Intensive Surveillance Cost-Effective in Stage II, III CRC

The cost-effectiveness of patients being surveilled intensely after having a resection for colorectal cancer (CRC) was highest in those who had stage II and III cancer, according to a study published in Japanese Journal of Clinical Oncology. Surveilling patients with stage I cancer was poor in terms of cost-effectiveness.

CRC is the third most common cancer with the second highest mortality rate around the world. Surveillance is recommended for 5 years after radical surgery in the United States and Japan but the interval for the surveillance differs by country. With health care expenditures increasing year over year, this study aimed to assess the different surveillance strategies in terms of their cost-effectiveness to determine what the best surveillance interval is for each stage of CRC.

Calculating expenses | Image credit: joyfotoliakid - stock.adobe.com

This study used retrospective data on patients who had undergone a curative resection between January 2005 and December 2016 at the National Cancer Center Hospital in Japan. Patients were excluded if they had a histological diagnosis other than adenocarcinoma, had preoperative treatment, or had a transanal local resection or CRC resection with no lymph node dissection. Medical records were used to collect data on recurrence, age, sex, and stage of cancer.

Quality-adjusted life-years (QALYs), sensitivity of examinations, and specificity of examinations were used as parameters to assess cost-effectiveness and were taken from previous reports. Health outcomes in patients after a resection were calculated by the construction of a state-transition model. Incremental cost-effectiveness ratios (ICERs) were used to present the results of the analyses for cost-effectiveness.

Five strategies were used for surveillance. Strategy 1 is the surveillance strategy for stage III by the Japanese Society for Cancer of the Colon and Rectum; strategy 2 is used by the National Comprehensive Cancer Network for stage II and III disease; strategy 3 is recommended by the European Society for Medical Oncology that has clinical and laboratory analyses once every 6 months for 3 years; strategy 4 is recommended by the American Society of Colon and Rectal Surgeons (ASCRS) for high-risk stage I to III disease, where patients have a clinical evaluation every 6 months for 2 years; and strategy 5 is recommended by ASCRS for high-risk stage I to III disease for an annual laboratory analysis, CT scan, and clinical evaluation for 5 years. Strategy 1 featured the most examinations and strategy 5 required the least.

There were 1316 patients who had stage I disease; 1082, stage II disease; and 1303, stage III disease included in the study, and their median age was 65 years. Advancing stage correlated with the amount of time between surgery and recurrence and the period between previous examination and first recurrence. A total of 72.1% of patients with stage I disease, 70.1% with stage II disease, and 74.8% with stage III disease who completed 5 years of surveillance.

The costs for strategy 1 were highest and strategy 5 had the lowest cost. QALYs decreased as surveillance decreased, with the difference between strategies 1 and 5 being 0.017 for stage I, 0.062 for stage II, and 0.057 for stage III. ICERs decreased with decreasing surveillance intensity as well, but did not do so linearly.

The most cost-effective option was strategy 4 when it came to stage I disease, at $26,555 per QALY. ICERs were $18,358 and $22,230 per QALY for strategy 3 when it came to stage II and III CRC, with strategy 2 having significantly higher ICERs at the same stages. Strategy 4 had an ICER of $4087 for stage II and $9130 for stage III. The closest strategy to the $43,500 to $52,200 per QALY threshold was strategy 3, which indicated that it was the most cost-effective for stages II and III.

There are some limitations to this study. The retrospective design could have introduced bias by not including infrequent treatments, differences in patient age were not examined, values are likely to change from the ones used in the base-case analysis, and absolute thresholds for cost-effectiveness do not exist, even as ICERs were used in this study.

The cost-effectiveness of surveillance was found to be best when using strategy 4, with 6-month evaluations for 2 years in patients at all stages of CRC. Strategy 3 can also be used in patients with stage II and III CRC. This can tell clinicians how to handle postoperation care in patients who required a resection.

Reference

Takayama Y, Tsukamoto S, Kudose Y, et al. Cost-effectiveness of surveillance intervals after curative resection of colorectal cancer. Jpn J Clin Oncol. Published online February 19, 2024. doi:10.1093/jjco/hyae018