Krasimir Ivanov

The Role of 3-D Endorectal Ultrasound in Rectal Cancer: Our Experience

In the last 20 years, endorectal ultrasound (ERUS) has been one of the main diagnostic methods for locoregional staging of rectal cancer. ERUS is accurate modality for evaluating local invasion of rectal carcinoma into the rectal wall layers (T category). Adding the three-dimensional modality (3-D) increases the capabilities of this diagnostic tool in rectal cancer patients. We review the literature and report our experience in preoperative 3-D ERUS in rectal cancer staging. In the group of 71 patients, the staging of preoperative 3-D endorectal ultrasonography was compared with the postoperative morphologic examination. Three-dimensional ERUS preoperative staging was confirmed with morphologic evaluation in 66 out of 71 cases (92.9%). The detection sensitivities of rectal cancer with 3-D ERUS were as follows: T1, 92.8%; T2, 93.1%; T3, 91.6%; and T4, 100.0%; with specificity values of T1, 98.2%; T2, 95.4%; T3, 97.8%; and T4, 98.5%. Three-dimensional ERUS correctly categorized patients with T1, 97.1%; T2, 94.3%; T3, 95.7%; and T4, 98.5%. The percentage of total overstaged cases was 2.75% and that of understaged cases was 6.87%. The metastatic status of the lymph nodes was determined with a sensitivity of 79.1% (19 of 24), specificity of 91.4% (43 of 47), and diagnostic accuracy of 87.3% (62 of 71). In our experience, 3-D ERUS has the potential to become the diagnostic modality of choice for the preoperative staging of rectal cancer.

Serum expression levels of miR-17, miR-21, and miR-92 as potential biomarkers for recurrence after adjuvant chemotherapy in colon cancer patients

The present study examined whether miR-17, miR-21, miR-29a, and miR-92 that are dysregulated in colon cancer (CC) can serve as potential predictive markers for relapse of disease after radical surgery and adjuvant chemotherapy. Real-time reverse transcription quantitative polymerase chain reaction was used to measure the expression levels of the miRNAs in serum samples from 37 patients with CC and 7 healthy individuals, tested as a control group. The area under the receiver operating characteristic curve (AUC) was then used to evaluate the predictive performance of the four miRNAs alone or in combination and compare it with carcinoembryonic antigen. The expression of miR-17, miR-21 and miR-92 were significantly higher in serum of patients with disease relapse. The AUCs for miR-17, miR-21, miR-92 for Nx patients were 0.844, 0.948, and 0.935, respectively (p < 0.05). Combining the four miRNAs for stage III patients increased the diagnostic performance, yielding an AUC of 0.881, with a sensitivity of 83.3% and a specificity of 85.7% (p < 0.05). Our study suggests that the expression levels of serum miR-21, miR-17, and miR-92 in patients with CC who underwent radical surgery and adjuvant chemotherapy may have diagnostic value for differentiating between recurred and non-recurred patients.

Intraoperative Sentinel Lymph Node Mapping in Patients with Colorectal Cancer

BACKGROUND/AIMS In about 1/3 of the patients with colorectal cancer without metastases which have been radically operated recurrences are observed and these patients die from cancer. This requires improvement of the surgical methods radicality as well as a more accurate determination of the indications for adjuvant chemotherapy administration. The introduction of a method for evaluating the degree of the metastases in colorectal cancer would highlight these issues. To this purpose we apply the method of sentinel mapping. METHODOLOGY For a period of one year we performed intraoperative sentinel mapping on 103 patients who had been operated for colon or rectal cancer. We used the dying method with Patent Blue V. An algorithm was worked out for sentinel mapping in colorectal cancer. RESULTS We achieved 100% performance success and 97% sensitivity. We increased the volume of the surgical intervention in 100% of the patients and elevated the clinical stage of 20% of the patients in Ist and IInd stage by means of ultrastaging with immunohistochemistry. CONCLUSIONS We conclude that sentinel lymph nodes mapping in colorectal cancer is a diagnostic method which is convenient for the surgeons allowing them for an individualized approach toward each patient.

Virilizing adrenal oncocytoma in a 9-year-old girl: rare neoplasm with an intriguing postoperative course.

Abstract Adrenal oncocytoma is an extremely rare neoplasm, which is mostly non-functional. Only five cases of childhood adrenal oncocytoma have been described so far, all of which were hormonally active. Currently, guidelines for management and follow-up are not available. We report a 9-year-old girl with benign adrenal oncocytoma, presenting with severe short-term virilization. After diagnostic work-up the patient underwent laparoscopic unilateral adrenalectomy. For the first 2 weeks following surgery she suffered marked mood swings, irritability and fatigue. There were no other clinical and/or laboratory abnormalities except the rapid drop-down of androgen levels to normal values. Follow-up showed no signs of recurrence and in the absence of signs of adrenal insufficiency, we speculate that, the rapid drop of androgen levels after removal of the tumor might be the reason for the deteriorated psychoemotional condition of our patient.

Smooth muscle sphincteroplasty in colostomy

Purpose: The present work elaborated on Schmidt’s idea of an effective smooth muscle sphincteroplasty. The aim of the study was to analyze the effects on the patients with a lower quadrant colostomy constructed after abdominoperineal extirpation of a modified smooth muscle sphincteroplasty combined with colon irrigations. Methods: Seventy-two rectal cancer patients (39 men and 33 women, median age, 54.5 years) with smooth muscle sphincteroplasty and 20 controls with conventional colostomy using colon irrigations (11 men and 9 women, median age, 63.2 years) were examined. A modified smooth muscle wrap of the colostomy with a free graft of a 4-cm-long colon segment without mucosa was applied. In this precolostomy segment a high intraluminal pressure was achieved. The functional capacity and anatomic integrity of the transplanted smooth muscle graft were examined manometrically, electromyo-graphically, and histomorphologically. The functional activity of the colostomy was assessed by periodic recording of the number of “spontaneous” and “directed” defecations. Results: In the patients with smooth muscle sphincteroplasty, the basal intraluminal pressure of the precolostomy segment two years after operation measured 29.7 mmHg. After dilatation of the transplant, these pressures reached up to 43 mmHg (P < 0.001). The weekly “spontaneous” stools were 3 to 5 times less frequent than in the controls (P < 0.001). Conclusions: The modified smooth muscle sphincteroplasty offers operative-technical opportunities for increasing intraluminal pressure in the precolostomy colon segment. Its combination with colonic irrigations facilitates control of the evacuatory rhythm and “spontaneous” stools in colostomy patients, thus improving their quality of life.

International scientific communications in the field of colorectal tumour markers

AIM To analyze scientometrically the dynamic science internationalization on colorectal tumour markers as reflected in five information portals and to outline the significant journals, scientists and institutions. METHODS A retrospective problem-oriented search was performed in Web of Science Core Collection (WoS), MEDLINE, BIOSIS Citation Index (BIOSIS) and Scopus for 1986-2015 as well as in Dervent Innovations Index (Derwent) for 1995-2015. Several specific scientometric parameters of the publication output and citation activity were comparatively analyzed. The following scientometric parameters were analyzed: (1) annual dynamics of publications; (2) scientific institutions; (3) journals; (4) authors; (5) scientific forums; (6) patents - number of patents, names and countries of inventors, and (7) citations (number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus). RESULTS There is a trend towards increasing publication output on colorectal tumour markers worldwide along with high citation rates. Authors from 70 countries have published their research results in journals and conference proceedings in 21 languages. There is considerable country stratification similar to that in most systematic investigations. The information provided to end users and scientometricians varies between these data-bases in terms of most parameters due to different journal coverage, indexing systems and editorial policy. The lists of the so-called “core” journals and most productive authors in WoS, BIOSIS, MEDLINE and Scopus along with the list of the most productive authors - inventors in Derwent present a particular interest to the beginners in the field, the institutional and national science managers and the journal editorial board members. The role of the purposeful assessment of scientific forums and patents is emphasized. CONCLUSION Our results along with this problem-oriented collection containing the researchers’ names, addresses and publications could contribute to a more effective international collaboration of the coloproctologists from smaller countries and thus improve their visibility on the world information market.

Adjuvant Treatment in Colon Cancer

Worldwide, more than 1 million people develop colorectal cancer (CRC) annually. CRC is a major health problem in the Western world and the second most common cause of cancer mortality. To improve performance, the role of chemotherapy for CRC has increased dramatically over the last decade. The vast majority of CRC patients now receive chemotherapy with multiple agents that are currently approved for the treatment in the appropriate setting [1]. However, it is a complex process to select the optimal chemotherapy for each patient and practice evidence gap is still a problem. Some guidelines for the treatment of CRC have been developed to promote the standardization of CRC treatment. Postoperative, or “adjuvant,” systemic therapy has become standard for stage III colon cancer. Adjuvant therapy should also be strongly considered in stage II patients. It is generally recommended for any medically fit patient with stage II cancer with unfavorable factors. The hypothesis that the antitumor activity of the combination agent, including oxaliplatin, irinotecan, bevacizumab, cetuximab in metastatic cure rates, would result in increased adjuvant proved to be often wrong. Although new drug development takes years, targeted drug use can occur more quickly with advanced tests and will be a focus of future work. In addition, efforts will focus on identifying biomarkers that predict response to systemic therapy so that tailored therapy can be initiated. The future of oncology will come with the better understand‐ ing of the biology and genetics of the tumor and its host. This will help to develop tailored approach to the patients, including more specific systemic therapy, aimed at molecular targets of the malignant tumor, thus reducing the negative effects. At that time, the treatment of oncological diseases will experience a new era, comparable to the introduction of antibiotics.

Laparoscopy in the Management of Colon Cancer

The minimally invasive techniques in surgical practice have been well introduced and widely accepted for certain procedures, including surgery for colon cancer. The advantages of the laparoscopic approach in terms of early and late postoperative results and the oncological safety have been established by numerous reports, including randomized controlled trials. The application of laparoscopic colon surgery for cancer has been adopted in various institutions. This chapter reviews the available literature data regarding the use of minimally invasive surgery for colon cancer, including early and late surgical and oncological results and new trends. Retrospective and prospec‐ tive trials published in the last 20 years are reviewed to address the issues. Technolog‐ ical advantages such as intracorproreal anastomosis, single incision, and natural orifice surgery are commented in the chapter.

Endoscopic Submucosal Dissection for Early Colon Cancer

Endoscopic submucosal dissection (ESD) was first implemented in early gastric cancer allowing for en-bloc resection of the lesions. With the experience came the expertise to introduce ESD for early colon cancer (ECC). ESD demonstrates several advantages in comparison with the endoscopic mucosa resection. It allows accurate histological assessment of the depth of invasion, minimizes the risk of local recurrence and helps in the determination of additional therapy. Indications for ESD are placed only after adequate endoscopic morphological classification of the lesions excluding higher risk of nodal metastases. This chapter provides an overview of the application of ESD techniques in ESD for ECC and provides assessment on its technical aspects and complications. In order to decrease the rate of complications a standard protocol for the ESD should be adopted. The protocol includes recommendations for patient selection, bowel and patient preparation, appropriate equipment (knives, endoscopes, and power devices). The chapter will review the current ESD techniques and oncological results. ESD could have great impact on the treatment of early colon cancer. Its role is already proven in rectal localizations and despite the challenges it should be adopted for the colon. Safe strategy for ESD is the cornerstone in decreasing complications, which includes suitable resection of specialized ESD devices.