Cervical Cancer Flashcards
Function of the female production system
- Producing eggs
- Facilitating fertilisation ( process by which sperm cell fuses with an egg to form a zygote initiating the development of a new organism)
- Supporting Pregnancy
- Giving Birth
Female Reproductive System main structures and function
- Ovaries: Produce eggs and female sex hormones
- Fallopian Tubes ( Oviducts): Transport eggs from ovaries to uterus and are the site of fertilisation
- Uterus (Womb): Holds and nourishes developing fetus during pregnancy
- Cervix: Connects uterus to vagina and produces mucus to aid sperm movement
- Vagina: Connects cervix to external genitalia and serves as birth canal
Cervical Anatomy
- Crucial to understanding HPV infection and impact on cervical cancer development
- Two main parts: ectocervix (exocervix): outer part of cervix visible during gynaecologic exam. Covered in thin, flat cells (squamous cells)
- Endocervix: inner part of the cervix forming canal connecting vagina to uterus. Covered in column-shaped glandular cells that make mucus.
- external opening of cervix: external os
- internal opening into uterus: internal os
- squamous columnar junction ( transfomation one): border where endo and ectocervix meet
Changes to the cervix during puberty/ pregnancy
Before puberty: junction between the squamous and columnar epithelium in the cervix located inside the cervical canal.
During puberty or pregnancy, :The transformation zone: columnar epithelium of the cervix turns outward, exposing it to the acidic environment of the vagina triggering squamous metaplasia, where the columnar cells transform into squamous cells.
this area becomes more susceptible to the development of cervical abnormalities, including precancerous and cancerous changes often linked to HPV infection .
Diagnosis; Cervical Cytology
Cytology: detects abnormalities in cervical cells that indicates precancerous or cancerous changes.
- Pap Smear or Cervical Cytology Test, cells are collected from the cervix using a swab and then smeared onto a glass slide or placed in a liquid medium- cells then examined under a microscope by a cytopathologist, who looks for changes in cell morphology, such as enlargement, irregular shape, or increased nuclear-to-cytoplasmic ratio, that may suggest cancerous growth.
- Used for early detection and intervention as part of screening to prevent the progression of cervical cancer and improve patient outcomes.
Diagnosis: Punch and Cone Biopsy vs LLETZ
- Help doctors assess the severity of abnormalities detected in cervical screening and guide further management decisions.
- Punch biopsy: removal of a small tissue sample from the cervix for microscopic examination,
- LLETZ (Large Loop Excision of the Transformation Zone): surgical procedure that removes a larger portion of abnormal cervical tissue for both diagnosis and treatment.
- cone biopsy/ conization: involves the surgical removal of a cone-shaped section of tissue from the cervix for both diagnostic and therapeutic purposes, particularly in cases of cervical dysplasia or early-stage cervical cancer.
TNM staging system for cervical cancer
- describes extent of cancer based on: T (tumor size and invasiveness), N (spread to nearby lymph nodes), and M (metastasis or spread to distant organs).
- allows doctor to detemine best treatment options/ determine prgoniss/ outxome for patients with cervical cancer
- Carcinoma in situ: Non-invasive cancer confined to the original site without spreading to surrounding tissues.
What is a multivalent vaccine
vaccine that targets multiple strains or types of a pathogen in a single formulation.
Structure and Genome Human Papilloma Virus (HPV)
Function of Genome
- Simple structure: Tiny ball or sphere
- tough outer shell ( capsid) surrounding its genetic material
- Genetic Material: Instruction manual for making more virus particles
genome: genetic material
- circular double stranded DNA molecule containing genes
Early genes : E1 to E6: involved in starting infection by helping virus copy itself and take control of cell
Late genes ( L1 and L2) : come into play later to build outer shell of new virus particles
both gene types function co-ordinately to ensure virus can infect cells and reproduce
Viral Life cycle: URR and ORI
URR (Upstream Regulatory Region)
ORI ( Origin of Replication)
ensure efficiency replication and propagation of virus within host cells
Mechanism of HPV Infection
C- HPV enters cervical cells though epithelial micro-abrasions
- Infects cervical cells integrating its DNA into host genome
- Infects basal epithelial cells and replicates spreading upwards through epithelial layers
-Cell regulation disrupted leading to uncontrolled cell growth and potentially cancerous changes
Role of HPV oncogenes (E6 and E7)
- produced by high-risk HPV strains.
- E6 targets tumor suppressor protein p53 for degradation, allowing infected cells to evade (escape) apoptosis.
- E7 binds and inactivates retinoblastoma
HPV and its link to cervical cancer
- Progresses to cervical intraepithelial neoplasia (CIN): characterised by abnormal changes in cervical cells
- CIN can progress to invasive cervical cancer spreading beyond epithelium and potentially metastasising to other organs if no intervention
- CIN scale: CIN1 (mild dysplasia), CIN2 (moderate dysplasia), and CIN3 (severe dysplasia and carcinoma in situ).
- Carcinoma in situ: cancer cells are present but haven’t spread beyond where they started growing.”
- Dysplasia: abnormal growth or development of cells, tissues, or organs, often indicating precancerous changes.
Immunohistochemistry - CIN detection
- HPV E6/E7 oncoprotens inactivate tumour suppressors P53 & RB: P16 over expressed and can be demonstrated by IHC
Detects and visualises specific proteins in tissue sections using antibodies labelled with a visible marker
P16 immunohistochemical staining in cervical intraepithelial neoplasia (CIN) indicates overexpression of p16 protein, suggestive of HPV-driven cellular changes and increased risk of progression to cervical cancer.
Strong and diffuse staining is characteristic of high-grade CIN lesions.
WHO Cervical Cancer Elimination Strategy
-Aims to reduce burden of cervical cancer world wide via comprehensive measures to reduce cervical cancer incidence and mortality rates globally:
- Vaccination: Promoting HPV vaccination to prevent HPV infection, focusing on reaching ADOLESCENT girls.
- Screening:, Understanding the scientific principles behind screening involves recognizing the role of HPV infection as the primary cause of cervical cancer and the effectiveness of early detection in preventing disease progression. Implementing evidence-based screening guidelines that balance sensitivity and specificity to maximize detection of high-risk lesions while minimizing unnecessary interventions and healthcare costs. Establishing regular cervical cancer screening programs, such as Pap smears or HPV testing, to detect precancerous lesions and early-stage cancers for timely intervention.
- Diagnosis and Treatment: Ensuring access to affordable and effective diagnostic tools and treatment options, including cryotherapy, loop electrosurgical excision procedure (LEEP), and surgery, for managing precancerous lesions and early-stage cervical cancer.
- Palliative Care: Provides specialized support to improve the quality of life for individuals with serious illnesses, focusing on symptom management including pain management and psychosocial support, and holistic well-being.
- Health Education: Conducting public awareness campaigns to educate communities about the importance of HPV vaccination, regular screening, and early treatment-seeking behavior.
