|Year : 2020 | Volume
| Issue : 3 | Page : 824-829
Study of the role of serum methylated septin9 in early detection of colorectal cancers in comparison with colonoscopy
Gamal S Eldeeb1, Ahmed N Fawzy2, Sally M El-Hefnawy3, Sherif Z Awad4, Ayman A Sakr1
1 Department of Tropical Medicine, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of General Surgery, Faculty of Medicine, Menoufia University, Menoufia, Egypt
3 Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
4 Department of Gastroenterology and Hepatology, Shebin El-Kom Teaching Hospital, Menoufia, Egypt
|Date of Submission||19-Jan-2020|
|Date of Decision||28-Jan-2020|
|Date of Acceptance||08-Feb-2020|
|Date of Web Publication||30-Sep-2020|
Sherif Z Awad
Source of Support: None, Conflict of Interest: None
To assess role of serum methylated septin9 (mSEPT9) in early detection of colorectal cancers (CRCs) in comparison with colonoscopy.
mSEPT9 has been suggested as a reliable biomarker in CRC detection. We aimed to determine the diagnostic role of mSEPT9 for CRCs detection in Egyptian patients. Moreover, we compared the diagnostic efficacy of adding mSEPT9 to carcinoembryonic antigen (CEA).
Patients and methods
A single-center prospective study was done on 90 patients presented with signs or symptoms of CRCs. They were divided into three groups: group I (n = 45) patients with CRCs, group II patients with colorectal polyps (benign lesions) (n = 25), and group III the control group (n = 20). All patients and controls were subjected to history taking, proper examination, and investigations. Serum samples were collected for mSEPT9 and CEA. Sensitivity and specificity were calculated to evaluate the diagnostic efficacy.
mSEPT9 achieved overall sensitivity of 84% and specificity of 78%, with an area under the curve value of 0.911. This was superior to CEA, which achieved overall sensitivity of 78% and specificity of 76%, with an area under the curve value of 0.911. The combination of mSEPT9 and CEA further improved sensitivity 100%, whereas specificity was declined to 56%.
mSEPT9 demonstrated better diagnostic ability in CRC detection compared with colonoscopy. The combination of mSEPT9 and CEA further improved diagnostic sensitivity, especially for early-stage disease, which may provide a new approach for future CRC screening.
Keywords: colonoscopy, colorectal cancer, methylated septin9, polyps, screening
|How to cite this article:|
Eldeeb GS, Fawzy AN, El-Hefnawy SM, Awad SZ, Sakr AA. Study of the role of serum methylated septin9 in early detection of colorectal cancers in comparison with colonoscopy. Menoufia Med J 2020;33:824-9
|How to cite this URL:|
Eldeeb GS, Fawzy AN, El-Hefnawy SM, Awad SZ, Sakr AA. Study of the role of serum methylated septin9 in early detection of colorectal cancers in comparison with colonoscopy. Menoufia Med J [serial online] 2020 [cited 2020 Nov 26];33:824-9. Available from: http://www.mmj.eg.net/text.asp?2020/33/3/824/296658
| Introduction|| |
Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the third leading cause of death related to cancer in both men and women worldwide. It is believed that proper screening could prevent the majority of these deaths, especially as early CRC is asymptomatic .
Nearly 55% of CRC cases occur in developed regions; however, higher mortality is reported in developing countries, including Egypt. This poor survival is probably owing to the lack of available health resources. However, high-income and low-income countries also show large variations in the proportion of the population included in CRC registries. These variations may arise from underdiagnoses, owing to local medical and economic situations .
Survival is strongly related to stage at diagnosis, with 5-year survival rates of 89.8% for localized cases (confined to the wall of the bowel), but only 67.7% for regional disease (disease with lymph node involvement) and 10.3% for distant metastatic patients. Screening and then diagnosis at an early stage can reduce the incidence of CRC in an advanced stage and hence mortality. An effective surveillance after treatment is also useful to find relapse timely, hence improve the patients' life quality and survival rate .
CRC screening programs must be adapted to the risk of each population. An average-risk population is defined as a population of individuals aged 50 years or older, with no additional risk factors. The recommended screening for the average-risk population is one of the following: an annual fecal immunochemical test, sigmoidoscopy every 5 years, or colonoscopy every 10 years. When subgroups are identified and characterized with a higher-than-average incidence of colorectal neoplasia, it is necessary to increase the screening frequency to achieve program cost-effectiveness .
To date, the screening tests used in CRC can be divided into two groups: (a) stool tests, which mainly detect cancer and include guaiac fecal occult blood testing (FOBT), fecal immunochemical test, and testing stool for exfoliated DNA, and (b) structural examinations, which can find cancer and advanced lesions as well as polyps and include flexible sigmoidoscopy, colonoscopy, double-contrast barium enema, and computed tomography colonography (also named virtual colonoscopy) .
Each of these tests has some disadvantages. Some lack specificity, others are expensive or invasive, or cause bleeding or infection, and some need bowel preparation and cause bowel tear. So, a perfect test used in screening and surveillance for CRC should be less invasive (or noninvasive), be easy to perform, have high sensitivity and specificity, be safe, and have low costs .
Many studies previously reported the role of serum methylated septin9 (mSEPT9) in early detection of CRC, regardless of the comparison with other markers. To the best of our knowledge, the study described herein may be one of the fewer studies that focus on the role of serum mSEPT9 in early detection of CRCs in comparison with other markers.
The aim of this study was to assess role of serum mSEPT9 in early detection of CRCs in comparison with colonoscopy.
| Patients and Methods|| |
This study was applied prospectively on 90 of 150 Egyptian patients who were admitted to the Gastroenterology, Oncology, or Surgery Departments of tertiary Menoufia University Hospitals from August 2018 to July 2019. Patients with signs and/or symptoms of CRC (changes in bowel habits, worsening constipation, rectal bleeding, unexplained iron-deficiency anemia, loss of weight, or feeling that the bowel does not empty properly) during hospital admission were included in the study. However, those unfit for colonoscopy, or patients who were receiving radiotherapy or chemotherapy for CRC, and critically ill-patients owing to any cause were excluded from the study.
All patients were subjected to (a) history taking with special attention to age, sex, smoking, given drugs, comorbid diseases, history of previous malignancy, history of inflammatory bowel disease (ulcerative colitis and Crohn's disease), or lower group I complaints; (b) examination, especially vital signs, calculation of BMI, oral pigmentations (Peutz–Jeghers syndrome), abdominal examination for organomegaly (hepatomegaly and splenomegaly), ascites, epigastric tenderness, or abdominal masses and rectal examination for rectal bleeding or rectal mass; and (c) investigations, where laboratory investigations included complete blood count, liver function tests, renal function tests, bleeding and coagulation profile, and measurement of serum mSEPT9 and carcinoembryonic antigen (CEA). For measurement of serum mSEPT9 and CEA, 2 ml of venous blood was withdrawn from every subject, transferred into a plain tube, and then centrifuged for 10 min at 4000 rpm. The serum obtained was kept frozen at −20°C till analysis (measurement of serum mSEPT9 and CEA). Human serum mSEPT9 was assayed using Sunred ELISA Kit (Shanghai Sunred Biological Technology Co. Ltd, Shanghai, China). The concentration of serum CEA was measured using the electrochemiluminescence immunoassay (Roche, Mannheim, Germany); the kit uses a double-antibody sandwich enzyme-linked immunosorbent assay. The resultant. positively correlated chroma of the assay and the concentration of the human mSEPT9 were positively correlated. Radiological investigations included abdominal ultrasonography, computed tomography, and colonoscopy (Olympus GIF-H180 Clifornia, USA). All enrolled patients who were fit for colonoscopy were examined endoscopically till the cecum. Colonoscopic findings were reported. Multiple biopsies were taken from suspected lesions, and histopathological examination was done to confirm the diagnosis. All findings found in colonoscopy were reported.
According to the clinical, laboratory, and colonoscopic findings, all patients were divided into three groups: group I (n = 45) included patients who presented and were confirmed by histopathology as having adenocarcinoma (CRC), group II (n = 25) included patients who presented and were confirmed by histopathology as having benign lesions (polyps), and group III (n = 20) included healthy control individuals who underwent colonoscopy and did not reveal any suspicious masses or polyps. Written informed consents were taken from every patient before participation in the study, and the project was approved by our university ethical board.
The following factors were reported: primary outcome measures (survival rate in early discovered patients and need for surgery in diagnosed patients) and secondary outcome measures (mortality in late diagnosis and early diagnosis of recurrence).
Data were collected, tabulated, and statistically analyzed using an IBM personal computer with Statistical Package of Social Science (SPSS), version 22 (SPSS Inc., Chicago, Illinois, USA). The following statistics were applied: descriptive statistics, in which quantitative data were presented in the form of mean, SD, range, and qualitative data were presented in the form numbers and percentages, and analytical statistics, which was used to find out the possible association between studied factors and the targeted disease. The used tests of significance included χ2 test, which was used to study association between two qualitative variables, and analysis of variance (F) test, which is a test of significance used for comparison between three or more groups having quantitative variables.
Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated according to the following formulas: sensitivity = a/(a + c), specificity = d/(b + d), accuracy=(a + d)/(a + b + c + d), negative predictive value = d/(c + d), and positive predictive value = a/(a + b), where a = true positive cases, b = false positive cases, c = false negative cases, and d = true negative cases.
| Results|| |
The mean age was higher in group I than the other two groups, with a high statistically significant difference (P = 0.001). However, there was no significant difference between the studied groups regarding their sexes (P = 0.799). Smoking activity showed high significant difference between the groups (P = 0.001), as group I had the highest rates of smoking at 62.2%, whereas group II and group III had rates of 32 and 30%, respectively [Table 1].
CRC presented with bleeding per rectum (BPR) in 17/45 (37.8%) patients in group I, whereas BPR was the presentation in eight (32%) patients in group II and a single (5%) patient in group III, with a high statistically significant difference between the groups (P = 0.004). However, anemic manifestations were presented in seven (15.6%) patients in group I, 10 (40%) patients in group II, and six (30%) patients in group III. Changes in bowel habits were predominant in seven (15.6%) patients in group I, three (12.0%) patients in group II, and four (20.0%) patients in group III with a high statistically significant difference between the groups (P = 0.004). Worsening constipation was detected mainly in group I (seven patients, 15.6%), with a high statistically significant difference (P = 0.004) [Table 2].
Regarding site affected, rectosigmoidal colon lesions predominated (24.4%; 11/45), compared with tumor locations in rectum only (11.1%), sigmoid colon (8.9%), descending colon (13.3%), transverse colon (15.6%), ascending colon (15.6%), and cecum (11.1%) [Table 3].
Regarding serum levels of mSEPT9 among the groups, there was a high statistically significant difference between the groups (P = 0.001). Group I (CRC) had significantly higher positive rates of mSEPT9 (mean = 1347.9 ± 928.6 ng/l), whereas group II and group III had lower rates (270.3 ± 148.5 and 73.1 ± 37.4 ng/l, respectively), with a cutoff point 231 ng/l. Additionally, the (P = 0.001) [Table 4] highest values of CEA was in group I (mean = 11.52 ± 9.61 ng/ml), whereas group II and group III had lower values (2.97 ± 1.79 and 3.72 ± 6.58 ng/ml, respectively), with a cutoff point of 2.90 ng/ml, with a high statistically significant difference (P = 0.001) [Table 4].
|Table 4: Carcinoembryonic antigen and methylated septin9 among the studied groups|
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mSEPT9 achieved overall sensitivity of 84% and specificity of 78%, with an area under the curve (AUC) value of 0.911, which was superior to CEA (sensitivity: 78%; specificity: 76%; and AUC: 0.808). The combination of mSEPT9 with CEA further improved the sensitivity 100%, though the specificity declined to 56% [Table 5] and [Figure 1].
|Table 5: Sensitivity and specificity of both methylated septin9 and carcinoembryonic antigen in detection of colorectal cancer|
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|Figure 1: ROC curve for sensitivity and specificity of both mSEPT9 and CEA in detection of colorectal cancer. CEA, carcinoembryonic antigen; mSEPT9, methylated septin9; ROC, receiver operating characteristic.|
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| Discussion|| |
CRC is caused by the gradual accumulation and interaction of pathogenic mechanisms such as polygenic mutation and epigenetic changes, and hence, studying the correlation between multiple pathogenesis of CRC is of great clinical significance, to explore simple, safe, more specific, and sensitive molecular indicators for screening, diagnosis, and prognostic evaluation of the disease. In a clinical setting, the screening of CRC at an early stage is still the most effective way to reduce morbidity and mortality .
The sensitivity and specificity of common CRC screening tests, such as FOBT, and glycoprotein tumor marker CEA measurement are low. However, patients are always willing to accept these screening methods because of the noninvasive nature .
FOBT demonstrated low sensitivity toward early screening of CRC. Although invasive colonoscopy has the highest sensitivity and specificity for CRC and adenoma detection, it has the lowest patient compliance rate owing to the need of bowel preparation and discomfort during the test. Furthermore, some patients with severe cardiopulmonary insufficiency, enterostenosis, or intestinal perforation are not suitable for invasive test. Hence, it is important to adopt a simple method with high sensitivity to make up for the limitations of the aforementioned common detection methods .
Aberrant epigenetic modifications are an early event in carcinogenesis, with the epigenetic landscape continuing to change during tumor progression and metastasis. Owing to the stability of cell-free DNA, the abnormal level of methylated DNA has been regarded as a promising candidate for a cancer biomarker. Nevertheless, it still posed a great challenge for the early screening of CRC owing to the lack of tumor markers with high sensitivity and specificity .
In this study, patients who were diagnosed with CRC had a mean age of ~ 53.6 years, which was higher than mean age of patients who diagnosed with benign lesions of 47.2 years. In comparison. years old with these data, Rawla et al.  reported that those who are older than 65 years are about three times more likely to be diagnosed with CRC than those 50–64 years old and about 30 times more likely to be diagnosed than those 25–49 years old.
In the current study, smoking and high BMI were associated with increased risk of development of CRC (significant P value). Our results were in agreement with Keum and Giovannucci  who revealed that smoking and high BMI were also more prevalent in patients with CRC.
In this study, there was a statistically high significant difference between the groups regarding their symptoms and signs, where 17 (37.8%) patients from group I presented with BPR and eight (32.0%) patients from group II, which was the main complaint in both groups. This was comparable with the study by Alecu et al., which performed colonoscopy on 1368 (1146 diagnostic and 222 with a therapeutic aim) patients in the Digestive Endoscopy Department of the Bucharest Institute of Oncology Surgical Clinic and revealed that the most important clinical sign was, however, lower group I bleeding, frequently intermittent and in small quantities.
In the current study, there was a high statistical significant difference between the groups regarding their CEA levels (significant P value). CRC group had the highest values (mean = 11.52 ± 9.61 ng/ml). On the contrary, benign and healthy groups had lower values (2.97 ± 1.79 and 3.72 ± 6.58 ng/ml, respectively). These data are in agreement with Zhong et al., who evaluated the association of CEA, CA19–9, CA7–24, and CA125 with disease characteristics, patient demographics, and disease progression in patients with CRC, and revealed that it was more common for a patient to express at least one of these markers before surgery and at disease recurrence than following surgery.
In this study, CRC group had significantly higher positive rates of mSEPT9 (mean = 1347.9 ± 928.6 ng/l), whereas benign and healthy groups had lower rates (270.3 ± 148.5 and 73.1 ± 37.4 ng/l, respectively), with cutoff point of 231 ng/l.
This was comparable with Xie et al.  who did a prospective study on 248 subjects, including 123 patients with CRC and 125 controls, aimed to determine the diagnostic value of mSEPT9 for CRC detection in Chinese patients. The study showed that overall 89 subjects were detected with mSEPT9 positive results. CRC case group had significantly higher positive rates of mSEPT9, compared with the control group (61.8 vs. 10.4%).
In our study, mSEPT9 achieved overall sensitivity of 84% and specificity of 78%, with an AUC value of 0.911. This was superior to CEA, with sensitivity of 78%, specificity of 76%, and AUC of 0.808. The combination of mSEPT9 with CEA further improved sensitivity to 100%, though the specificity declined to 56%.
| Conclusion|| |
The current study demonstrates that mSEPT9 may has diagnostic ability in CRC detection. The combination of mSEPT9 and CEA may improve sensitivity especially for early-stage disease, which may provide a new approach for future CRC screening, though further investigations are warranted. The role of mSEPT9 in diagnosis of CRC need to be further evaluated and validated in large prospective cohort studies and randomized trials. Additionally, the role of mSEPT9 has to be studied in postoperative patients with CRC to show whether it can be used as a prognostic marker.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]