The National Health Insurance Service (NHIS) said on Thursday that the health insurance treatment data of breast cancer patients recorded a 30.5 percent increase from 2017 to 2021.

The cases rose from 206,308 in 2017 to 269,313 in 2021. The average annual growth rate is estimated at 6.9 percent.

According to the NHIS, women over 40 accounted for 95 percent of all breast cancer patients. Among the 269,313 breast cancer patients in 2021, 22.4 percent were in their 40s, 34.9 percent were in their 50s, and 25.9 percent were in their 60s.

Westernized diets and declining births were cited as the main cause for the increase in breast cancer cases. Consequently, healthcare costs have gone up by more than 70 percent in five years.

Particularly, the increase in the number of breast cancer patients among the elderly was significant. Among all breast cancer patients, those aged 80 and older increased by 80.6 percent in five years, from 3,874 in 2017 to 6,996 in 2021. Those in their 60s and 70s also increased by 58.9 percent and 47.1 percent, respectively, over the same period.

Correspondingly, the total medical expenses for health insurance for breast cancer patients increased by 70.2 percent from 79.67 billion won ($60 million) in 2017 to 1.356 trillion won in 2021, growing at an average annual growth rate of 14.2 percent.

The per capita medical expenditure for breast cancer was 503 million won, and those in their 20s consumed the most at 7.24 million won.

"The highest recurrence rate of breast cancer is within two to three years after treatment, but treatment after recurrence allows patients to control cancer for a long time and maintain their lives," Professor Hur Ho of Surgery at the National Health Insurance Service Ilsan Hospital said. "This is why the median age of breast cancer patients increased from 46.9 years in 2000 to 52.3 years in 2021."