Local treatment for rectal cancer

The Impact of Novel Radiation Treatment Techniques on Toxicity and Clinical Outcomes In Rectal Cancer

Purpose of review

Three-dimensional conformal radiation therapy (3DCRT) has been the standard technique in the treatment of rectal cancer. The use of new radiation treatment technologies such as intensity-modulated radiation therapy (IMRT), proton therapy (PT), stereotactic body radiation therapy (SBRT) and brachytherapy (BT) has been increasing over the past 10 years. This review will highlight the advantages and drawbacks of these techniques.

Recent findings

IMRT, PT, SBRT and BT achieve a higher target coverage conformity, a higher organ at risk sparing and enable dose escalation compared to 3DCRT. Some studies suggested a reduction in gastrointestinal and hematologic toxicities and an increase in the complete pathologic response rate; however, the clinical benefit of these techniques remains controversial.

Summary

The results of these new techniques seem encouraging despite conclusive data. Further trials are required to establish their role in rectal cancer.

The evaluation of the oxidative stress for patients receiving neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Hypothesis: Nowadays, rectal cancer is an important healthcare challenge that affects many thousands of people each year worldwide, being diagnosed especially after the age of 50 years. Objective: This study attempted to evaluate the oxidative stress in patients with rectal cancer. Methods and results: 30 patients from the "Prof. Dr. Al. Trestioreanu" Institute of Oncology in Bucharest were treated with neoadjuvant radiochemotherapy during 2014 and 2016 and were included in the clinical study. Blood samples were obtained in dynamics during the treatment. From the blood samples, the serum was separated and used to identify the biochemical oxidative stress parameters. Results: Regarding the determination of lipid peroxides, albumin thiols, the cuprum oxidase activity of ceruloplasmin, the values registered in the dynamic of the treatment highlighted their increase to a maximum at the treatment's endpoint due to an important oxidative stress. Regarding the serum values for total antioxidants, the results pointed out the activation of the natural protection systems, which in time were overwhelmed, due to the installed oxidative stress. Conclusion: Part of the cytotoxic effect of radiotherapy was due to the production of oxidative stress. The cell was constantly exposed to the cytotoxic action of the reactive oxygen species. The obtained results indicated the dual relation to which the tumoral cell exposed itself and the installed oxidative stress, respectively, the oxidative stress being a cause or a consequence of the malign transformation. Abbreviations: CT = computed tomography, MRI = magnetic resonance imaging, ESMO = European Society for Medical Oncology, ECOG = performance status scale.

Ablative therapies for colorectal polyps and malignancy

Endoscopic techniques are gaining popularity in the management of colorectal polyps and occasionally superficial cancers. While their use is in many times palliative, they have proven to be curative in carefully selected patients with polyps or malignancies, with less morbidity than radical resection. However, one should note that data supporting local and ablative therapies for colorectal cancer is scarce and may be subject to publication bias. Therefore, for curative intent, these techniques should only be considered in highly select cases as higher rates of local recurrences have also been reported. The aim of this review is to explain the different modalities of local and ablative therapies specific to colorectal neoplasia and explain the indications and circumstances where they have been most successful.

Oncological outcomes of transanal local excision for high risk T1 rectal cancers

AIM: To evaluate the oncological outcomes of transanal local excision and the need for immediate conventional reoperation in the treatment of patients with high risk T₁ rectal cancers.

METHODS: Twenty five high risk T₁ rectal cancers treated by transanal local excision at the Guangdong General Hospital were analyzed retrospectively. Twelve patients received transanal local excision and 13 patients underwent subsequent immediate surgical rescue after transanal local excision within 4 wk. Differences in the local recurrence rates and 5-year overall survival rates between the two groups were analyzed. The prognostic value of immediate conventional reoperation for high risk T₁ rectal cancers was also evaluated.

RESULTS: The median follow-up period was 62 mo. The local recurrence rates after transanal local excision for high risk T₁ rectal cancer were 50%. By immediate conventional reoperation, the local recurrence rates were significantly reduced to 7.7%. The difference between these two groups was statistically significant (P = 0.030). Kaplan-Meier survival analysis showed a trend for decreased 5-year overall survival rates for patients treated by transanal local excision compared with immediate conventional reoperation (63% vs 89%).

CONCLUSION: Transanal local excision cannot be considered sufficient treatment for patients with high risk T₁ rectal cancers. Immediate conventional reoperation should be performed if the pathology of the local excision is high risk.