Abstract
Objective
This study aimed to estimate the medical costs among patients with ovarian cancer across distinct phases of care and surgical years.
Methods
This population-based retrospective cohort study identified newly diagnosed ovarian cancer patients who underwent surgery based on nationwide claims data from Korea (2012–2019). Medical costs were categorized into 5 phases: neoadjuvant chemotherapy, surgery, frontline chemotherapy, monitoring, and recurrence. Total and cancer-related costs were analyzed by surgical year on a per patient and per patient per month (PPPM) basis. Per patient costs were estimated for each phase, with up to one year of follow-up per phase, for patients identified between 2013 and 2016. Generalized linear models (GLMs) examined associations between surgical year and cancer-related costs.
Results
Among 10,594 patients, median cancer-related costs per patient were highest in the recurrent phase ($20,548), followed by the frontline chemotherapy ($7,005), neoadjuvant chemotherapy ($5,870), surgery ($4,965), and monitoring phases ($1,906). The median surgery phase costs per patient increased from $4,254 in 2013 to $5,676 in 2016; recurrent phase costs increased from $17,289 to $26,750. GLM analysis revealed that per patient and PPPM costs significantly increased over time, particularly in the surgery and recurrent phases. Compared with the cost per patient in 2013, the cost per patient in 2016 was 27% higher for the surgery phase and 49% higher for the recurrent phase.
Conclusion
Ovarian cancer-related costs have significantly increased over time, especially in the surgery and recurrent phases, thus highlighting the growing economic burden and the need for cost-effective care strategies.
Keywords: Ovarian Neoplasms, Costs and Cost Analysis, Health Expenditures
Synopsis
This study examined ovarian cancer-related costs across 5 phases of care using nationwide claims data. This large-scale, multiyear analysis showed significant cost increases over surgical years. The increase was particularly notable in surgery and recurrent phases. These findings highlight the growing economic burden of ovarian cancer care in Korea.
INTRODUCTION
Ovarian cancer is a malignant tumor with one of the highest global mortality rates among females, contributing to more than 207,000 deaths annually [1]. Owing to the lack of disease-specific symptoms, ovarian cancer is often diagnosed at an advanced stage, leading to high rates of recurrence and mortality despite initial treatment efforts [2,3]. Beyond its clinical burden, ovarian cancer is associated with the highest healthcare costs among gynecological cancers, reflecting its substantial economic implications [4,5,6].
The economic burden of ovarian cancer treatment varies significantly across different phases of the disease. Previous studies from the United States and Australia have examined medical costs across different treatment phases, such as initial treatment, maintenance, and terminal care [7,8]. These studies have attempted to estimate phase-specific costs using broad time-based categorizations, typically anchored around major events such as diagnosis and death. For instance, a U.S. study defined the initial phase as the first six months following diagnosis, the end-of-life phase as the last six months before death, and the remaining period as the continuing care phase [7]. Previous studies have reported that medical costs tend to be higher during the initial and terminal phases of care, with relatively lower costs observed during the maintenance phase.
The variation in costs across phases may be influenced by the treatments performed at each stage. For example, initial phase costs are likely influenced by the expense of surgery. Additionally, the introduction of targeted therapies such as bevacizumab and poly (ADP-ribose) polymerase (PARP) inhibitors has contributed to changes in treatment costs. However, broad time-based definitions used in prior studies—such as grouping costs into initial, continuing, and terminal phases—do not adequately reflect the structured treatment course of ovarian cancer, which is largely dictated by clinical decisions and disease progression. The introduction of novel medications and/or advanced medical technologies has the potential to influence health care costs, with the impact varying based on the stage of care.
These insights are critical for developing cost-effective treatment strategies and supporting evidence-based decision-making. However, few studies have evaluated phase-specific costs in a way that reflects the real-world treatment trajectory of ovarian cancer. Therefore, this study aimed to examine the costs of ovarian cancer treatment across 5 phases of care (neoadjuvant chemotherapy, surgery, frontline chemotherapy, monitoring, and recurrence) and across different surgical years.
MATERIALS AND METHODS
1. Data source and ethical considerations
This study analyzed national claims data from the Cancer Public Library Database (CPLD) in Korea [9]. The CPLD integrates data from 4 major population-based public sources: the Korea National Cancer Incidence Database in the Korea Central Cancer Registry, cause-of-death data in Statistics Korea, the National Health Information Database in the National Health Insurance Service, and the National Health Insurance Research Database in the Health Insurance Review & Assessment Service. The database encompasses information on patient demographics, cancer-related characteristics, health care resource utilization, direct costs reimbursed by the National Health Insurance System, and mortality records. The CPLD, with approximately 98% completeness [10], serves as a comprehensive resource for generating real-world evidence under Korea’s universal health coverage system and fee-for-service model. This study received approval from the Institutional Review Board of the National Cancer Center, Republic of Korea (NCC2023-0218). As the CPLD contains anonymized and deidentified data, the requirement for informed consent was waived.
2. Study design and population
This retrospective cohort study used claims data from January 1, 2012, to December 31, 2019. The study population consisted of patients who were newly diagnosed with ovarian cancer and underwent surgery. To identify eligible patients, claims data for adult patients with ovarian cancer (the International Classification of Disease-10th revision [ICD-10] code ‘C56’), newly diagnosed between 2012 and 2019, were retrieved from the CPLD. Patients were included if they met the following criteria: 1) had a history of ovarian cancer surgery performed either within 30 days before or at any time after the date of first diagnosis and 2) had their first ovarian cancer surgery within the index period, defined as January 1, 2013, to December 31, 2018. Ovarian cancer surgery was defined based on gynecological surgery claims during hospitalization, with ovarian cancer documented as either the primary or secondary diagnosis.
3. Definition of the phase of care
To reflect the clinical course of ovarian cancer care, we divided the treatment course into 5 distinct phases based on real-world treatment patterns: neoadjuvant chemotherapy (NAC), surgery, frontline chemotherapy, monitoring, and recurrence (Fig. 1A). This phase-based approach was designed to align with standard practice guidelines, which recommend surgery as the primary treatment [11], often accompanied by neoadjuvant or adjuvant chemotherapy depending on the clinical context. Recurrence was also considered a major clinical event, as it typically requires the initiation of additional surgery or systemic therapy.
Fig. 1. Patient flow chart and study design. (A) Study design and (B) patient flow chart.
Details for the definition of each phase are as follows: 1) The NAC phase was defined as starting on the date of the first claim for paclitaxel/carboplatin within 6 months prior to surgery and ending the day before surgery. The 6-month period was selected based on the 3 to 6 cycles of NAC administered every 3 weeks [12]. 2) The surgery phase commenced on the admission date for the first ovarian cancer surgery and ended on the discharge date. Costs for the surgery phase were analyzed only for patients who did not receive adjuvant chemotherapy during hospitalization; therefore, this study focused on the costs specifically attributable to the surgery and its associated expenses. 3) The frontline chemotherapy phase began on the date of the first claim for platinum-based therapy within 30 days after ovarian cancer surgery and was defined as ending on the date of the last prescription. To exclude surgery-related costs from this phase, for patients who initiated chemotherapy during hospitalization, the phase was considered to begin on the day following the end of the surgery phase. The addition of bevacizumab to platinum-based therapy was considered part of the frontline chemotherapy phase, whereas bevacizumab monotherapy following platinum-based therapy was not included in this phase. 4) The monitoring phase began the day after the last frontline chemotherapy claim (only if there was a gap of more than 6 months without any additional surgery or chemotherapy), and it ended at the time of additional surgery, chemotherapy, death, or the dataset cutoff date (December 31, 2019), whichever came first. 5) The recurrence phase was defined as beginning on the date of the first claim for surgery or chemotherapy following the frontline chemotherapy phase and ending at death or the dataset cutoff date. Recurrence was defined by the initiation of a new chemotherapy regimen or by a treatment interval of more than 6 months, followed by the resumption of the same regimen. The chemotherapy agents and surgical procedures used to define each phase are detailed in Table S1.
4. Study outcomes and baseline characteristics
The primary outcome of this study was ovarian cancer-related medical costs, categorized by phase of care. Ovarian cancer-related costs were defined as medical expenditures associated with claims that listed ovarian cancer (ICD-10 code ‘C56’) as either a primary or secondary diagnosis. These costs reflect direct healthcare utilization related to the diagnosis and treatment of ovarian cancer. Total medical costs, on the other hand, included all healthcare expenditures regardless of diagnosis, encompassing all inpatient, outpatient, and prescription claims. This broader measure captures overall healthcare utilization during each phase of care. Costs were analyzed across all surgical years, with subgroup analyses by surgical year to examine trends over time. The costs incurred in later calendar years were attributed to the initial surgical year. Additionally, subgroup analyses by age group and Surveillance, Epidemiology, and End Results (SEER) stage at initial diagnosis were performed.
Costs were analyzed on both a per patient basis and a per patient per month (PPPM) basis for each phase of care. Per patient costs were calculated by summing all costs incurred from the start of each phase through a follow-up period of up to one year, to ensure comparability across surgical years and to avoid misinterpretation of per-patient cost trends due to varying follow-up durations. To obtain sufficient follow-up data, per-patient estimates were only calculated among patients who underwent their first ovarian cancer surgery between 2013 and 2016. PPPM costs were calculated by dividing the total costs during each phase of care by patient-months. Additionally, per patient and per patient per year (PPPY) cancer-related costs were calculated for the entire cohort by summing costs from the admission date of the first ovarian cancer surgery to either death or the dataset cutoff date, with PPPY costs divided by patient-years. Costs were converted from Korean won (KRW) to the United States dollar (USD) using the 2019 exchange rate of 1,156.4 KRW/USD and adjusted for inflation based on the medical care component of Korea’s 2019 consumer price index.
The demographic characteristics included in the analysis were age group at the time of the first ovarian cancer surgery, SEER stage at initial diagnosis, histology, use of NAC, insurance type, income level, and year of surgery. Hospital characteristics, including geographic region and type, were assessed based on the institution where the surgery was performed. Additionally, as exploratory analyses, we assessed the annual proportion of patients in the recurrent phase who received PARP inhibitors or bevacizumab, based on claims data for each calendar year. We also examined the composition of per patient ovarian cancer-related costs by cost component for each phase of care. Costs were classified based on billing categories, including examination/imaging fee, hospitalization fee, injection fee, surgery/procedure fee, doctor’s fee, administration fee, physical therapy fee, psychiatric therapy fee, anesthesia fee, and outpatient prescription fee. For each phase, we identified the components that accounted for 10% or more of per patient cancer-related costs.
5. Statistical analysis
Demographic and hospital characteristics were summarized via descriptive statistics, reported as frequencies and proportions. Medical costs are presented as medians with interquartile ranges (IQRs), whereas the length of each phase of care is expressed as means and standard deviations (SDs). Generalized linear models (GLMs) with gamma distributions and log link functions were applied to each phase of care to assess the associations between surgical year and ovarian cancer-related costs, adjusting for the aforementioned demographic characteristics and hospital characteristics. This method was selected due to the right-skewed and nonnegative nature of health care cost data [13]. To test the robustness of our findings to model specification, a sensitivity analysis was conducted using a GLM with a normal distribution and identity link function, applied to log-transformed cost data. Statistical significance was determined via a 2-tailed value of p<0.05. All analyses were performed via SAS Viya version 03.05 (SAS Institute, Inc., Cary, NC, USA).
RESULTS
1. Baseline characteristics
A total of 10,594 patients who were newly diagnosed with ovarian cancer were identified and included in the analysis (Fig. 1B). The baseline patient characteristics are summarized in Table 1. Among these, 80.0% were younger than 65 years, and 20.0% were aged 65 years or older. At initial diagnosis, 47.6% of patients presented with localized or regional disease, whereas 48.4% presented with distant disease. A majority (66.9%) of initial surgeries were performed in tertiary hospitals, and 70.6% were performed in the capital area.
Table 1. Baseline characteristics of patients with ovarian cancer.
| Characteristics | Number of patients (%) (n=10,594) | |
|---|---|---|
| Age group (yr) | ||
| 19–40 | 1,318 (12.4) | |
| 40–64 | 7,154 (67.5) | |
| ≥65 | 2,122 (20.0) | |
| SEER stage at initial diagnosis | ||
| Localized/regional | 5,047 (47.6) | |
| Distant | 5,123 (48.4) | |
| Unknown | 424 (4.0) | |
| Histology | ||
| Serous | 5,417 (51.1) | |
| Non-serous | 5,177 (48.9) | |
| Neoadjuvant therapy | ||
| No | 9,231 (87.1) | |
| Yes | 1,363 (12.9) | |
| Insurance type | ||
| National health insurance | 10,241 (96.7) | |
| Medical aid or veterans | 353 (3.3) | |
| Income level | ||
| Lower 30% | 2,815 (26.6) | |
| Middle 40%–70% | 3,575 (33.8) | |
| Upper 30% | 4,009 (37.8) | |
| Unknown | 195 (1.8) | |
| Hospital type for initial surgery | ||
| Tertiary hospital | 7,087 (66.9) | |
| Others | 3,507 (33.1) | |
| Geographic region of hospital | ||
| Capital area | 7,475 (70.6) | |
| Metropolitans | 2,043 (19.3) | |
| Others | 1,076 (10.2) | |
| Year of surgery | ||
| 2013 | 1,453 (13.7) | |
| 2014 | 1,597 (15.1) | |
| 2015 | 1,609 (15.2) | |
| 2016 | 1,820 (17.2) | |
| 2017 | 1,974 (18.6) | |
| 2018 | 2,141 (20.2) | |
All percentages may not be a total of 100% due to rounding.
SEER, Surveillance, Epidemiology, and End Results.
2. Medical costs by phase of care
Based on up to 1 year of follow-up within each phase, the recurrent phase incurred the highest median per patient cancer-related costs ($20,548), followed by the frontline chemotherapy phase ($7,005) and the NAC phase ($5,870). The surgery phase had a median per patient cancer-related cost of $4,965, and the monitoring phase recorded the lowest cost ($1,906) (Table 2). The median PPPM cancer-related costs also varied across phases of care. The recurrent phase had median PPPM cancer-related costs of $2,427, followed by the NAC phase ($2,317), frontline chemotherapy phase ($2,050), and monitoring phase ($146) (Table 3).
Table 2. Per patient medical costs by phase of care* .
| Phase of care | Number of patients | Length of phase (mo) | Total costs (USD) | Ovarian cancer-related costs† (USD) |
|---|---|---|---|---|
| Mean±SD | Median (IQR) | Median (IQR) | ||
| Neoadjuvant chemotherapy phase | 753 | 2.7±0.8 | 6,377 (4,807–8,376) | 5,870 (4,111–7,793) |
| Surgery phase‡ | 4,429 | 0.6±1.3 | 4,986 (3,414–7,566) | 4,965 (3,381–7,517) |
| Frontline chemotherapy phase | 4,219 | 3.9±1.9 | 7,293 (5,076–10,583) | 7,005 (4,805–10,169) |
| Monitoring phase | 3,522 | 11.4±1.4 | 2,735 (1,695–4,906) | 1,906 (1,117–3,510) |
| Recurrent phase | 2,217 | 10.6±2.9 | 22,174 (13,206–34,663) | 20,548 (11,495–32,741) |
IQR, interquartile range; SD, standard deviation; USD, United States dollar.
*Per-patient costs were estimated for up to one year per phase for patients who underwent ovarian cancer surgery between 2013 and 2016, to ensure consistent phase-specific estimates across surgical years.
†“Ovarian cancer-related” refers to the claims with primary or secondary diagnosis of ovarian cancer.
‡Patients who received chemotherapy during hospitalization for surgery were excluded from the calculation for surgery phase costs.
Table 3. Medical costs per patient per month by phase of care* .
| Phase of care | Number of patients | Length of phase (mo) | Total costs (USD) | Ovarian cancer-related costs† (USD) |
|---|---|---|---|---|
| Mean±SD | Median (IQR) | Median (IQR) | ||
| Neoadjuvant chemotherapy phase | 1,363 | 2.7±0.9 | 2,521 (1,882–3,357) | 2,317 (1,649–3,192) |
| Surgery phase‡,§ | 7,654 | 0.7±1.4 | 5,469 (3,713–8,479) | 5,451 (3,674–8,431) |
| Frontline chemotherapy phase | 6,753 | 4.3±3.0 | 2,129 (1,627–2,873) | 2,050 (1,548–2,762) |
| Monitoring phase | 5,470 | 30.6±20.8 | 237 (141–457) | 146 (81–306) |
| Recurrent phase | 3,077 | 21.0±16.6 | 2,657 (1,531–4,140) | 2,427 (1,325–3,923) |
IQR, interquartile range; SD, standard deviation; USD, United States dollar.
*Analysis conducted on patients who underwent ovarian cancer surgery during the index period (2013–2018).
†“Ovarian cancer-related” refers to the claims with primary or secondary diagnosis of ovarian cancer.
‡Patients who received chemotherapy during hospitalization for surgery were excluded from the calculation for surgery phase costs.
§The surgery phase costs are presented as per patient cost, not per patient per month cost, as the mean phase length is less than 1 month.
The median per patient and PPPY cancer-related costs for the entire cohort were $24,383 (IQR, $14,141–$50,785) and $10,273 (IQR, $4,111–$24,230), respectively, with a mean follow-up of 3.2 years. For both per patient and PPPM costs, all phases of care except the monitoring phase demonstrated median cancer-related costs exceeding 90% of the median total costs. In the monitoring phase, the proportion of cancer-related costs ranged from 60% to 70%. The results of the subgroup analysis for per patient and PPPM cancer-related costs by age group and SEER stage are presented in Tables S2 and S3. Patients with distant disease at diagnosis consistently had higher costs across all phases of care except the NAC phase than did those with localized or regional disease.
3. Cancer-related cost trends across surgical years
Trends in cancer-related costs by surgical year are depicted in Fig. 2. In the recurrent phase, median per patient costs increased from $17,289 in 2013 to $18,707 in 2014 (+8.2%), $21,719 in 2015 (+25.6%), and $26,750 in 2016 (+54.7%). In contrast, the median patient cost within the NAC, frontline chemotherapy, and monitoring phases differed by about 10% or less between 2013 and 2016 (Fig. 2A). The surgery phase demonstrated a notable increase in median per patient costs from $4,254 in 2013 to $5,676 in 2016 (+33.4%) and further to $6,659 in 2018 (+56.5%). For the recurrent phase, median PPPM costs showed a consistent upward trend, increasing from $1,708 in 2013 to $2,817 in 2016 (+64.9%) and $3,445 in 2018 (+101.7%). In the monitoring phase, median PPPM costs also increased steadily, from $112 in 2013 to $153 in 2016 (+36.6%) and $181 in 2018 (+61.6%) (Fig. 2B).
Fig. 2. Median ovarian cancer-related costs by phase of care across subgroups of surgical years. (A) Per patient costs and (B) PPPM costs.
The surgery phase costs are presented as per patient cost, not per patient per month cost, as the mean phase length is less than one month. Per-patient costs were estimated for up to one year per phase for patients who underwent ovarian cancer surgery between 2013 and 2016, to ensure consistent phase-specific estimates across surgical years.
NAC, neoadjuvant chemotherapy; PPPM, per patient per month.
According to exploratory analyses, the proportion of patients in the recurrent phase who received bevacizumab increased from 0.3% in 2014 to 22.3% in 2019. Use of PARP inhibitors was first observed in 2017 (2.6%) and increased to 9.7% in 2019 (Fig. S1). The distribution of cost components varied across phases of care. Injection costs accounted for the largest share, exceeding 40%, in the neoadjuvant, frontline chemotherapy, and recurrent phases. In the surgery phase, surgery/procedure and examination/imaging costs were the major contributors, each accounting for approximately 20%–30%. The monitoring phase was mainly driven by examination/imaging costs, which accounted for over 40%. Detailed breakdowns of cost components by phase and surgical year are provided in Figs. S2-S6.
4. Association between surgical year and cancer-related costs
Table 4 shows the results of the GLM analysis for per patient cancer-related costs by phase of care. After adjusting for demographic characteristics and hospital characteristics, patients who underwent surgery in 2016 had costs approximately 1.27 times higher than those who underwent surgery in 2013 for the surgery phase (95% confidence interval [CI]=1.21–1.32). Similarly, patients who underwent surgery in 2016 had higher costs than patients who underwent surgery in 2013 across the following phases of care: 1.22 times higher for the frontline chemotherapy phase (95% CI=1.14–1.30), 1.15 times higher for the monitoring phase (95% CI=1.03–1.28), and 1.49 times higher for the recurrent phase (95% CI=1.32–1.67). In the GLM analysis for the NAC phase, surgery year was not a statistically significant factor in determining cancer-related costs (p=0.866). Table S4 presents the GLM results for PPPM cancer-related costs by phase of care. Across all phases, surgical year was a statistically significant factor associated with PPPM costs (p=0.008 for the NAC phase and p<0.001 for the other phases).
Table 4. Association between surgical year and per patient ovarian cancer-related costs by phase of care* .
| Year of surgery | Costs of neoadjuvant chemotherapy phase | Costs of surgery phase | Costs of frontline chemotherapy phase | Costs of monitoring phase | Costs of recurrent phase | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| exp(Coefficient)† (95% CI) | p-value | exp(Coefficient)† (95% CI) | p-value | exp(Coefficient)† (95% CI) | p-value | exp(Coefficient)† (95% CI) | p-value | exp(Coefficient)† (95% CI) | p-value | |
| 2013 | reference | 0.866 | reference | <0.001 | reference | <0.001 | reference | <0.001 | reference | <0.001 |
| 2014 | 0.97 (0.78–1.21) | 1.10 (1.05–1.15) | 1.04 (0.97–1.12) | 0.94 (0.84–1.05) | 1.14 (1.01–1.28) | |||||
| 2015 | 1.06 (0.85–1.31) | 1.19 (1.13–1.25) | 1.08 (1.00–1.15) | 1.13 (1.01–1.26) | 1.28 (1.14–1.43) | |||||
| 2016 | 1.00 (0.82–1.23) | 1.27 (1.21–1.32) | 1.22 (1.14–1.30) | 1.15 (1.03–1.28) | 1.49 (1.32–1.67) | |||||
Bold values denote statistical significance at the p<0.05 level.
CI, confidence interval; SEER, Surveillance, Epidemiology, and End Results.
*Adjusted for age group, SEER stage at initial diagnosis, histology, neoadjuvant therapy, insurance type, income level, type of hospital for initial diagnosis, and geographic region of hospital using generalized linear models with gamma distributions and log link functions.
†The exponent coefficients represent cost ratios from generalized linear models for ovarian cancer-related costs (per patient) by surgical year (2013–2016), with up to one year of follow-up, compared to the reference group.
To assess the robustness of these findings, we performed sensitivity analyses using GLMs with normal distributions and identity link functions applied to log-transformed cost data. The direction and magnitude of associations were largely consistent with the base-case analysis. However, under the alternative model, the association between surgical year and per patient cost in the monitoring phase was not statistically significant (p=0.062; Table S5), and the association with PPPM cost in the neoadjuvant chemotherapy phase was also not statistically significant (p=0.821; Table S6). These differences suggest that the associations in the monitoring and neoadjuvant chemotherapy phases may be sensitive to model specification.
DISCUSSION
This study examined trends in ovarian cancer-related costs across phases of care and surgical years, revealing substantial increases over time. The recurrent phase incurred the highest per patient costs, with consistent increases in PPPM costs. The surgery phase also demonstrated a considerable increase in costs. The monitoring phase costs remained relatively low compared with those of the other phases but exhibited an increasing trend in PPPM costs. Notably, surgical year was a significant factor influencing costs in most phases of care, emphasizing the growing economic burden of ovarian cancer care in Korea.
This study is clinically important, as it estimates the costs associated with each treatment phase. While no previous studies have analyzed costs by treatment phase in the same way, the cost patterns observed herein align with those of previous studies. The U.S. and Australian studies categorized treatment phases into initial, continuing, and terminal phases [7,8]. The Australian study reported Australian dollar (AUD) 40,556 for the initial phase, AUD 9,514 for the continuing care phase, and AUD 49,208 for the terminal phase. Similarly, the U.S. study reported annual costs of over $200,000 for the initial phase, $26,000–$88,000 for the continuing care phase, and over $129,000 for the terminal phase. In our study, the combined average length of the neoadjuvant, surgery and frontline chemotherapy phases was 7.2 months, with a median cancer-related cost per patient of $17,840. The monitoring phase, lasting an average of 30.6 months, incurred a median PPPM cost of $146, whereas the recurrent phase, lasting an average of 21 months, had a median PPPM cost of $2,427. Considering that 47% of patients die during the recurrent phase, the costs incurred during this phase may be comparable to those of the terminal phase. Overall, similar to previous studies, our results showed that substantial costs occur shortly after diagnosis, with a subsequent decrease observed during continuous monitoring, followed by an increase in costs as the patient’s condition worsens.
In this study, rising costs were observed across various phases of ovarian cancer care. The increase in the recurrent phase is likely influenced by the introduction of high-cost targeted therapies. For example, bevacizumab became reimbursable for platinum-resistant ovarian cancer in Korea in 2015, and its use among patients in the recurrent phase increased from 11.1% in 2015 to 22.3% in 2019. Similarly, the proportion of patients in the recurrent phase receiving PARP inhibitors rose from 2.6% in 2017 to 9.7% in 2019, following the reimbursement of olaparib in 2017 and niraparib in 2019. The observed increase in the proportion of patients receiving these targeted therapies suggests that their introduction may have contributed to the upward trend in recurrent phase costs. This finding is consistent with a previous study that reported higher costs for patients treated with bevacizumab compared to those who were not [14]. As niraparib became reimbursable for homologous recombination deficiency-positive ovarian cancer in 2024, costs may further increase in the future, thus highlighting the need for continued monitoring of the economic burden.
This large-scale, multiyear analysis of ovarian cancer costs examined all reimbursed inpatient, outpatient, and prescription claims via national health insurance data under a fee-for-service model. By categorizing costs into distinct phases, this study provides insights into the financial burden of ovarian cancer care, highlighting areas requiring cost-effective strategies. Furthermore, phase-specific cost data can serve as valuable resources for future economic evaluations of ovarian cancer treatments and for optimizing resource allocation. Despite its strengths, our study has several limitations. First, owing to the constraints inherent in the database, the analysis is restricted to reimbursed direct medical costs; therefore, non-reimbursed services and indirect costs, such as productivity loss or caregiving burdens, were excluded. While this approach ensured that the cost data were standardized, it does not capture the full economic burden of ovarian cancer. Second, starting the frontline chemotherapy phase the day after the surgery phase for patients who initiated chemotherapy during hospitalization may have underestimated both the per patient cost and the length of the phase. This approach, however, was intended to clearly separate chemotherapy-related costs from surgery-related costs. Third, the definitions of treatment phases were based on claims data rather than detailed clinical records, which may have led to potential misclassification or overlapping of phases, particularly when treatment dates were closely spaced. To minimize this risk, we developed phase definitions grounded in standard clinical practice patterns and applied specific criteria, such as time windows and treatment types. Nonetheless, some degree of misclassification may be unavoidable due to the inherent limitations of claims data. Fourth, due to the lack of International Federation of Gynecology and Obstetrics stage information, the SEER stage at initial diagnosis was used as a proxy. Finally, the findings, though reflective of the Korean health care system, may have limited generalizability to other countries with differing health care systems and policies.
In this nationwide population-based cohort study, we found that patients with ovarian cancer incurred substantial costs shortly after diagnosis, followed by a decrease during monitoring and an increase due to recurrence. Additionally, ovarian cancer-related costs have increased over time due to changes in the treatment landscape, thus highlighting the growing economic burden of care. These findings underscore the need to manage rising costs and improve the sustainability of ovarian cancer care.
Footnotes
Funding: This work was supported by grants from the Ministry of Health and Welfare, Korea (No. 2332740-1) and the National Cancer Center, Korea (NCC-2310500). The funders had no role in the design or conduct of the study; collection, management, analysis, or interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.
Conflict of Interest: No potential conflict of interest relevant to this article was reported.
- Conceptualization: O.B.C., P.S.K., K.S.
- Data curation: O.B.C., P.S.K.
- Formal analysis: O.B.C., P.S.K.
- Funding acquisition: K.S.
- Investigation: K.S.
- Methodology: O.B.C., P.S.K., K.S.
- Software: O.B.C., P.S.K.
- Supervision: K.S.
- Validation: P.S.K.
- Visualization: O.B.C., P.S.K., K.S.
- Writing - original draft: O.B.C., P.S.K.
- Writing - review & editing: O.B.C., P.S.K., K.S.
SUPPLEMENTARY MATERIALS
Chemotherapy agents and surgical procedures used to define each phase of ovarian cancer care
Subgroup analysis of per patient ovarian cancer-related costs by age group and SEER stage*
Subgroup analysis of per patient per month ovarian cancer-related costs by age group and SEER stage
Association between surgical year and per patient per month ovarian cancer-related costs by phase of care*
Sensitivity analysis of the association between surgical year and per patient ovarian cancer-related costs by phase of care*
Sensitivity analysis of the association between surgical year and per patient per month ovarian cancer-related costs by phase of care*
Proportion of patients treated with PARP inhibitors and bevacizumab during the recurrent phase.
Breakdown of per-patient ovarian cancer–related costs by category in the neoadjuvant chemotherapy phase.
Breakdown of per-patient ovarian cancer–related costs by category in the surgery phase.
Breakdown of per-patient ovarian cancer–related costs by category in the frontline chemotherapy phase.
Breakdown of per-patient ovarian cancer–related costs by category in the monitoring phase.
Breakdown of per-patient ovarian cancer–related costs by category in the recurrent phase.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Chemotherapy agents and surgical procedures used to define each phase of ovarian cancer care
Subgroup analysis of per patient ovarian cancer-related costs by age group and SEER stage*
Subgroup analysis of per patient per month ovarian cancer-related costs by age group and SEER stage
Association between surgical year and per patient per month ovarian cancer-related costs by phase of care*
Sensitivity analysis of the association between surgical year and per patient ovarian cancer-related costs by phase of care*
Sensitivity analysis of the association between surgical year and per patient per month ovarian cancer-related costs by phase of care*
Proportion of patients treated with PARP inhibitors and bevacizumab during the recurrent phase.
Breakdown of per-patient ovarian cancer–related costs by category in the neoadjuvant chemotherapy phase.
Breakdown of per-patient ovarian cancer–related costs by category in the surgery phase.
Breakdown of per-patient ovarian cancer–related costs by category in the frontline chemotherapy phase.
Breakdown of per-patient ovarian cancer–related costs by category in the monitoring phase.
Breakdown of per-patient ovarian cancer–related costs by category in the recurrent phase.