Introduction

Colorectal cancer (CRC) encompasses malignancies originating in the colon and rectum and represents a major global health challenge. According to the World Health Organisation, CRC is the third most commonly diagnosed cancer worldwide and the fourth leading cause of cancer-related mortality [1]. In 2018 alone, over 1.8 million new CRC cases were reported globally, with approximately 881,000 deaths attributed to the disease. The burden of CRC is not uniformly distributed; developed countries report higher incidence rates, a trend often linked to lifestyle factors such as diet, physical inactivity, and obesity [2].

In Iraq, the epidemiological landscape of CRC has undergone notable changes in recent decades. Historically considered a low-incidence region for CRC, Iraq has witnessed a concerning rise in both incidence and mortality rates associated with the disease [3]. Data from the Iraqi National Cancer Registry indicate that the overall CRC incidence proportion increased from 2.28 to 6.18 per 100,000 population between 2000 and 2019, reflecting an annual percentage change of 5.11%. This upward trend is observed across various age groups, with a particularly notable increase among individuals aged 20 to 50 years, where the incidence proportion rose from 1.46 to 4.36 per 100,000 population during the same period. These statistics underscore the shifting burden of CRC within the Iraqi population and highlight the need for comprehensive research to elucidate the underlying factors contributing to this rise [4].

Several studies have attempted to characterise CRC’s clinical and histopathological features in Iraq. A survey conducted between 2015 and 2021 in Baghdad analysed 60 cases of CRC and found a higher incidence in patients aged 60–90 years, with a slight female predominance (52%). The left colon was the most frequent tumour site (59.6%), and moderately differentiated adenocarcinoma was the predominant histological type (67.3%) [5]. Another study focusing on trends over two decades reported that CRC in Iraq remains predominantly a disease of the elderly but is rising in incidence and mortality across all age groups [6]. These findings suggest potential shifts in risk factors, disease presentation, and possibly genetic predispositions within the Iraqi population.

Globally, the aetiology of CRC is multifactorial, involving a complex interplay between genetic and environmental factors. Dietary patterns, in particular high consumption of red and processed meats coupled with low fibre intake, have been implicated in increasing CRC risk [7]. Sedentary lifestyles, obesity, and smoking are additional modifiable risk factors. Genetic predispositions, such as familial adenomatous polyposis and Lynch syndrome, also contribute to CRC development, although these account for a smaller proportion of cases. In Iraq, rapid urbanisation, adoption of Westernised diets, and lifestyle changes may contribute to the rising CRC incidence. However, comprehensive data delineating these associations are limited, necessitating further investigation [8].

Histopathological analysis remains a cornerstone in the diagnosis and management of CRC. It provides critical insights into tumour type, grade, and stage, essential for prognostication and guiding therapeutic decisions [9]. The World Health Organisation classifies CRC into histological subtypes, including classic adenocarcinoma, mucinous adenocarcinoma, and signet-ring cell carcinoma. Each subtype carries distinct prognostic implications. For instance, mucinous adenocarcinoma, characterised by abundant extracellular mucin, is associated with a poorer prognosis than classic adenocarcinoma. Understanding the distribution of these histological subtypes within the Iraqi population can inform tailored treatment approaches and resource allocation [10].

Despite the increasing recognition of CRC as a public health concern in Iraq, there remains a paucity of comprehensive studies examining its histopathological characteristics and prevalence across different regions of the country. Small sample sizes, single-centre designs, and a lack of longitudinal data often limit existing research. This gap in knowledge hinders the development of effective screening programs and targeted interventions. Given the rising incidence and the potential for improved outcomes through early detection and appropriate management, there is an urgent need for robust epidemiological and histopathological studies to inform public health strategies [11].

Aim

This study addresses these gaps by conducting a comprehensive pathological analysis of CRC cases across multiple medical centres in Iraq. By examining a large and diverse patient cohort, we seek to elucidate the prevalence, demographic distribution, tumour characteristics, and staging of CRC within the Iraqi population. The insights gained from this research will contribute to a more nuanced understanding of CRC in Iraq and support the development of evidence-based strategies for screening, prevention, and management.

Material and methods

This retrospective study was conducted across several oncology centres and private laboratories in different Iraqi cities from January 2015 to December 2021.

Patient selection

A total of 150 cases of colorectal tumours were identified from the pathology archives of the participating centres and laboratories. Inclusion criteria encompassed patients diagnosed with colorectal adenocarcinoma and its subtypes, who underwent surgical resection or biopsy during the study period. Exclusion criteria included patients with recurrent CRC, those who received neoadjuvant therapy before tissue sampling, and cases with incomplete clinical data. After applying these criteria, 120 cases were included in the final analysis.

Data collection

Clinical information was collected from patient records, including age, gender, tumour size, tumour location, pathological grade, and stage. Tumour locations were categorised as right colon (cecum to transverse colon), left colon (descending and sigmoid colon), and rectum. Tumour sizes were recorded as the largest diameter measured during pathological examination. Pathological grading was based on the degree of differentiation: well differentiated, moderately differentiated, and poorly differentiated. Staging was performed according to the American Joint Committee on Cancer (AJCC) 8th edition TNM staging system.

Histopathological examination

Formalin-fixed, paraffin-embedded tissue blocks were sectioned at 4–5 µm thickness and stained with Haematoxylin and Eosin (H&E). Experienced pathologists conducted histopathological evaluations to confirm the diagnosis and assess tumour characteristics. Special attention was paid to histological subtypes, the presence of mucin production, lymphovascular invasion, perineural invasion, and tumour budding.

Statistical analysis

Data were analysed using SPSS version 26.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were used to summarise patient demographics and tumour characteristics. Continuous variables were expressed as mean ± standard deviation (SD), while categorical variables were presented as frequencies and percentages. The c² test assessed associations between categorical variables, and independent t-tests were used for continuous variables. A p-value of ≤ 0.05 was considered statistically significant.

Results

The clinical and histopathological analysis of colorectal adenocarcinoma among Iraqi patients yielded in Tables I–III.

Discussion

The analysis of CRC cases among Iraqi patients reveals several noteworthy findings. The mean age of diagnosis was 58.6 years, with a significant proportion (55%) of patients aged 50–69 years. This aligns with global data indicating increased CRC risk with advancing age. However, 35% of cases occurred in patients under 50 years old, suggesting a shift towards earlier onset, consistent with regional studies reporting rising CRC incidence in younger populations [12].

Gender distribution showed a slight male predominance (54.2%), resulting in a male-to-female ratio of 1.18 : 1. This aligns with global trends, in which males exhibit higher CRC incidence, potentially due to lifestyle factors and genetic predispositions.

Tumour location analysis indicated that the left colon was the most common site (41.7%), followed by the right colon and rectum (29.2% each). This contrasts with some Western studies reporting a higher prevalence of right-sided tumours, particularly among older populations. The reasons for this variation may include genetic, environmental, and dietary factors [13].

Histopathologically, moderately differentiated adenocarcinoma was the predominant type (66.7%), consistent with global data. Mucinous adenocarcinoma accounted for 12.5% of cases, aligning with other studies reporting its association with poorer prognosis and distinct genetic profiles.

Regarding tumour staging, a significant proportion of patients were diagnosed at Stage II (41.7%) and Stage III (33.3%), indicating advanced disease at presentation. This underscores the need for improved screening and early detection strategies in Iraq. The presence of lymphovascular invasion (37.5%), perineural invasion (25%), and tumour budding (16.7%) are recognised adverse prognostic factors, highlighting the importance of thorough histopathological evaluation [14].

The rising incidence of colorectal adenocarcinoma in Iraq, particularly among younger populations, may be attributed to changes in dietary habits, increased prevalence of obesity, and lifestyle modifications. Adopting a more Westernised diet, characterised by high consumption of red and processed meats and low fibre intake, has been implicated in increasing CRC risk. Additionally, low participation rates in screening programs and limited public awareness about CRC symptoms contribute to delayed diagnoses and advanced disease stages at presentation [15].

These findings underscore the urgent need for public health initiatives to increase awareness about CRC risk factors and symptoms. Implementation of nationwide screening programs, particularly targeting high-risk groups, could facilitate earlier detection and improve outcomes. Furthermore, promoting healthy lifestyle changes, such as increased physical activity and dietary modifications, may help reduce CRC incidence [16].

Conclusions

This study provides valuable insights into the histopathological characteristics of CRC among Iraqi patients. The data highlight the critical need for enhanced screening programs, public awareness campaigns, and lifestyle interventions to facilitate early detection and improve patient outcomes in Iraq.

Funding

No external funding.

Ethical approval

Not applicable.

Conflict of interest

The author declares no conflict of interest.

References