This document provides information about cancer and genetics. It discusses cancer incidence and predisposing factors. It describes the characteristics, appearance, growth, and spread of tumors. It covers the classification of tumors including epithelial tumors, mesenchymal tumors, and tumors of mixed cell layers. The document also discusses genetics, teratogens that cause birth defects, genetic disorders like Angelman syndrome and Down syndrome, and muscular dystrophies.

1. CANCER
AND
GENETICS

2. CANCER INCIDENCE
• Predisposing Factors
– Familial and genetic factors
– Racial and geographic factors
– Environmental and cultural factors
– Age or sex
• Pre-Malignant Conditions
– Carcinoma in situ
• Malignant cells are confined to epithelium without invasion across the
basement membrane
–Some benign tumors – not all benign tumors become malignant
–Miscellaneous conditions – certain inflammatory/hyperplastic
conditions

3. CHARACTERISTICS OF TUMORS
• Rate of Growth
• Phenotype
• Clinical Appearance
• Gross Features
• Microscopic Features
• Local Invasion (Direct Spread)
• Metastasis (Distant Spread)

4. TUMORS: RATE OF GROWTH
•Tumor cells grow in half the time as normal
cells
•Growth rate depends on the number of cells
remaining in the proliferative pool (growth
fraction)
•Tumor cell loss by shedding

5. TUMORS: PHENOTYPE
• Disobey growth control signals to proliferate rapidly
• Escape death signals to achieve immortality
• Imbalance between cell proliferation and cell death causes
excessive growth
• Lose properties of differentiation
• Perform little to no functions
• Genetically unstable
• Develop new mutations as a result of growth control loss
• Ability to travel from site of origin to other sites to colonize and
establish distant spread

6. TUMORS: CLINICAL APPEARANCE
• Benign Tumors
–Generally slow-growing
–May remain asymptomatic
• Malignant Tumors
–Grow rapidly
–May ulcerate on the surface
–Invade locally into deeper tissues to metastasize
–Produce systemic symptoms like weight loss, anorexia,
anemia

7. TUMORS: GROSS FEATURES
• Benign Tumors
–Generally spherical or oval
–Encapsulated or well-circumscribed
–Freely movable and firm
–Uniform unless hemorrhage occurs
• Malignant Tumors
–Irregular in shape
–Poorly circumscribed
–Extend into adjacent tissues
–Cause secondary changes like hemorrhage more often

8. TUMORS: MICROSCOPIC FEATURES
• Tumors have a microscopic pattern
• Variety of patterns exist
• Pattern depends on the type of tumor

9. CYTOMORPHOLOGY OF NEOPLASTIC CELLS
• Differentiation
– Extent of morphological and functional resemblance of tumor cell to
normal cell
• Anaplasia
– Lack of differentiation
– Characteristic feature of most malignant tumors
• Tumor Angiogenesis
– New blood vessels are formed from pre-existing ones
– Takes place under the influence of angiogenic factors elaborated by
tumor cells
• Inflammatory Reaction

10. TUMORS: LOCAL INVASION/LOCAL SPREAD
• Benign Tumors
–Form encapsulated masses that expand and push aside
the normal surrounding tissues without actually invading
• Malignant Tumors
–Enlarge by expansion
–Some may be partially encapsulated
–Distinguished from benign tumors by invasion, infiltration,
and destruction of the surrounding tissue

11. TUMORS: METASTASIS
• Metastasis - Distant Spread
– Spread of tumor by invasion in such a way that discontinuous secondary
tumor masses are formed at the site and lodge
• Two most important factors used to distinguish malignant tumors from
benign tumors:
– Metastasis
– Invasiveness
• Routes of Metastasis
– Lymphatic Spread (Carcinoma)
– Hematogenous Spread (Sarcoma)
– Spread through the body cavity or natural passages

13. CLASSIFICATION OF TUMORS
• Tumors of One Parenchymal Cell Type
–Epithelial Tumors
–Non-Epithelial (Mesenchymal) Tumors
• Mixed Tumors
• Tumors of more than one germ cell layer

14. EPITHELIAL TUMORS
• Squamous Epithelium
–Benign: Squamous Cell Papilloma
–Malignant: Squamous Cell Carcinoma
• Transitional Epithelium
–Benign: Transitional Cell Papilloma
–Malignant: Transitional Cell Carcinoma
• Glandular Epithelium
–Benign: Adenoma
–Malignant: Adenocarcinoma

15. EPITHELIAL TUMORS
• Basal Cell Layer
– No benign
– Malignant: Basal Cell Carcinoma
• Neuroecoderm
– Benign: Naevus
– Malignant: Melanoma, Melanocarcinoma
• Hepatocytes
– Benign: Liver Cell Adenoma
– Malignant: Hepatoma, Hepatocellular carcinoma
• Placenta (Chorionic Epithelium)
– Benign: Hydatdiform Mole
– Malignant: Choriocarcinoma

16. MESENCHYMAL TUMORS
• Adipose Tissue
–Benign: Lipoma
–Malignant: Liposarcoma
• Adult Fibrous Tissue
–Benign: Fibroma
–Malignant: Fibrosarcoma
• Embryonic Fibrous Tissue
–Benign: Myxoma
–Malignant: Myxosarcoma

17. MESENCHYMAL TUMORS
• Cartilage
–Benign: Chondroma
–Malignant: Chondrosarcoma
• Bone
–Benign: Osteoma
–Malignant: Osteosarcoma
• Synovium
–Benign: Benign Synovioma
–Malignant: Synovial Sarcoma

18. MESENCHYMAL TUMORS
• Smooth Muscle
–Benign: Leiomyoma
–Malignant: Leiomyosarcoma
• Skeletal Muscle
–Benign: Rhabdomyoma
–Malignant: Rhabdomyosarcoma
• Mesothelium
–No benign
–Malignant: Mesothelioma

19. MESENCHYMAL TUMORS
• Blood Vessels
–Benign: Hemangioma
–Malignant: Angiosarcoma
• Lymph Vessels
–Benign: Lymphangioma
–Malignant: Lymphangiosarcoma
• Glomus
–Benign: glomus tumor
–No malignant

20. MESENCHYMAL TUMORS
• Meninges
–Benign: Meningioma
–Malignant: Invasive Meningioma
• Hematopoietic Cells
–No benign
–Malignant: Leukemia
• Lymphoid Tissues
– Benign: pseudolymphoma
– Malignant: lymphoma

21. MESENCHYMAL TUMORS
• Nerve Sheath
–Benign: neurolemmoma, neurofibroma
–Malignant: neurogenic sarcoma
• Nerve Cells
–Benign: ganglioneuroma
–Malignant: neuroblastoma

22. MIXED TUMORS
• Salivary Glands
–Benign: Pleomorphic Adenoma
–Malignant: Malignant Mixed Salivary Tumor

23. TUMORS OF MORE THAN ONE GERM
CELL LAYER
• Totipotent Cells in Gonads or Embryonal Rests
–Benign: Mature Teratoma
–Malignant: Immature Teratoma

24. CAUTION: SIGNS OF CANCER
• Changes in bowel or urinary habits
• A sore that does not heal
• Unusual bleeding or discharge
• Thickening or lump in the breast
• Indigestion or difficulty swallowing w/unexplained
weight loss
• Obvious changes in moles

25. BLADDER CANCER
• Early stages show
bleeding in the urine
but little to no pain
• Hematuria is the first
sign of bladder cancer,
followed by changes in
urination

26. BREAST CANCER
• A new lump is the most common symptom
• Manual palpation is better at catching breast cancer
than mammograms

27. CERVICAL CANCER
• Often asymptomatic
• When women do experience
symptoms, they may experience
unusual vaginal discharge,
abnormal bleeding, or pain
during intercourse

28. COLORECTAL CANCER
• Most common sign/symptom
is change in bowel habits
• Diarrhea, constipation, narrow
stools, or blood in stool are
common
• Bright blood in feces indicates
lower GI problems
• Dark blood in feces indicates
upper GI problems

29. LUNG CANCER
• Most common symptom is a
persistent cough with or
without chest pain
• Feeling of an infection that
just won’t go away

30. PROSTATE CANCER
• Weak and interrupted urine flow
• Frequent urination, especially at night

31. RENAL CANCER
• Low back pain
• Check if pain is associated
with injury

32. SKIN CANCER
• Any new growth on the skin should be examined
• Observe for spots or bumps that change size or have
irregular borders, and sores that will not heal

33. GENETICS
• Genetics is the study of heredity and the variation of inherited
characteristics
• Chromosome
– An entire DNA molecule + protein
– 46 molecules
• 23 pairs
• 44 somatic chromosomes
• 2 sex chromosomes (X or Y)
• Gene
– Constitute different regions on the chromosome
– Each gene codes fo a protein product
– Differences in proteins bring about differences between individuals

35. TERATOGENS
• Teratogens are certain chemicals, drugs, physical agents,
and biologic agents that are known to induce birth
defects and developmental effects
• May result in one of the following outcomes
–Intrauterine Death
–Intrauterine Growth Retardation
–Functional Defects
–Malformation

37. CLASSIFICATION OF
DEVELOPMENTAL DEFECTS
• Agenesis – complete absence
of an organ
• Aplasia – absence of
development of an organ
with presence of rudiment
• Hypoplasia – incomplete
development of an organ not
reaching the normal adult
size
• Atresia – incomplete
formation of lumen in hollow
• Developmental Dysplasia –
defective developmental cells
and tissues result in abnormal
or primitive histogenic
structures
• Dystrophic Anomalies – defects
resulting from failure of fusion
• Ectopia or Heterotropia –
abnormal location of tissue at
an ectopic site

38. KARYOTYPIC ABNORMALITIES
• Numerical Abnormalities
– Polyploidy: # of chromosomes is a multiple of a haploid
(triploid, 3N with 69 chromosomes)
– Aneuploidy: # of chromosomes not an exact multiple of a
haploid (hypodiploid, 2N-1 with 45 chromosomes)
• Structural Abnormalities
–Balanced structural alteration: no change in total
number of genes or genetic material
–Unbalanced structural alteration: gene rearrangement
resulting in loss or gain or genetic materials

39. GENETIC DISORDERS
• Angelman Syndrome
– Cause: X-linked, lose a portion of the chromosome
– Characteristics: flat head, protruding tongue, odd bouts of laughter, or
balance disorders
• Cri du Chat
– Cause: missing part of chromosome #5 due to a mutation
– Characteristics: high-pitched crying, webbed toes and fingers, or
downward slant to wideset eyes
• Downs Syndrome
– Cause: trisomy 21
– Characteristics: flat face, upward slanted eyes, or hypotonia

40. GENETIC DISORDERS
• Fragile X Syndrome
– Cause: fragile X retardation protein
– Characteristics: large head with prominent forehead and long face in
males
• Neurofibromatosis
– Cause: autosomal dominant
– Characteristics: effects on the nervous system and skin, birthmarks called
café-au-lait, purplish/rubbery lesions on skin, and freckles in the armpit
and groin
• Prader Will Syndrome
– Cause: chromosome XV
– Characteristics: extreme hunger, over-eating, obsession with food, temper

41. GENETIC DISORDERS
• Smith-Magenis Syndrome
– Cause: deletion at chromosome XVII
– Characteristics: broad nasal bridge, protruding jaw, ear anomalies, speech
and middle ear problems, and sleep disturbances
• Klinefelter’s Syndrome
– Cause: men with an extra X chromosome
– Characteristics: less developed teenagers, prepubescent testosterone
• Turner Syndrome
– Cause: females with only 1 X chromosome
– Characteristics: webbed neck, underdeveloped breasts, hypertension, and
type II diabetes

42. GENETIC DISORDERS
• Triple X Syndrome
– Cause: extra X chromosome
– Characteristics: females are very tall, does not produce long-term
problems
• Williams Syndrome
– Cause: random mutation of chromosome 4
– Characteristics: 50% retardation, puffiness around eyes, long neck, sloping
shoulders, and poor depth perception
• Cystic Fibrosis
– Cause: single point mutation
– Characteristics: limits lifespan to 30s, frequent coughing with thick
sputum, frequent lung infections, and salty skin

43. MUSCULAR DYSTROPHY
• Cause: Dystrophin malfunction.
• Over 30 different genetic diseases
– Duchenne
• Most common
• Missing dystrophin
• Affects skeletal and cardiac muscle
– Fascioscapulohumeral
• Faulty dystrophin
– Myotonic
• Congenital, juvenile, adult, or late onset