Citations

Abstract Purpose: The glutathione S-transferases (GSTs) catalyze the glutathione conjugation of reactive electrophiles, including carcinogens and many antineoplastic drugs. GSTT1 and GSTM1 are polymorphically deleted, but the full range of genetic variation in these two genes has not yet been explored. We set out to systematically identify common polymorphisms in GSTT1 and GSTM1, followed by functional genomic studies. Experimental Design: First, multiplex PCR was used to determine GSTT1 and GSTM1 copy number in 400 DNA samples (100 each from 4 ethnic groups). Exons, splice junctions, and 5′-flanking regions (5′-FR) were then resequenced using DNA samples that contained at least one copy of GSTT1 or GSTM1. Results: Gene deletion frequencies among ethnic groups were from 33.5% to 73.5% for GSTT1 and from 50.5% to 78.0% for GSTM1. GSTT1 deletion data correlated with the results of mRNA microarray expression studies. The 18 single nucleotide polymorphisms (SNP) observed in GSTT1 included three nonsynonymous coding SNPs (cSNPs) and one single-nucleotide deletion, whereas the 51 GSTM1 SNPs included two nonsynonymous cSNPs. Two of the GSTT1 nonsynonymous cSNPs resulted in decreases in levels of immunoreactive protein to 56% and 12% of wild type (WT), whereas those in GSTM1 resulted in modest increases in protein levels. Reporter gene assays showed that one GSTT1 5′-FR haplotype, with a frequency of 32% in African-American subjects, resulted in an increase in transcription in JEG-3 cells to 351% of that for the WT sequence, and one GSTM1 5′-FR haplotype resulted in an increase in transcription in JEG-3 cells to 129% of WT. Conclusions: These observations suggest that functionally significant pharmacogenomic variation beyond GSTT1 and GSTM1 gene deletion may contribute to carcinogenesis or individual variation in antineoplastic drug therapy response.

To investigate the concerns of parents, questionnaires were given to the "first 100" parents waiting for their child's pediatric appointment in four different medical settings. They were asked to rate whether they worry "frequently," "occasionally," or "not at all" about 17 physical health issues, 16 psychosocial problems, 7 possible injuries, 4 instances of victimization, and 4 questions about parents' ability to provide discipline, affection, values and financial support. The response rate was 94% ; 89% were completed adequately for analysis. Parental concerns were compared to data from the National Center for Health Statistics about the statistical likelihood of the risks occurring. Ear infections (65%) were the most common health concern, followed by reaction to immunization (57%), common colds (51%), and cancer (50%). The greatest psychosocial concern was about children watching too much television (53%), followed by concerns about the quality of day care (50%). Three-quarters of parents worry about car accidents and 72% worry about abduction of their children. Parents worry significantly about their own contribution to their child's welfare: appropriate discipline (73%), affection (56%), values and being a role model (55%), and financial support (66%). Parents who had not completed high school worried more than parents who had more than a high school education (P < 0.03).

Among 1138 newborns in a Level II nursery, breast-fed and formula-fed infants were comparable in terms of sex, mode of delivery, gestational age, birth weight, and birth temperature. Breast-fed neonates subsequently lost more weight and a greater percentage of their birth weight (mean, 7.4% vs. 4.9%) than did formula-fed infants. Loss of more than 10 percent of birth weight was associated with short gestation and low birth weight and with breast feeding. Birth weight loss of ≥3 percent was associated with a risk of fever (≥37.5°C) among breast-fed and formula-fed infants, but there was no gradient of increasing risk of fever with increasing percentage weight loss beyond 3 percent. After weight loss and other significant variables were adjusted for in a multivariate analysis, breast feeding was not independently predictive of fever. Although breast feeding may be associated with weight loss, it is not prudent to assume that this is the cause of fever in a breast-fed neonate.

Purpose The traditional end point for assessing efficacy of first-line chemotherapies for advanced cancer is overall survival (OS), but this end point requires prolonged follow-up and is potentially confounded by the effects of second-line therapies. We investigated whether progression-free survival (PFS) could be considered a valid surrogate for OS in advanced colorectal cancer. Patients and Methods Individual patient data were available from 10 historical trials comparing fluouracil (FU) + leucovorin with either FU alone (1,744 patients) or with raltitrexed (1,345 patients) and from three validation trials comparing FU + leucovorin with or without irinotecan or oxaliplatin (1,263 patients). Correlation coefficients were estimated in historical trials between the end points of PFS and OS, and between the treatment effects on these end points. Treatment effects on OS were predicted in validation trials, and compared with the observed effects. Results In historical trials, 1,760 patients (57%) had progressed or died at 6 months, and 1,622 (52%) had died at 12 months. The rank correlation coefficient between PFS and OS was equal to 0.82 (95% CI, 0.82 to 0.83). The correlation coefficient between treatment effects on PFS and on OS ranged from 0.99 (95% CI, 0.94 to 1.04) when all trials were considered to 0.74 (95% CI, 0.44 to 1.04) after exclusion of one highly influential trial. In the validation trials, the observed OS hazard ratios were within the 95% prediction intervals. A hazard ratio of 0.77 or lower in terms of PFS would predict a benefit in terms of OS. Conclusion PFS is an acceptable surrogate for OS in advanced colorectal cancer.

Abstract The frequency of colorectal cancer (CRC) among the Alaska Native people is the highest of any ethnic group in the United States. In this study, CRC from 329 Alaska Native people (165 Eskimo, 111 Indians, and 53 Aleut) were evaluated for evidence of defective DNA mismatch repair (MMR) by testing tumors for altered protein expression (hMLH1, hMSH2, and hMSH6) and for the presence of microsatellite instability. Of the 329 samples tested, 46 (14%) showed both microsatellite instability and altered protein expression; 42 (91%) with a loss of hMLH1, 3 (7%) hMSH2, and 1 (2%) hMLH1/hMSH6. Tumors with loss of hMLH1 were further evaluated for hMLH1 promoter hypermethylation and for the presence of the BRAF-V600E mutation. Among cases tested, all 19 (100%) tumors among the Eskimo patients showed hMLH1 promoter hypermethylation, whereas this was the case for only 3 of the 7 (42%) tumors among the Aleut (P = 0.002) and 5 of the 10 (50%) tumors from the Indians (P = 0.002). The majority of hypermethylated cases (23 of 27) tested positive for the V600E alteration. Of the nine tumors from the Aleut and Indian patients that did not exhibit hMLH1 hypermethylation, eight tested negative for V600E. Overall, the frequency of defective MMR among the three groups was not statistically different (P = 0.75). However, the data suggest that the pathogenesis of CRC may differ between the three groups. The CRC with defective MMR among the Eskimo sample fit the typical profile for hMLH1-related cancer associated with sporadic CRC, whereas the pattern in the Aleut and Indian suggests the possibility that germ line hMLH1 mutations may be present. (Cancer Epidemiol Biomarkers Prev 2007;16(11):2344–50)

Abstract The 2007 Santa Monica Conference on Assessing and Treating Early-Stage Colon and Rectal Cancer, a multidisciplinary meeting of leaders in surgery, medical and radiation oncology, and pathology, was convened on January 12 to 13, 2007. The purpose of the meeting was to assess current data and issues in the field and to develop recommendations for advancing patient care and clinical research. Topics included pathologic assessment and staging, transanal versus laparoscopic versus open resection, adjuvant therapy, genetic testing and counseling, cooperative group strategies, and the use of biological therapies and novel agents. A review of the key issues discussed, as well as conclusions and recommendations considered significant to the field, is summarized below and presented at greater length in the individual manuscripts and accompanying discussion that comprise the full conference proceedings. Although the management of early-stage colon and rectal cancers remains a challenge for all of us, the development and use of new technologies and methods of assessment and treatment over the past several decades is yielding encouraging results. A variety of opportunities to further improve outcomes were addressed in this forum, including recommendations that specific protocols be adopted regarding surgical and pathologic dissection and reporting, particularly for stage II disease; the corollary need to increase active multidisciplinary collaboration; and the development of comprehensive consensus guidelines and recommendations to standardize care in early-stage colorectal cancer.

Hands-on training courses with local mentoring are excellent educational tools in laparoscopic surgery; however, the need for the physical presence of specialized instructors represents a limitation because of costs, time, and geographic constraints. Remote robotic telementoring using a wireless videoconferencing mobile robot could represent an alternative to local instruction. The authors compare local active and passive mentoring with remote robotic telementoring using the wireless RP-6 Robot that worked through a WiFi 802.11b connection during a hands-on laparoscopic training session. Surgeons were mentored once in France from the United States. Robot mentoring was well received and appreciated (assessment score of 2.65; scale, 0 to 4). There was no statistical difference in the different mentoring sessions (active, passive, and remote). Mobile wireless robot is a valuable tool in laparoscopic telementoring. Robotic-assisted telementoring may not replace onsite mentoring, but it may enhance educational opportunities and the quality of hands-on training courses by implementing tutoring with expert assistance from remote locations.