Israel Medical Association Journal

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterized by hamartomatous polyps throughout the gastrointestinal tract, with an estimated prevalence of 1 in 100,000 individuals. While most cases follow an autosomal dominant inheritance pattern, some are caused by de novo mutations [1].

The age of onset for JPS is typically during childhood or adolescence, with a mean age at diagnosis of 18.5 years [2]. A major concern in JPS is the increased risk of colorectal cancer (CRC), requiring close lifelong surveillance. The cumulative lifetime risk for CRC ranges from 38% to 68%, with a mean age at diagnosis between 34 and 44 years [3].

Although juvenile polyps were initially considered to have low malignant potential, studies have identified two pathways of carcinogenesis in JPS: progression from hamartomatous polyps to adenoma and then to adenocarcinoma or direct transformation of hamartomatous polyps into adenocarcinoma. The management of JPS is tailored to each patient's specific manifestations and clinical presentation. The primary treatment goal is to prevent morbidity associated with gastrointestinal polyps, such as bleeding and intestinal obstruction.

Background: For locally advanced rectal cancer patients a watch-and-wait strategy is an acceptable treatment option in cases of complete tumor response. Clinicians need robust methods of patient selection after neoadjuvant chemoradiation.

Objectives: To predict pathologic complete response (pCR) using computer vision. To analyze radiomic wavelet transform to predict pCR.

Methods: Neoadjuvant chemoradiation for patients with locally advanced rectal adenocarcinoma who passed computed tomography (CT)-based simulation procedures were examined. Gross tumor volume was examind on the set of CT simulation images. The volume has been analyzed using radiomics software package with wavelets feature extraction module. Statistical analysis using descriptive statistics and logistic regression was performed was used. For prediction evaluation a multilayer perceptron algorithm and Random Forest model were used.

Results: In the study 140 patients with II–III stage cancer were included. After a long course of chemoradiation and further surgery the pathology examination showed pCR in 38 (27.1%) of the patients. CT-simulation images of tumor volume were extracted with 850 parameters (119,000 total features). Logistic regression showed high value of wavelet contribution to model. A multilayer perceptron model showed high predictive importance of wavelet. We applied random forest analysis for classifying the texture and predominant features of wavelet parameters. Importance was assigned to wavelets.

Conclusions: We evaluated the feasibility of using non-diagnostic CT images as a data source for texture analysis combined with wavelets feature analysis for predicting pCR in locally advanced rectal cancer patients. The model performance showed the importance of including wavelets features in radiomics analysis.

Background: The learning curve for transition from open to laparoscopic proctectomies is difficult. Most surgeons have considerable laparoscopic experience prior to performing robotic-assisted procedures. There are data regarding the transition from open to robotic proctectomies. Minimally invasive anterior resection for rectal cancer has gained widespread popularity in recent years, especially when using a robotic platform.

Objectives: To analyze the experience to the transition from open to robotic anterior resection for rectal cancer.

Methods: We performed a retrospective analysis of a computerized database. All patients who had a robotic-assisted proctectomy between December 2016 and March 2019 were included and were compared to patients who underwent an open anterior resection in the same time period. A single experienced colorectal surgeon with no prior experience in colorectal laparoscopic surgery performed the procedures.

Results: During the study period, 55 patients underwent robotic-assisted proctectomy and 55 had an open proctectomy. Patients had similar pre-operative demographic and clinical characteristics with the majority of patients receiving neoadjuvant chemoradiation. The surgical time was significantly lower in the open surgery group (168 minutes vs. 310 minutes, P = 0.005). Both the surgical and pathological outcomes did not differ significantly between the two groups, with good short-term oncologic outcomes and low complication rates.

Conclusions: The transition from open to robotic-assisted proctectomy is feasible and safe and provides a good alternative for undertaking a minimally invasive surgery for the experienced open colorectal surgeon

Background: Lymph node (LN) retrieval and assessment is essential for accurate staging and treatment planning in colorectal cancer (CRC). According to U.S. National Cancer Institute recommendations, the minimal number of LNs needed for accurately staging of node-negative CRC is 12. Awareness and implementation of the guidelines has been shown to improve after assigning an opinion leader who has a special interest in CRC.

Objectives: To evaluate the impact of dialogue between surgeons and pathologists in LN evaluation.

Methods: Consecutively treated CRC patients at the Department of Surgery B at Rambam Medical Center from January 1, 2000 through July 30, 2005 were identified from hospital discharge files. Demographic, surgical, and pathological data were extracted. Patients were divided into two groups. Group I patients underwent surgery before the initiation of a structured surgical oncology service (January 1, 2000 to October 30, 2004). Group II patients underwent surgery after the initiation of the service (November 1, 2004 to July 30, 2005).

Results: The study comprised 212 patients (Group I: n=170; Group II: n=42). The median number of LNs examined was 9 in Group I and 14 in Group II (P = 0.003). Only 35% of patients in Group I received adequate LN evaluation compared to 79% in Group II (P = 0.0001). Patients with left-sided or rectal cancer were less likely to receive adequate LN evaluation than patients with right-sided cancers.

Conclusions: A durable improvement in LN evaluation was realized through a multi-pronged change initiative aimed at both surgeons and pathologists.

Background: Gastrointestinal malignancies comprise a broad spectrum of neoplasms and have a high overall incidence. The incidence rates in Israel vary among ethnic groups due to different risk factors.

Objectives: To investigate incidence trends of these cancers in Israel in both Jewish and Arab ethnic groups in order to better understand the risks in those groups.

Methods: This study is based on data published by the Israel National Cancer Registry and the Central Bureau of Statistics. We compared statistics between ethnicities and genders. We examined the eight most common gastrointestinal cancers, focusing on colon, rectal and gastric cancers.

Results: Between 1980 and 2012 there was a decline in the incidence of gastric cancer in the Jewish population; in contrast, a significant increase occurred in Arab women, but there was no significant change in Arab men. Colon cancer showed a relative decrease in incidence in the Jewish population, but an increase in the Arab population. A decrease in the incidence of rectal cancer in the Jewish population and an increase in the Arab population was observed. 

Conclusions: Gastric, colon and rectal cancers exhibit differences in incidence and outcome between Jewish and Arab populations in Israel. These differences were not observed in the other five types of less common gastrointestinal cancers.

 

Background: The treatment of rectal cancer has changed significantly over the last few decades. Advanced surgical techniques have led to an increase in the rate of sphincter-preserving operations, even for low rectal tumors. This was facilitated by preoperative oncologic treatment and the use of chemoradiation to downstage the tumor before resection. The introduction of total mesorectal excision further improved the oncologic outcome and became the standard of care. The use of laparoscopy for rectal resection is the most recent addition to this series of improvements, but in contrast to the use of laparoscopy in colon cancer its role is not yet well defined.

Objectives: To present our experience with laparoscopic surgery for upper and lower rectal tumors.

Methods: A database was used to prospectively collect all data on laparoscopic rectal surgery in our department since we started performing these procedures in 1997. Follow-up data were collected from outpatient clinic visits, oncology files and telephone interviews. Updated survival data were retrieved from the national census.

Results: Of 750 laparoscopic colorectal procedures performed over a 13 year period, 67 were for rectal cancer. Of these, 29 were resections for tumors in the upper rectum (11–15 cm from the anal verge) and 38 for tumors at 10 cm or below. Surgery was performed in 24 patients after neoadjuvant chemoradiation. There were 54 sphincter-preserving operations and 13 abdominoperineal resections. The mean operative time was 283 minutes. Conversion to an open procedure was required in 22% of the cases. Anastomotic leaks occurred in 17% of cases. Postoperative mortality was 4.5%. Long-term follow-up was available for 77% of the group, for a mean period of 42 months. Local recurrence was diagnosed in 4.5% of the patients and overall 5 year survival was 68%.

Conclusions: Laparoscopic rectal resection is a demanding procedure. However, laparoscopy may become the preferred approach since it is a minimally invasive procedure and has an acceptable oncologic outcome that is comparable to the open approach. This conclusion, however, needs further validation.
 

The laparoscopic approach to the treatment of colon and rectal cancer was controversial long after it was accepted for benign conditions. Laparoscopic cancer resection should meet appropriate oncologic standards and achieve a long-term oncologic outcome at least equivalent to that of open resection. Several international randomized controlled trials have provided adequate data to ascertain the oncologic quality of laparoscopic colon resection, showing a benefit in short-term outcome over open resection. The use of laparoscopic resection for rectal cancer is awaiting further investigation.

Background: An accurate preoperative definition of tumor and lymph node status is needed for reaching the correct decision regarding rectal cancer treatment. Transrectal ultrasonography is the most commonly used diagnostic modality for the local staging of rectal cancer.

Objectives: To determine the accuracy of TRUS[1] in the staging of rectal cancer.

Methods: We conducted a retrospective study on 95 patients evaluated by TRUS. The rectum was subdivided into two parts (lower and upper).

Results: Sixty patients underwent radical surgery. Of these, 34 received no preoperative chemo-irradiation owing to µT1, µT2 tumor or the patient’s choice (neo-adjuvant treatment was suggested to patients with adenocarcinoma that proved to be µT3). The overall accuracy rate was 80% for T stage. Overstaging was found in 13.3% and understaging in 6.7%.The N-stage was correctly assessed in 70%. The overall accuracy rate for tumors was 73.9% in the lower part and 90.9% in the upper. A trend towards a lower accuracy rate for low-lying tumors compared to high-located rectal tumors was found (P = 0.532), which did not reach statistical significance.

Conclusions: TRUS gave better results for T1 and T3 stage rectal tumors but was inaccurate for stage T2, indicating the possible need for local excision in order to base the final treatment for T2 tumors on pathologic staging.
[1] TRUS = transrectal ultrasonography
 

Objectives: To assess the feasibility and efficacy of high dose preoperative radiotherapy and TATA[1] as a sphincter-preserving method in Jiangsu, an economically well-developed region of China with a population of 70 million people.

Methods: From September 1994 to September 2000, 25 consecutive patients with pathologically confirmed distal rectal adenocarcinoma were treated preoperatively with a total dose of 45–46 Gy at 1.8–2.0 Gy per fraction during 5 weeks. Sphincter-preserving surgery by TATA was performed 4–6 weeks after radiotherapy.　

Results: Acute toxicity of preoperative radiotherapy was tolerable. Eight percent of the patients presented pathologic complete tumor response after preoperative radiotherapy. All patients underwent TATA as scheduled. During a median follow-up of 70 months, the 5 year survival rate was 88%. The 5 year survival rate for those tumors down-staged to pathological T0 or to pT1 was 100%.

Conclusions: High dose preoperative radiotherapy and TATA as a sphincter-preserving method was feasible and efficient in Chinese patients with distal rectal cancer. In this study, the subset of patients with a good response to radiotherapy had a better clinical outcome.

Objectives: To analyze our 8 year experience using TEM[1] for the management of rectal cancer.

Methods: Local resection by TEM was performed in patients with benign tumors and early rectal cancer. In addition, selected patients with T2 and T3 rectal cancers who were either medically unfit or unwilling to undergo radical surgery were also treated with this modality. Radical surgery was offered to all patients with incomplete tumor excision by TEM.

Results: Overall, 116 TEM operations for rectal tumors were carried out between 1995 and 2003, including 74 patients with rectal adenomas and 42 patients with rectal carcinomas. Twenty-five patients had T1 tumors that were all successfully removed, with clear tumor margins, by TEM. Fourteen patients had T2 cancer and 3 of them (21%) required additional radical surgery due to incomplete excision. Local recurrence was observed in one patient with T2 cancer. There was no mortality. Major surgery, or radiotherapy-related complications requiring additional surgical intervention was needed in five patients with T2 cancer.

Conclusions: Local excision by TEM is a safe surgical procedure and should be offered to highly selected patients with early rectal cancer.

Objective: To investigate the effectiveness of preoperative chemoradiation in increasing the resectability rates of rectal cancer and increasing the anal sphincter preservation rate.

Methods: The study group included 66 patients aged 33–84 years with T₂–T₃ rectal carcinoma who were treated in our institute from 1997 to 2002 with preoperative chemoradiation followed by surgery 6 weeks later. All patients underwent preoperative transrectal endoscopic ultrasound for tumor staging and localization. The duration of follow-up was 25 months.

Results: Chemoradiation led to tumor downstaging in 61 patients (92.4%), all of whom underwent low anterior resection. Only 11.4% of this group needed a temporary (6 weeks) loop colostomy/ileostomy. None of the 16 patients with post-treatment T₀ tumors had evidence of malignant cells on pathologic study. Five patients (7.6%) failed to respond to chemoradiation and underwent APR[1]. There were no major complications, such as leakage, and no deaths.

Conclusions: Neoadjuvant chemoradiation is an effective modality to downstage advanced rectal cancer, improving patient quality of life by significantly reducing the need for a terminal permanent colostomy, or even a temporary one.

Background: Preoperative radiotherapy is standard treatment for rectal cancer and is often combined with 5-fluorouracil-based chemotherapy. UFT, a new oral 5FU[1] derivative, given daily during a course of radiotherapy mimics the effect of continuous-infusion 5FU.

Objectives: To determine the maximum tolerated dose of oral UFT and leucovorin with preoperative pelvic irradiation for rectal cancer, and assess tumor response.

Methods: In this phase 1 trial, 16 patients aged 42–79 years with tumors within 12 cm of the anal verge received radiotherapy, 45 Gy over 5 weeks, an escalating dose of oral UFT, and a fixed dose of 30 mg/day leucovorin. UFT and leucovorin were given for 28 consecutive days concomitant with the first 4 weeks of radiotherapy. Surgery was scheduled for 4–6 weeks after completion of radiotherapy. The surgical procedure was determined by the surgeon at the time of surgery.

Results: No grade III toxicity was seen at 200 mg/m²/day UFT. Of eight patients who received 240 mg/m²/day UFT, one developed grade IV diarrhea; of four patients who received 270 mg/m²/day UFT, one was hospitalized with grade IV diarrhea and leukopenic fever and died during hospitalization. Of the 15 evaluable patients, 9 had pathologic tumor down-staging including 4 patients with complete response. Only one patient required a colostomy.
Conclusions: The MTD[2] of UFT together with leucovorin and preoperative radiotherapy for rectal cancer is 240 mg/m². The major toxicity was diarrhea. Down-staging was noted in 60% of patients, allowing sphincter-preserving surgery even in patients with low tumors.

Background: Mid- and lower rectum cancer is a technical challenge to the surgeon aiming to preserve the anal sphincter. The choice between abdominoperineal resection and anterior resection is often related to surgical skills.

Objectives: To evaluate the role of a specialized colorectal unit in preserving the anal sphincter mechanism in the treatment of rectal cancer.

Methods: Between 1991 and 1996, 75 patients with rectal cancer up to 12 cm from the anal verge were operated at the Sheba Medical Center. Among them, 21 patients (group 1) underwent surgery in the colorectal unit and 54 patients (group 2) in the other two surgical departments. All patients had a complete preoperative investigation and were followed for 12–90 months.

Results: Background and tumor parameters were similar for both groups. In group 1, 20 patients (95%) had low anterior resection and 1 patient (5%) had abdominoperineal resection as compared to 20 patients (37%) and 34 patients (63%), respectively, in group 2 (P < 0.005). There was no statistical difference in the systemic recurrence rate. Local recurrence was more frequent in group 2 (P < 0.05).

Conclusions: Special training in colorectal surgery enables the surgeon, in keeping with the principles of oncologic surgery, to preserve the anal sphincter mechanism in most patients with adenocarcinoma located in the mid- and lower third of the rectum.