Cancer Definitions

the presence of diverse cell populations within a single tumor, which can differ in their genetic, epigenetic, and phenotypic characteristics. This variation can affect how tumors grow, respond to treatment, and lead to challenges in effective cancer therapy

smaller pieces of proteins, often called peptides, that result from the breakdown of larger proteins. These fragments can play crucial roles in understanding cancer mechanisms, as they may serve as biomarkers for diagnosis, treatment, and monitoring of cancer progression

a type of immune cell found in high numbers within the microenvironment of solid tumors. They play a significant role in promoting tumor growth, invasion, and metastasis, often exhibiting a tumor-promoting phenotype that can suppress anti-tumor immune responses

a process where the immune system interacts with tumor cells, influencing their development and resistance to immune responses. It consists of three phases: elimination, equilibrium, and escape, which together determine how tumors grow and evade the immune system

a type of immunotherapy used in cancer treatment that block proteins on immune cells or cancer cells, allowing the immune system to better recognize and attack cancer cells. They work by preventing cancer cells from using these proteins to evade detection by the immune system

antibodies that block the CTLA-4 protein, which is involved in downregulating immune responses. These antibodies, such as ipilimumab, are used in cancer immunotherapy to enhance the immune system’s ability to attack tumors

a type of cancer treatment that blocks the PD-L1 protein on tumor cells, which helps prevent the immune system from attacking the cancer. By inhibiting this protein, anti-PD-L1 therapies aim to enhance the immune response against tumors, making them a promising option in cancer immunotherapy

a type of cancer treatment that uses drugs to block the PD-1 protein on immune cells, enhancing the immune system’s ability to attack cancer cells. These drugs are part of a broader category known as immune checkpoint inhibitors, which help improve the body’s immune response against tumors

types of cancer that are linked to infections caused by specific viruses. These cancers can arise when viruses insert their genetic material into host cells, leading to changes that may result in cancer development

An invasive malignant tumor derived from epithelial tissue that tends to metastasize to other areas of the body Common characteristics - Epithelial origin - Tends to spread via lymphatics first Typical age - Usually adults Giveaways - Comes from lining or gland tissue - Makes up the majority of cancers Mental hook - If it lines or secretes, think carcinoma

Any of several forms of carcinoma that originate in glandular tissue Common characteristics - Gland formation, mucin production - Epithelial origin - Often chromosomal instability Typical age - Middle-aged to older adults Common sites - Colon, breast, lung, pancreas, prostate, stomach Giveaways - “Irregular glands” - Mucus - Liver metastases from GI tumors - Desmoplastic stroma (esp. pancreas) Mental hook - Glands that forgot how to behave

A carcinoma that arises from squamous epithelium and is the most common form of skin cancer Common characteristics - Keratin production - Intercellular bridges - High mutation burden Typical age - Older adults Common sites - Skin, lung, head & neck, esophagus, cervix Risk factors - Smoking, UV exposure, HPV, alcohol Giveaways - Keratin pearls - Surface/lining tissue - Strong environmental link Mental hook - Tough cells, ugly mutations

also known as transitional cell carcinoma, a type of cancer that originates in the urothelial cells lining the bladder, kidneys, and ureters Common characteristics - Arises from transitional epithelium - Often multifocal - High mutational burden Typical age - Older adults Common sites - Bladder (most common), ureter, renal pelvis Risk factors - Smoking - Industrial chemicals (aromatic amines) Giveaways - Painless hematuria - Papillary or flat lesions - Recurs frequently Mental hook - Stretchy lining, unstable genome

a type of malignant tumor of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue Common characteristics - Mesenchymal origin - Spindle-shaped cells - Often driven by specific translocations Typical age - Children, teens, young adults (many types) Common sites - Bone, muscle, fat, connective tissue Giveaways - Soft tissue mass - Not epithelial - Rare, but aggressive Mental hook - Structural tissue gone rogue

a type of bone cancer that typically begins in the long bones of the arms or legs, particularly around the joints. It is most commonly found in teenagers and young adults and can cause symptoms like bone pain, swelling, and unexplained fractures Common characteristics - Malignant osteoid production - Highly aggressive Typical age - Adolescents (growth spurts) - Second peak in elderly (Paget disease) Common sites - Metaphysis of long bones (knee region) Giveaways - Bone pain + swelling - Sunburst pattern on imaging - Produces bone where it shouldn’t Mental hook - Bone-making cells gone feral

a very aggressive sarcoma of smooth muscle; occurs most often in the digestive tract, uterus, bladder, or prostate Common characteristics - Smooth muscle origin - Spindle-shaped cells Typical age - Adults Common sites - Uterus, GI tract, soft tissue, blood vessels Giveaways - Deep soft tissue mass - Smooth muscle lineage markers Mental hook - Smooth muscle, rough behavior

a rare type of cancer that originates in fat cells, typically found in the muscles of the limbs or the abdomen Common characteristics - Fat differentiation - Often large, deep-seated Typical age - Adults (40–60) Giveaways - Adipocyte-like cells - Retroperitoneal masses Mental hook - Fat that won’t behave

a rare and aggressive type of cancer that originates in the inner lining of blood vessels and lymphatic vessels. It can occur anywhere in the body but most commonly affects the skin, breast, liver, and spleen Common characteristics - Endothelial (vascular) origin - Highly aggressive, infiltrative Typical age - Older adults Common sites - Skin (scalp, face), liver, breast Risk factors - Chronic lymphedema - Radiation exposure Giveaways - Bruise-like lesion that doesn’t heal - Vascular channels lined by malignant cells Mental hook - Blood vessels turned lethal

acute leukemia characterized by proliferation of granular leukocytes; most common in adolescents and young adults Common characteristics - Myeloid blasts - Blocked differentiation Typical age - Adults Giveaways - Auer rods - Pancytopenia - Rapid onset symptoms Mental hook - Myeloid cells stuck at “blast”

a type of blood cancer that starts in the blood-forming myeloid cells in the bone marrow. It is characterized by the slow growth of abnormal white blood cells Common Characteristics - Myeloid lineage - BCR-ABL fusion (Philadelphia chromosome) Typical age - Middle-aged adults Giveaways - Granulocytes at all stages - Dramatic response to targeted therapy Mental hook - One fusion gene, one runaway pathway

acute leukemia characterized by proliferation of immature lymphoblast-like cells in bone marrow, lymph nodes, spleen, and blood; most common in children Common characteristics - Lymphoid blasts - Bone marrow failure Typical age - Children (most common pediatric cancer) Giveaways - Fatigue, bruising, infections - Very high blast count Mental hook - Childhood leukemia of arrested lymphocytes

chronic leukemia characterized by lymphoblast-like cells; more common in older men Common characteristics - Mature lymphocytes - Often indolent Typical age - Older adults Giveaways - High lymphocyte count - Lymphadenopathy + marrow involvement Mental hook - Lymphocytes that won’t retire

a type of blood cancer that originates in the lymphatic system, specifically affecting white blood cells called lymphocytes. It is characterized by the presence of abnormal cells known as Reed-Sternberg cells and is considered one of the most treatable forms of cancer Common characteristics - Reed–Sternberg cells - Few malignant cells, many reactive cells Typical age - Bimodal (young adults + older adults) Giveaways - CD15/CD30 positivity - Ordered spread between nodes Mental hook - One bad cell causing immune chaos

a type of cancer that originates in the lymphatic system, specifically affecting white blood cells called lymphocytes. It includes various subtypes and is more common than Hodgkin lymphoma, with symptoms such as swollen lymph nodes, fever, and fatigue Common characteristics - Many malignant lymphocytes - Diverse subtypes Typical age - Usually older adults Giveaways - Sheets of lymphoid cells - Bone marrow + blood involvement common Mental hook - Lymphoma without subtlety