Original article
Epidemiological situation of colon cancer in the Hospital de Paysandú from 2017 to 2020
Jonatan Marchetti, Raúl Perdomo, Alfonso Rossi, Valentina Da Rosa
Hospital de Paysandú, Uruguay
The authors declare no conflict of interest.
Jonatan Marchetti: Jonamar0012@gmail.com
Received: May 2022. Accepted: February 2023
Jonatan Marchetti: 0000-0001-7995-0727
Raúl Perdomo: 0000-0001-9463-9355
Alfonso Rossi: 0000-0002-2946-3397
Valentina Da Rosa: 0000-0002-0145-3015
Astract
Introduction: Colorectal cancer (CRC) is an important cause of morbidity and mortality worldwide. Screening can identify and therefore lead to the cure of the patient with CRC in early stages.
Material and Methods: The study was conducted. A retrospective observational study was carried out at the Hospital de Paysandú from January 2017 to December 2020. It included all patients in the age range of 50 to 74 years, in whom CRC screening was performed through chromatographic immunoassay test for the qualitative detection of human fecal occult blood (FOBT). The colonoscopies performed for positive FOBTs and the histopathology reports of the lesions found were subsequently analyzed.
Results: From a total of 12,830 patients in the age range of 50 to 74 years, 6522 had a FOBT and 652 (10%) were positive. Only 240 colonoscopies were performed and 52 histopathology samples corresponding to 48 patients were analyzed. Eight samples were positive for malignancy.
Discussion: From the data obtained, it can be inferred that there is a lack of information on the part of both patients and physicians for CRC screening in the population at greatest risk. Likewise, it is evident that the vast majority of patients with positive FOBT do not undergo the corresponding endoscopy.
Conclusions: Based on this study, the need for awareness campaigns to carry out CRC screening is raised, as well as the importance of achieving adequate training of health personnel.
Keywords: colorectal cancer; FOBT; early detection
Introduction
CRC, an important cause of morbidity and mortality worldwide, is the third most frequent malignant neoplasm in men and the second in women.1 Most tumors are sporadic (70-80%), while a small proportion are hereditary.2 Between 14% and 33% of cases are diagnosed as an emergency.3
However, it is a cancer that is potentially detectable at an early stage and curable. In developed countries, a decrease in CRC mortality has been observed, probably due to the development of screening policies and improvements in treatment.4
In Uruguay, during the period 2013-2017, according to the Honorary Commission for the Fight against Cancer, the incidence of CRC in men was 13.39% and somewhat higher in women, 13.68%. In turn, mortality was 11.68% and 14.28%, respectively. These figures show that it is the second most frequent cancer in Uruguay and also the second cause of death, with almost 2,000 new cases per year.4 The incidence has been maintained during the period 2002-2016, while mortality has increased in men and decreased in women. The cause of this difference is unknown.4
Regarding the distribution by age, there is a clear upward trend in the incidence from the age of 50 onwards in both sexes5 with more than 90% of cases presenting from this age.
A screening program is considered adequate when: 1) the disease constitutes a serious and frequent health problem, 2) the tests used to detect the disease are sufficiently accurate in the early stages, accepted by patients, and feasible in daily clinical practice, 3) the treatment that a patient diagnosed by screening undergoes improves their prognosis and 4) there is evidence that the benefit outweighs the potential harm and costs of the program.6
Numerous studies have shown that both the guaiac fecal occult blood test and the immunochemical test are cost-effective screening methods.1 The latter is of greater interest since it does not react with hemoglobins of any other species, nor does it have peroxidase activity, so it is not modified by food or drugs, presenting high specificity.4
In Uruguay, since 2018, the Ministry of Public Health has published a series of guidelines on CRC screening. However, we have observed a high number of patients diagnosed in advanced or complicated stages. For this reason, in this study we will evaluate the compliance and performance of the screening tests, in order to provide precise data that will allow us to correctly apply the different tests.
Material and methods
A retrospective observational study was carried out from January 2017 to December 2020 at the Hospital de Paysandú, a public entity. It included all patients screened for CRC with fecal occult blood test (FOBT). The chromatographic immunoassay test was used for the qualitative detection of occult blood in human feces. The brand was ABON®, which has a relative sensitivity of 93.6%, specificity of 99.1%, and accuracy of 97.9%.
The colonoscopies performed by the positive FOBTs and the histopathological studies of the lesions found were subsequently analyzed.
The variables collected were: the total number of users and the total number by gender. Name and surname, identity card, age, date of completion and result of FOBT were collected.
The following data were collected from the colonoscopies: total number of studies performed, findings, topography of the lesion, whether it was suggestive of malignancy or whether it was a polyp (type, topography, size, and quadrant it occupied).
From the histopathology report, the date of completion, topography, histologic type, degree of differentiation, depth of invasion, free or compromised margins, number of excised and compromised lymph nodes and their topography were collected.
Results
Out of an assisted population of 65,430 people, 12,830 were in the age range of 50 to 74 years; 5,918 (46.1%) were men and 6,912 (53.9%) women.
FOBT data were obtained from the laboratory database. A total of 6,522 samples were processed, of which 915 (14%) were positive: 652 (10%) in patients in the 50-74 age range, 140 (2.1%) in patients under 50 years of age, and 123 (1.9 %) in people older than 74 years. (Fig.1). From the analysis of the FOBT data, it stands out that 49 patients had a weak positive result and in 12 patients the data was not recorded.
Figure 1. Results of FOBTs performed at different ages.
Regarding the colonoscopies, the data was collected from the operative records. In the period analyzed, a total of 240 colonoscopies were performed, 95 (39.6%) in people 50 to 59 years old, 115 (47.9%) in people 60 to 69 years old, and 30 (12.5%) in people older than 70 years. years; 139 (57.9%) were women and 101 (42.1%) men; 191 (79.5%) endoscopies were complete and 49 (20.5%) incomplete. In 133 (55.4%) individuals there were no findings and in 85 (44.6%) material was obtained for histopathology.
The histopathology data were obtained from the Pathology records: 52 samples corresponding to a total of 48 patients were analyzed. Of these, 33 (63.4%) were tubulovillous adenomas, 7 (13.4%) hyperplastic polyps, 4 (7.6%) sessile serrated polyps, and 8 (15.3%) positive for malignancy (Fig. 2).
Figure 2. Histopathological results of the 52 samples obtained.
Of the adenomatous polyps analyzed, 18 presented mild to moderate dysplasia and 16 moderate to severe dysplasia. It should be noted that only 2 samples reported that the base of the polyp was free. Three of the 8 patients with positive samples for malignancy did not have a postoperative pathology sample, because they did not have surgical resolution due to their staging. The location of the other 5 malignant lesions is shown in Fig. 3. These 5 samples corresponded to adenocarcinoma, 4 well differentiated and one moderately differentiated. It was also reported that all 5 had free margins and 12 or more resected lymph nodes. It should be noted that of these excised lymph nodes, 3 samples presented metastases and 2 did not. Other data obtained was total parietal infiltration with pericolonic fat involvement in 4 cases and partial infiltration of the muscularis propria in 1 case. Thus, we found one patient in stage I, two in stage IIA, one in stage IIIB, and one in stage IV. The average age was 64.8 years. The predominant sex was male with 32 patients.
Figure 3. Topography of the 5 removed malignant lesions.
Discussion
A retrospective series of 12830 patients in the age range of 50 to 74 years, in whom screening is indicated, was presented. From the analysis of the data obtained, we can highlight that only 6522 (50.8%) underwent FOBT in the 4-year period of the study. In addition, we found 263 patients out of age range with positive FOBT. We do not know the reason why it was requested, taking into account that colonoscopy should be requested as a first-line study outside the age range.
The laboratory of the Hospital de Paysandú uses the qualitative guaiac test, this not being the study recommended by the guidelines of the Ministry of Public Health. In this study, the patient should be asked to suspend the consumption of red meat, nonsteroidal anti-inflammatory drugs, antibiotics, and laxatives the days before. We do not know whether the physicians correctly provided this information to the patient, since otherwise, a large part of these results could be false positives. This could be reflected in the fact that only 44.5% of the endoscopies obtained positive findings.
On the other hand, it was found that only 36.8% of patients with positive FOBT underwent colonoscopy. In turn, 35.4% of patients had pathological findings that warranted biopsy.
The age in which there was a greater adherence to performing the colonoscopy was between 60 and 69 years, with a total of 47.9%. Regarding sex, the female prevailed with 57.9%, which could be correlated with the lower mortality in said sex and the assumption of greater adherence.
However, we must mention that many of the endoscopic data could not be obtained due to incomplete descriptions.
With respect to the pathological data, it is noteworthy that most of the patients had adenomatous polyps. Free resection margin was reported in only 2, so it is unknown if the rest of the patients had a complete resection.
Only 5 out of 8 patients with carcinoma in the screening had operative histopathology and of these the uninvolved margins and the sufficient quantity of excised lymph nodes stand out, demonstrating a good surgical technique despite not being a high-volume center.
As we can see from the data obtained, there may be a lack of information from both the patients and the physicians to carry out the screening tests in the population at greatest risk. It was found that the vast majority of patients who underwent FOBT and obtained a positive result did not undergo the corresponding endoscopy. This could reflect the patient's ignorance of the importance of performing this study due to a lack of information, or the physicians' ignorance of the steps to follow in the event of a positive FOBT result.
Conclusions
Based on this study, the need for awareness campaigns to carry out colorectal cancer screening is raised. At the same time, adequate training of health personnel is necessary.
We also propose the use of an immunohistochemistry test for the detection of fecal occult blood, due to its higher sensitivity and specificity.
Limitations
Since we proposed a retrospective observational study, we found ourselves largely lacking information when collecting the data. This limits the quality of scientific evidence in studies of this type.
References
1. Lin, G., Feng, Z., Liu, H. et al. Mass screening for colorectal cancer in a population of two million older adults in Guangzhou, China. Sci Rep. 2019; 9:10424.
2. Morillas JD, Castells A, Oriol I, Pastor A, Pérez-Segura P, Echevarría JM, et al. Alianza para la prevención del cáncer de colon en España: un compromiso cívico con la sociedad. Gastroenterol Hepatol. 2012; 35:109-28.
3. Renzi C, Lyratzopoulos G, Hamilton W, Rachet B. Opportunities for reducing emergency diagnoses of colon cancer in women and men: A data-linkage study on pre-diagnostic symptomatic presentations and benign diagnoses. Eur J Cancer Care (Engl). 2019; 28:e13000.
4. Basso J, Quian J, Rosa R, Ruocco H, Brescia A, Echevarría J. Guía de práctica clínica de tamizaje del cáncer colo-rectal 2018.
5. Piñol V, Bessa X, Saló J, Elizalde JI, Castells A. La detección precoz del cáncer colorrectal. Medicina Integral. 2001; 37:118-26.
6. Castells, A. Cribado del cáncer colorrectal. Gastroenterol Hepatol. 2011: 34 (Supl 1):59-63.