Cervical Cancer (Cancer of the cervix)
Overview
When cancer occurs in the cervix it is called cervical cancer. Depending on the source, cervical cancer is ranked as the third or fourth most common cancer in women worldwide. In 2008, cervical cancer accounted for 2.38 per 100,000 deaths in the United States, and worldwide it is quoted as the most common cause of cancer-related deaths in women. Cervical cancer has a specific characteristic that makes it quite different from other cancers; it has a known cause! Human Papilloma virus (HPV) has been identified as a sexually transmitted DNA tumor virus that is responsible for causing cervical cancer. As a result, a woman’s risk of developing cervical cancer is determined to a significant extent by her risk of being exposed to HPV. This unique feature of cervical cancer makes it possible for women to be screened periodically for cervical cancer or any precancerous cervical lesions. The screening is called a “papanicolau ‘pap’ smear” test and it is performed with or without HPV testing. Widespread screening is the single reason behind the 50% decrease in the incidence of cervical cancer over the last 30 years in the United States. That being said, it is important to note that in parts of the United States and worldwide where cervical cancer screening is not performed, the incidence, prevalence and cancer-related deaths from this cancer are alarmingly high. It is therefore of great importance that every female makes every effort to be compliant with annual gynecologic well woman examination and routine cervical cancer screening.
What is Cervical Cancer?
The cervix is the lower part of the uterus in the human female reproductive system. It connects the uterus to the vagina. Cancer of the cervix results when cells in the cervix become abnormal and divide uncontrollably, creating a mass of extra tissue called a tumor. The key thing to remember is that the development of cancer of the cervix occurs in a stepwise fashion. In other words, prior to cancer occurring, the cells on the cervix undergo changes which we describe as precancerous lesions. Subsequently, these abnormal cells begin to multiply without control or order, leading to the mass of extra tissue called cancer of the cervix. Knowing this, in order to prevent cancer of the cervix, screening for these abnormal cells (pre-cancerous cells) before they transform into cancerous cells is key.
The cervix (https://www.jostrust.org.uk)
Risk Factors for Cervical Cancer
1. Pap test history
The Pap test is a screening test in which cells of the cervix are examined to detect any abnormalities that are precancerous or cancerous in nature. Precancerous lesions, if detected, can be treated to prevent progression to cancer. If cancer is detected, it will be managed appropriately by a gynecologist that is specialized in managing cancer. It is now well established that women, who have either never had Pap tests or have not had them as frequently as recommended, have a higher risk of developing cervical cancer. In the US, inadequately screened populations such as African-American and Hispanic women have a higher incidence of cervical cancer. It remains true, however,
that regardless of race, the women who remain most susceptible to the development of cervical cancer are those who do not receive screening at all.
2. Sexual History
Women who are sexually active at a very early age and/or have had many sexual partners have a higher risk of developing cancer of the cervix.
3. Human Papillomavirus (HPV) infection
HPV is a sexually transmitted virus that is now recognized as the major cause of cancer of the cervix. There are different types/strains of this virus, some of which cause cancer and others which cause non cancerous lesions such as warts. HPV types 16 & 18 are the major causes of cervical cancer and are referred to as ‘high risk HPV’. When a woman is found to have high risk HPV, she needs to be managed based on established guidelines by a gynecologist.
4. Smoking
Although the mechanism by which it contributes to the development of cancer of cervix is not well known, smoking remains a risk factor for cervical cancer. The suggested theories include: (a) the chemicals associated with smoking may induce normal cells of the cervix to become abnormal (i.e. precancerous) and (b) by lowering a woman’s individual immune surveillance, smoking increases her risk of developing cancer of the cervix.
5. HIV infection
Women with HIV infection have a higher risk of developing cancer of the cervix. This could be related to the weakened immune system from the HIV infection that results in the body's defense system being unable to kill the precancerous cells in the early stages of the cancer development (sort of a weakened immune surveillance).
6. Oral contraceptive use (OCP)
Use of OCP has been identified as a risk factor for cervical cancer. This is likely because patients on OCPs are less likely to use condoms, hence are at increased risk for STD transmission
7. History of sexually transmitted infections
Particularly chlamydia trachomatis and genital herpes
Symptoms of Cervical Cancer
Pre-cancerous lesions and early cervical cancer are not associated with pain, and often do not cause any symptoms. In fact, by the time a patient has any symptoms which usually include vaginal/pelvic pain, pain during intercourse, abnormal uterine bleeding or abnormal vaginal discharge, the cancer is at an advanced and often incurable stage. This is why regular screening is critical, and why it is important to present to a gynecologist for evaluation of any of the symptoms mentioned above.
Prevention of Cervical Cancer
1. Gardasil vaccine
Given the pivotal role human papillomavirus (HPV) plays in the development of cervical cancer, it is not surprising that any strategy directed against this virus is bound to be critical in preventing cervical cancer, hence the HPV vaccine (also known as Gardasil). Gardasil is a human papillomavirus (HPV) vaccine that helps protect against 4 HPV types in males and females from age 9 to 26. This vaccine may not fully protect everyone and does not prevent ALL types of cervical cancer, but this much is known now: • Gardasil protects against HPV types 6, 11, 16 and 18. • Although it helps protect against HPV types 16 & 18 which are responsible for 70% of cervical cancers, women who have had this vaccine must continue routine cervical cancer screenings.
2. Screening for cervical cancer
Since its introduction in the 1940s, Pap smear has proven to be one of the most costeffective, evidence-based preventive tests ever developed in medicine. When current screening guidelines are followed, the rate of cervical cancer invariably declines, as has been demonstrated in the developed countries. Cervical cancer screening includes a Pap test and HPV testing, and current consensus guidelines recommend that cervical cancer screening should be initiated at age 21 regardless of the age of sexual initiation or the presence of other behavior-related risk factors. The recommended screening interval ranges from every 3 to 5 years depending on the woman’s age and what type of test is performed, i.e. pap test alone or pap test and HPV testing (co-testing). The screening guidelines are accompanied by management guidelines in order to standardize how different pre-cancerous lesions are managed. These guidelines may differ based on coexistence of diseases that compromise the immune system such as HIV.
Management Options
If a pre-cancerous lesion is identified during screening or a woman is found to have high risk HPV, management options depend on the grade of the pre-cancerous lesion and can range from repeat testing in a year to an excision of the portion of the cervix that is affected in a procedure known as a loop electrosurgical excision procedure (LEEP) or a cold knife cone biopsy. Once the diagnosis of cancer of the cervix is established, there are basically three main options of management:
• Surgery
• Radiation therapy and/or
• Chemotherapy
The treatment regimen is dependent on the stage of disease and is managed by a gynecologic oncologist.
References:
NIH Fact sheet – cervical cancer
ACOG practice bulletin #131. Screening for Cervical Cancer
QUIZ ON CERVICAL CANCER
Choose the best response to the questions below.
(1) Cervical cancer is so rare that it is not even in the top ten causes of cancer death among women. (True or False)
(2) Just like pancreatic cancer, there no good tools for screening for cervical cancer. (True or False)
(3) Your best chance to reduce your risk of cervical cancer is (a) Avoid drinking alcohol (b) Avoid oral contraceptives (c) Get annual mammography (d) Regular gynecologic exam with pap smear and be screened for HPV
(4) Gardasil (HPV) vaccine protects against all kinds of cervical cancer, that means once you have had the vaccine, there is no need to get regular pap smear. (True or False)
(5) Risk factors for cervical cancer include: (a) Use of oral contraceptives (b) smoking (c) Multiple sex partners (d) All of the above
Correct Responses
1. False. Cervical cancer is among the top four most common cancers in women worldwide and a leading cause of death too.
2. False. There are good tools for screening for cancer of the cervix, which include pap smear and HPV screen.
3. The correct response is (d). Although oral contraceptive is a risk factor for cervical cancer, the jury is clear that your best chance to reduce your risk of this cancer is pap smear and HPV screen. By so doing you can nip the cancer or the precancerous state in the bud.
4. False. The HPV vaccine has been established to reduce the risk of getting cervical cancer. That said, we have to remember that the vaccine does not protect against all the HPV serotypes that cause cervical cancer. Besides, there is no evidence that HPV is the only causative agent for cancer of the cervix. Therefore, even though we know that those who have received this vaccine have reduced risk of cancer of the cervix, regular screening is still recommended for them for the aforementioned reasons.
5.The correct response is (d).
Charles Okorie MD (Chief Medical Officer, BHO)
Last updated August 19, 2015
