Cancer does not need radiotherapy thanks to blood tests after surgery

Ongoing testing at more than 40 hospitals in Australia and New Zealand will help cancer patients get rid of excessive chemotherapy after tumor removal surgery.

Scientists are testing a new blood test that helps surgical patients know whether cancer cells remain in their bodies after surgery.

When cancer cells weaken and die, they release free waste into the circulating blood throughout the body, including the specific type of cancer DNA. This DNA is called the free blood cancer DNA (ctDNA) . The discovery of DNA after surgery indicates that the microcrystalline cancer cells that the standard tests do not "catch" remain in the patient's body.

The CTDNA blood test helps detect the risk of cancer recurrence through the rate of cancer DNA in the blood.(Photo: Medical Xpress).

The new study showed that patients with positive CTDNA results after surgery had an extremely high risk of recurrence of cancer, up to nearly 100%, and those with negative CTDNA results had a very low risk of recurrence. less than 10%.

New types of tests have been tested in colon cancer patients early in 2015. The results show that the ctDNA test can classify patients into two low and high risk groups. The trial has been extended to women with ovarian cancer since 2017 and will soon start on pancreatic cancer patients.

The CTDNA blood test is significant because there are currently no other reliable methods to determine the likelihood of cancer recurrence after surgery, so early-stage cancer patients are often chemotherapy after treatment. Surgical treatment for prevention. According to The Conversation, chemotherapy to clean up cancer cells survives many serious side effects. In the short term, chemotherapy makes patients painful, tired, nausea, many digestive problems, bleeding, increased risk of infection. In the long term, chemotherapy causes many problems for memory, nerves, lungs, heart and fertility.

In addition, the ctDNA test results will help doctors reduce the dose depending on the risk of cancer in patients who need chemotherapy.

When a patient is diagnosed with cancer, such as early stage colon cancer. During surgery, their tumors are limited to the colon without evidence of metastasis to other parts of the body. But after surgery, although successful, about a third of patients will have cancer in another part of the body in the following years.

That means, the cells were spread at the time of diagnosis but could not be detected by standard methods of imaging and blood tests currently available. If these patients receive chemotherapy after surgery, the risk of re-cancer will be stopped because the excess super small cancer cells will be destroyed.

In the case, the determination of whether the patient should be chemotherapy depends on the assessment of the tumor removed at the time of surgery. The probability of cancer having metastasized will increase if the patient has cancer cells in the lymph glands located next to the colon (stage 3 cancer),

The CTDNA blood test is very reliable to determine the possibility of cancer recurrence after surgery.

Therefore, many colon cancer patients now receive another 6 months of chemotherapy and suffer from related side effects, although it may not be necessary for them. Others seem to be low-risk and will benefit from chemotherapy and not realize this need. Therefore, a blood test of a ctDNA after surgery helps doctors make more appropriate and accurate decisions.

Currently, the number of patients who participated in the ctDNA test has reached more than 400 and it is expected to increase to 2,000. The trial is expected to last until 2021 for colon cancer and 2019 for ovarian cancer.

The ctDNA test is a collaboration between the Walter & Eliza Hall academy and the Johns Hopkins Kimmel cancer center in the United States. Johns Hopkins Kimmel Cancer Center is part of the famous Johns Hopkins Hospital non-profit hospital system with 22 years topping the ranking of the best hospitals in the US and many years in the top 10 US cancer treatment hospitals News & World Report.

If successful, the ability to search and measure DNA for cancer in the blood will be a revolution in cancer treatment.