Purpose
The molecular basis of the adenoma to carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas.
Experimental Design
We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach.
Results
Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer-driver genes (APC, KRAS, FBXW7, TCF7L2) and allelic imbalances in chromosomes 5, 7 and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation.
Conclusions
The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis.
The switch of HR status after NCT is remarkable for HR-positive tumors. An HR-negative switch may identify patients who would benefit from alternative systemic therapies.
BackgroundTo evaluate the relationship between body mass index (BMI) and response to neoadjuvant chemotherapy (NCT) for breast cancer among Chinese women.Patients and MethodsA total of 307 eligible patients were assigned to receive four cycles of paclitaxel and carboplatin before standard surgery for breast cancer from 2007 to 2011 at Shanghai Cancer Hospital. The patients were categorized as obese, overweight, normal weight, or underweight based on BMI according to World Health Organization (WHO) criteria. Pathological complete response (pCR) was defined as no invasive cancer in the breast or axillary tissue. A logistic regression and the Chi-squared test were used for detecting the predictors of pCR and determining the relationship between BMI category and pCR rate in the subgroup analysis with respect to other variables.ResultsCategorical BMI, estrogen receptor (ER), and progesterone receptor (PR) status were independent predictors of pCR according to the multivariate analysis. Patients with BMI≥25 were less likely to achieve a pCR to NCT compared with patients with BMI<25 (Odds ratio: 0.454, p = 0.033, multivariate analysis). In the subgroup analysis, the predictive value of BMI for pCR to NCT was significantly shown in post-menopausal patients (p = 0.004) and hormonal receptor status-negative patients (p = 0.038). The incidence of treatment-induced toxicity was similar among the different BMI categories.ConclusionHigher BMI was associated with worse pCR to NCT. Further approaches to investigating the mechanism of this influence of BMI on treatment response and a more appropriate schedule for calculating NCT dose for high-BMI-patients should be considered.
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