Does removing the primary tumor impact survival in metastatic cancer?

The authors evaluated the survival benefits associated with an operation to remove the primary tumor among patients with metastatic stage IV colorectal cancer.

While approximately 6% of colorectal cancer patients with metastatic disease (cancer that has spread throughout the body) present with complications related to their primary (initial) tumor, the majority of patients do not have symptoms related to the primary tumor. Therefore, the decision to resect (surgically remove) the primary tumor is controversial.

The aims of this study were to analyze overall survival and colorectal cancer-specific survival (length of time patients do not die from colorectal cancer) associated with operation on the primary tumor versus non-operative treatment among chemotherapy-treated stage IV colorectal cancer patients.

Of 11,716 patients evaluated, 8,599 underwent surgical removal of the primary tumor while 3,117 did not. All patients had been treated with chemotherapy.

In a simple analysis, patients who underwent resection had an average overall survival of 21 months compared to 10 months in those who did not undergo resection. Patients who underwent resection had a colorectal cancer-specific survival of 22 months compared to 12 months in those who did not undergo resection.

In patients greater than 70 years of age, overall survival was 17 months in those who underwent resection compared to 7 months for those who did not. Colorectal cancer-specific survival was 19 months in those who underwent resection compared to 9 months in those who did not.

Surgical resection of the primary tumor was associated with a 58% reduction in the risk of death. Surgical resection of the primary tumor was associated with a 57% reduction in the risk of colorectal cancer-specific death.

The authors reported that resection of the primary tumor among chemotherapy-treated stage IV colorectal cancer patients is associated with improved overall and cancer-specific survival.

The authors could not determine whether patients had symptoms prior to surgery.