With the increase in the average life expectancy of human beings, the probability of getting cancer is also getting higher and higher, and now people often sigh: "Why are there more and more people getting cancer?" ”。 Talking about cancer discoloration is still the mentality of most people when facing cancer, and even think that with cancer, treatment without treatment is meaningless. Is this really the case?
In January 2022, the National Cancer Institute released its latest National Cancer Data Annual Report, which statistics on new cancer cases and deaths in the United States, and published it in the A CANCER JOURNAL FOR CLINICIANS, with an impact factor of 508.
From this report, we can see that cancer mortality in the United States continues to decline, falling by 32% between 1991 and 2019. In particular, from 2015 to 2019, the risk of cancer death decreased by about 2% per year. This data strongly illustrates the remarkable effects of cancer prevention, control, diagnosis and treatment in recent years. So, what is the trend of disease and death of various cancer species in recent years? What can we learn from this?
Overall data
★ Projected new and fatalities: Figure 1 shows the projected number of new cases and deaths for men and women in 2022.
For men, prostate, lung and colorectal cancers are among the top three in terms of prevalence, with prostate cancer bearing the brunt of the attack, accounting for 27% of new cases. Among women, the incidence of breast, lung and colorectal cancers is as high as 52%.
Lung, prostate and colorectal cancers in men and lung, breast and colorectal cancers in women remain the leading causes of death in terms of deaths.
Figure 1:New cases and deaths projected by sex in the United States in 2022
★ The gender gap in incidence is decreasing: the overall prevalence among men has generally declined from the early 1990s to around 2013 and has remained largely stable after 2018; the prevalence among women has increased at a rate of 0.2% per year in recent years.
Figure 2:Trends in cancer incidence and mortality in the United States, 1975-2019
★ Male and female incidence trends: From Figure 3 we can see the trend of changes in various cancer types in recent years.
First of all, the incidence of prostate cancer has decreased significantly from 2007 to 2014, while the incidence of breast cancer in women has slowly increased at a rate of about 0.5% per year. Between 2014 and 2018, the incidence of thyroid cancer in both men and women declined at a rate of 2.5% per year.
Notably, from 2009 to 2018, the incidence of lung cancer in men fell by nearly 3% per year, and in women by about 1% per year. Since the mid-1970s, the incidence of non-Hodgkin lymphoma has begun to decline. The incidence of melanoma and liver cancer has stabilized in recent years, while the incidence of oral and pharyngeal cancer, kidney and pancreatic cancer is increasing at a rate of 1% per year.
Figure 3:Cancer incidence in men and women in the United States from 1975 to 2018
★ Overall five-year survival rates for cancer are increasing: From 2011 to 2017, the relative five-year survival rate for all cancers in the United States increased from 49 percent to 68 percent. Among them, the five-year survival rate of prostate cancer is as high as 98%, and the female breast cancer is also as high as 90%, but the five-year survival rate of pancreatic cancer, esophageal cancer and lung cancer is still very low.
★ Trends in cancer mortality: First, for most of the 20th century, cancer mortality rates have been on the rise, largely due to the sharp rise in lung cancer deaths caused by tobacco epidemics. Overall, the death rate has fallen by 32% as of 2019, and is expected to save about 3.5 million lives each year.
Figure 4.Trends in cancer mortality among men and women in the United States, 1930-2019
Cause analysis
1. Lung cancer mortality rate decreased by 32%, and the three-year survival rate increased by 10%
The most notable thing in the report is that the three-year survival rate of lung cancer has increased by 10% from 21% in 2004 to 31% in 2018, and the cancer mortality rate has decreased by 32%, why is there such a significant improvement?
Mainly due to the improvement of diagnosis and treatment level, many lung cancer patients are screened and diagnosed at an early stage, and with the progress of thoracoscopic surgery, the progress of targeted drugs such as EGFR-TKI and ALK-TKI and the application of immunotherapy, more and more patients have significantly extended their five-year survival.
In addition, it is also due to the strict tobacco control measures that began in the United States in the 60s. More than 80% of lung cancers are related to smoking, and according to statistics, people who smoke have 25 times more likely to develop lung cancer than non-smokers! About 8 (81%) of the 10 people expected to die from lung cancer in 2022 are caused by smoking. Since the tobacco control campaign, the number of smokers in the United States has continued to decline for 40 years, from 1990 to 2019, the lung cancer mortality rate in men fell by 56%, and from 2002 to 2019, the lung cancer mortality rate in women fell by 32%.
2. The mortality rate of colorectal cancer is decreasing year by year
Colon cancer mortality has fallen by 55% in men and 60% in women since 1969, and in people over the age of 50, the incidence of colorectal cancer is falling at a rate of 2% per year. But among young adults, the incidence of colorectal cancer rises at a rate of 1.5 percent per year.
Analysis of the reasons: due to the progress of colonoscopy and other examinations, the precancerous lesions have been detected early, and the incidence of colorectal cancer has been declining. The reason for the increase in incidence in young people may be related to their poor lifestyle.
3. The incidence of breast cancer has increased in recent years
The study data shows that the mortality rate of breast cancer in women peaked in 1989 and has since fallen by 42% with advances in diagnostic techniques and optimization of treatment levels. Since the 21st century, the incidence of breast cancer has risen again. This may be due to the development of screening techniques that have allowed early breast cancer to be detected. In addition, the decline in fertility rates, overweight and other reasons will also lead to an increase in the incidence of breast cancer.
4. The mortality rate of prostate cancer has decreased by 53%, and the mortality rate of cervical cancer has increased year by year
Prostate cancer mortality has fallen by 53% since 1993, thanks to the widespread use of PSA testing and increased treatments. In contrast to the reduction in most cancer mortality rates, cervical cancer mortality rates are increasing year on year, becoming the second leading cause of death among women aged 20-39 years. Among them, persistent infection of high-risk HPV is the main cause of cervical cancer, and poor prognosis of cervical adenocarcinoma and difficulty in detecting through cytology screening are also a major factor in the high mortality rate.
conclusion
According to the latest Annual Report on Cancer Data in the United States, we found the most pronounced decline in mortality from lung cancer, resulting in a 32% reduction in overall mortality. The reason for this is that the number of smokers has decreased, resulting in a significant reduction in lung cancer mortality. In addition, there is a significant downward trend in the mortality rate of colorectal, breast and prostate cancers. The improvement of the level of diagnosis has enabled the timely diagnosis of certain cancers, the progress of treatment options such as adjuvant chemotherapy, targeted therapy and integrated therapy has significantly improved the prognosis of patients, new surgical techniques and treatment methods have provided patients with more choices, and innovative therapies have brought new treatment hopes to patients.
It can be seen that we should pay attention to the prevention and early screening of cancer, and focus on the protection of high-risk groups. Increase investment in targeted drugs and immunotherapy, better achieve precision treatment, and achieve long-term survival of tumor patients. Cancer knows no borders, learn from the strengths of all, learn from each other's strengths, and work together to declare war on cancer!
参考文献：Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2022. CA Cancer J Clin. 2022 Jan;72(1):7-33. doi: 10.3322/caac.21708. Epub 2022 Jan 12. PMID: 35020204.