A research team at the Catholic University of Korea Seoul St. Mary's Hospital has developed a scoring model to predict the prognosis of metastatic breast cancer patients who underwent surgical resection.
Patients were classified into four groups according to their scores, with predicted survival scores ranging from 0 to 10 points.
The team, led by Professors Chae Byung-joo채병주 and Yoo Tae-kyung유태경, investigated 2,232 patients enrolled in breast cancer registry at the Korean Breast Cancer Society한국유방암학회 from 1990 to 2014 to identify the characteristics of patients who could survive for long after operation among those with metastatic breast cancer at the time of diagnosis.
The analysis of prognostic factors in patients with metastatic breast cancer was based on the size of the breast tumor, the grade of cancer, lymphovascular invasion, cancer hormone receptors, tumor cell proliferation index of Ki- 67, and tumor marker levels associated with the prognosis.
Although the prevalence of metastatic breast cancer among domestic patients is less than 5 percent, the five-year survival rate is low at 34.0 percent, and a strategy for improving survival rate is urgent, the hospital said.
The overall three-year survival rate of metastatic breast cancer was 56.4 percent and the median survival time was 44 months. The three-year survival rate was 38.7 percent in the 1990s, 50.5 percent in 2000-2004, 57.3 percent in 2005-2009, and 70.1 percent in 2010-2014, confirming that the overall survival rate of metastatic breast cancer patients is 24 years.
Of the totals, 1,541 patients (69 percent) underwent axillary surgery, 588 patients did not undergo surgery (26.3 percent), and 103 patients underwent partial mastectomy (4.6 percent).
The three-year survival rate was 62.6 percent in patients who underwent axillary surgery, and the median survival time was 53 months, which was longer than the 31 months in the un-operated group.
The three-year survival rate of the group with the lowest risk score of 0-3 was 87.3 percent, which was 30.9 percent higher than the three-year survival rate of all patients (56.4 percent).
At the time of diagnosis, patients with metastatic breast cancer received chemotherapy or anti-hormonal treatment first. However, there have been several retrospective studies showing that the survival rate of patients with metastatic breast cancer is higher than that of patients without surgery.
The team expects that the prediction model, which can select patients suitable for surgery by scoring the prognostic factors of patients who underwent surgery, will be easily applied to the medical field.
“This study does not mean that the survival rate increases by surgery, but that patients with a high probability of long-term survival are more likely to undergo surgery,” said Professor Yoo. "If they undergo an operation, they should stop chemical treatment, and therefore we should correctly select patients with high chances of long-term survival.
"We are working on an optimized treatment approach to increase the survival rate of metastatic breast cancer patients with a lower survival rate than those of standard breast cancer, and this study could be useful when we consider active axillary surgery among metastatic breast cancer patients." Professor Chae added.