% of patients within 2 years of stoma formation. Complications of PSH reduce a patient's quality of life and can be severe (e.g. bowel obstruction). PSHs are difficult to manage and can recur after surgical repair. Therefore, it is very important to prevent a PSH. Surgeons create stomas in different ways and both patient and surgical factors are believed to influence the development of PSH. The aim of the CIPHER study is to investigate the influence of different surgical techniques on the development of PSH. METHOD: The UK cohort study to investigate the prevention of parastomal hernia (the CIPHER study) aims to recruit 4000 patients undergoing elective or expedited surgery with the intention of forming an ileostomy or colostomy, irrespective of the primary indication for the planned surgery. For each patient, surgeons will describe their methods of trephine formation, mesh reinforcement of the stoma trephine, use of the stoma as a specimen extraction site and wound closure. The primary outcome will be incident PSH during follow-up, defined as symptoms of PSH (custom-designed questionnaire) and anatomical PSH, ascertained by independent reading of usual care CT scans. Secondary outcomes will include surgical site infection, the Comprehensive Complication Index, quality of life (EQ-5D-5L and SF-12), PSH repair and use of NHS resources. RESULTS: Results of the study will be submitted for publication in peer-reviewed journals. All publications relating to the results of CIPHER will use a corporate authorship, 'The CIPHER Study Investigators' with named writing committee members. CONCLUSION: The CIPHER study will be the first to investigate detailed surgical methods of stoma formation in a large, representative cohort of patients with a range of primary indications, both cancer and noncancer.

The OMACS-PIL study: a randomised controlled trial within the OMACS observational study.

BACKGROUND: There has been little research to investigate whether the appearance of paper patient information leaflets (PILs) used to describe research studies to potential participants influences their decision to take part. Embedding a study within a trial (SWAT) is an efficient way of answering this type of methodological question. We included a randomised SWAT within a large cohort study, Outcome Monitoring after Cardiac Surgery (OMACS), to address this question. METHODS: Potential participants for the OMACS study were randomised to receive one of three PILs, which were identical in content but with varying formatting and use of colour: PIL A (enhanced format), PIL B (hybrid format) and PIL C (standard format). Consent to OMACS was the primary outcome. Consent rates using the three different PIL formats were collected and compared. Qualitative feedback on the different formats was obtained from a public and patient involvement (PPI) group. RESULTS: For the SWAT, 1517 PILs were sent to potential participants, of whom 640 (42%) consented to take part in OMACS. PIL B had the highest recruitment rate, with 45% of patients consenting to participation; 40% and 41% of patients consented to participation after receiving PILs A and C, respectively. Compared to PIL C, the consent rate was 4% higher with PIL B (45% versus 41%, 95% confidence interval (CI) -2% to + 10%, p = 0.16) and 1% lower with PIL A (40% versus 41%, 95% CI - 7% to + 5%, p = 0.72). CONCLUSIONS: Consent rates were similar for all three PIL formats. PIL B is being used for the remainder of the host study and will be used to inform the design of PILs for other research studies, as it was the preferred format of the PPI group. TRIAL REGISTRATION: International Clinical Trials Registry, ISRCTN90204321. Registered on 21 January 2015.

Knockdown of PAK4 or PAK1 inhibits the proliferation of mutant KRAS colon cancer cells independently of RAF/MEK/ERK and PI3K/AKT signaling.

The p21-activated kinase (PAK) serine/threonine kinases are important effectors of the small GTPases Rac and Cdc42, and play significant roles in controlling cell growth, motility, and transformation. Knockdown of PAK4 or PAK1 inhibited the proliferation of mutant KRAS or BRAF colon cancer cells in vitro. Dependence on PAK4 or PAK1 protein for colon cancer cell proliferation was independent of PAK4 or PAK1 protein expression levels. Mutant KRAS HCT116 colorectal cells were the most sensitive to PAK4 or PAK1 knockdown resulting in the potent inhibition of anchorage-dependent and -independent proliferation as well as the formation and proliferation of HCT116 colon cancer spheroids. This inhibition of proliferation did not correlate with inhibition of RAF/MEK/ERK or PI3K/AKT signaling. In HCT116 cells, knockdown of PAK4 or PAK1 caused changes to the actin cytoskeleton resulting in reduced basal spread and cell elongation and increased cell rounding. These cytoskeletal rearrangements seemed to be independent of LIMK/cofilin/paxillin phosphorylation. PAK4 or PAK1 knockdown initially induced growth arrest in HCT116 cells followed by cell death at later time points. Inhibition of the antiapoptotic proteins Bcl-2 and Bcl-X(L) with the pharmacologic inhibitor ABT-737 increased effector caspase activation and apoptosis, and reduced cell survival with PAK4 or PAK1 knockdown. These results support a role for the PAKs in the proliferation of mutant KRAS-driven colorectal carcinoma cells via pathways not involving RAF/MEK/ERK and PI3K/AKT signaling.