50 Years of Progress in Cancer

The New England Journal of Medicine September 3, 2020 pp897-900 | Perspective | “A half-century of progress in health: The National Academy of Medicine at 50” “Progress in Cancer Research, Prevention, are Care” by RL Schilsky, S Nass, MM Le Beau and EJ Benz.

See NEJM.org for audio and Perspective Article.

Still the second leading cause of death in high-income countries “cancer-related mortality has been declining steadily. The five-year survival rate was 49% in 1970 and is 70% today with most progress directly attributable to better “cancer prevention and early detection.” “The National Cancer Act of 1971 catalyzed much of the progress made during three past five decades." A National Cancer Program was established resulting in the creation of Comprehensive Cancer Centers, increased R&D, a focus on “important risk factors for cancer (e.g., tobacco use, obesity, alcohol consumption, physical inactivity and oncogenic infections)…and a national clinical trials network.”

Over this time key milestones in elucidating cancer biology were: 1970s-abnormal proliferation, local invasion, and metastasis as common elements of all cancers, 1980s-applying molecular genetics led to identifying cancer genes-oncogenes and -tumor-suppressor genes, 1990s-Human Genome Project helped identify “Mutations disrupting specific cellular functions.” Leveraging these findings in basic research, targeted and multimodality treatments were discovered and put into practice. Examples from this “Molecular Oncology” in the 1990s were “targeted therapy” such as anti-her-2-neu therapy for breast cancer and a inhibitor of the BCR-ABL1 “oncoprotein” for CML. The promise of targeted therapies give hope but so far “Long-term disease control is rare.” More recently, immunobiology breakthroughs have identified targets to stop cancers from evading immunosurveillance. “Some of these proteins have been characterized (including CTLA-4, PD-1, and PD-L1) and targeted by monoclonal antibodies against “checkpoint” inhibitors that reverse immunosuppression.” “…these approaches appear to offer the most promising path toward broadly effective cancer treatments.” So far, however, only a small fraction of patients is helped by these therapies. See table below for more detail on the triad of "Prevention and Early-Detection Advances", "Key Policy Milestones" and "Treatment Advances" from the perspective article.

Not surprisingly, “benefits of progress have not been equitably distributed.” “Future progress will be stymied without more enlightened policies to address the social determinants of health, mitigate disparities, and foster universal, affordable health care coverage.” With so much progress made, “Maximizing the benefits of these advances…require[s] a renewed, national dedication to confronting cancer…”.