Chapter 69 Uterine Cervix Flashcards Preview

Perez and Brady's Principles and Practice of Radiation Oncology 6th Edition > Chapter 69 Uterine Cervix > Flashcards

Flashcards in Chapter 69 Uterine Cervix Deck (20):
1

Dimension of Uterus

7-8cm long

5-7cm wide

2-3cm thick. 

2

Dimension of Cervix

approximately 3 by 3 cm

The cervix is divided into an upper or supravaginal portion, above the ring containing the endocervical canal, and the vaginal portion, projecting in the vaginal vault.

Central in the rounded vaginal region is the external os, bounded by the anterior and posterior lips of the cervix, extending inward to the internal os, the endocervical canal, and endometrial canal.

3

Describe the relation of uterus to surrounding structures

The uterus is partially covered by peritoneum in its fundal portion and posteriorly

its anterior and lateral surfaces are related to the bladder and the broad ligaments, respectively.

It is attached to the surrounding structures in the pelvis by two pairs of ligaments—the broad and the round ligaments.

 

4

Define broad ligament

The broad ligament is a double layer of peritoneum extending from the lateral margin of the uterus to the lateral wall of the pelvis.

It contains the fallopian tubes.

The two layers of peritoneum forming the broad ligament enclose the parametrium as it reaches the uterus. Inferiorly, the broad ligament follows the plane of the pelvic floor and ends medially in the upper portion of the vagina

5

Describe Round ligament of uterus

The round ligament, a band of smooth muscle and connec- tive tissue that contains small vessels and nerves, extends forward horizontally from its attachment in the anterolateral portion of the uterus to the lateral pelvic wall.

The cord ascending from the lateral wall of the true pelvis crosses the pelvic brim and extends laterally to reach the abdominoinguinal ring, through which it leaves the abdomen to traverse the inguinal canal and terminates in the superficial fascia.

6

Describe Uterosacral ligament

The uterosacral ligaments are paired supports for the lower uterus, extending from the uterus to the sacrum and running along the recto-uterine-peritoneal fields.

 

7

Describe Cardinal ligament

The cardinal ligaments, also called transverse cervical ligaments (Mackenrodt’s), are thickened connective tissue and fascia arising at the upper lateral margins of the cervix and inserting into the fascial covering of the pelvic diaphragm.

8

Describe lymphatic supply of uterus

drains principally into the paracervical lymph nodes; from there it goes to the external iliac (of which the obturator nodes are the innermost component) and the hypogastric lymph nodes.

The pelvic lymphatics drain into the common iliac and the para-aortic lymph nodes.

Lymphatics from the fundus pass laterally across the broad ligament continuous with those of the ovary, ascending along the ovarian vessels into the para-aortic lymph nodes. Some of the fundal lymphatics also drain into the common iliac lymph nodes.

9

Describe blood supply of Uterus

The main artery supplying the uterus is the uterine artery, which originates from the anterior division of the hypogastric artery.

10

Most common cause of cervical cancer

Estimates indicate that >90% of cervical cancers are related to the presence of human papilloma virus (HPV) and are contracted via sexual intercourse. HPV is a small, double-stranded DNA virus; HPV 16 and 18, as well as a long list of other, less frequent subtypes, including but not limited to HPV 31, 33, 35, 39, 45, 51, 52, 56, and 58, have been well characterized as causative agents for cervical cancer, with some geographic variation. 

11

Describe pathogenesis of HPV in cervical cancer

The HPV genome integrates into the host cell chro- mosomes in cervical epithelial cells and codes for six early and two late open reading frame proteins, of which three (E5, E6, and E7) alter cellular proliferation. Two viral genes, E6 and E7, are typically expressed in HPV-positive cervical-cancer cells. The E6 protein inactivates the major tumor suppressor p53,this causes chromosomal instability, inhibits apoptosis, and activates telomerase. The E7 protein affects the retinoblastoma protein (Rb), resulting in a loss of regulation of the cell’s proliferation and immortalization

12

Peak age for prevalence of HPV in cervical cancer

 25 to 35 years

<15% of exposed women develop persistent infection that results in dysplasia,whereas the majority of women clear the infection within 2 years. 

13

How long does it take for cervical cancer to develop after initial exposure to HPV

10 to 20 years

14

Social factors related to cervial cancer associated with HPV transmission

early age of first intercourse

a history of multiple sexual partners

a male partner with a history of multiple sexual partners

a large number of pregnancies

a history of sexually transmitted disease, including gonorrhea, chlamydia,herpes simplex virus II, and/or human immunodeficiency virus (HIV)

15

what are causes of higher incidence of cervical cancer 

spouses are known or suspected to have had higher exposure to HPV or whose partners have a history of penile carcinoma

16

does circumision has a protective role women in HPV transmission

Whether circumcision may be protective to women is controversial because circumcision may be a surrogate for unknown factors related to HPV transmission

17

what are other causes of cervical cancer besides social factors?

Chemical, hormonal, or other carcinogens may be impli- cated in cervical cancer.

An association between cervical carcinoma and oral contraceptive use has been reported but is considered controversial.

Prenatal exposure to diethylstilbestrol (DES) is linked to the development of clear-cell adenocarcinoma, although the overall incidence is small (0.14 to 1.4 per 1,000 DES-exposed women).

Cigarette smoking may increase the risk of cervical cancer.However, passive smoking may not be an independent factor in the absence of active smoking.

A review of >50 studies considers smoking a cofactor for HPV infection and carcinogenesis, although one study does not confirm this. 

Current smoking (relative risk [RR] = 1.55) and younger age at HPV exposure (RR = 1.75) are considered risk factors among HIV-positive women.

Intrauterine device use may decrease cervical cancer risk, potentially through an increase in cellular immunity triggered by the device.

18

Vaccination for HPV in cervical cancer

The quadrivalent human papillomavirus recombinant vaccine for HPV types 6, 11, 16, and 18, first approved in the United States in 2006

for girls and women ages 9 to 26 years,

is now available for boys ages 9 to 26 years,

with the goal of eradicating HPV- related gynecologic, penile, anal, and oropharyngeal cancers.

A second vaccine with strong immunogenicity to HPV types 16 and 18, approved for girls 9 to 25 years old, is more frequently administered in Europe.

Although its development is a major advance in the prevention of cancer, vaccine implementation has been hindered worldwide by cost and access. With an increase in understanding and availability, the hope is that all children will be given a vaccine covering all subtypes in the future.

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