Genome sequencing-based personalized chemotherapy is given to patients with rectal cancer at National Taipei Medical University Hospital with better drug response and reduced side effects reported compared with traditional anti-cancer medicine, the hospital said yesterday.
A 43-year-old man, surnamed Lai (賴), had experienced a month of seeing a large amount of blood in his stool before seeking medical attention and undertaking a tumor marker blood test and fecal occult blood test, neither of which indicated abnormalities with his rectum.
It was not until the hospital’s division of colon and rectal surgery director Kuo Li-jen (郭立人) found an ulcer in Lai’s rectum while performing a rectal exam and colonoscopy that stage three rectal cancer was confirmed.
“The tumor was about two-thirds the size of the rectum caliber, so it was pretty serious,” Kuo said yesterday.
He added that if he had taken the blood in Lai’s stool simply as a result of a rectal ulcer and failed to press for a colonoscopy, the timing for effective treatment could have been missed.
To avoid the side effects of traditional chemotherapy, Kuo used genome sequencing in order to choose the best chemotherapy drugs for the patient with the best treatment response and fewest side effects.
The hospital’s vice superintendent and the director of its cancer center, Chiu Chung-feng (邱仲峰), said two years ago the hospital started using genome sequencing for the development of anti-cancer drugs and target drugs to treat patients afflicted with colon cancer.
“About twenty genomes [from each patient] were analyzed, and we found what kind of drugs better achieve the effective dose within [the patient’s] body with [his or her] metabolic products,” Chiu said.
The 110 cases of stage four colon cancer in the development project reported an increased drug response rate of 68 percent — compared with 45 percent in the general statistics, Chiu said.
The rate of side effects has also decreased from 25 percent in general to 12 percent among the participating patients, Chiu added.
To be free of possible complications resulting from open surgery, the chemotherapy was administered in tandem with a microsurgery using the da Vinci robotic surgical system.
Kuo said the system “provides a magnified image [of the surgical site] and thereby helps with the removal of the tumor and the preservation of blood vessels and nerves.”
Kuo said that the minimally invasive sphincter-preserving surgery performed on Lai successfully preserved his anal sphincter and removed the tumor.
Kuo said that now about 90 percent of the hospital’s patients with lower rectal cancer could preserve their anal sphincter and the five-year survival rate was more than 80 percent.