i)First Screening: This should be done approximately 3 years after first sexual intercourse or by age 21, whichever comes first.

ii)Women up to the age of 30- The recommendation for this age group is to screen annually.

iii)Women aged 30 years or older- Screening for this age group should be every 2 to 3 years, if three consecutive annual cervical cytology results are negative or if combined cervical cytology testing and high risk HPV testing are negative.

However screening should be more frequent in patients with a positive pap smear or positive high-risk HPV test, HIV infection, immunosuppression, previous history of cervical cancer and DES exposure.

iv)Women with hysterectomy: Routine screening for cervical cancer should be discontinued if the uterus was removed for benign reasons and there is no history of  abnormal or cancerous cell growth. However if there is a history of abnormal cell growth, she should be screened annually, and should be discontinued if three consecutive vaginal cytology tests are negative.

v) Older Women: The American Cancer Society recommends that screening should be discontinued in women after 70 years of age if three consecutive pap tests are negative and Pap smear results in the prior 10 years have been negative. However the society also recommends continued screening in healthy women if there is a history of cervical cancer,HIV infection, DES exposure in utero, HIV infection or a weak immune system.

References:

Pages 435 to 437. The Female Genetalia, Chapter 12. Bates Guide toPhysical Examination and History Taking.

The introduction of widespread screening for cervical cancer has led to a significant decline in the incidence and mortality of cervical cancer.

The screening done for cervical cancer is the papanicolaou (Pap) smear.

According to the U.S. Preventive Services Task Force “The goal of cytological screening in cervical cancer is to sample the transformation zone (the area where physiologic transformation from columnar endocervical epithelium to squamous-ectocervical epithelium takes place and where dysplasia and cancer arise.”

Types of cervical cancer:

There are two main types of cervical cancer; squamous cell carcinomas (80 to 90 %) and adenocarcinomas (10 to 20%).

Technique of Papanicolaou Smear:

Papanicolaou smear spicemens (for cytological examination) must be taken from a non-menstruating patient.

The smear should be spread on a single slide, and fixed or rinsed directly into preservative solution if a thin layer slide system (Thin Prep) is to be used.

A wooden or plastic spatula can be used to obtain the specimen from the squamocolumnar junction. Specimen may also be taken from the endocervix with a cotton swab or nylon brush.

The cytological report of a pap smear:

There are several ways of reporting the cytological report of a pap smear. The CIN classification is the most common classification used

Classification Systems for Papanicolaou Smears:

Numerical:

1,2,3,4,5

Dysplasia:

i)Benign

ii)Benign with inflammation

iii)Mild dysplasia

iv)Moderate dysplasia

v)Severe dysplasia

vi)Carcinoma in situ

v)Invasive cancer

Cervical Intraepithelial Neoplasia CIN:

i)Benign

ii)Benign with inflammation

iii)CIN I

iv)CIN II

v)CIN III

vi)Invasive cancer

Bethesda System:

i)Normal

ii)Normal, ASC-US (atypical squamous cells of undetermined significance.

iii)Low grade SIL (squamous intraepithelial lesion).

iv)High grade SIL (squamous intraepithelial lesion).

v)Invasive cancer.

Major Risk Factors of Cervical Carcinoma (Cervical Cancer)

The risk factors can be classified into viral and behavioral.

The most important risk factor is the Human Papilloma Virus (HPV, high risk strains).HPV is found in 95% to 100% of all squamous cell cancers.

The most common forms of HPV infections resolve spontaneously (usually within 5 years). In some women the infection may persist giving severe lesions.

Other risk factors include early sexual activity,history of STD’s ,multiple sexual partners,smoking, age, failure to receive screening,nutrition, immune status and genetic polymorphisms which can affect the entry of HPV DNA into cervical cells.

References:

Pages 734 to 735, Chapter 17 .Gynaecology. Current Medical Diagnosis and Treatment 2006. 45th Edition.Edited by Lawrence M. Tierney,Jr. Stephen J. McPhee and Maxine A. Papadakis.

Pages 435 to 437. The Female Genetalia, Chapter 12. Bates Guide toPhysical Examination and History Taking.

]]> http://www.askdrshihaan.org/pregnancy/2009/01/papanicolaou-smear-pap-cervical-cancer-screening-part-1/feed/ 0 http://www.askdrshihaan.org/pregnancy/2008/12/cancer-of-the-cervix-incidence-risk-factors-and-prevention/ http://www.askdrshihaan.org/pregnancy/2008/12/cancer-of-the-cervix-incidence-risk-factors-and-prevention/#comments Fri, 05 Dec 2008 15:20:43 +0000 Dr Shihaan http://www.askdrshihaan.org/pregnancy/?p=244 Incidence and prevalence

Cancer of the cervix is the second most common cancer among women worldwide.

There were 524,000 new cases (incidence) in 1995 alone.

80% of the cases of cancer of the cervix are in the developing countries.

Western Europe, North America and the Eastern Mediterranean have the lowest rates ,while Latin America, Sub- Saharan Africa and South-East Asia have the highest rates.

Cause/ Causative agent of carcinoma of the cervix

There is evidence that carcinoma of the cervix can be caused by the Human Papilloma Virus (HPV). Human papilloma virus is sexually transmitted. This virus is found in 95% of the cases of carcinoma of the cervix.

It is thought that the virus does not cause the cancer alone. Other co-factors might be important.

Risk factors for the cancer of the cervix.

a) Sexual intercourse and marital status: Sexual intercourse is the major factor in the genesis of carcinoma of the cervix (The squamous type). Medical records of nuns have shown that carcinoma of the cervix is very rare in this group of ladies. The fact that cancer of the cervix is very common among prostitutes and almost unknown among virgins suggests that the disease could be linked to sexual intercourse.

Number of husbands and number of coital partners and how promiscuous the women have been are important factors.

b) Genital warts and other sexual transmitted diseases: past history and/or present occurrence of clinical genital warts is an important risk factor in the development of carcinoma of the cervix.

Women with sexually transmitted diseases like gonorrhoea, syphilis,trichomonos and genital herpes have a higher incidence of cervical cancer than matched controls.

There appears to be some connection between herpes virus type 2 hominis and cervical cancer, but it is not as strong as the association between human papilloma virus (HPV) and cancer of the cervix.

c) The age at first intercourse: The age at first sexual intercourse is very significant and there is no doubt at all that sexual intercourse at adolescence predisposes women to this dredful disease.

Other risks such as early marriage ,early coitus, repeated childbirth and early childbearing are also probably related to the age at first sexual intercourse.

d) Oral contraceptives: Recent evidence suggests a possible relationship between the use of oral contraceptives and the development of invasive cervical cancer. A recent WHO study found that there is an increased risk of carcinoma of the cervix with increased duration of pill use and with the use of oral contraceptives with high oestrogen.

e) Socio-economic class: There is higher incidence of cervical cancer among women from lower socio-economic status, and although poor personal hygeine, sexual hygiene, loose living habits, unstable marriage and prostitution may all be contributory, it is most likely that early sexual intercourse among this group is the most significant factor.

Prevention and control of Cancer of the cervix

a)Primary prevention: The causative factors are not yet fully understood. So at this time primary prevention is not possible .However as seen in developed countries, reduction in the incidence of cancer of the cervix can be achieved by birth control and personal hygiene.

b)Secondary Prevention: This is essentially early detection od cases through screening and treatment by radical surgery and radiotherapy.

For carcinoma in site the 5-year survival rate is nearly 100%, therefore early detection is extremely important. It is 79% for locally invasive disease and 45% for regionally invasive disease.

References:

Page 291, Chapter 6. Epidemiology of Chronic Non-communicable Diseases and Conditions.Park’s Textbook of Preventive and Social Medicine. 17th edition by K. Park

Clinical signs and symptoms of cancer of the cervix

The important aspects of the diagnosis of cancer of the cervix are:

i) Abnormal uterine bleeding and vaginal discharge

ii)Presence of a cervical lesion on inspection as a tumour or ulceration.

iii)Vaginal cytology is usually positive. However it must be confirmed by biopsy.

The most common symptoms are metrorrhagia and postcoital bleeding (postcoital spotting). An important sign is the presence of cervical ulceration.

After invasion, bloody or purulent odorous, nonpruritic (Not itching) discharge may appear.

Late symptoms include bladder and rectal dysfunction, pain and or fistulas.

Staging of Cancer of the Cervix:

It is important to stage cancer of the cervix (Usually done under anaesthesia). Abdominal and pelvic CT scanning or MRI may also be very useful in staging

FIGO staging of cancer of the cervix

Preinvasive carcinoma

STAGE 0   :  Carcinoma in situ.

——————————————————————————————-

Invasive carcinoma

STAGE I :  Carcinoma is strictly confined to the cervix.

1A  :  In stage 1A invasive cancer can be diagnosed only on microscopy. It must be noted that all gross lesions, including superficial invasion ,are stage 1B.

1A1 Measured invasion of stroma no greater than 3mm in depth and no wider than 7mm.

1A2 Measured invasion of stroma greater than 3mm in depth and no greater than 5mm in depth and no wider than 7mm

1B Clinical lesion confined to the cervix or pre-clinical lesions greater than 1A.

1B1 Clinical lesion no greater than 4 cm.

1B2 Clinical lesions greater than 4 cm

STAGE II: Carcinoma extends beyond the cervix but has not extended to the pelvic wall.The carcinoma involves the vagina but not as far as the lower third.

IIA : No obvious parametrial involvement

IIB : Obvious parametrial involvement

STAGE III: Carcinoma has extended either to the lower third of the vagina or to the pelvic side wall. This also includes all cases of hydronephrosis.

IIIA: Involvement of the lower third of the vagina. No extension to the pelvic side wall

IIIB: Extension to the pelvic wall and /or hydronephrosis or nonfunctioning kidney.

STAGE IV: Carcinoma extends beyond the true pelvis or clinically involving the mucosa of the bladder or rectum.

IVA: Spread of growth to the adjacent organs.

IVB: Spread of growth to distant organs.

References:

Page 736 to 737 Chapter 18 Obstetrics CMDT 2006 -Current Medical Diagnosis and Treatment. Edited by Lawrence M. Tierney, Jr. ,Stephen J. McPhee, Maxine A. Papadakis 45th edition Lange Publications.Mc Graw Hill