Radiation therapy for gastrointestinal cancer

Radiation in Gastroenterology

The benefit of radiation is immense in the field of gastroenterology. Radiation is used daily in different gastrointestinal imaging and diagnostic and therapeutic interventional procedures. Radiotherapy is one of the primary modalities of treatment of gastrointestinal malignancies. There are various modalities of radiotherapy. Radiotherapy can injure malignant cells by directly damaging DNA, RNA, proteins, and lipids and indirectly by forming free radicals. External beam radiation, internal beam radiation and radio-isotope therapy are the major ways of delivering radiation to the malignant tissue. Radiation can also cause inflammation, fibrosis, organ dysfunction, and malignancy. Patients with repeated exposure to radiation for diagnostic imaging and therapeutic procedures are at slightly increased risk of malignancy. Gastrointestinal endoscopists performing fluoroscopy-guided procedures are also at increased risk of malignancy and cataract formation. The radiological protection society recommends certain preventive and protective measures to avoid side effects of radiation. Gastrointestinal complications related to radiation therapy for oncologic processes, and exposure risks for patients and health care providers involved in diagnostic or therapeutic imaging will be discussed in this review.

Non-Coding RNAs and Resistance to Anticancer Drugs in Gastrointestinal Tumors

Non-coding RNAs are important regulators of gene expression and transcription. It is well established that impaired non-coding RNA expression especially the one of long non-coding RNAs and microRNAs is involved in a number of pathological conditions including cancer. Non-coding RNAs are responsible for the development of resistance to anticancer treatments as they regulate drug resistance-related genes, affect intracellular drug concentrations, induce alternative signaling pathways, alter drug efficiency via blocking cell cycle regulation, and DNA damage response. Furthermore, they can prevent therapeutic-induced cell death and promote epithelial-mesenchymal transition (EMT) and elicit non-cell autonomous mechanisms of resistance. In this review, we summarize the role of non-coding RNAs for different mechanisms resulting in drug resistance (e.g., drug transport, drug metabolism, cell cycle regulation, regulation of apoptotic pathways, cancer stem cells, and EMT) in the context of gastrointestinal cancers.

Double layered self-expanding metal stents for malignant esophageal obstruction, especially across the gastroesophageal junction

AIM: To evaluate the clinical outcomes of double-layered self-expanding metal stents (SEMS) for treatment of malignant esophageal obstruction according to whether SEMS crosses the gastroesophageal junction (GEJ).

METHODS: Forty eight patients who underwent the SEMS insertion for malignant esophageal obstruction were enrolled. Patients were classified as GEJ group (SEMS across GEJ, 18 patients) and non-GEJ group (SEMS above GEJ, 30 patients) according to SEMS position. Double layered (outer uncovered and inner covered stent) esophageal stents were placed.

RESULTS: The SEMS insertion and the clinical improvement were achieved in all patients in both groups. Stent malfunction occurred in seven patients in the GEJ group and nine patients in the non-GEJ group. Tumor overgrowth occurred in five and eight patients, respectively, food impaction occurred in one patient in each group, and stent migration occurred in one and no patient, respectively. There were no significant differences between the two groups. Reflux esophagitis occurred more frequently in the GEJ group (eight vs five patients, P = 0.036) and was controlled by proton pump inhibitor. Aspiration pneumonia occurred in zero and five patients, respectively, and tracheoesophageal fistula occurred in zero and two patients, respectively.

CONCLUSION: Double-layered SEMS are a feasible and effective treatment when placed across the GEJ for malignant esophageal obstruction. Double-layered SEMS provide acceptable complications, especially migration, although reflux esophagitis is more common in the GEJ group.

Long-term clinical outcomes of self-expanding metal stents for treatment of malignant gastroesophageal junction obstructions and prognostic factors for stent patency: effects of anticancer treatments

BACKGROUND

Self-expanding metal stent has emerged as an effective treatment option for malignant gastroesophageal junction obstruction. However, data on the clinicopathologic factors associated with stent patency are still lacking.

AIM

To investigate the long-term clinical outcomes and prognostic factors, including treatment modalities, affecting stent patency in patients with malignant gastroesophageal junction obstruction given self-expanding metal stent insertions.

METHODS

A total 89 patients who underwent self-expanding metal stent insertion for malignant gastroesophageal junction obstruction were enrolled. We analysed technical and clinical success rates, complications, and prognostic factors affecting stent patency.

RESULTS

Self-expanding metal stent insertion was successful in all patients and clinical improvement was achieved in 93.3%. Stent malfunction occurred in 32.9% of patients. The median overall survival time and stent patency time were 143 (95% CI: 99-187) and 190 days (95% CI: 108-272), respectively. In multivariate analysis, radiation therapy after stent placement significantly prolonged stent patency (OR: 0.221; 95% CI: 0.055-0.884; p=0.033). A higher migration rate was observed in those patients given chemotherapy after covered self-expanding metal stent placement (no anticancer treatment: 10.0%, chemotherapy: 42.9%, chemoradiation therapy: 9.1%, p=0.042).

CONCLUSIONS

Self-expanding metal stent is a feasible and effective treatment for malignant gastroesophageal junction obstruction. Radiation therapy after stent placement significantly prolongs overall stent patency and chemotherapy increases the migration rate of covered stents.

Physical activity and gastrointestinal cancer survivorship

Research examining physical activity in gastrointestinal cancer survivors is in its early stages and has focused primarily on colorectal cancer. Moreover, the majority of the research to date has been observational in nature, with very little interventional research. Though limited, the results of this research have been promising in nature, showing positive associations between physical activity and quality of life as well as disease outcomes, including improved disease-free and overall survival. The potential benefits of physical activity for gastrointestinal cancer survivors warrant further research on the underlying mechanisms of the relationship between physical activity and colorectal cancer disease outcomes, to determine if these associations extend to other gastrointestinal cancers, and to determine appropriate physical activity interventions to realize any potential supportive care benefits in various gastrointestinal cancer survivor groups.

Review of 120 anal cancer patients

OBJECTIVE

Chemoradiotherapy is the mainstay of treatment for the majority of patients with anal cancer, with abdominoperineal resection reserved for salvage. The purpose of this study was to evaluate our results after radiotherapy with or without chemotherapy, and/or surgery in terms of overall survival and colostomy free survival in patients with anal cancer.

METHOD

A review of patients diagnosed with anal cancer between 1991 and 2004 was performed. The principle end-points of the study were overall and colostomy-free survival.

RESULTS

One hundred and twenty patients were identified. The T stage distribution was T1 32, T2 44, T3 19, T4 17 and TX 8. Eighteen patients had clinically involved regional nodes. Eighty patients received radiotherapy as a component of their treatment. Twenty-four of the 80 patients had a colostomy. The most common late toxicity was faecal incontinence. The overall survival and colostomy-free survival rates for all 120 patients were 58% and 79% at 5 years, respectively. For the 80 patients who received radiotherapy, the corresponding figures were 66% and 82% at 5 years, respectively.

CONCLUSION

Chemoradiation is effective organ preserving treatment for anal cancer. Grade 1 and 2 faecal incontinence is a relatively common late toxicity experienced by patients.