Immunotherapy has changed the landscape of cancer medicine. The good news about its recent success in treating rectal cancer marked a new milestone in curing cancers. Rectal Cancers Are Gone After the Treatment A research paper published in the New England Journal of Medicine on June 23, 2022, reported that 12 patients with rectal cancer treated with the immunotherapy drug dostarlimab have all achieved complete remission – the cancers vanished or are undetectable after the treatment. Doctors followed up with these 12 patients for 6 to 25 months after the treatment, and the results from all patients are remarkable: The tumor is undetectable on MRI scan and endoscopic examination; No progression or recurrence had been reported during the follow-up period; No severe adverse events have been reported for all patients since the treatment. This type of outstanding treatment outcome has not happened before. Genetic Testing Played a Critical Role This unprecedented treatment outcome proved that developing genetic testing technology and applying it to cancer treatment is worth its decade-long research efforts. All patients received genetic testing before being selected for the clinical trial. These 12 patients were recruited for the trial because they tested positive for a genetic instability called mismatch repair deficiency (MMR-d). Research has shown that patients with MMR-d may respond better to dostarlimab treatment than patients without it. The genetic testing on MMR-d played a critical role in successfully treating this cohort of patients. Actually, the combination of genetic-testing-based patient selection and immunotherapy led to the complete remission of all patients in this clinical trial. NFCR is a Pioneer in Genetic Testing Research The National Foundation for Cancer Research (NFCR) is a pioneer in funding genetic testing research. As early as 2005, NFCR started to support cancer molecular profiling research at the Translational Genomics Research Institute (TGen). Today, molecular profiling and other genetic testing technologies have become powerful tools for doctors to match patients with personalized therapies for their cancers. With the rapid adoption of genetic testing technology in hospitals, we will see more successful cases like this in the future. Precision medicine combined with immunotherapy provides a better treatment option for untreatable or uncontrollable cancers under standard therapies. Reference: PD-1 Blockade in Mismatch Repair–Deficient, Locally Advanced Rectal Cancer. The New England Journal of Medicine, June 23, 2022.