Sandbox:Cancer screening and primary care

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vishal Devarkonda, M.B.B.S[2]

Overview

Worldwide, cancer is among the leading causes of morbidity and mortality; cancer contributed to approximately 8.2 million deaths in 2012, or an estimated 13% of overall deaths. WHO expects a 70% increase in the number of new cancer cases over the next two decades. The burden of cancer is substantial and increasing worldwide. The incidence, prevalence, and mortality of specific cancers vary widely across countries as a result of variations in lifestyle risk factors (such as tobacco use, physical inactivity, excess body weight, reproductive patterns), the prevalence of carcinogenic infections (e.g., Hepatitis B, Hepatitis C, HPV), genetics, and the availability of health care resources. In 2012, lung, prostate, colorectal, gastric, and liver carcinomas were the most common cancers among men, while breast, colorectal, lung, cervical, and gastric carcinomas were most common among women. In 2014, the Agency for Healthcare Research and Quality estimated the direct medical costs associated with cancer in United States at $87.7 billion dollars. It is estimated that HBV/HCV and HPV are responsible for up to 20% of cancer deaths in low- and middle-income countries. It is also estimated that more than 30% of these cases are preventable. Measures to prevent some types of cancer include effective screening, vaccination, and lifestyle modifications. This page provides information about the epidemiology and primary care aspects of preventing cancer.

Epidemiology

Worldwide, cancer is among the leading causes of morbidity and mortality; cancer contributed to approximately 8.2 million deaths in 2012, or an estimated 13% of overall deaths. The most common type of cancer (excluding non-melanoma skin cancers) is breast cancer; it is estimated that there were more than 249,000 new cases in the United States in 2016. The next most common cancers are lung cancer and prostate cancer. In the United States, to qualify as a common cancer, the estimated annual incidence for 2016 had to be 40,000 cases or more.

The following table presents official estimates of new cases and deaths in the United States for each common cancer type:

American Cancer Society: Cancer Facts & Figures 2016
Cancer Type	Estimated New Cases	Estimated Deaths
Breast	249,200	40,890
Lung (Including Bronchus)	224,390	158,080
Prostate	180,890	26,120
Colon and Rectal (Combined)	134,490	49,190
Bladder	76,960	16,390
Melanoma	76,380	10,130
Non-Hodgkin Lymphoma	72,580	20,150
Thyroid	64,300	1,980
Kidney (Renal Cell and Renal Pelvis) Cancer	62,700	14,240
Leukemia (All Types)	60,140	24,400
Endometrial	60,050	10,470
Pancreatic	53,070	41,780

Adulthood Cancers

Top 10 Cancers by Incidence and Mortality
by Incidence		by Mortality
Cancer type	Incidence	Cancer type	Mortality Childhood Cancers In 2013, the most commonly diagnosed cancers and leading causes of cancer-related death in children aged 0 to 19 years were leukemia and central nervous system cancers. Childhood Cancers Incidence Mortality Cancer type 0-14 years 0-19 years 0-14 years 0-19 years All cancers combined 16.8 18.0 2.1 2.3 Leukemias 4.8 4.3 0.6 0.6 Brain and Central nervous system cancer 3.6 3.2 0.7 0.7 * Rates are per 100,000 persons and are age-adjusted to the 2000 U.S. standard population. Please click here to know more about the cancer epidemiology Prevention Effective measures for cancer prevention include: Screening Vaccination Lifestyle modifications Screening Breast Cancer United States Preventive Services Task Force Recommendations for Breast Cancer Screenings Population Recommendation Grade Women, 40 Years and Older The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of clinical breast examination (CBE) beyond screening mammography in women 40 years or older. I Women, Age 50-74 Years The USPSTF recommends biennial screening mammography for women 50-74 years. B Women, Before the Age of 50 Years The decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient's values regarding specific benefits and harms. C Women, 75 Years and Older The USPSTF concludes that the current evidence is insufficient to assess the benefits and harms of screening mammography in women 75 years and older. I Relevance of Breast Cancer Screening Studies have reported that, for women of all age groups with an average risk, breast cancer screening was associated with a reduction in breast cancer mortality of approximately 20%, although there was an uncertainty in the quantitative estimates of outcomes for different breast cancer screening strategies in the United States. Please click here to learn more about Breast cancer screening. Colon Cancer United States Preventive Services Task Force Recommendations for Colon Cancer Screening Population Recommendation Grade Adults aged 50 to 75 years The USPSTF recommends screening for colorectal cancer starting at age 50 years and continuing until age 75 years. A Adults aged 76 to 85 years The decision to screen for colorectal cancer in adults aged 76 to 85 years should be an individual one, taking into account the patient’s overall health and prior screening history. Adults in this age group who have never been screened for colorectal cancer are more likely to benefit from screenings. Screening would be most appropriate among adults who 1) are healthy enough to undergo treatment if colorectal cancer is detected and 2) do not have co-morbid conditions that would significantly limit their life expectancy. C Relevance of Colon Cancer Screenings Studies have reported a 40% to 60% risk reduction for the incidence o colorectal cancer and mortality from colorectal cancer after screening colonoscopy. Please click here to know more about Colon cancer screening. Cervical Cancer United States Preventive Services Task Force Recommendations for Cervical Cancer Screening Population Recommendation Grade Women aged 21 to 65 (Pap Smear) or 30-65 (in combo with HPV testing) The USPSTF recommends screening for cervical cancer in women age 21 to 65 years with cytology (Pap smear) every 3 years or, for women age 30 to 65 years who want to lengthen the screening interval, screening with a combination of cytology and human papillomavirus (HPV) testing every 5 years. A Relevance of Cervical Cancer Screening Studies have shown that, in patients undergoing regular cervical cancer screenings, approximately 70%-80% of cervical cancer deaths can be prevented. Please click here to learn more about Cervical cancer screening. Lung Cancer United States Preventive Services Task Force Recommendations for Lung Cancer Screening Population Recommendation Grade Adults aged 55-80, with a history of smoking The USPSTF recommends annual screening for lung cancer with low-dose computed tomography (LDCT) in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability/willingness to have curative lung surgery. B Relevance of Lung Cancer Screening The National Lung Screen Trial (NLST), a randomized controlled trial involving 50,000 participants, demonstrated a 20% relative lung cancer mortality benefit for screening. Please click here to learn more about lung cancer screening. Vaccination Vaccine Recommendation HPV vaccine Age <15 years Two doses of HPV vaccine at least six months apart. Age >15 years Three doses of HPV vaccine over a span of 24 weeks, with a minimum of 4 weeks interval between the first two doses, and 12 weeks between second and third doses. Young women can get the HPV vaccine until they are 27 years old and young men can get the HPV vaccine until they are 22 years old. Hepatitis B vaccine All infants should receive their first dose of hepatitis B vaccine as soon as possible after birth, preferably within 24 hours, followed by two or three additional doses. The vaccination schedule for children and adults involves 3 intramuscular injections, the second and third doses administered 1 and 6 months after the first. HPV vaccine relevance in cancer prevention Studies have reported, that introduction of the 4vHPV vaccine, has decreased the prevalence of HPV 6/11/16/18 cervical/vaginal infections, genital warts, low- and high-grade cytological abnormalities, CIN2, CIN3, and AIS among females in their teens and 20s. Please click here to learn more about the HPV vaccine. Relevance of the Hepatits B vaccine in cancer prevention Strong evidence that hepatocellular cancer (HCC) can be prevented is provided by a cluster randomized controlled trial of the immunization of 75,000 newborns with hepatitis B virus (HBV) vaccine. After a median of about 25 years of follow-up, the incidence ratio of primary liver cancer in the vaccination-at-birth group to the control group (68% of whom received catch-up vaccinations at ages 10–14 years) was 0.16 (95% confidence interval, 0.03–0.77). These findings suggest that if HBV can be prevented, then much HCC can be prevented. Please click here for know more about Hepatitis B vaccine. Lifestyle modifications Life style modifications Avoiding Tobacco Cigarette Smoking Lung cancer is the leading cause of cancer death, and cigarette smoking causes almost all cases. Compared to nonsmokers, current smokers are about 25 times more likely to die from lung cancer. Smoking causes about 80% to 90% of lung cancer deaths. Smoking also causes cancer of the mouth and throat, esophagus, stomach, colon, rectum, liver, pancreas, voicebox (larynx), trachea, bronchus, kidney and renal pelvis, urinary bladder, and cervix, and causes acute myeloid leukemia. Secondhand Smoke Adults who are exposed to secondhand smoke at home or at work increase their risk of developing lung cancer by 20% to 30%. Concentrations of many cancer-causing and toxic chemicals are higher in secondhand smoke than in the smoke inhaled by smokers. Please click here to know more about smoking cessation Please click here to know more about Lung cancer Protecting Your Skin Skin cancer is the most common kind of cancer in the United States. Exposure to ultraviolet (UV) rays from the sun and tanning beds appears to be the most important environmental factor involved with developing skin cancer. To help prevent skin cancer while still having fun outdoors, protect yourself by seeking shade, applying sunscreen, and wearing sun-protective clothing, a hat, and sunglasses. Please click here to know more about Skin cancer Limiting Alcohol Intake Studies around the world have shown that drinking alcohol regularly increases the risk of getting mouth, voice box, and throat cancers. A large number of studies provide strong evidence that drinking alcohol is a risk factor for primary liver cancer, and more than 100 studies have found an increased risk of breast cancer with increasing alcohol intake. The link between alcohol consumption and colorectal (colon) cancer has been reported in more than 50 studies. Please click here to know more about alcoholism Keeping a Healthy Weight Research has shown that being overweight or obese substantially raises a person’s risk of getting endometrial (uterine), breast, prostate, and colorectal cancers. Overweight is defined as a body mass index (BMI) of 25 to 29, and obesity is defined as a BMI of 30 or higher. Please click here to know more about obesity management Getting Tested for Hepatitis C Hepatitis is inflammation of the liver, which is most often caused by a virus. In the United States, the most common type of viral hepatitis is Hepatitis C. Over time, chronic Hepatitis C can lead to serious liver problems including liver damage, cirrhosis, liver failure, or liver cancer. CDC recommends that anyone who was born between 1945 and 1965 get tested for Hepatitis C. Please click here to know more about Hepatitis C Please click here to know more about Cancer prevention References