The power of immunotherapy: Cancer-free patients are now a reality
Traditionally, cancer treatments have involved a combination of risky surgeries and invasive chemicals. To get rid of cancer cells, patients are normally supposed to undergo a series of cycles in which they are administered the necessary chemicals to inhibit their [malignant cells] growth and rapid replication- a treatment denominated chemotherapy. Likewise, some cancer treatments need targeted radiation that breaks down the DNA of cancer cells to prevent its growth- radiotherapy. Bottom line, both methods have been proven to be an incredible success at eliminating malignant tumors in the past decades. Nonetheless, the aggressive nature and countless serious side effects of these treatments have prompted scientists and medical experts to seek cleaner, safer and cheaper therapies to treat a wide variety of cancers. ¿What have they found? New York, June 2022 Located in the heart of Brooklyn, the Memorial Sloan Kettering Cancer Center (MSKCC) has always looked after its vision: to harness the latest research techniques to conquer cancer. As of their recent breakthrough, they have achieved total remission of rectal cancer in a clinical trial involving 14 patients with Stage II or III locally advanced cancers (where the tumor has already expanded). Such a statistic is astoundingly unusual when discussing cancer therapies, even for small clinical trials like this one. But what was their secret? Did they use a different combination of chemicals? Or instead, they employed a different pattern of radiation beams? The answer is none. The key to their success lies in using immunotherapy, which consists of harnessing the body´s own immune system to fight cancerous cells. As Dr. Diane Reidy-Lagune, medical oncologist at MKSCC puts in an episode of “Cancer straight talk” back in 2020: “Is it (immunotherapy) like Dorothy´s shoes? Did we have the power to cure ourselves all along?” These exciting lines of inquiry motivated Dr. Luis Díaz and Dr. Andrea Cercek, head scientists of the clinical trial at MSKCC, to pursue a pilot study using the patients´ immune systems. Nonetheless, what nuts and bolts made this clinical trial unique? First of all, 100% of the patients involved in the clinical trial had tumors with a genetic makeup denominated as Mismatch Repair Deficiency (MMRd), which is caused by mutations (changes in the DNA sequence) in genes involved in correcting mistakes when the DNA is replicated in a cell. The accumulation of these mutations in a tumor cell is able to trigger the immune system to attack cancer cells. However, instead of having an immune response taking place, malignant tumors have managed to suppress it by activating so-called immune cells´ “checkpoints”- enabling the tumor to grow always under the radar. This was the key element of the MKSCC clinical trial, as the therapy used for immune enhancement was meant to target these checkpoints. As explained by Dr. Cercek: “When the brakes are taken off the immune cells MMRd cells look especially strange because they have so many mutations. So the immune cells can attack with much more force” This line of reasoning, which was formerly a hypothesis yet to be tested, was proven to be successful. Immunotherapy made cancer cells disappear quickly from the patients by just making them visible to the immune cells. Nonetheless, the most fascinating breakthrough was that none of the patients received a single radiation beam or surgery of any kind. Furthermore, in comparison to traditional treatments, none of the patients treated with immunotherapy showed any sign of compromising side effects. As for future steps, immunotherapy has lifted the veil on a world full of opportunities to treat cancer. It is found as a big shot to potentially replace traditional treatments such as chemotherapy, radiotherapy, and surgery. However, although it has the potential to lead to many other breakthroughs, prudence must pave the way for a responsible application of these therapies. It is worth pointing out that the success (for now) is limited to patients that had cancers with MMRd mutations, that only integrate less than 10% of rectal cancers overall. Nevertheless, given the rapidness and effectiveness, it has shown to terminate cancer, immunotherapy has indeed shown it has power. Sources Memorial Sloan Kettering Cancer Center. (2022). Rectal Cancer Disappears After Experimental Use of Immunotherapy | Memorial Sloan Kettering Cancer Center. Www.mskcc.org; MSKCC. https://www.mskcc.org/news/rectal-cancer-disappears-after-experimental-use-immunotherapy National Cancer Institute. (2011, February 2). https://www.cancer.gov/publications/dictionaries/cancer-terms/def/mismatch-repair-deficiency. Www.cancer.gov. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/mismatch-repair-deficiency Reidy-Lagunes, D. (2020). Immunotherapy: Transforming How Cancers Are Treated | Memorial Sloan Kettering Cancer Center (Memorial Sloan Kettering Cancer Center, Ed.). Www.mskcc.org. https://www.mskcc.org/videos/immunotherapy-transforming-how-cancers-are-treated
