When is the best time to start chemotherapy?

Posted by Specialist Doctor I Le Thi Nha Hien - Internal Oncologist - Department of Medical Examination & Internal Medicine - Vinmec Nha Trang International General Hospital.

Cancer patients often wonder about the time interval between treatments (surgery, chemotherapy, radiation, etc.) that doctors have given. However, researchers are still trying to figure out the timing of chemotherapy for tumors or how the type of cancer affects this time period.

Chemotherapy is often given after surgery to ensure that all cancer cells are removed, thereby reducing the risk of disease progression or recurrence. However, there are currently no clear guidelines to tell oncologists when adjuvant chemotherapy is best, as "residual" cancer cells can be difficult to detect.
Although doctors generally do not want to delay chemotherapy, patients often need some time to recover from surgery and prepare for chemotherapy. However, delaying it too long can cause leftover cancer cells to start growing or become resistant to anticancer drugs.
A recent study conducted at the University of Texas aimed to find the ideal time frame between surgery and chemotherapy for breast cancer patients. Their findings showed there was no problem with starting chemotherapy 30 to 90 days after surgery, but patients who waited more than 90 days had a 34 percent higher risk of dying within five years.

A recent University of Texas study was conducted on patients with breast cancer. Other studies have looked at the timing of chemotherapy and other follow-up procedures for different types of cancer.
For example, research done on colorectal cancer, the second most common cancer in the United States, showed similar results. A Korean study looked at 159 stage 3 colorectal cancer patients undergoing surgery and chemotherapy follow-up. Some patients received chemotherapy within 2 weeks of surgery, while the second group received chemotherapy within 3 to 4 weeks and the third group received chemotherapy more than 5 weeks later.
After 5 years, almost 74% of the patients in the first group and 67% of the patients in the second group survived; This includes everyone who received chemotherapy within one month of surgery. However, only 55.2% of patients who waited longer than a month were still alive.
It would be best to have a chemotherapy plan after surgery on a case-by-case basis. But in the end, studies show the best outcomes for patients who receive adjuvant chemotherapy within a month of surgery.
In summary, chemotherapy is often prescribed after surgery to ensure the exclusion of cancer cells. However, there are currently no clear guidelines for telling oncologists the best time to have cancer chemotherapy, as "residual" cancer cells can be difficult to detect.