Israel Medical Association Journal

Background: With age, colorectal cancer (CRC) prevalence rises. The elderly (> 75 years), and the very elderly (> 85 years) are especially vulnerable. The advantages of screening must be assessed in the context of diminished life span and co-morbidities.

Objective: To compare CRC findings in colonoscopies that were performed following a positive fecal occult blood test/fecal immunochemical test (FOBT/FIT) in both elderly and very elderly age groups with those of younger patients.

Methods: We identified colonoscopies conducted between 1998 and 2019 following a positive stool test for occult blood in asymptomatic individuals. A finding of malignancy was compared between the two patient age groups. Furthermore, a sub-analysis was performed for positive malignancy findings in FOBT/FIT among patients > 85 years compared to younger than < 75 years.

Results: We compared the colonoscopy findings in 10,472 patients: 40–75 years old (n=10,146) vs. 76–110 years old (n=326). There was no significant difference in prevalence of CRC detection rate between the groups following positive FOBT/FIT (2.1% vs. 2.7%, P = 0.47). Similar results for non-significant differences were obtained in the sub-analysis compared to malignancy detection rates in the very elderly 0% (n=0) vs. 2.1% for < 75 years old (n=18), P = 0.59.

Conclusions: Although the prevalence of CRC increases with age, no significant increase in the detection rate of CRC by FOBT was found in either the elderly or very elderly age groups. Screening colonoscopies in elderly patients should be performed only after careful consideration of potential benefits, risks, and patient preferences.

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: Evaluation of mismatch repair (MMR) deficiency is conducted via immunohistochemistry or by microsatellite instability (MSI) analysis. Heterogeneous immunohistochemistry staining for MMR proteins may show different patterns; however, according to current guidelines, all of those patterns should be interpreted as MMR proficient. This conclusion might lead to false negative results because although most cases of heterogeneity stem from technical factors and biological variability, other types of heterogeneity represent true MMR deficiency.

Objectives: To identify a unique heterogeneity pattern that is associated with true MMR loss.

Methods: We analyzed 145 cases of colorectal carcinoma. Immunohistochemistry staining for MLH1, PMS2, MSH2, and MSH6 were performed. We defined geographic heterogeneity as areas of tumor nuclear staining adjacent to areas of loss of tumor nuclear staining with intact staining in the surrounding stroma. All cases were evaluated for the presence of geographic heterogeneity. In addition, 24 cases were also evaluated by MSI testing.

Results: Of the 145 cases, 24 (16.5%) were MMR deficient. Of the 24 cases for which MSI analysis was also available, 10 cases (41.7%) demonstrated biological heterogeneity, 5 (20.8%) demonstrated technical heterogeneity, and 2 (8.3%) demonstrated geographic heterogeneity. Only the two cases with geographic heterogeneity were MSI-high via MSI analysis. In addition, a germline mutation in MSH-6 was identified in one of these cases.

Conclusions: Geographic heterogeneity may raise a suspicion for a MMR-deficient case, which should be further analyzed using additional methodologies such as MSI analysis.

Background: Unlike the elective treatment of metastatic colorectal cancer (MCRC), sufficient data and consensual guidelines on acute care are lacking.

Objectives: To analyze a cohort of MCRC patients who required urgent surgery due to acute abdomen and to identify risk factors contributing to the patient's perioperative mortality and morbidity.

Methods: A retrospective analysis was conducted of patients diagnosed with stage IV colorectal cancer who required urgent laparotomy at the Rabin Medical Center. Comparative analysis was performed using Pearson’s chi-square and Student`s t-test.

Results: Between 2010 and 2015, 113 patients underwent urgent laparotomy due to colorectal cancer complications, of which 62 patients were found to have a metastatic, stage IV, disease. Large bowel obstruction was the most common indication for urgent laparotomy. In-hospital mortality was 30% (n=19), and overall 30 day mortality was 43%. Fifteen patients (24%) required more than one surgery. The average length of hospital stay was 21 days. Age and lactate levels at presentation were the only prognostic factor found for mortality (P < 0.05).

Conclusions: MCRC laparotomy patients incur a significant burden of care and have a relatively high incidence of early mortality. Our data suggest high, verging on unacceptable, mortality and complication rates in this subgroup of patients. This finding is further accentuated in the subgroup of older patients presenting with lactatemia. These data should be considered by surgeons when discussing treatment options with patients and families.

Background: Evidence has been emerging that Helicobacter pylori may also impact colorectal cancer (CRC). Positron emission tomography/computed tomography (PET/CT) imaging can predict overall survival in CRC patients.

Objectives: To determine a possible association between H. pylori seropositivity and all-cause mortality among CRC patients evaluated by PET/CT scans.

Methods: This prospective cohort study was comprised of 110 consecutive CRC patients who had undergone a PET/CT evaluation in a tertiary academic medical center. Data included demographics, body mass index (BMI), tumor node metastasis stage at diagnosis, treatment, time from diagnosis to PET/CT, and PET/CT findings. All patients were tested for anti-H. pylori immunoglobulin G (IgG) antibodies and followed for 36 months from the day of the PET/CT scan. Mortality was documented. Univariate and multivariate Cox regression was used to estimate the hazard ratio (HR) of H. pylori serological status.

Results: During the follow-up period, of the 110 CRC patients 41 (37.3%) died and 69 (62.7%) survived. Of the 41 patients, 26 (63.4%) were H. pylori seropositive and 15 (36.6%) were seronegative. Multivariate analysis showed that H. pylori seropositivity was associated with increased mortality (HR 3.46, 95% confidence interval 1.63–7.32), stage IV at diagnosis, metastatic disease found on PET/CT, longer time from diagnosis to PET/CT, lower BMI, and older age.

Conclusions: Our findings suggest that H. pylori infection may be a risk factor for all-cause mortality among CRC patients who are evaluated by PET/CT. Multicenter studies with larger patient groups are needed to confirm our findings.

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: Predictive biomarkers for personalized treatment of neoplasms are suggested to be a major advancement in oncology and are increasingly used in clinical practice, albeit based on level II evidence. Target Now® (TN) employs immunostaining and RNA expression on tumor samples to identify potentially beneficial or ineffective drugs. 

Objectives: To explore retrospectively the predictive value of TN for patients with colorectal and gastric carcinomas. 

Methods: The study group comprised colorectal and gastric carcinoma patients with TN test reports. We identified chemotherapy regimens given for stage IV disease for which TN reports indicated prediction. Protocols were classified as having clinical benefit (CB; i.e., stable disease or any objective response) or progressive disease, and this was compared with the TN prediction. 

Results: Nineteen patients – 12 colorectal and 7 gastric carcinomas – met the inclusion criteria. There were 26 evaluable treatment protocols; of 18 with a CB 15 were predicted to have a CB while 3 were predicted to have a lack of CB. Of eight protocols that had no CB, seven were predicted to have a CB and one was predicted to have a lack of CB. A chi-square test was non-significant (P = 0.78). An exploratory analysis yielded a positive predictive value of 68% and a sensitivity of 83% for the TN test. 

Conclusions: This study emphasizes the need for larger multicenter studies to validate the TN test before it is adopted into clinical practice. 

 

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.
 

Background: Major changes in the evaluation and treatment of curable colorectal cancer (CRC) have emerged in the last two decades. These changes have led to better patient outcome over time.

Objectives: To evaluate the impact of these changes as reflected in the difference in long-term outcome of a consecutive group of recently laparoscopically operated curable CRC[1] patients and a consecutive group of patients operated 20 years earlier in the same department.

Methods: Data of the new group were taken from our prospectively collected data of patients who underwent elective laparoscopic surgery for CRC in recent years. Data regarding patients operated on 20 years ago were retrieved from previous prospectively collected data on the long-term survival of CRC patients operated in the same department.

Results: The recently operated group comprised 203 patients and the previous group 199 patients. Perioperative mortality was 0.5% in the new group versus 1.5% in the old group (not significant). There were more early-stage and more proximal tumors in the recently operated group. A Kaplan-Meier 5-year survival analysis revealed no difference between stage I patients of the two groups. However, there was a significant increase in 5-year survival in the new group for stage II (85% vs. 63%, P = 0.004) and for stage III patients (57% vs. 39%, P = 0.01). This trend was maintained after removing the rectal cancer patients from the calculated data.

Conclusions: We have demonstrated improved survival for stage II and III CRC patients over a 20-year period in the same medical center. This change most likely reflects advances both in imaging techniques leading to more accurate staging and in adjuvant treatments.