The coronavirus pandemic took over the headlines and preoccupied our minds in 2020. Nevertheless, research in other medical areas continued. This year, cancer researchers made important strides against “the emperor of all maladies,” some of which have been overlooked amid the pandemic. To that end, here’s a roundup of some important discoveries and developments in cancer research this year. Scientists sequence cancer genomes Remember the Human Genome Project? Scientists all over the world worked together to sequence the entire human genome, which they completed in 2003. Earlier this year, cancer researchers announced the completion of the Pan-Cancer Analysis of Whole Genomes (PCAWG), a project that performed whole-genome sequencing on more than 2,600 primary cancers across 38 tumor types. “This study revealed the extensive role played by large-scale structural mutations in cancer, identified previously-unknown cancer-related mutations in gene regulatory regions, inferred tumor evolution across multiple cancer types, illuminated the interactions between somatic mutations and the transcriptome, and studied the role of germline genetic variants in modulating mutational processes,” wrote the editors of the journal Nature. More than 20 research papers from the PCAWG group appeared in the February 5, 2020 issue of Nature. But there’s much more work ahead. “We must now translate this knowledge into sustainable, meaningful clinical treatments,” wrote the members of the PCAWG consortium. “Building meaningful clinical predictors from genomic data can be achieved, but will require knowledge banks comprising tens of thousands of patients with comprehensive clinical characterization.” A mechanism of breast cancer metastasis—and a solution to it? Researchers have identified a gene—TRIM37—that’s responsible for the metastasis of triple-negative breast cancer. They’ve also developed a way that might stop it, which could help about 80% of patients with the disease. TRIM37 not only causes metastasis but also enables the cancer to resist chemotherapy. In a study published recently in Cancer Research, investigators showed that nanoparticles loaded with TRIM37-targeted antibodies reduced the gene’s expression in cancer cells. This both increased the efficacy of chemotherapy and prevented metastasis. The treatment might eventually benefit other cancer patients, too. “This is a delivery platform, not only for targeting our protein of interest but for many other chemotherapeutic drugs that can be packaged into the nanoparticles and selectively delivered,” said the study’s lead investigator. FDA approves ‘game-changing’ treatment for liver cancer For the first time in more than a decade, researchers have developed a first-line treatment that’s better than standard therapy for patients with hepatocellular carcinoma, the most common type of liver cancer. The FDA approved the treatment after the researchers published positive results in The New England Journal of Medicine in May 2020. The treatment involves the combination of atezolizumab (a programmed death-ligand 1 [PD-L1] inhibitor) and bevacizumab (a monoclonal antibody that targets vascular endothelial growth factor [VEGF]). Compared with standard therapy, the combination treatment reduced the risk of the disease progression by 41% and the risk of death by 42%. It also increased median progression-free survival by 2.5 months and doubled the percentage of patients whose cancer shrank or disappeared. “The therapy is a real game-changer for people diagnosed with this aggressive disease,” said the study’s principal investigator. "We now have a new therapy that not only improves survival for people with the disease, which is very challenging to treat, but that helps them live longer while maintaining a high quality of life.” Task force recommends colon cancer screening at age 45 The US Preventive Services Task Force (USPSTF) issued a draft statement in October 2020 that recommended screening for colorectal cancer should start at age 45. Prior to this announcement, the USPSTF recommended that screening begin at age 50. Both direct-visualization tests and stool-based tests are acceptable forms of screening, according to the draft recommendation. “New science about colorectal cancer in younger people has enabled us to expand our recommendation to screen all adults starting at age 45, especially Black adults who are more likely to die from this disease,” said USPSTF member Michael Barry, MD, director of the Informed Medical Decisions Program at Massachusetts General Hospital. “Screening earlier will help prevent more people from dying from colorectal cancer.” The draft recommendation is now being finalized. ‘One-size-fits-all’ cancer immunotherapy Researchers have found a new type of killer T-cell that may be used as a “universal” cancer therapy, which they reported in Nature Immunology early this year. Laboratory studies showed that these T-cells were able to kill lung, skin, blood, colon, breast, bone, prostate, ovarian, kidney, and cervical cancer cells—but left healthy cells alone. The researchers used genome-wide CRISPR–Cas9 screening to discover these T-cells, which have a unique T-cell receptor (TCR) that can identify and destroy many types of cancer by recognizing a single molecule called MR1. Although this molecule is present on both cancerous and normal cells, TCR binds to MR1 on cancer cells but bypasses healthy cells. “Cancer-targeting via MR1-restricted T-cells is an exciting new frontier—it raises the prospect of a ‘one-size-fits-all’ cancer treatment; a single type of T-cell that could be capable of destroying many different types of cancers across the population,” said lead author Andrew Sewell, PhD, professor, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, Wales. “Previously nobody believed this could be possible,” he added. The next step, according to the researchers, is testing the therapy for safety in human patients. Cancer mortality rate continues to decline Some of the best news in cancer research came early in 2020. In January, the American Cancer Society’s annual report on cancer rates revealed that the overall mortality rate from cancer is steadily declining, with the largest single-year drop in cancer deaths ever reported—2.2% from 2016 to 2017. “The cancer death rate rose until 1991, then fell continuously through 2017, resulting in an overall decline of 29% that translates into an estimated 2.9 million fewer cancer deaths than would have occurred if peak rates had persisted,” the researchers wrote. “This progress is driven by long‐term declines in death rates for the 4 leading cancers (lung, colorectal, breast, prostate); however, over the past decade (2008‐2017), reductions slowed for female breast and colorectal cancers, and halted for prostate cancer.” Notably, death rates plummeted in recent years for lung cancer and melanoma. “The accelerated drops in lung cancer mortality as well as in melanoma that we’re seeing are likely due at least in part to advances in cancer treatment over the past decade, such as immunotherapy,” said William G. Cance, MD, chief medical and scientific officer for the American Cancer Society. “They are a profound reminder of how rapidly this area of research is expanding, and now leading to real hope for cancer patients.” Source
