GREAT RESOURCES FOR RESIDENCY
CANCER SCREENING
Practical information to screen your patients in clinic
COLORECTAL CANCER
Indications for screening for people at average risk according to USPSTF
Adults aged 50 to 75 years.
USPSTF recommends against routine screening adults aged 76 to 85 years.
USPSTF recommends against screening of adults >85 years.
In addition to above, for people with increased risk of colorectal cancer the US Multi-Society Task Force recommends:
What test(s) to perform?
Stool-based test:
Guaiac-based Fecal Occult Blood Test* (gFOBT) every year
Yearly Fecal Immunochemical Test (FIT) every year (results not influenced by food or medications)
FIT-DNA every 1-3 years
Colonoscopy every 10 years
CT colonography every 5 years
Flexible sigmoidoscopy every 5 years
Flexible sigmoidoscopy every 10 years with yearly FIT
These alternatives are similarly effective to detect cancer. There are no studies comparing them head-to-head and each have their own advantages and disadvantages (see Resources section). Make sure to discuss with your patient which approach is more convenient to them as this increases screening uptake.
(*) Highly sensitive versions of gFOBT should be used, which consist of the take-home multiple sample method (3 samples over 3 days). A gFOBT done during a digital rectal exam in the doctor’s office is not enough for screening. FIT is a single-day test.
Follow-up algorithm
If FOBT or sigmoidoscopy are positive the patient needs to undergo a colonoscopy.
If colonoscopy is positive for polyps:
Benefits
Screening for colorectal cancer in adults aged 50 to 75 years reduces colorectal cancer mortality (e.g. relative risk of death with annual FOBT screening was 0.68; 95% CI 0.56 to 0.82)1.
Adults who have never been screened are more likely to benefit.
Screening is most appropriate for those healthy enough to undergo treatment and those without comorbid conditions that significantly limit their life expectancy.
Harms
The harms of screening for colorectal cancer in adults aged 50 to 75 years are small.
The majority of harms result from the use of colonoscopy, either as the screening test or as follow-up for positive findings detected by other screening tests.
The rate of serious adverse events from colorectal cancer screening increases with age. Thus, the harms of screening for colorectal cancer in adults 76 years and older are small to moderate.
High-Value - Cost conscious
Colorectal cancer screening by any modality is cost-effective.
Consistent trends reveal that FIT performs well compared with other screening tests. Colonoscopy also performs well in most models and, in general, the traditional tests are more cost-effective than the newer modalities.
Resources
Shared Decision Making - Online Tools:
To estimate your patient´s risk of colon cancer click here. This is a great resource, just a little bit long. May take a few minutes and is ideally performed with patient present due to detailed questions.
For advantages and disadvantages of each testing method click here.
For insurance information click here.
Bibliography
LUNG CANCER
Indications for Screening according to USPSTF
Adults aged 55 to 80 years
History of >30 pack-year of smoking and currently smoke or have quit within the past 15 years
Discontinue low-dose chest CT (LDCT) if patient has not smoked for 15 years or has a health problem that significantly limits life expectancy
Of note, Medicare covers lung cancer screening for patients aged 55 to 77 years only
What test to perform?
Yearly low-dose chest CT (LDCT)
Make sure your patient understands that lung cancer screening is not a single test, but a process that must be done correctly under the direction of a physician.
Lung cancer screening is NOT an alternative to smoking cessation, which is the most important intervention to decrease the risk of dying from lung cancer.
Follow-up algorithm
Usually Radiology will make a recommendation on how and when to follow-up a positive test. Most often this involves repeat imaging and, occasionally, invasive tests like a biopsy.
Benefits - Recommend to discuss using a shared-decision making tool (see Resources section)
Annual screening for lung cancer with LDCT in high-risk persons can prevent a substantial number of lung cancer–related deaths.
The magnitude of benefit to a particular individual depends on that person's risk for lung cancer — those who are at highest risk are most likely to benefit.
Screening cannot prevent most lung cancer–related deaths, and smoking cessation remains essential.
Harms - Recommend to discuss using a shared-decision making tool (see Resources section)
Harms include false-negative and false-positive results, incidental findings, overdiagnosis, and radiation exposure.
False-positive LDCT results occur in a substantial proportion of screened persons; 95% of all positive results do not lead to a diagnosis of cancer.
A modeling study performed for the USPSTF estimated that 10% to 12% of screen-detected cancer cases are overdiagnosed —that is, they would not have been detected in the patient's lifetime without screening.
Resources
Shared-decision making tools online:
Lung cancer risk calculator. Great guide to use with your patients.
Shared-decision making tools print:
Lung Cancer Screening: A Summary Guide for Primary Care Clinicians
Lung Cancer Screening: A Clinician’s Checklist
H. Gilbert Welch has done extensive research on the risk of overdiagnosis and cancer screening. Check his paper Overdiagnosis in cancer or, if interested in a more in-depth review of these topics, his books Overdiagnosed and Less Medicine More Health are great reads.
Bibliography
Screening for Lung Cancer: Systematic Review to Update the U.S. Preventive Services Task Force Recommendation
PROSTATE CANCER
Indications for screening
No consensus regarding who to screen or if to screen at all.
Indications for men at average risk of prostate cancer according to different organizations.
The USPSTF is currently reviewing their recommendations to consider screening men between ages 55-69 (see bibliography for reference).
Who is considered high risk?
African American men
Men with a first-degree relative with prostate cancer, particularly if diagnosed <65 years of age.
What test to perform?
ACP recommends screening with PSA testing only. The role of digital rectal examination (DRE) is unclear.
A PSA >4.0 µg/L has:
A sensitivity of 21% for detecting any prostate cancer and 51% for detecting high-grade cancers (Gleason ≥8)
A specificity of ~91%
A PPV of ~25% (a PSA >10 µg/L has a PPV of 42 to 64%).
A PSA <4.0µg/L has a NPV of 85%.
Frequency of screening
It is unknown how often testing should be done.
A reasonable approach based on the ERSPC trial (European Randomized Study of Screening for Prostate Cancer) is to test every 4 years (range 2 - 7 years in that trial). The PLCO trial screened men yearly and found no benefit.
Follow-up algorithm (based on ACS guidelines)
PSA <2.5 µg/L: normal, no further testing.
PSA 2.5 - 4.0 µg/L: considered intermediate. Per ACS a DRE may be helpful in this population to decide whether or not to do a biopsy.
PSA >4.0 µg/L: has been traditionally considered positive requiring further testing (e.g. biopsy).
Important: there are no true PSA cutoffs to distinguish cancer from noncancer. Please take the information above very carefully as this recommendations do not come from high-quality studies. Also keep in mind that the PSA test has poorer discriminating ability in men with symptomatic BPH.
Benefits
Based on 2 high quality studies, the PLCO (Prostate, Lung, Colorectal, and Ovarian) Cancer Screening Trial and the ERSPC trials, 1000 men need to be screened for 10-15 years to prevent 1 death from prostate cancer.
The ERSPC study showed a small benefit from cancer screening in patients aged 55-69 years. Accordingto this study 781 men need to be screened for 13 years to prevent 1 death from prostate cancer.
The PLCO study tested men aged 55-74 years with PSA and DRE yearly for an average of 13 years and did not show a mortality benefit from prostate cancer screening.
Harms
False alarms related to number of high false-positive results associated with DRE and especially PSA
High false-negative rates
Overdiagnosis (detection of cancer that is not destined to cause future morbidity and mortality)
Overtreatment and associated harms, including bleeding, pain, and hospitalization
Anxiety and discomfort
Positive screening results may lead to further testing, such as biopsies, which not only can be painful but can also lead to complications, such as infections
Value of Screening
According to ACP, prostate cancer screening with PSA is considered low-value care given that “the chances of harm with screening outweigh the chances of benefit for most men and that the direct and indirect costs associated with biopsy, repeated testing, aggressive therapy, patient anxiety, and missed work are significant.”
Resources
Points to discuss on a shared-decision making approach per ACP
Bibliography