GYNECOLOGIC ONCOLOGY
CERVICAL CANCER
Cervical cancer is a cancer that often affects younger women and grows from the cells of the cervix - the short narrowing at the bottom of the uterus connecting to the upper end of the vagina. Like in other cancers, cervical cancer develops when the immune system cannot keep up with cleaning mutated cells from the body (in this case cervix) before they replicate and start forming masses. Research has shown that human papillomavirus (HPV, a sexually transmitted disease, STD) can play a role in cervical cell mutation (as well as in the development of other cancers, including vaginal and vulvar cancer). In recent years, a vaccine against some strains of this virus (especially types 16 and 18) has been developed, which - though not a complete protection and not a substitute for healthy and sexually safe behaviors - may reduce the risk of developing cervical cancer in certain patients.
There are two main parts of the cervix, the outer cervix facing the vagina (exocervix) and the inner cervix facing the cervical canal leading up the the uterus (endocervix). These also determine the two major types of cervical cancer. Squamous cell carcinoma develops from the flat scale-like cells of the exocervix, while adenocarcinoma develops form the elongated glandular (lubricating, mucus secreting) cells of the endocervix. There are also some types of cervical cancers of an intermediate (mixed squamous cell and adenocarcinoma) molecular makeup (sometimes referred to as adenosquamous carcinomas). The vast majority of cervical cancers (up to 70% or 80%) are squamous cell carcinomas, with adenocarcinoma (about 15%) and mixed (intermediate) cervical cancer types being relatively rare.
Risk Factors
The causes of cervical cancer are not well understood, but as in most cancers, there are believed to be both genetic and environmental factors contributing to the mutation of cervical cells. Factors that can increase the risk of developing cervical cancer include both a prior patient and/or family history of cervical cancer, as well as lifestyle choices such as smoking, diet, extended use of oral contraceptives, and sexually risky behaviors (including early onset of sexual activity and high numbers of sexual partners), which increases the risk of contracting sexually transmitted diseases (STD). A woman who suffers from other sexually transmitted diseases (STDs), especially chlamydia (a bacterial infection that forms a symbiosis with and enhances the growth of HPV), but also gonorrhea, syphilis or HIV, is more likely to contract HPV - and by extension develop cervical cancer. Furthermore, a weakened immune system (due to natural causes such as HIV or because a patient is taking immunosuppressant drugs, including steroids) decreases the likelihood that mutated cells are cleared from the body before they form masses, thereby increasing the risk of developing cancer.
Symptoms
The symptoms of cervical cancer - like many of the gynecological cancers that are not breast cancer - are unspecific, and therefore not always easy to spot. The most important symptoms include irregular vaginal bleeding, foul-smelling vaginal discharge, and pelvic pain. These symptoms in themselves may not give cause for worry, but they should be a reason to obtain additional diagnostic workup.
Diagnosis
The first step in diagnosing cervical cancer is to obtain a pelvic exam from an OB/GYN. During this exam, the doctor may manually feel the vagina and cervix for abnormalities (palpation) and/or insert a colposcope (a microscope with a light, cervical equivalent to a hysteroscope). Moreover, during such an exam, which is generally recommended as a routine screening practice for most adult women, a Pap smear and HPV test are usually performed. The former can show whether there are abnormal cervical cells present (although not all abnormal cells are cancerous), whereas the latter indicates whether there is an active infection with HPV. If abnormalities are suspected, follow-up measures should be performed including diagnostic imaging (X-Ray, CT, MRI, PET). In order to definitively diagnose cervical cancer, a biopsy with subsequent histological analysis must be done. Often a small cell sample can be sufficient to diagnose cervical cancer. This can be obtained will minimally invasive techniques (such as endocervical curettage, colposcopic punch biopsy) and under local anesthesia at the doctor's office. If this histology shows inconclusive results and a larger cell sample is needed for analysis, a cone biopsy (either using a laser, hot wire or cold knife) sometimes has to be performed, which is frequently done in a hospital setting (generally outpatient) and under general anesthesia. If a biopsy is positive for cervical cancer, follow-up studies may be performed to determine the spread and stage of the cancer. These usually involve visualization of adjoining structures, such as the urinary tract (bladder) and digestive tract (rectum) with scopes and other imaging.
Treatments
Surgery is often the primary treatment fo cervical cancer. This can be done in varying degrees of invasiveness. If the cervical cancer is not too advanced, it may be possible to remove the cancer only while leaving the cervix and other reproductive organs intact (excision surgery, laser or cry ablation). If this is not possible, a trachelectomy (removal of the cervix only) may be suggested. While this is a more invasive procedure, it does preserve the possibility of future pregnancies, because the uterus remains intact. If the cancer is more aggressive, or if the risk of recurrence is feared, it can be decided to perform a hysterectomy (removal of the cervix, uterus, and - often - adjoining structures, which can be performed open abdominally, vaginally or laparoscopically). Alternatively to surgery (and sometimes after surgery to reduce risk of recurrence), radiation therapy (internal or external), often in combination with chemotherapy (PO, orally, or IV, intravenously), can be performed. This form of treatment can be very effective for cervical cancer - especially in tumors that cannot be fully resected - and can be less invasive than surgery as well. Targeted therapy (such as the monoclonal antibody and angiogenesis inhibitor bevacizumab, which reduces blood vessel formation around cancerous masses, thereby starving them to death) and immunotherapy (which changes the molecular makeup of cancer cells to make them more easily recognizable for the immune system) are also increasingly used treatments.