Oncology Guidelines

Cancer Screening

The American Cancer Society recommends average-risk adults undergo screening for breast, cervical, colorectal, and lung cancers based on age-specific and risk-stratified protocols, while prostate cancer screening requires shared decision-making 1, 2, 3
For breast cancer screening, mammography is recommended annually for women aged 45-54 years, with the option to transition to biennial screening after age 55 1
Clinical breast examination can be performed during cancer-related checkups 4, 3
For cervical cancer screening, women aged 21-29 should have cervical cytology (Pap test) every 3 years, while women aged 30-65 can have either cytology every 3 years or cytology + hrHPV co-testing every 5 years 1, 3
Colorectal cancer screening should begin at age 45 for average-risk adults and continue through age 75, with options including annual high-sensitivity guaiac-based fecal occult blood test (gFOBT) or fecal immunochemical test (FIT), multitarget stool DNA (mtsDNA) test every 3 years, colonoscopy every 10 years, flexible sigmoidoscopy every 5 years, CT colonography (virtual colonoscopy) every 5 years, or double-contrast barium enema every 5 years 1, 5
Lung cancer screening with low-dose CT (LDCT) is recommended annually for adults aged 50-80 years with ≥20 pack-year smoking history who currently smoke or have quit within the past 15 years 2, 3

Tumor markers are primarily used for prognosis, treatment selection, and monitoring rather than screening, with most lacking sufficient sensitivity and specificity for population-based screening 7, 8
Genomic tests with strong recommendations include Lynch syndrome screening for colorectal cancer, 1p/19q deletion for glioma diagnosis and prognosis, Oncotype DX for breast cancer, RET mutation for thyroid cancer, KRAS mutation for colorectal cancer, EGFR mutation for non-small cell lung cancer, ALK rearrangement for non-small cell lung cancer, and BRAF mutation for melanoma and colorectal cancer 7, 8

Chemotherapy remains the cornerstone of cancer treatment, with myelosuppression being the most common dose-limiting toxicity across most classes 9
Myelosuppression is the primary cause of unplanned dose reductions and treatment delays, with approximately 50% of patients with early-stage breast cancer and non-Hodgkin's lymphoma receiving <85% relative dose intensity (RDI) 9

Paraneoplastic syndromes are systemic effects of cancer that occur at sites distant from the tumor or its metastases, caused by tumor secretion of hormones, cytokines, or immune-mediated mechanisms 9
Examples of paraneoplastic syndromes include syndrome of inappropriate antidiuretic hormone (SIADH), Cushing syndrome, hypercalcemia of malignancy, hypoglycemia, Lambert-Eaton myasthenic syndrome, paraneoplastic cerebellar degeneration, and encephalomyelitis 9

Tumor lysis syndrome (TLS) occurs when rapid tumor cell death releases intracellular contents into the bloodstream, causing life-threatening metabolic derangements, most commonly in hematologic malignancies with high tumor burden or rapidly proliferating solid tumors 9
Classic electrolyte abnormalities in TLS include hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia, which can lead to acute kidney injury and other complications 9
Prevention and management of TLS involve aggressive IV hydration, allopurinol or rasburicase to prevent uric acid formation, and close monitoring of electrolytes and renal function 2, 3, 6, 9