Apoptotic desensitization is a hallmark of cancer cells, but present knowledge of molecular systems controlling apoptosis has yet to provide significant prognostic insights. Here, we report findings from a systems study of the intrinsic pathway of apoptosis by BCL2 family proteins and clinical translation of its findings into a model with applications in colorectal cancer (CRC). By determining absolute protein quantifications in CRC cells and patient tumor samples, we found that BAK and BAX were expressed more highly than their antiapoptotic inhibitors. This counterintuitive finding suggested that sole inhibition of effector BAX and BAK could not be sufficient for systems stability in nonstressed cells. Assuming a model of direct effector activation by BH3-only proteins, we calculated that the amount of stress-induced BH3-only proteins required to activate mitochondrial apoptosis could predict individual death responses of CRC cells to 5-fluorouracil/oxaliplatin. Applying this model predictor to protein profiles in tumor and matched normal tissue samples from 26 patients with CRCs, we found that differences in protein quantities were sufficient to model the increased tumor sensitivity to chemotherapy compared with normal tissue. In addition, these differences were sufficient to differentiate clinical responders from nonresponders with high confidence. Applications of our model, termed DR_MOMP, were used to assess the impact of apoptosis-sensitizing dugs in lowering the necessary dose of state-of-the-art chemotherapy in individual patients. Together, our findings offer a ready clinical tool with the potential to tailor chemotherapy to individual patients. Cancer Res; 73(2); 519-28. Ó2012 AACR.
Electrosurgical midline incision in elective surgery has significant advantages over scalpel use on the basis of incision time, blood loss, early postoperative pain and analgesia requirements.
IMPORTANCE Surgical site infections (SSIs) are common after laparotomy wounds and are associated with a significant economic burden. The use of negative pressure wound therapy (NPWT) has recently been broadened to closed surgical incisions. OBJECTIVE To evaluate the association of prophylactic NPWT with SSI rates in closed laparotomy incisions performed for general and colorectal surgery in elective and emergency settings. DATA SOURCES The PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched without language restrictions for relevant articles from inception until December 2017. The latest search was performed on December 31, 2017. The bibliographies of retrieved studies were further screened for potential additional studies. STUDY SELECTION Randomized clinical trials and nonrandomized studies were included. Unpublished reports were excluded, as were studies that examined NPWT (or standard nonpressure) dressings only without a comparator group. Studies that evaluated the use of NPWT in open abdominal incisions were also excluded. Disagreement was resolved by discussion, and if the question remained unsettled, the opinion of the senior author was sought. A total of 198 citations were identified, and 189 were excluded. DATA EXTRACTION AND SYNTHESIS This meta-analysis was conducted according to PRISMA guidelines. Data were independently extracted by 2 authors. A random-effects model was used for statistical analysis. MAIN OUTCOMES AND MEASURES The primary outcome measure was SSI, and secondary outcomes included seroma and wound dehiscence rates. These outcomes were chosen before data collection. RESULTS Nine unique studies (3 randomized trials and 2 prospective and 4 retrospective studies) capturing 1266 unique patients were included. Of these, 1187 patients with 1189 incisions were included in the final analysis (52.3% male among 7 studies reporting data on sex; mean [SD] age, 52 [15] years among 8 studies reporting data on age). Significant clinical and methodologic heterogeneity existed among studies. On random-effects analysis, NPWT was associated with a significantly lower rate of SSI compared with standard dressings (pooled odds ratio [OR], 0.25; 95% CI, 0.12-0.52; P < .001). However, no difference in rates of seroma (pooled OR, 0.38; 95% CI, 0.12-1.23; P = .11) or wound dehiscence (pooled OR, 2.03; 95% CI, 0.61-6.78; P = .25) was found. On sensitivity analysis, focusing solely on colorectal procedures, NPWT significantly reduced SSI rates (pooled OR, 0.16; 95% CI, 0.07-0.36; P < .001). CONCLUSIONS AND RELEVANCE Application of NPWT on closed laparotomy wounds in general and colorectal surgery is associated with reduced SSI rates but similar rates of seroma and wound dehiscence compared with conventional nonpressure dressings.
Increased copy number alterations (CNAs) indicative of chromosomal instability (CIN) have been associated with poor cancer outcome. Here, we study CNAs as potential biomarkers of bevacizumab (BVZ) response in metastatic colorectal cancer (mCRC). We cluster 409 mCRCs in three subclusters characterized by different degrees of CIN. Tumors belonging to intermediate-to-high instability clusters have improved outcome following chemotherapy plus BVZ versus chemotherapy alone. In contrast, low instability tumors, which amongst others consist of POLE-mutated and microsatellite-instable tumors, derive no further benefit from BVZ. This is confirmed in 81 mCRC tumors from the phase 2 MoMa study involving BVZ. CNA clusters overlap with CRC consensus molecular subtypes (CMS); CMS2/4 xenografts correspond to intermediate-to-high instability clusters and respond to FOLFOX chemotherapy plus mouse avastin (B20), while CMS1/3 xenografts match with low instability clusters and fail to respond. Overall, we identify copy number load as a novel potential predictive biomarker of BVZ combination therapy.
DR_MOMP delivers a system-based biomarker with significant potential as a prognostic tool for stage III CRC that significantly improves established histopathological risk factors.
Our study represents the first proof-of-concept example demonstrating the significant clinical potential of systems biology-based approaches for predicting patient outcome and responsiveness to novel targeted treatment paradigms.
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