Cancer Screening Guidelines : A Rapid Review

Introduction Cancer, as a major public health is the leading cause of death globally. Unfortunately, the burden of cancer has been expected to increase due to population growth and aging; lifestyle behaviors such as smoking, poor diet, physical inactivity, and reproductive changes in women especially in developing countries. Globally, lung cancer and breast cancer have been known as the leading causes of death in men and women respectively. 3 To prevent the mortality and burden of cancers, governmental and scientific associations have tried to develop and update cancer guidelines worldwide. In this paper, the guidelines of most important cancers have been briefly reviewed.


Introduction
2][3] Unfortunately, the burden of cancer has been expected to increase due to population growth and aging; lifestyle behaviors such as smoking, poor diet, physical inactivity, and reproductive changes in women especially in developing countries.Globally, lung cancer and breast cancer have been known as the leading causes of death in men and women respectively. 2,3  prevent the mortality and burden of cancers, governmental and scientific associations have tried to develop and update cancer guidelines worldwide.In this paper, the guidelines of most important cancers have been briefly reviewed.

Breast Cancer
Breast cancer is the most common cancer of women worldwide.Several guidelines have been developed for breast cancer screening.Mammography is a popular modality for breast screening.The American Cancer Society (ACS) has recommend that mammography must begin annually at the age of 40 years for all women.In addition, Breast Self-Examination (BSE) (regularly (monthly) or irregularly, beginning in their early 20s), and Clinical Breast Examination (CBE) (preferably at least every 3 years for women in their 20s and 30s and preferably annually for asymptomatic women aged ≥40 y) have been considered. 4,5 e United States Preventive Service Task Force (USPSTF) recommended biennial screening mammography for women aged 50 to 74 years.Albeit, beginning mammography prior to age 50 years has been considered as an individual option especially for women with a parent, sibling, or child with breast cancer.In addition, the balance of benefits and harms of screening mammography in women aged 75 years or older is not sufficient. 5,6 e Canadian Task Force on Preventive Health Care (CTFPHC) recommended routinely screening with mammography every 2 to 3 years for women aged 50-69 and 70-74 years.Although, for women aged 40-49, routinely screening with mammography was not recommended.In addition, BSE and CBE is not recommended routinely. 7he American College of Physician (ACP) recommended mammography in women age 40-70 years.Although the benefit of screening in older women is higher.Based on the United Kingdom National Health Service (UK-NHS) guideline, routine screening is not recommended in women age 40-49 years.Albeit, digital mammography is more accurate in women 40-49 years in compare with film mammography.In women aged 50-70 years it has been recommend to perform mammography screening of all women every 3 years. 8][10] Based on UK-NHS, routine screening before the age of 25 is not recommended.Cytology every 3 and 5 years has been recommended for women between 25-49 years and women between 50-64 years respectively.In women age >=65 years, it has been recommended to screen women who have not screened since the age of 50 years or who have had a history of abnormal test results.Albeit, if all the previous screening were negative, the screening ended. 8he American College of Obstetrics and Gynecology (ACOG) recommend to begin screening at the age of 21 years independent of the sexual history every 2 years from 21 to 29 years.In women >= 30 years, we could screen every 2-3 years if they have three consecutive negative screens, no history of cervical intraepithelial neoplasia 2 or 3, not immunocompromised, no HIV, and not exposed to DES. 5,8,10 Colorectal Cancer It has been reported that colorectal cancer is the third most commonly diagnosed cancer in males and the second in females worldwide.As mentioned above, screening begins at the age of 50 years in average-risk adults. 8,11 SIG, DCBE and CTC performs every 5 years while colonoscopy performs every 10 years as gold standard for colon colorectal cancer screening.It has been recommended to perform gFOBT and FIT (iFOBT) annually.Unfortunately, the interval of stool DNA test is not clearly defined (8, 12).UK-NHS recommended screening with FOBT every 2 years in adults aged between 60-69 years.The Australian guideline has also recommended it but for adults aged between 50-74 years. 8,11  those at increased risk based on family history but without a definable genetic syndrome, ACS and U.S. Multisociety Task Force on Colorectal Cancer (USMTFCC) recommended screening with colonoscopy at the age of 40 years or 10 years younger than the earliest diagnosis in the immediate family which must be repeated every 5 years.Also, in very-high-risk hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome) patients, screening with colonoscopy every 2 years beginning at the age of 20-25 years then yearly at the age of 40 years has been recommended. 8,11  case of classic Familial Adenomatous Polyposis (FAP), it has been recommended that at-risk children should be offered genetic testing at the ages of 10-12 years.Also, flexible sigmoidoscopy or colonoscopy every 12 months starting at the ages of 10-12 years is recommended.
Elective colectomy based on the number and histology of polyps is usually done by the early 20s.In addition, upper endoscopy every 5 years if no gastric or duodenal polyps starting in early 20s has been recommended. 8,12 state Cancer It has been stated that prostate cancer is the second most frequently diagnosed cancer in men worldwide.The use of PSA testing leads to various incidence rates worldwide. 2[20][21] Based on the ACP guideline, in men between the ages of 50 and 69 years, PSA testing is not offered unless the patient expresses a clear preference for screening.Also, PSA testing is not offered in average-risk men younger than 50 or 70 years and older or in men with a life expectancy of less than 10-15 years. 8The European Association of Urology (EAU) stated that there is a lack of evidence to support or disregard screening with PSA testing for early detection of prostate cancer. 8,22,23 Bed on UK-NHS and NCCN, PSA testing is offered for healthy men between 45-70 years.It has been recommended retesting in 5 years in men at the ages of 45-49 with PSA<0.7 ng/mL; while in men age 45-49 with PSA >0.7 ng/mL and those at the ages of 50-59 with PSA >0.9 ng/mL, retesting is offered every 1-2 years. 8

Lung Cancer
As mentioned, lung cancer has been known as a leading cause of death in men. 2,3,24 Bsed on USPSTF and AAFP guidelines, there is no sufficient evidence to recommend for or against lung cancer screening.Also, the American College of Chest Physicians (ACCP) and the American Society of Clinical Oncology (ASCO) stated that routine screening for lung CA with chest x-ray (CXR) and sputum cytology is not recommended.26]

Conclusion
While cancer screening guidelines could be important in the reduction of cancer death, early diagnosis and better cancer management.However, it is important to consider their benefits and harms, direct and indirect costs, accessibility, physician's and population's acceptability.
The National Comprehensive Cancer Network (NCCN) recommended CBE every 1-3 years-breast awareness education in women age 25-40 years with average risk.Albeit, an annual CBE and annual mammogram has been recommended in women age> 40 year.MRI has not been recommended in average-risk patients.