Prediction of Cancer Incidence and Mortality in Korea, 2026.

Introduction
Cancer is the leading cause of death in Korea [1] and has been a major public health concern since 1983. In 2023, approximately 289,000 new cancer cases were diagnosed in Korea, and 24% of total deaths were attributed to cancer [1,2]. Although Korea maintains a nationwide cancer registry, a time lag of at least two years is required to finalize incidence statistics, while mortality data become available more rapidly. To support timely cancer control planning, projections of the current cancer burden are necessary. This study presents projections of cancer incidence and mortality for 2026 based on observed incidence data through 2023 and mortality data through 2024.

Materials and Methods
The Korean Ministry of Health and Welfare initiated a nationwide, hospital-based cancer registry, known as the Korea Central Cancer Registry (KCCR), in 1980. The history, objectives, and activities of the KCCR have been documented in detail elsewhere [3]. Cancer incidence data from 1999 to 2023 were obtained from the Korea National Cancer Incidence Database (KNCI DB). Cancer cases were classified according to the International Classification of Diseases for Oncology, 3rd edition [4] and converted according to the International Classification of Diseases, 10th edition (ICD-10) [5]. Mortality data from 1993 to 2024 were acquired from the Ministry of Data and Statistics [1]. The cause of death was coded and classified according to the ICD-10 [5].
The cancer sites included in this study were (1) all cancer sites combined and (2) the 24 cancer sites as follows: lips, oral cavity, and pharynx (C00-C14), esophagus (C15), stomach (C16), colon and rectum (C18-C20), liver (C22), gallbladder etc. (C23-C24), pancreas (C25), larynx (C32), lung (C33-C34), breast (C50), cervix uteri (C53), corpus uteri (C54), ovary (C56), prostate (C61), testis (C62), kidney (C64), bladder (C67), brain and central nervous system (C70-C72), thyroid (C73), Hodgkin lymphoma (C81), non-Hodgkin lymphoma (C82-C86, C96), multiple myeloma (C90), leukemia (C91-C95), and other and ill-defined sites (remainder of C00-C96).
The population data from 1993 to 2026 were obtained from the resident registration population data, reported by the Ministry of Data and Statistics. Data of the mid-year population (July 1 of the respective year) were used as the denominator to obtain the annual incidence and mortality rates. However, for the year 2026, we used the population data on December 31, 2025, as the mid-2026 resident registration population data were not yet available at the time of the analysis.
Linear regression models [6] were used to assess time trends and create projections. We first performed a joinpoint regression analysis on the data available to detect the year when significant changes occurred in cancer trends according to sex and cancer site. A joinpoint regression describes changes in data trends by connecting several different line segments on a log scale at “Joinpoints.” This analysis was performed using Joinpoint software ver. 5.0.2.2 (http://surveillance.cancer.gov/joinpoint) from the Surveillance Research Program of the U.S. National Cancer Institute [7]. For the analysis, we arranged to have at least four data points between consecutive joinpoints. Secondly, to predict age-specific cancer rates, a linear regression model was fitted to age-specific rates by 5-year age groups against their respective years, based on the observed cancer incidence data of the latest trends. Finally, we multiplied the projected age-specific rates by the age-specific population to get the projected number of cancer cases and deaths for the year 2026.
We summarized the results using crude rates (CRs) and age-standardized rates (ASRs) of cancer incidence and mortality. ASRs were standardized using the Segi’s world standard population [8] and expressed per 100,000 persons.

Results

1. Incidence
In total, 308,876 new cancer cases are expected to occur in 2026 (Table 1, Fig. 1); more men (n=159,609) than women (n=149,267) are expected to be affected.
The projected CRs per 100,000 for all of the sites combined in 2026 are 627.5 cases and 581.2 cases for men and women, respectively (Table 2). The projected ASRs per 100,000 for all of the sites combined are 290.4 cases and 314.9 cases for men and women, respectively. In men, the five leading primary sites of cancer are expected to be the prostate (CR, 115.0; ASR, 43.6), lung (CR, 85.4; ASR, 33.4), colon and rectum (CR, 79.6; ASR, 41.1), stomach (CR, 57.8; ASR, 24.5), and thyroid (CR, 44.4; ASR, 32.2), accounting for 60.9% of all new cancer cases in 2026. In women, the five leading primary sites are expected to be the breast (CR, 132.7; ASR, 78.5), thyroid (CR, 113.3; ASR, 87.3), colon and rectum (CR, 57.6; ASR, 27.4), lung (CR, 49.1; ASR, 18.4), and stomach (CR, 31.4; ASR, 12.6), accounting for 66.1% of all new cancer cases in 2026 (Fig. 1).
The five most common cancer sites expected in 2026 according to sex and age group are shown in Table 3. Leukemia and thyroid cancer are expected to be the most common forms of cancer in both sexes for those aged 0-14 years and 15-34 years, respectively. Colorectal cancer is predicted to be the most common cancer in men aged 35-64 years, while prostate cancer is expected to be more frequent in men aged 65 years and above. Breast cancer is predicted to be the most common cancer in women aged 35-64 years and 65 years and above. According to the projection, the incidences of stomach, lung, liver, colorectal, and prostate cancers will increase gradually with age for men (Fig. 2A). In women, the age-specific incidence rates for stomach, colorectal, liver, lung, and cervical cancers denote an increasing trend with age; however, the incidences of breast and thyroid cancers in women are expected to level off after the age of 45 and 50 years, respectively (Fig. 2B).

2. Mortality
It is estimated that 86,317 cancer deaths will occur in Korea during 2026 (Table 1, Fig. 1). The projected CRs per 100,000 for all of the sites combined in 2026 for men and women are 208.0 cases and 130.1 cases, respectively, whereas the projected ASRs per 100,000 for all sites combined for men and women are expected to be 79.5 cases and 40.8 cases, respectively (Table 4). The predicted five leading cancer sites causing mortality in men are the lung (CR, 53.0; ASR, 19.1), liver (CR, 25.7; ASR, 10.1), colon and rectum (CR, 19.5; ASR, 7.7), stomach (CR, 17.3; ASR, 6.9), and pancreas (CR, 17.1; ASR, 6.7). During the same period, lung cancer (CR, 18.8; ASR, 5.3) is projected to be the leading cause of cancer death in women, followed by pancreatic (CR, 16.5; ASR, 4.8), colon and rectal (CR, 15.4; ASR, 4.2), breast (CR, 11.9; ASR, 5.4), and gallbladder (CR, 10.5; ASR, 2.5) cancers.
The predicted age-specific mortality rates of the leading causes of cancer-associated death in men and women in 2026 are shown in detail in Fig. 3. According to age, Korean men and women aged at least 60 years are expected to have the highest mortality rates due to lung cancer.

Conclusion
A total of 308,876 new cancer cases and 86,317 cancer deaths are expected to occur in Korea during 2026. Prostate cancer, which became the leading cancer among men in 2023, is expected to maintain its position, reflecting sustained increases associated with population aging and detection patterns. Breast cancer continues to dominate among women, while pancreatic cancer has emerged as a major contributor to female cancer mortality.
Although overall age-standardized mortality continues to decline, the cancer burden is increasingly driven by cancers prevalent in older populations. These projections underscore the structural shift in Korea’s cancer profile toward age-related malignancies and highlight the need for tailored prevention and management strategies in an aging society.
Since the estimates are model-based, the results should be interpreted cautiously, particularly in light of potential disruptions in cancer diagnosis and reporting following the COVID-19 pandemic.