Vol 5, No 3 (2015)

Сancer stem cells (CSC) play a significant role in the development and progression of colorectal cancer. They are capable of self-senewal and multipotent differentiation. CSC can be formed from stem cells or mutant by dedifferentiation of crypt epithelial cells. Recently, much attention is paid to CSC in colon cancer, but very little has been published regarding their expression in colon polyps. In 2010 The World Health Organization attributed the so-called serrated lesions, including hyperplastic polyp, serrated sessile adenoma and traditional serrated adenoma to a group of precancerous lesions of the colon in addition to the classical tubular, villous and tubulo-villous adenomas. Despite the large number of publications devoted to the newly selected category, a full understanding of the processes involved in the formation of polyps and their progression into colon cancer, there is still no. Identification of CSC in colon polyps will assess their potential malignancy conduct adequate therapy, determine the amount of the operation and further treatment strategy. This in turn will contribute to the early detection and prevention of cancer. Identification of CSC, an assessment of their localization and distribution in tubular adenomas, serrated adenoma broad-based, traditional serrated adenoma and hyperplastic polyps allow to evaluate the potential of malignancy and prognosis for each of the polyps. In this regard, the definition of markers characteristic of colon CSC, is interesting not only from a scientific, but also from a practical point of view.

Background. Our aim was to investigate efficacy of neoadjuvant chemotherapy in colon cancer based on tumor regression.

Materials and methods. This retrospective study included colon cancer patients, who underwent treatment at the department of oncoproctology of Russian N. N. Blokhin Cancer Research Center during 2007–2014 and who received a minimum of 2 cycles of neoadjuvant chemotherapy. Primary endpoint was tumor regression. Tumor regression was analyzed separately considering treatment scheme, number of treatment cycles and presence of lymph node metastases.

Results. 18 patients were included (9 male and 9 female). 9 patients had locally advanced T4N0–2M0 colon cancer and 9 patients had metastatic T3–4N0–2M1 colon cancer. 17 (94.4 %) patients had macroscopic signs of residual tumor. Grade 1 and 2 tumor regression
(Dworak) was observed in 6 (33.3 %) and 10 (55.5 %) patients respectively. 2 (11.1 %) patients had no signs of tumor regression. Grade 2 tumor regression was most frequently (in 6/10 patients) observed after XELOX or FOLFOX chemotherapy.

Conclusions. Neoadjuvant chemotherapy leads to tumor regression inn most colorectal cancer patients. In our group chemotherapy regimens including oxliplatin were more effective.

Adenocarcinoma of the anal canal is a rare cancer. There are a few publications dedicated to this problem only, since patients with this nosological entity are combined with groups of those with lower ampullary cancer of the rectum (despite differences in the nature of these diseases). This paper describes 2 clinical cases of multistep combination treatment for locally advanced and disseminated cancer (adenocarcinoma) of the anal canal. It shows that it is appropriate to apply an aggregate approach to diagnosing this rare disease. Successful experience in treating patients with locally advanced and disseminated cancer of the anal canal is demonstrated. Nonstandard therapeutic approaches and clinical decisions are used. Magnetic resonance imaging was a key technique to diagnose local disease advance in both cases. Radiation sensitizers with different mechanisms of action were used during chemotherapy; preference was given to organ-sparing surgical treatment in the patient with metastatic cancer to maintain quality of life. The paper gives a concise literature review of current methods for the diagnosis and treatment of this disease. Despite the fact that there are no uniform standards, most authors adhere to the opinion that treatment should be started with prolonged chemoradiation therapy cycles followed by surgery. The treatment of patients with the isseminated forms of the disease is strictly individual and calls for a special approach, by taking into account of quality of life and prognosis in a patient.