Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related death worldwide. It was estimated that there were 1.93 million new CRC cases and 0.94 million CRC deaths in 2020 (1). The global new cases and deaths are projected to increase to 2.2 million and 1.1 million by 2030, respectively (2). Europe and North America have higher incidence rates than most other parts of the world (1). In 2024, it was estimated that there were 0.15 million new cases in the United States and 0.15 million deaths in the European Union (3, 4). In China, the age-standardized incidence rate (ASIR) and mortality rate (ASMR) were 30.55 per 100,000 and 13.86 per 100, 000, respectively, in 2019 (5). Despite lower rates compared with developed countries such as the United States (ASIR: 41.86 per 100,000; ASMR: 14.77 per 100,000), China has the highest number of new CRC cases and CRC deaths worldwide due to its large population. In 2020, 0.55 million new CRC cases and 0.28 million CRC-related deaths occurred in China, accounting for 28.8% of newly diagnosed cases and 30.6% of CRC-related deaths worldwide, respectively (6, 7).

CRC has become a heavy economic burden in many countries. The estimated total medical costs of CRC were €19.1 billion in Europe in 2015 (8) and $24.3 billion in the United States in 2020 (9). In China, the economic burden of CRC reached 170.5 billion Chinese Yuan (CNY) in 2019, reaching 0.189% of the local GDP, and it is expected to reach 560 billion in 2030 without effective intervention (10).

CRC prevention programs and targeted treatment methods are therefore needed to alleviate the economic burden of CRC, which necessitates a thorough understanding of the structure of CRC medical treatment costs. Previous studies mostly focused on the medical costs of CRC in Western countries (11–14), while there have been limited studies focusing on a Chinese context. Existing studies on China have only estimated the total medical costs of CRC, rather than dissecting the costs into different categories, such as medication, examination, and surgery, to provide insights into the structure of costs (15, 16). By contrast, the aim of this study was to estimate the inpatient CRC medical treatment costs by cost categories (i.e., material cost, medication cost, surgery cost, treatment cost, examination cost, and hospital service cost), and compare the costs by patient sociodemographic characteristics, tumor sites, and cancer stages, in a real-life clinical setting of a tertiary hospital in Ningbo, Zhejiang, China. The CRC prevalence in Zhejiang has caused a heavier economic burden than other Chinese provinces (17, 18), making it a good example to study the costs of CRC treatment and relevant contributors.

The data contained a total of 722 inpatients diagnosed with CRC between 2020 and 2022, with 538 subjects satisfying the criteria for inclusion in this study (Figure 1). A total of 538 inpatients were included in this study, with 63.9% were male, 53.7% aged between 60 and 79, 83.6% elected not to take TCM during hospitalization, and 67.5% diagnosed with rectal cancer (Table 1). The proportions of patients at Stages I, II, III, and IV were 21.2, 31.6, 35.5, and 11.7%, respectively. Patients with rectal cancer had a significantly younger age structure (p < 0.001), with 22.9% under the age of 59, compared to 10.8% with colon cancer. There were significant differences in cancer stage between colon cancer and rectal cancer (p < 0.001), as higher percentages of Stage III (36.4%) and Stage II (37.1%) were found in rectum cancer and colon cancer, respectively. Figure 1 details the sample procedure and inclusion process.

The mean total medical cost for CRC treatment was ¥37946.13 per patient, with ¥9101.29 for materials, ¥9830.81 for medications, ¥5091.29 for surgeries, ¥3070.79 for treatment, ¥8421.13 for examinations, and ¥2521.28 for hospital services (Table 1). The mean costs across all cost categories were significantly higher for colon cancer than rectal cancer (p < 0.001).

Table 2 displays the changes in the cost structures of CRC medical costs from 2020 to 2022. The proportions of material cost and surgery cost increased, while the proportion of medication costs decreased. The proportions of other cost categories were relatively stable, with minor changes.

Table 3 summarizes the mean cost by patient characteristics for inpatients with rectal and colon cancers. The total cost for rectal cancer was found to be significantly higher in male patients (p = 0.012) and older patients (p < 0.001), but not for colon cancer. The total cost of patients was significantly higher for those using TCM for both rectal (p = 0.002) and colon (p = 0.005) cancers. The medical treatment cost increased significantly with stage levels for rectal cancer in any cost category (p < 0.001). By contrast, no significant difference in the medical treatment cost across cancer stages was observed for colon cancer.

Figure 2 shows the cost structures of medical treatment costs by cancer stage and tumor site. Medical costs for rectal and colon cancer exhibited similar cost structures, with medication, examination, and materials as the three major cost drivers, contributing to over 70% of total costs. Medication was the largest cost source for rectal cancer, ranging from 25% to 29%, depending on the cancer stage, and it was also the largest source for colon cancer at Stages II (26%) and IV (27%). However, the largest cost source for colon cancer at Stages I (27%) and III (30%) was material cost. The proportion of examination cost was relatively stable for both rectal and colon cancers, ranging from 20% to 23%, depending on the cancer stage and tumor site. Treatment and hospital services remained the least important contributors for both rectal and colon cancers, with stable proportions of 7%−9%. When comparing the cost structures between rectal and colon cancers, the proportion of material cost was substantially higher in colon cancer than in rectal cancer at Stages I, II, and III, except for Stage IV. The differences in other costs were relatively small.

This study found that the mean costs were significantly higher in colon cancer across all cost categories than in rectal cancer. This contrasts with previous studies, some of which reported that the costs for rectal cancer were higher than those for colon cancer (15, 21, 22), while others found no significant difference between the costs of rectal and colon cancers (12, 23). Two reasons may account for this difference. First, rectal cancer is more likely to be diagnosed at an earlier stage, due to specific initial symptoms such as rectal bleeding (24). As a result, the proportion of patients at Stage I was higher in the rectal cancer sample than the colon cancer sample (25.3% vs. 12.6%) in this study, leading to lower medical costs. In contrast, the proportions of patients at an early stage were similar between rectal and colon cancers in previous literature, such as 59% for rectal cancer vs. 58% for colon cancer (22) or 49% for rectal cancer vs. 51% for colon cancer (12). Second, older patients are more likely to experience complications and comorbidities (25, 26), and in our study, the proportion of patients aged above 80 was higher for colon cancer than for rectal cancer (36.6% vs. 22.9%), which may have raised medical costs.

This study also found that the mean cost of CRC increased with the TNM stage of diagnosis, which is consistent with previous studies (23, 27, 28). However, colon and rectal cancers showed different cost features along with cancer stages. For the patients with rectal cancer, costs in all categories increased significantly from Stage I to Stage IV, as later stages usually require more complicated treatment strategies and additional medication to combat complications and comorbidities. Moreover, rectal cancer at Stages III and IV usually involves resection of a larger part of the rectum and adjacent tissues or organs invaded by cancer cells (29), which could cause greater damage to the digestive and immune systems and therefore raise relevant costs. For colon cancer, medical costs generally increased from Stage I to Stage IV in our study, although the differences between costs across stages were not significant. It may be because there were fewer colon cancer patients than rectal cancer patients included in our study (175 vs. 363), and the limited number of observations may influence the power of the estimation.

Medication, materials, and examinations were the three major sources of medical costs for CRC, which was similar to a recent research based on a tertiary hospital in Shanghai (30). The proportions of medication cost in total costs varied from 23% to 29%, depending on the cancer stage and tumor site. This was similar to some foreigner studies conducted in Serbia (31%) (13) and the EU (27%) (11), but differed from previous studies in France (5%) (14), Finland (12% in primary disease state to 60% in metastatic state) (12), Jordan (54%) (23), and Vietnam (62%) (31). Such disparities may be attributed to the differences in drug prices and pharmacy prescription regulations across countries. The proportion of examination cost in our study ranged from 20% to 23%, which was comparable to studies in Serbia (18%) (13) and Jordan (22%) (23). The surgery cost made up 11% to 16% of total costs in our study, and the proportions were comparable to those in Serbia (11%−13%) (13), and Vietnam (12%) (31), but differed from studies in Jordan (5%) (23) and the US (53%) (32). The proportion of medication costs in our study witnessed a dramatically decrease from 2020 to 2022, with an annual rate of −11.87%. It is worth noting that the Chinese government has been exerting efforts to regulate the medical market to reduce the economic burden of cancer drugs for its citizens, which could partly explain the decreasing proportion of medication costs in our study. However, the proportion of surgery costs increased by 10.07% annually from 2020 to 2022, and this might be attributed to the increased material costs (20.87% in 2020 to 26.92% in 2022).

CRC-related costs were found to be related to patient characteristics. Male patients had significantly higher medical costs than females for rectal cancer, but not for colon cancer. This might be due to the narrower and deeper pelvises of males, which make the treatment of rectal cancer more difficult and therefore costlier (33). In addition, rectal cancer was found to be more sensitive to smoking (34) and alcohol consumption (35) than colon cancer. Males were found more likely than females to have unhealthy lifestyle habits such as alcohol consumption and smoking (36, 37) that increase the risk of rectal cancer, which may result in higher medical costs. Patients over 80 showed significantly higher costs for rectal cancer in all cost categories than patients below 60, probably due to weaker physical function and poorer immune systems. This feature was also observed in the treatment cost and examination cost for colon cancer. However, previous studies in Western countries have reported a contrasting feature, as seen in France (14), Finland (12), and the USA (38). This highlights the complex relationship between age and CRC-related costs, which is worth further investigation as a research topic. Rectal cancer patients who used TCM had significantly higher CRC-related costs than those who did not. This is probably because patients with TCM usage had a higher average age (74.51 vs. 69.38), and TCM was more likely to be used as a complementary and alternative therapy for older patients (39).

The findings of this study may have important implications for China's health policies. The stage at diagnosis was found to play a critical role in influencing the costs of rectal and colon cancers. CRC patients at later stages (III and IV) had higher medical costs than patients at earlier stages (I and II). Thus, CRC prevention measures like screening should be encouraged to be implemented for early diagnosis. CRC screening has been widely implemented as a basic public health welfare in many developed countries (40). In comparison, the current overall CRC screening uptake in China is still limited because of its huge population and limited healthcare resources (7). The limited participation in CRC screening of Chinese citizens had led to later diagnosis and thus increased the economic burden. In 2019, the Healthy China Action by the Chinese government was proposed to increase the cancer screening coverage of the overall population (16). To achieve this, the Chinese government may develop risk-prediction models to identify the population at high risk of CRC and introduce health awareness campaigns to encourage participation in CRC screening programs, particularly among population with higher CRC risks (41). With respect to the cost structure of CRC, medication, materials, and examinations are the three major sources of medical expenditures for rectal cancer and colon cancer. The government may incorporate more types of medication and medical materials into the centralized purchasing system to decrease the economic burden for CRC patients caused by materials and medication. Improvements may also be made in surgical and treatment strategies and technologies to reduce the economic burden of CRC treatment. Additionally, this study also showed the variations in CRC-related costs by patient age and gender, suggesting the potential improvements that could be made in patient treatment strategies for heterogeneous patients.

This study has some strengths relative to previous studies examining the costs of treating CRCs. First, it explored the cost structure of CRC-related costs by dividing costs into six sub-categories, providing more detailed and specific insights into CRC costs. Second, the sample was separated by tumor site (rectum and colon) to better reflect the heterogeneity effect on CRC costs by tumor site. By contrast, previous studies grouped colon cancer and rectal cancer together, without considering their differences in anatomy and treatment (15, 16, 30). However, some limitations should be acknowledged. First, due to data limitations, this study did not include outpatient costs such as radiotherapy and chemotherapy. Second, we only included patients diagnosed with CRC and received treatment in the study hospital, while patients who received multiple treatments and those who were transferred to other hospitals were not considered. Third, we did not take into account the impacts of patients' social-economic status (SES) on CRC medical costs. Fourth, this study was based on Ningbo in Eastern China, while the incidence rate and CRC medical costs may vary due to regional differences in lifestyle, environment, and SES across different parts of China. This may affect the representativeness and generalizability of our results. A well-designed research with a larger population that includes both direct and indirect costs should be conducted in the future to construct an estimate and prediction of the cost burden on the health system.

This retrospective study estimated the costs of CRC patients by cost category in real-life clinical settings in Ningbo, China. Medication, materials, and examinations were the main cost drivers of CRC treatment. The cost was significantly higher for colon cancer, which was typically identified at a later stage. The mean medical cost increased significantly from Stage I to Stage IV for rectal cancer. The findings suggest implications for the management of rectal and colon cancers, specifically the importance of early screening among the higher risk population for colon cancer and tailored treatment strategies for different tumor sites. Future studies should include the outpatient and indirect costs of CRC, and data from other regions of China.