Small Intestinal Cancer: Why the Rarity?

Prediction of distant metastasis and specific survival prediction of small intestine cancer patients with metastasis: A population-based study

BACKGROUND

Small intestine cancer (SIC) is difficult to diagnose early and presents a poor prognosis due to distant metastasis. This study aimed to develop nomograms for diagnosing and assessing the prognosis of SIC with distant metastasis.

METHODS

Patients diagnosed with SIC between 2010 and 2015 were included from the Surveillance, Epidemiology and End Results database. Univariate and multifactor analysis determined independent risk factors for distant metastasis and prognostic factors for overall and cancer-specific survival. We then constructed the corresponding three nomograms and assessed the diagnostic accuracy of the nomograms by net reclassification improvement, receiver operating characteristic curves and calibration curves, assessed the clinical utility by decision curve analysis.

RESULTS

The cohort consisted of 6697 patients, of whom 1299 had distant metastasis at diagnosis. Tstage, Nstage, age, tumor size, grade, and histological type were independent risk factors for distant metastasis. Age, histological type, T stage, N stage, grade, tumor size, whether receiving surgery, number of lymph nodes removed, and the presence of bone or lung metastases were predictors of both overall survival and cancer-specific survival. The nomograms showed excellent accuracy in predicting distant metastasis and prognosis.

CONCLUSION

Nomograms were developed and validated for SIC patients with distant metastasis, aiding physicians in making rational and personalized clinical decisions.

Therapeutic targeting of the oncogenic Wnt signaling pathway for treating colorectal cancer and other colonic disorders

The canonical Wnt pathway is one of the key cellular signaling cascades that regulates, via the transcriptional co-activator β-catenin, numerous embryogenic developmental processes, as well as tissue homeostasis. It is therefore not surprising that misregulation of the Wnt/β-catenin pathway has been implicated in carcinogenesis. Aberrant Wnt signaling has been reported in a variety of malignancies, and its role in both hereditary and sporadic colorectal cancer (CRC), has been the subject of intensive study. Interestingly, the vast majority of colorectal tumors harbor mutations in the tumor suppressor gene adenomatous polyposis coli (APC). The Wnt pathway is complex, and despite decades of research, the mechanisms that underlie its functions are not completely known. Thus, although the Wnt cascade is an attractive target for therapeutic intervention against CRC, one of the malignancies with the highest morbidity and mortality rates, achieving efficacy and safety is yet extremely challenging. Here, we review the current knowledge of the Wnt different epistatic signaling components and the mechanism/s by which the signal is transduced in both health and disease, focusing on CRC. We address some of the important questions in the field and describe various therapeutic strategies designed to combat unregulated Wnt signaling, the development of targeted therapy approaches and the emerging challenges that are associated with these advanced methods.

The interplay between intrinsic and extrinsic Wnt signaling in controlling intestinal transformation

The intestinal epithelial layer is the fastest renewing tissue in the human body. Due to its incredible turnover rate, the intestine is especially prone to develop cancer, in particular in the colon. Colorectal cancer (CRC) development is characterized by the stepwise accumulation of mutations over time, of which mutations in the tumor suppressor APC are often very early to occur. Generally, mutations in this gene lead to truncated APC proteins that cannot bind to β-catenin to promote its degradation, resulting in a constant overstimulation of the Wnt pathway. The level of intrinsic Wnt activation is dependent on the number of functional β-catenin binding sites remaining within the APC proteins, and the right amount of Wnt signaling is rate-limiting in the formation of polyps. In addition, the intestinal niche provides an extensive spectrum of Wnt ligands, amplifiers and antagonists that locally regulate basal Wnt levels and consequently influence polyp formation propensity. Here we will discuss the crosstalk between transforming epithelial cells and their regional niche in the development of intestinal cancer.