Image-guided radiation therapy using surgical clips for localization of colonic metastasis from thyroid cancer

Postoperative locoregional recurrence pattern and treatment management of stage pT4 sigmoid colon cancer: a retrospective cohort study

BACKGROUND

This study aimed to explore the pattern of locoregional recurrence after surgery in patients with non-metastatic stage pT4 sigmoid colon cancer and the role of adjuvant radiotherapy on survival.

METHODS

We retrospectively analyzed data from 208 patients who underwent surgery in our hospital. The patients were randomly divided into training and validation groups at a 1:1 ratio. Patients at high risk for locoregional recurrence were screened using Cox regression analysis. Based on the data of 2,886 patients in the Surveillance, Epidemiology, and End Results (SEER) database, the effect of adjuvant radiotherapy on overall survival (OS) and cancer-specific survival (CSS) was evaluated by Kaplan-Meier curves.

RESULTS

Of the 208 patients, 57 (27.4%) presented with locoregional recurrences (14 anastomotic and 43 abdominal or pelvic lymph node recurrences). Multivariate analysis showed that serum CEA, differentiation, lymph node dissection number, and N stage were independent predictors of locoregional recurrence-free survival (all p < 0.05). A risk-stratification model was constructed, and a total score of ≥ 6.5 points was considered the high-risk group for locoregional recurrence. Both the training and validation sets presented that the model had a good predictive ability (area under the curve = 0.828 and 0.724, respectively). Analysis of SEER data revealed that adjuvant radiotherapy significantly prolonged OS and CSS in the high-risk population (all p < 0.05, vs. no radiotherapy).

CONCLUSIONS

Patients with a total risk score of 6.5 or more had a high likelihood of locoregional recurrence, and perhaps adjuvant radiotherapy could improve their survival.

Prognostic analysis and beneficiary identification of adjuvant external beam radiotherapy for stage pT4b sigmoid colon cancer

The clinical efficacy of adjuvant radiotherapy in sigmoid colon cancer remains questioned. To evaluate the clinical efficacy of adjuvant external beam radiotherapy (EBRT) for patients with pathologic stage T4b sigmoid colon cancer. Patients with stage pT4b sigmoid colon cancer receiving adjuvant EBRT or not followed by surgery between 2004 and 2016 were extracted from the Surveillance, Epidemiology, and End Results database. Analysis of overall survival (OS) was performed using Kaplan-Meier curves and prognostic factors were identified using Cox proportional hazards regression models with 95% confidence intervals within the entire cohort. A risk-stratification system was then developed based on the β regression coefficient. Among 2073 patients, 284 (13.7%) underwent adjuvant EBRT. The median OS in the group receiving adjuvant EBRT was significantly longer than that in the non-radiotherapy group (p < 0.001). Age, serum carcinoembryonic antigen (CEA) level, perineural invasion, lymph node dissection (LND) number, and adjuvant EBRT were independent factors associated with OS. A risk-stratification system was generated, which showed that low-risk patients had a higher 5-year survival rate than high-risk patients (75.6% vs. 42.3%, p < 0.001). Adjuvant EBRT significantly prolonged the 5-year survival rate of high-risk patients (62.6% vs. 38.3%, p = 0.009) but showed no survival benefit among low-risk patients (87.7% vs. 73.2%, p = 0.100). Our risk-stratification model comprising age, serum CEA, perineural invasion, and LND number predicted the outcomes of patients with stage pT4b sigmoid colon cancer based on which subgroup of high-risk patients should receive adjuvant EBRT.

Assessing the Effect of Radiotherapy in Addition to Surgery in Colon Adenocarcinomas: a Systematic Review and Meta-analysis of Contemporary Evidence

PURPOSE

This study aims to review the contemporary evidence investigating radiotherapy (RT) in addition to surgery for colon adenocarcinomas.

METHODS

We searched the following databases: PubMed, Science Direct, Scopus, ASCOpubs, the Cochrane Library, and Google Scholar. Studies (since January 2005) comparing outcomes of high-risk colon adenocarcinomas who underwent RT in addition to surgery versus no RT were eligible. Pooling of outcomes from published results or from analysis of survival curves was done. Subgroup analysis was conducted to determine if the efficacy of RT varies with RT timing.

RESULTS

Eight studies were included (five retrospective cohorts, three population-based studies). Pooled analysis from retrospective cohorts showed a reduction in 5-year LR (OR 0.41; 95% CI 0.21-0.79; p = 0.007) in the RT group. A benefit in 3-year (OR 1.81; 95% CI 1.15-2.87; p = 0.01) and 5-year (OR 2.10; 95% CI 1.21-3.63; p = 0.008) DFS and in 3-year (OR 2.55; 95% CI 1.43-4.54; p = 0.001) and 5-year (OR 2.00; 95% CI 1.17-3.41; p = 0.01) OS was seen in the RT group. The OS benefit was demonstrated in the subgroup analysis of neoadjuvant RT, but not with adjuvant RT. The improvement in OS with neoadjuvant RT was supported by a population-based study from NCDB, while results from two population-based studies investigating adjuvant RT were conflicting.

CONCLUSION

Taking into account the limitations of the studies, our review of evidence suggests a possible role of RT in improving oncologic outcomes of select colon adenocarcinomas. Prospective studies are needed to definitively assess the value of RT for colon cancer.

Transcriptome network of the papillary thyroid carcinoma radiation marker CLIP2

Background

We present a functional gene association network of the CLIP2 gene, generated by de-novo reconstruction from transcriptomic microarray data. CLIP2 was previously identified as a potential marker for radiation induced papillary thyroid carcinoma (PTC) of young patients in the aftermath of the Chernobyl reactor accident. Considering the rising thyroid cancer incidence rates in western societies, potentially related to medical radiation exposure, the functional characterization of CLIP2 is of relevance and contributes to the knowledge about radiation-induced thyroid malignancies.

Methods

We generated a transcriptomic mRNA expression data set from a CLIP2-perturbed thyroid cancer cell line (TPC-1) with induced CLIP2 mRNA overexpression and siRNA knockdown, respectively, followed by gene-association network reconstruction using the partial correlation-based approach GeneNet. Furthermore, we investigated different approaches for prioritizing differentially expressed genes for network reconstruction and compared the resulting networks with existing functional interaction networks from the Reactome, Biogrid and STRING databases. The derived CLIP2 interaction partners were validated on transcript and protein level.

Results

The best reconstructed network with regard to selection parameters contained a set of 20 genes in the 1st neighborhood of CLIP2 and suggests involvement of CLIP2 in the biological processes DNA repair/maintenance, chromosomal instability, promotion of proliferation and metastasis. Peptidylprolyl Isomerase Like 3 (PPIL3), previously identified as a potential direct interaction partner of CLIP2, was confirmed in this study by co-expression at the transcript and protein level.

Conclusion

In our study we present an optimized preselection approach for genes subjected to gene-association network reconstruction, which was applied to CLIP2 perturbation transcriptome data of a thyroid cancer cell culture model. Our data support the potential carcinogenic role of CLIP2 overexpression in radiation-induced PTC and further suggest potential interaction partners of the gene.