**Question:** Overall survival is increased by screening in

A. Breast cancer
B. Colorectal cancer
C. Prostate cancer
D. Endometrial cancer

**Core Concept:** Screening is the process of detecting diseases or abnormalities in asymptomatic individuals with the aim of improving outcomes by early intervention. In oncology, screening is often aimed at early detection of cancer to increase overall survival.

**Why the Correct Answer is Right:** Screening for colorectal cancer (CRC) has been shown to increase overall survival by early detection and treatment of cancer. Regular screening through colonoscopy, fecal occult blood tests, or fecal immunochemical tests can identify precancerous polyps and early-stage cancers, allowing for their removal and preventing progression to advanced disease. This leads to improved patient outcomes, including increased survival rates.

**Why Each Wrong Option is Incorrect:**

A. Breast cancer: While screening mammography can detect breast cancer at an early stage, its impact on overall survival is not as significant as colorectal cancer screening. Additionally, mammography is not recommended in all age groups due to false positives and potential harm from unnecessary biopsies.

B. Colorectal cancer: As mentioned earlier, screening for CRC does increase overall survival. However, this option is not correct as it is the correct answer.

C. Prostate cancer: Screening for prostate cancer using prostate-specific antigen (PSA) testing is controversial, with inconclusive evidence regarding its impact on overall survival.

D. Endometrial cancer: Screening for endometrial cancer is not widely recommended due to limited evidence regarding its impact on overall survival and potential harm from unnecessary interventions.

**Clinical Pearl:** The impact of screening on overall survival varies depending on the disease and the screening method employed. In the case of colorectal cancer, effective screening methods and early detection can significantly improve outcomes, including overall survival. However, the benefits of screening for other cancers may not be as clear-cut, and potential harms from unnecessary interventions must be carefully balanced against potential benefits. Always consider the specific disease, available screening methods, and potential risks when evaluating screening recommendations.