The value of post-operative chemotherapy after chemoradiotherapy in patients with high-risk locally advanced rectal cancer-results from the RAPIDO trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) rather than radiotherapy (RT) has resulted in fewer locoregional recurrences (LRRs), but no decrease in distant metastasis (DM) rate for patients with locally advanced rectal cancer (LARC). In many countries, patients receive post-operative chemotherapy (pCT) to improve oncological outcomes. We investigated the value of pCT after pre-operative CRT in the RAPIDO trial.

PATIENTS AND METHODS

Patients were randomised between experimental (short-course RT, chemotherapy and surgery) and standard-of-care treatment (CRT, surgery and pCT depending on hospital policy). In this substudy, we compared curatively resected patients from the standard-of-care group who received pCT (pCT+ group) with those who did not (pCT- group). Subsequently, patients from the pCT+ group who received at least 75% of the prescribed chemotherapy cycles (pCT ≥75% group) were compared with patients who did not receive pCT (pCT-/- group). By propensity score stratification (PSS), we adjusted for the following unbalanced confounders: age, clinical extramural vascular invasion, distance to the anal verge, ypT stage, ypN stage, residual tumour, serious adverse event (SAE) and/or readmission within 6 weeks after surgery and SAE related to pre-operative CRT. Cumulative probability of disease-free survival (DFS), DM, LRR and overall survival (OS) was analysed by Cox regression.

RESULTS

In total, 396/452 patients had a curative resection. The number of patients in the pCT+, pCT >75%, pCT- and pCT-/- groups was 184, 112, 154 and 149, respectively. The PSS-adjusted analyses for all endpoints demonstrated hazard ratios between approximately 0.7 and 0.8 (pCT+ versus pCT-), and 0.5 and 0.8 (pCT ≥75% versus pCT-/-). However, all 95% confidence intervals included 1.

CONCLUSIONS

These data suggest a benefit of pCT after pre-operative CRT for patients with high-risk LARC, with approximately 20%-25% improvement in DFS and OS and 20%-25% risk reductions in DM and LRR. Compliance with pCT additionally reduces or improves all endpoints by 10%-20%. However, differences are not statistically significant.

The mitochondrial DNA constitution shaping T-cell immunity in patients with rectal cancer at high risk of metastatic progression

PURPOSE

A significant percentage of colorectal cancer patients proceeds to metastatic disease. We hypothesised that mitochondrial DNA (mtDNA) polymorphisms, generated by the high mtDNA mutation rate of energy-demanding clonal immune cell expansions and assessable in peripheral blood, reflect how efficiently systemic immunity impedes metastasis.

PATIENTS AND METHODS

We studied 44 rectal cancer patients from a population-based prospective biomarker study, given curative-intent neoadjuvant radiation and radical surgery for high-risk tumour stage and followed for metastatic failure. Blood specimens were sampled at the time of diagnosis and analysed for the full-length mtDNA sequence, composition of immune cell subpopulations and damaged serum mtDNA.

RESULTS

Whole blood total mtDNA variant number above the median value for the study cohort, coexisting with an mtDNA non-H haplogroup, was representative for the mtDNA of circulating immune cells and associated with low risk of a metastatic event. Abundant mtDNA variants correlated with proliferating helper T cells and cytotoxic effector T cells in the circulation. Patients without metastatic progression had high relative levels of circulating tumour-targeting effector T cells and, of note, the naïve (LAG-3+) helper T-cell population, with the proportion of LAG-3+ cells inversely correlating with cell-free damaged mtDNA in serum known to cause antagonising inflammation.

CONCLUSION

Numerous mtDNA polymorphisms in peripheral blood reflected clonal expansion of circulating helper and cytotoxic T-cell populations in patients without metastatic failure. The statistical associations suggested that patient's constitutional mtDNA manifests the helper T-cell capacity to mount immunity that controls metastatic susceptibility.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01816607; registration date: 22 March 2013.

Inhibiting Interleukin 36 Receptor Signaling Reduces Fibrosis in Mice With Chronic Intestinal Inflammation

BACKGROUND & AIMS

Intestinal fibrosis is a long-term complication in inflammatory bowel diseases (IBD) that frequently results in functional damage, bowel obstruction, and surgery. Interleukin (IL) 36 is a group of cytokines in the IL1 family with inflammatory effects. We studied the expression of IL36 and its receptor, interleukin 1 receptor like 2 (IL1RL2 or IL36R) in the development of intestinal fibrosis in human tissues and mice.

METHODS

We obtained intestinal tissues from 92 patients with Crohn's disease (CD), 48 patients with ulcerative colitis, and 26 patients without inflammatory bowel diseases (control individuals). Tissues were analyzed by histology to detect fibrosis and by immunohistochemistry to determine the distribution of fibroblasts and levels of IL36R ligands. Human and mouse fibroblasts were incubated with IL36 or control medium, and transcriptome-wide RNA sequences were analyzed. Mice were given neutralizing antibodies against IL36R, and we studied intestinal tissues from Il1rl2^-/- mice; colitis and fibrosis were induced in mice by repetitive administration of DSS or TNBS. Bone marrow cells were transplanted from Il1rl2^-/- to irradiated wild-type mice and intestinal tissues were analyzed. Antibodies against IL36R were applied to mice with established chronic colitis and fibrosis and intestinal tissues were studied.

RESULTS

Mucosal and submucosal tissue from patients with CD or ulcerative colitis had higher levels of collagens, including type VI collagen, compared with tissue from control individuals. In tissues from patients with fibrostenotic CD, significantly higher levels of IL36A were noted, which correlated with high numbers of activated fibroblasts that expressed α-smooth muscle actin. IL36R activation of mouse and human fibroblasts resulted in expression of genes that regulate fibrosis and tissue remodeling, as well as expression of collagen type VI. Il1rl2^-/- mice and mice given injections of an antibody against IL36R developed less severe colitis and fibrosis after administration of DSS or TNBS, but bone marrow cells from Il1rl2^-/- mice did not prevent induction of colitis and fibrosis. Injection of antibodies against IL36R significantly reduced established fibrosis in mice with chronic intestinal inflammation.

CONCLUSION

We found higher levels of IL36A in fibrotic intestinal tissues from patients with IBD compared with control individuals. IL36 induced expression of genes that regulate fibrogenesis in fibroblasts. Inhibition or knockout of the IL36R gene in mice reduces chronic colitis and intestinal fibrosis. Agents designed to block IL36R signaling could be developed for prevention and treatment of intestinal fibrosis in patients with IBD.

Epidermal growth factor receptor-inhibition (EGFR-I) in the treatment of neuropathic pain

BACKGROUND

Neurobiological work has demonstrated that expression of mitogen-activated protein kinases (MAPK) is upregulated on neurones and glial cells after nerve damage. Furthermore, the epidermal growth factor receptor (EGFR) has been identified as having a key role in this process and subsequent interruption of this using EGFR-Inhibitors (EGFR-I), may improve neuropathic pain. The aim of this report was to explore if EGFR-I attenuated neuropathic pain in humans.

METHODS

A selection of patients with neuropathic pain were treated off-label with one of four EGFR-Is, approved for the treatment of cancer. All patients had chronic and severe neuropathic pain (as defined by diagnostic criteria). Pain intensity, interference with function, and adverse events were prospectively registered.

RESULTS

Twenty patients were treated. Eighteen patients experienced clinically significant pain relief after treatment with EGFR-I. Median observed pain reduction for all patients was 8.5 (IQR=5-9.5) points on a 0-10 numeric rating scale. Neuropathic pain spike duration and frequency also improved. Pain relief was most often achieved within 24 h and was more rapid in cases of i.v. than oral administration. All four EGFR-I that were tested were of equal efficacy. The duration of pain relief was consistent with the individual drugs' half-lives. No cases of drug-tolerance were observed. Side-effects were predominantly skin reactions. One grade 3 adverse event was registered. Median follow-up for responders was 7 months (Range 1-37).

CONCLUSIONS

EGFR-I improves neuropathic pain and this is in keeping with basic science work. Controlled clinical trials are now eagerly awaited to assess this further.

P5-18-07: Presence of Disseminated Tumor Cells after Adjuvant Chemotherapy in Breast Cancer and Disseminated Tumor Cells Monitoring during Secondary Adjuvant Treatment

Introduction: Detection of disseminated tumor cells (DTC) after completion of systemic adjuvant treatment is a strong predictor of early systemic relapse and death. This analysis can discover early failure of a chosen adjuvant systemic treatment. In this study, we wanted to evaluate the value of DTC detection in bone marrow (BM) as a surrogate marker for response to docetaxel rescue treatment, to predict the effect of this treatment. Further, we wanted to compare disease free survival between patients treated with docetaxel resulting in eradication of DTC after treatment and patients treated with docetaxel where DTC persists after treatment. The follow up of the study is still ongoing. Here, we present the preliminary descriptive data from the study.

Materials and Methods: A total of 1128 pts with node positive or high risk node negative disease (T1c/T2GII-IIIN0) was enrolled in the period from October 2003 to May 2008. All patients had completed primary surgery and received 6 cycles of adjuvant antracycline containing chemotherapy. The first BM aspiration was performed 8–12 weeks after termination of adjuvant chemotherapy (BM1). A second BM aspiration was performed 6 months later (BM2). The processing of BM and DTC analysis (by ICC) were performed as previsously described (Wiedswang G et al, J Clin Oncol 2003). If BM2 was positive (+) for DTC, the patient was treated with docetaxel (3qw, 6 courses) Docetaxel-treated patients were reexamined at the inclusion hospital with new BM analysis at approximately 1 month (BM3) and 13 months (BM4) after the last docetaxel infusion.

Results: Of 997 patients with conclusive DTC results for both BM1 and BM2, 83 patients (8.3%) were BM1 positive and 78 (7.8%) BM2 positive. Among the BM1+ patients, 15 (18.1%) were BM2+. The concordance between BM1 and BM2 were 87%. Of the patients positive at one or both time points, the concordance was 10% (15/146). The BM1 was not significantly associated with primary tumor characteristics (although borderline significance for Grade and ER status), whereas for BM2, DTC+ patients had increased frequency of node positive disease and pN2-3 stage (p=0.001, chi-square), and were positively associated with lobular carcinoma (p=0.01, chi-square). At BM1 24.7% of the DTC+ patients had >1 DTC, and 9.9% had ≥3 DTC. For BM2, 48.2% had >1 DTC, and 25.7% had ≥3 DTC. For patients with positive BM2 receiving docetaxel, the BM3 turned DTC negative in 55 of 66 evaluable cases (83.3%), and 48 of 59 were negative in BM4 (81.4%). Of 67 patients with a conclusive BM result at either BM3 or BM4, 12 were BM positive. Of 16 patients with ≥3 DTC before docetaxel treatment, only 4 patients were positive after treatment (25%).

Conclusions: DTC status after adjuvant antracycline containing chemotherapy changes during the first 9 months of FU, with increased DTC positivity among patients with pN+ disease and lobular carcinomas. After docetaxel rescue treatment, the majority of patients experience disappearance of the DTCs. The clinical significance of these results awaits mature FU data, but the present results may indicate possibility for eradication of residual disease by alternative chemotherapy.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-18-07.

An educational improvement project to track patient encounters: toward a more complete understanding of third-year medical students' experiences

BACKGROUND

At the University of Missouri School of Medicine (MUSOM), "commitment to improving quality and safety in healthcare" is one of eight key characteristics set as goals for our graduates. As educators, we have modelled our commitment to continuous improvement in the educational experiences through the creation of a method to monitor and analyse patient encounters in the third year of medical school. This educational improvement project allowed course directors to (1) confirm adequate clinical exposure, (2) obtain prompt information on student experiences, (3) adjust individual student rotations to meet requirements and (4) ascertain the range of clinical experiences available to students.

DISCUSSION

Data illustrate high levels of use and satisfaction with the educational innovation. We are in our second year using the new Patient Log (PLOG) process and are now considering expanding the use of PLOG into the fourth year of medical school.

Determination of the inflammatory potential of bioaerosols from a duck-fattening unit by using a limulus amebocyte lysate assay and human whole blood cytokine response

Inhalation of bioaerosols from animal houses can induce acute inflammatory reactions in the respiratory tract. Determination of the concentration of airborne endotoxins is widely used to characterize this risk. In this study, the activity of bioaerosol samples from a duck-fattening unit to induce interleukin-1beta (IL-1beta) in human blood and to react with Limulus Amebocyte Lysate (LAL) was investigated. The activity detected in the whole blood assay correlated well with the endotoxic activity found in the LAL assay (Spearmen's rho = 0.902). However in all samples, the inflammation-inducing potential was overestimated by the LAL assay. It is assumed that this overestimation could be, in part, a result of an overestimation of the inflammatory potential of endotoxins originating from Pseudomonadaceae by the LAL assay. Pseudomonadaceae were regularly isolated from the air of the duck-fattening unit. The results presented here indicate that the whole blood assay can be used besides the LAL assay as an additional method to characterize the inflammation-inducing potential of bioaerosols.

Evaluation of a parent child drug education program

The purpose of the study was to evaluate the effectiveness of a parent-child drug education program. One thousand four hundred and forty-seven fourth, fifth, and sixth grade students and 2,036 of their parents participated in the study. Results indicated that the program produced changes in the responses of children and their parents to questions concerning attitudes, use, perceptions of use, and intended use of drugs.