Our knowledge of cancer is always expanding. Researchers and healthcare professionals take the knowledge gained from research studies and use it to develop better practices that will help prevent, detect and treat cervical cancer, as well as improve the quality of life of people with cervical cancer.
The following information is a selection of research showing promise for cervical cancer.
Risk reduction
Risk reduction strategies may reduce the chance of developing cancer.
Noteworthy research includes:
- Human papillomavirus (HPV) is the most common cause of cervical cancer. Two types of HPV, HPV-16 and HPV-18, are linked to about 70% of all cervical cancers. There are 2 vaccines approved for use in Canada to prevent infection with HPV.
- Gardasil is a vaccine that protects against 4 types of HPV: HPV-16, HPV-18, HPV-6 and HPV-11. It is used to prevent precancerous changes of the cervix caused by HPV-16, HPV-18 and similar viruses in the same family. Gardasil also prevents genital warts associated with HPV-6 and HPV-11.
- Cervarix is a vaccine that protects against 2 types of HPV: HPV-16 and HPV-18.
- The manufacturers of both vaccines recommend the injections be given 3 times over a 6-month period. Researchers are trying to find out if fewer doses of the vaccines can be given to get the same level of protection (Journal of the National Cancer Institute, PMID* 21908768). At this time, Canada’s National Advisory Committee on Immunization (NACI) does not recommend fewer doses of either HPV vaccine.
- Researchers are also developing vaccines to treat HPV infections. By treating HPV with vaccines, precancerous cervical lesions may be destroyed through an immune reaction against the HPV-infected cells (Vaccine, PMID 20003917).
- Cervical intraepithelial neoplasia (CIN) II and III are precancerous conditions of the cervix that can lead to cervical cancer if left untreated. Women with CIN II and III are often treated with surgery, but researchers are studying other non-surgical treatment options. Imiquimod (Aldara) is a type of biological therapy in the form of a topical cream. Researchers are studying imiquimod as a possible treatment for CIN II and III (ASCO**, Abstract 5041).
Screening
Researchers are working to improve screening techniques for precancerous conditions of the cervix and cervical cancer so that they can be found early and treated.
Noteworthy research includes:
- Liquid-based Pap tests differ from conventional Pap tests in that the collected cervical cells are placed in a container of liquid, usually ethanol, instead of being smeared onto a glass microscope slide. Researchers have shown that liquid-based Pap tests are as sensitive in detecting abnormal cells as conventional Pap tests. However, liquid-based Pap tests have the advantage of being able to test for specific types of HPV using the same sample of cells (Annals of Internal Medicine, PMID 22711081; Human Cell, PMID 21166883; Journal of the National Comprehensive Cancer Network, PMID 21147902; Cancer Cytopathology, PMID 20731006; Diagnostic Cytopathology, PMID 19813268).
- The human papillomavirus (HPV) test can determine if a woman has certain high-risk types of HPV that can lead to cervical cancer if left untreated. Multiple screening trials have demonstrated that HPV testing is more sensitive than cytology (Pap test) in detecting a precancerous condition of the cervix called cervical intraepithelial neoplasia (CIN). Currently, the HPV test may be used in combination with a Pap test to screen for cervical cancer in women 30 years and older. HPV testing may also be used to prioritize the treatment and follow-up of women with abnormal Pap tests (Journal of the National Comprehensive Cancer Network, PMID 21147902). The HPV test is available in Canada, but the cost is not covered in all provinces and territories.
- The United States Preventative Services Task Force, American Cancer Society, American Society for Colposcopy and Cervical Pathology and American Society for Clinical Pathology state that there is enough evidence to show that women ages 30-65 who wish to lengthen the screening interval from 3 to 5 years may do so with a combination of screening with HPV and Pap testing (Annals of Internal Medicine, PMID 22711081; CA: A Cancer Journal for Clinicians, PMID 22422631).
- A large randomized study in the Netherlands compared screening with both the HPV test and Pap test versus the Pap test alone in women ages 29–56. The study found that screening with both the HPV and Pap tests led to earlier detection of CIN II compared to cytology. The study did 2 rounds of testing, 5 years apart. Women who were found to have CIN II or worse in the first round were treated. Researchers found that the group who had both HPV and Pap testing had a lower risk of having CIN III or cervical cancer in the second round of testing compared to those who had Pap testing alone (Lancet Oncology, PMID 22177579).
- Canadian researchers are studying the HPV test to see if it would be better than the Pap test as the primary screening tool for cervical cancer. This study is called the HPV FOCAL study. Researchers also hope to find out if the HPV test may allow women to be screened less often. The study is currently ongoing in British Columbia (BMC Cancer, PMID 20334685).
- The ARTISTIC trial in the United Kingdom is trying to find out if it is safe to delay cervical cancer screening in women who have a negative HPV test. The trial results suggest that women who have a negative HPV test may need 3 rounds of testing before it is safe to determine that cervical cancer screening can be extended to 3 years instead of being done more often (such as every year) (Lancet Oncology, PMID 19540162). The ARTISTIC trial also reported that longer screening intervals may even be safe if the HPV test replaced the Pap test as the primary screening test (European Journal of Cancer, PMID 21334200).
- In Finland, researchers are studying the HPV test as the main test to screen for cervical cancer. If a woman has a positive HPV test, she would then have a Pap test. They found that an HPV test with follow-up Pap test is more reliable than routine screening with cytology to detect precancerous conditions of the cervix and helps to avoid unnecessary follow-up tests. The study also reported that the HPV test with follow-up Pap test is better at ruling out cancer than routine screening with cytology in women 35 years and older. This reduced the number of unnecessary investigations and follow-up tests in women of this age group (Journal of the National Cancer Institute, PMID 19903804).
- A large study in China found that the HPV test may be used as a reliable screening test for women in multiple age groups, including those less than 35 years of age. More research is needed to find out which age groups would most likely benefit from this test (Lancet Oncology, PMID 21075054).
- Canadian and international researchers are looking at the possibility of women using home kits to collect their own cervical cell samples for HPV testing. They hope that this will encourage more women to participate in cervical cancer screening (Journal of Medical Screening, PMID 22438506; Journal of the National Cancer Institute, PMID 22271765; Lancet, PMID 22051739; Canadian Journal of Public Health, PMID 19994740).
- A computerized Pap test uses a computer to examine a cell sample and mark areas of abnormal cells. The technologist or pathologist then takes a closer look at the areas identified by the computer. More research is needed to determine if computerized Pap tests will be a useful tool for cervical cancer screening (Health Technology Assessment, PMID 21266159; Lancet Oncology, PMID 21146458).
Diagnosis
A key area of research activity involves developing better ways to diagnose and stage cervical cancer.
Noteworthy research includes:
- The sentinel lymph node is the first lymph node or group of lymph nodes that a cancer cell travels to as it spreads through the lymphatic system and the rest of the body. Researchers are studying sentinel lymph node biopsy (SLNB) to see if this technique is accurate in determining whether or not cancer has spread to the lymph nodes from the cervix without removing all of the lymph nodes. It may be used in women with early stage cervical cancer as an alternative to pelvic lymphadenectomy (complete removal of all lymph nodes in the pelvis) to limit the extent of surgery. A radioisotope dye, blue dye or both are injected before the surgery begins. When the surgery starts, the surgeon identifies the sentinel lymph nodes by the radioisotope, or blue dye, and removes them. This procedure may also be used during laparoscopic surgery (Gynecologic Oncology, PMID 21529908, PMID 19875161; Journal of Clinical Oncology, PMID 21444878; International Journal of Gynecological Cancer, PMID 20975360).
Prognostic factors
Prognostic factors that may help determine the outcome of the disease are being studied in cervical cancer. They can be used to predict the chances of recovery or of cancer coming back. Doctors may also use prognostic factors to help them make treatment recommendations.
Noteworthy research includes:
- Sentinel lymph node biopsy may help doctors predict prognosis in women with cervical cancer. Researchers have reported that women with cervical cancer that has spread to the sentinel lymph nodes have a less favourable prognosis (Gynecologic Oncology, PMID 22120175).
- Clusterin is a protein associated with programmed cell death (apoptosis). Japanese researchers have found that the expression of clusterin is linked to decreased survival and poor response to neoadjuvant chemotherapy in women with cervical cancer. Clusterin expression was also associated with a poor response to chemotherapy and decreased survival (Pathology & Oncology Research, PMID 20058210). Another study found that the expression of clusterin may be helpful in determining overall survival in women with cervical cancer (International Journal of Gynecological Cancer, PMID 21633299).
- A study found that a high expression of vascular endothelial growth factor (VEGF) receptor (VEGFR) and a low expression of the tissue inhibitor metalloproteinases 2 (TIMP2) is associated with a less favourable outcome in women with cervical cancer. VEGFR is the receptor that binds VEGF, a protein that stimulates new blood vessels to form. TIMP2 is thought to help prevent the spread of cancer (ASCO, Abstract e15507).
Treatment
Researchers are looking for new ways to improve the treatment of cervical cancer. Advances in cancer treatment and new ways to manage the side effects related to treatment have improved the outlook and quality of life for many people with cancer.
Noteworthy research includes:
- Studies showed that laparoscopic radical hysterectomy can be an alternative to standard abdominal radical hysterectomy for treating early stage cervical cancer. Laparoscopic hysterectomy is a procedure in which a thin, flexible lighted tube and surgical instruments are inserted through a small incision in the abdomen (laparoscopy) to remove the uterus. There is evidence that laparoscopic radical hysterectomy is associated with less post-operative complications and a shorter recovery time than abdominal radical hysterectomy (which requires a large abdominal incision). Long-term follow-up is needed to assess the safety and effectiveness of this technique (International Journal of Gynecological Cancer, PMID 22146764; Annals of Oncology, PMID 21841155).
- Robotic radical hysterectomy is a type of laparoscopic radical hysterectomy that is also being used to treat women with cervical cancer. The surgeon sits near the operating table and controls robotic arms to perform the operation through several small incisions in the woman’s abdomen.
- This procedure has been successfully performed in women with stage IA1–IIA cervical cancer with minimal complications, resulting in same-day hospital discharge. Studies have found that robotic hysterectomy had a shorter operating time than laparoscopy and was associated with significantly less blood loss and fewer complications than abdominal hysterectomy (Gynecologic Oncology, PMID 21872911; PMID 21353294; Annals of Surgical Oncology, PMID 21394663; Gynecological Surgery, PMID 20700514).
- A small study in Norway found that robotic hysterectomy was associated with a higher rate of recurrence compared to laparoscopic or abdominal hysterectomy (Gynecologic Oncology, PMID 21353294).
- Researchers are studying laparoscopic pelvic lymphadenectomy as an alternative to open pelvic lymphadenectomy, which uses a larger incision. Both approaches are used in women with early stage cervical cancer to remove lymph nodes in the pelvis to see if they contain cancer. A study showed that laparoscopic pelvic lymphadenectomy is an effective way to check for cancer in the pelvic lymph nodes (International Journal of Gynecological Oncology, PMID 21857347).
- More research is needed to determine how robotic surgical techniques may play a role in treating women with cervical cancer in the future.
- Amodified radical hysterectomy is a type of surgery that removes less tissues and organs than a standard radical hysterectomy. A modified radical hysterectomy removes the uterus, cervix, upper part of the vagina and ligaments and tissues that closely surround these organs. Lymph nodes are also removed. Italian researchers found that women who had a modified radical hysterectomy for early stage cervical cancer had bettersexual function after surgery than women who had a standard radical hysterectomy (Journal of Sexual Medicine, PMID 22372655).
- Doctors are studying a new technique of hysterectomy called a total mesometrial resection (TMMR) in women with stage IB–IIB cervical cancer. TMMR removes the uterus along with part of the surrounding tissue where cancer is most likely to spread. A study has shown that TMMR alone (without adjuvant radiation therapy) may improve survival rates in women who normally would be treated with radical hysterectomy (Lancet Oncology, PMID 19482513). More studies on TMMR are needed before this technique can be used routinely.
- Radical trachelectomy is a surgical alternative to radical hysterectomy for women of child-bearing age with early stage cervical cancer who would like to preserve their fertility. A radical trachelectomy removes only the cervix, the surrounding supporting ligaments and the upper part of the vagina. The remainder of the uterus and the ovaries are left in place. Surgeons are also performing laparoscopic radical trachelectomy with good results. Early studies have shown that it is a safe and effective alternative to radical hysterectomy in women with early stage cervical cancer (BJOG: An International Journal of Obstetrics and Gynecology, PMID 20015309).
- Robotic techniques are also being developed as a way to perform radical trachelectomy. A study found that women who had robotic radical trachelectomy had less blood loss and a shorter hospital stay compared to women who had an open radical trachelectomy (Gynecologic Oncology, PMID 22035808, PMID 19944451; International Journal of Gynecological Oncology, PMID 21270622).
- Drugs called angiogenesis inhibitors block the formation of new blood vessels, which tumours need to grow and spread. Most cervical cancer cells express a protein called vascular endothelial growth factor (VEGF), which promotes the formation of new blood vessels. Researchers are studying angiogenesis inhibitors, such as bevacizumab (Avastin) and pazopanib (Votrient), to treat cervical cancers that express VEGF (Critical Reviews in Oncology/Hematology, PMID 20456972; Gynecologic Oncology, PMID 19861227).
- A phase III clinical trial found that giving gemcitabine (Gemzar) and cisplatin (Platinol AQ) chemotherapy and radiation therapy (chemoradiation therapy) followed by adjuvant gemcitabine and cisplatin improved survival in women with stage IIB–IVA cervical cancer compared to standard treatment of carboplatin (Paraplatin) and radiation therapy. However, there were more toxic side effects with the gemcitabine and cisplatin chemoradiation therapy regimen (Journal of Clinical Oncology, PMID 21444871).
- A study found that neoadjuvant chemotherapy with irinotecan (Camptosar) and cisplatin before surgery is an effective treatment for women with locally advanced cervical cancer (cancer that has spread to surrounding tissues but not to distant areas). Using neoadjuvant chemotherapy resulted in less cancer spread to the stroma (the supporting connective tissue layer of the cervix) and a lower chance of cancer at the surgical margin compared to surgery alone. Women who responded well to neoadjuvant therapy also had lower rates of cancer spread to the pelvic lymph nodes compared to women who did not respond well to the treatment (Gynecologic Oncology, PMID 21741694).
- Researchers are studying intensity-modulated radiation therapy (IMRT) for the treatment of cervical cancer. IMRT uses computer technology to give different beam strengths across the treatment area to maximize radiation delivered to tumour cells and minimize damage to normal surrounding tissue. The tumour receives radiation from a series of small beams of different strengths. Because less normal tissue is irradiated with IMRT, women tend to have fewer side effects and less toxicity. Studies are also looking at combining IMRT with chemotherapy or brachytherapy, which uses implants to deliver radiation directly into or near a tumour (Gynecologic Oncology, PMID 21514629; Journal of the National Comprehensive Cancer Network, PMID 21147905; International Journal of Radiation Oncology, Biology, Physics, PMID 20708346, PMID 19880262; European Journal of Gynaecological Oncology, PMID 19899413).
- Brachytherapy is commonly used to treat cervical cancer. Brachytherapy is internal radiation therapy that uses a radioactive substance (isotope) placed right next to the tumour. Researchers are studying pulsed-dose-rate (PDR) brachytherapy in women with cervical cancer. PDR brachytherapy is given remotely from a special machine attached to catheters or needles that are inserted into the tumour. The treatment is given over several hours or days with short pulses of radiation that can be stopped to allow the healthcare team and family to enter the room without being harmed by the radiation (American Journal of Clinical Oncology, PMID 19841576).
Supportive care
Living with cancer can be challenging in many different ways. Supportive care can help people cope with cancer, its treatment and possible side effects.
Noteworthy research includes:
- Radiation therapy for cervical cancer targets the pelvis. Pelvic radiation has been associated with an increased risk of osteoporosis and bone fractures as a result of bone loss. Some researchers have suggested that women who have pelvic radiation to treat cervical cancer should undergo bone mineral density screening, which is a technique used to identify loss of bone density. Women with reduced bone density may be prescribed medications to help treat and prevent osteoporosis (Cancer, PMID 20052724).
- Radiation therapy for cervical cancer can lead to painful inflammation of the rectum and bladder. Researchers are studying hyperbaric oxygentherapy as a way to manage these kinds of side effects in women with gynaecological cancers, including cervical cancer. Hyperbaric oxygen therapy is given with a special pressure chamber. A woman sits in the chamber, and the pressure inside is increased above the normal pressure of the atmosphere. At higher pressure, higher levels of oxygen get into a person’s blood. These high levels of oxygen can help heal damaged and infected tissues (Supportive Care in Cancer, PMID 22246598; Current Oncology, PMID 21980249).
*PMID is the National Library of Medicine PubMed abstract identity number.
**ASCO is the American Society of Clinical Oncology.
Find out more about the research process.